space news
JUNE 2023
NEIL DEGRASSE TYSON
The partisanship surrounding space exploration and the retrenching of U.S. space
policy are part of a more general trend: the decline of science in the United States.
As its interest in science wanes, the country loses ground to the rest of the
industrialized world in every measure of technological proficiency.
James Webb highlights ancient galaxies
"Let there be light!" James Webb discovers ancient galaxies that gave our universe its first glow
Plus, the lauded telescope detected the most extensive spray of water ever seen in space from Saturn's frozen moon
By MATTHEW ROZSA - SALON
Staff Writer
PUBLISHED JUNE 15, 2023 5:30AM (EDT)
Quasar SDSS J0100+2802, EIGER (Emission-line galaxies and Intergalactic Gas in the Epoch of Reionization) Survey (NASA, ESA, CSA, Simon Lilly (ETH Zürich), Daichi Kashino (Nagoya University), Jorryt Matthee (ETH Zürich), Christina Eilers (MIT), Rob Simcoe (MIT), Rongmon Bordoloi (NCSU), Ruari Mackenzie (ETH Zürich); Image Processing: Alyssa Pagan (STScI) Ruari Macken)
Fac
While the James Webb Space Telescope is a secular achievement, the pioneering telescope nevertheless conjured up that Biblical imagery of "Let there be light!" with its most recent revelation: There could have been hundreds of ancient galaxies at the universe's beginning, instead of only a handful, and we can still see some of that light that shone at the time.
According to the new study, the newly-detected galaxies came into being as early as 600 million years after the Big Bang. The researchers focused on two regions of the vast sky: A section of the Ursa Minor constellation and another region near the Fornax cluster. They discovered more than 700 young galaxies that allow scientists to get a sense of how all of existence appeared during the earliest stages of its history.
"If you took the whole universe and shrunk it down to a two hour movie, you are seeing the first five minutes of the movie," Kevin Hainline, a lead author of the study and an assistant research professor at the Steward Observatory in Arizona, told reporters and scientists last week at the 242nd meeting of the American Astronomical Society in Albuquerque. "These are the galaxies that are starting the process of making the elements and the complexity that we see in the world around us today."
Perhaps the most notable detail from the findings is that the 717 newly-discovered galaxies are much more sophisticated than one might expect from such ancient celestial features. They span thousands of light years in size and contain complex structures. Although the two regions that contain them have been endlessly examined by previous astronomers, their telescopes simply did not have the power to show them with as much detail and clarity as the James Webb Space Telescope is able to bring to the table.
"What we were seeing before were just the brightest, most extreme examples of bright galaxies in the early universe," Hainline explained when speaking on Monday. "Now we are really probing down to more normal, everyday galaxies in a turbulent young universe."
This is only one step for the space program in its mission to unlock the mysteries of the universe's origins. Although the most prominent details of the study focused on galaxies that existed when the universe was between 370 million and 650 million years old, the international collaboration known as the JWST Advanced Deep Extragalactic Survey (JADES) also looked at the region of the universe from when it was between 500 to 850 million years old. They wanted to see the galaxies that existed during that phase in our cosmic history after the Big Bang.
In the process, they may have found clues as to how the dust-filled havoc of the early cosmos was cleared up by literal light.
Specifically, they found that one out of six galaxies from this region had features indicating that their atoms had been ionized by starlight and then cooled down to be combined with other molecules. This suggests that those early galaxies were creating stars and that these, in turn, added "torrents of ultraviolet protons" into their galaxies.
"These extreme emission lines are actually relatively common in the very early universe," explained Ryan Endsley, a postdoctoral researcher at the University of Texas who led the second study, during the Monday presentation. "Almost every single galaxy that we are finding shows these unusually strong emission line signatures indicating intense recent star formation. These early galaxies were very good at creating hot, massive stars."
This was not the only major astronomy news to recently come from the James Webb Space Telescope. Also this week, scientists using the telescope discovered the most extensive spray of water ever seen in space. At 6,000 miles long, the spray coming from Saturn's frozen moon Enceladus could reach from Los Angeles to Buenos Aires. In addition to establishing Enceladus as "the prime source of water across the Saturnian system," the researchers wrote that this discovery demonstrates "the unique ability of JWST in providing critical support to the exploration of distant icy bodies and cryovolcanic plumes," particularly as humanity continues to "prepare to send new spacecraft into the outer solar system."
The telescope has made myriad other discoveries since it was unveiled last year. In February, it observed an early galaxy, the so-called "Sparkler," that resembled our own Milky Way in its infancy. During that same month, the telescope found six massive galaxies whose very existence is a conundrum since they appear to be older than any galaxies ought to be given what we know so far about the universe.
According to the new study, the newly-detected galaxies came into being as early as 600 million years after the Big Bang. The researchers focused on two regions of the vast sky: A section of the Ursa Minor constellation and another region near the Fornax cluster. They discovered more than 700 young galaxies that allow scientists to get a sense of how all of existence appeared during the earliest stages of its history.
"If you took the whole universe and shrunk it down to a two hour movie, you are seeing the first five minutes of the movie," Kevin Hainline, a lead author of the study and an assistant research professor at the Steward Observatory in Arizona, told reporters and scientists last week at the 242nd meeting of the American Astronomical Society in Albuquerque. "These are the galaxies that are starting the process of making the elements and the complexity that we see in the world around us today."
Perhaps the most notable detail from the findings is that the 717 newly-discovered galaxies are much more sophisticated than one might expect from such ancient celestial features. They span thousands of light years in size and contain complex structures. Although the two regions that contain them have been endlessly examined by previous astronomers, their telescopes simply did not have the power to show them with as much detail and clarity as the James Webb Space Telescope is able to bring to the table.
"What we were seeing before were just the brightest, most extreme examples of bright galaxies in the early universe," Hainline explained when speaking on Monday. "Now we are really probing down to more normal, everyday galaxies in a turbulent young universe."
This is only one step for the space program in its mission to unlock the mysteries of the universe's origins. Although the most prominent details of the study focused on galaxies that existed when the universe was between 370 million and 650 million years old, the international collaboration known as the JWST Advanced Deep Extragalactic Survey (JADES) also looked at the region of the universe from when it was between 500 to 850 million years old. They wanted to see the galaxies that existed during that phase in our cosmic history after the Big Bang.
In the process, they may have found clues as to how the dust-filled havoc of the early cosmos was cleared up by literal light.
Specifically, they found that one out of six galaxies from this region had features indicating that their atoms had been ionized by starlight and then cooled down to be combined with other molecules. This suggests that those early galaxies were creating stars and that these, in turn, added "torrents of ultraviolet protons" into their galaxies.
"These extreme emission lines are actually relatively common in the very early universe," explained Ryan Endsley, a postdoctoral researcher at the University of Texas who led the second study, during the Monday presentation. "Almost every single galaxy that we are finding shows these unusually strong emission line signatures indicating intense recent star formation. These early galaxies were very good at creating hot, massive stars."
This was not the only major astronomy news to recently come from the James Webb Space Telescope. Also this week, scientists using the telescope discovered the most extensive spray of water ever seen in space. At 6,000 miles long, the spray coming from Saturn's frozen moon Enceladus could reach from Los Angeles to Buenos Aires. In addition to establishing Enceladus as "the prime source of water across the Saturnian system," the researchers wrote that this discovery demonstrates "the unique ability of JWST in providing critical support to the exploration of distant icy bodies and cryovolcanic plumes," particularly as humanity continues to "prepare to send new spacecraft into the outer solar system."
The telescope has made myriad other discoveries since it was unveiled last year. In February, it observed an early galaxy, the so-called "Sparkler," that resembled our own Milky Way in its infancy. During that same month, the telescope found six massive galaxies whose very existence is a conundrum since they appear to be older than any galaxies ought to be given what we know so far about the universe.
Scientists discover new planet orbiting nearest star to solar system
Proxima d is the third planet to have been spotted circling Proxima Centauri four light years away
Ian Sample Science editor
the guardian
Thu 10 Feb 2022 08.00 EST
Astronomers have found evidence for a new planet circling Proxima Centauri, the nearest star to the sun.
The alien world is only a quarter of the mass of Earth and orbits extremely close to its parent star, at one tenth of the distance between the sun and Mercury, the solar system’s innermost planet.
Researchers spotted the new planet after studying tiny wobbles in the motion of Proxima Centauri caused by the gravitational pull it exerts as it swings around the star. Observations taken with the European Southern Observatory’s Very Large Telescope (VLT) in Chile suggest the planet completes a full orbit of the star every five days.
The discovery shows that our closest stellar neighbour is “packed with interesting new worlds” within reach of further study and future exploration, said João Faria, a researcher at the Institute of Astrophysics and Space Sciences in Portugal and lead author on the study.
Scientists believe the planet orbits about 2.4m miles (4m km) from Proxima Centauri, meaning it is closer to the star than its habitable zone where the temperature range is just right for water to run freely. Details are published in the journal Astronomy & Astrophysics.
Named Proxima d, the planet is the third – and the lightest – to be spotted around Proxima Centauri, which at four light years away is the closest star to the solar system. It joins Proxima b, a planet with a mass comparable to that of Earth, which completes an orbit every 11 days, and Proxima c, which is believed to take about five years to circle the star.
The first hints of the planet came in 2020 when astronomers were observing Proxima Centauri to confirm the existence of Proxima b. The measurements revealed a weak signal in the star’s motion that had the hallmarks of being caused by a planet orbiting every five days.
Further observations taken with an instrument on ESO’s telescope called Espresso confirmed astronomers’ suspicions that a planet was the cause and not changes in the star itself.
“This is a very low mass planet, and is the third candidate around the star closest to us,” Faria said. “It shows that these planets, similar to the Earth, may be common in our galaxy, and just close by. And it makes us wonder about the possible conditions for habitability in these planet systems and if it’s possible for life to appear in other places in the universe.”
The alien world is only a quarter of the mass of Earth and orbits extremely close to its parent star, at one tenth of the distance between the sun and Mercury, the solar system’s innermost planet.
Researchers spotted the new planet after studying tiny wobbles in the motion of Proxima Centauri caused by the gravitational pull it exerts as it swings around the star. Observations taken with the European Southern Observatory’s Very Large Telescope (VLT) in Chile suggest the planet completes a full orbit of the star every five days.
The discovery shows that our closest stellar neighbour is “packed with interesting new worlds” within reach of further study and future exploration, said João Faria, a researcher at the Institute of Astrophysics and Space Sciences in Portugal and lead author on the study.
Scientists believe the planet orbits about 2.4m miles (4m km) from Proxima Centauri, meaning it is closer to the star than its habitable zone where the temperature range is just right for water to run freely. Details are published in the journal Astronomy & Astrophysics.
Named Proxima d, the planet is the third – and the lightest – to be spotted around Proxima Centauri, which at four light years away is the closest star to the solar system. It joins Proxima b, a planet with a mass comparable to that of Earth, which completes an orbit every 11 days, and Proxima c, which is believed to take about five years to circle the star.
The first hints of the planet came in 2020 when astronomers were observing Proxima Centauri to confirm the existence of Proxima b. The measurements revealed a weak signal in the star’s motion that had the hallmarks of being caused by a planet orbiting every five days.
Further observations taken with an instrument on ESO’s telescope called Espresso confirmed astronomers’ suspicions that a planet was the cause and not changes in the star itself.
“This is a very low mass planet, and is the third candidate around the star closest to us,” Faria said. “It shows that these planets, similar to the Earth, may be common in our galaxy, and just close by. And it makes us wonder about the possible conditions for habitability in these planet systems and if it’s possible for life to appear in other places in the universe.”
EXCERPT: A space anomaly blinks slowly at Earth
The flickering oddity may be a long-hypothesized breed of space object called an "ultra-long period magnetar"
In Earth's galactic backyard, a never-before-seen space anomaly blinks on and off
The flickering oddity may be a long-hypothesized breed of space object called an "ultra-long period magnetar"
By NICOLE KARLIS - SALON
PUBLISHED FEBRUARY 1, 2022 5:29AM (EST)
Astronomers believe they may have discovered an "'ultra-long period magnetar," a hypothetical type of neutron star that rotates remarkably slowly due to the way it interacts with surrounding ionized gas — yet scientists caution that more observational data is needed to better confirm this so-called "spooky" unknown object that is not that far away (galactically speaking) from Earth.
The object belongs to a caste of astronomical events called "transients," which are by nature short-lived and in flux. When astronomers are observing transients in the universe, they are generally observing the unusual activity of a massive star, or the behavior of the remnants that star has left behind. Pulsars, which sometimes emit a bright flash over a period of second or milliseconds, are known as fast transients. Slow transients, such as a supernovae, become extremely luminous over days or months. And then there are fast-radio bursts, or FRBs for short, which are very brief yet incredibly powerful bursts of radio wave energy that appear to be coming from all corners of the universe, yet whose origins are still ill-understood.
Now, astronomers have discovered a new, unknown kind of transient in our galaxy that flashes three times an hour — about every 18 minutes. This transient object has become one of the brightest radio objects in the sky, and its flash lasts between a half of a second to a minute. This slow timeframe, compounded with extreme brightness, makes it a peculiar discovery, according to a paper published in Nature.
"The emission is highly linearly polarized, bright, persists for 30–60 [seconds] on each occurrence and is visible across a broad frequency range," the scientists explain in the paper. "At times, the pulses comprise short-duration (<0.5 [second]) bursts; at others, a smoother profile is observed."
The co-authors add: "By measuring the dispersion of the radio pulses with respect to frequency, we have localized the source to within our own Galaxy and suggest that it could be an ultra-long-period magnetar."
A magnetar is a specific type of neutron star with a very strong magnetic field; neutron stars are the collapsed remnants of much-larger stars. They are formed when a large star becomes so dense in its core that gravity collapses it in on itself, resulting in a chain reaction that smushes negative electrons and positive protons together into neutral neutrons, releasing huge amounts of energy in the process. Essentially huge balls of neutrons, neutron stars have the density of atomic nuclei, the mass of suns, yet are small — typically the width of human cities. Their density is legendary; a commonly quoted and true statistic is that a teaspoon of neutron star material would weigh around one billion tons.
Neutron stars generally spin fast on their axes, and the energetic processes which take place within release powerful radio waves from their poles. The radio emissions from such stars were initially believed to be aliens when such signals were first detected in 1967.
The reason that neutron stars generally rotate so fast is the same reason that a swivel chair spins faster if you extend your arms and bring them in as you start to spin. Because of conservation of angular momentum, a physics principle, any object that is spinning will spin faster if it suddenly shrinks in width. For instance, Earth's sun spins about once every 22 days, though if the sun were to suddenly contract into a tiny neutron star, it would spin thousands of times per second.
This is partly what makes this new discovery so unusual. Unlike many neutron stars, which spin hundreds or thousands of times per second, this theoretical ultra-long period magnetar is spinning much more slowly than any other one observed.
Astronomers made the discovery of this likely ultra-long period magnetar by using the Murchison Widefield Array (MWA) telescope, a low-frequency radio telescope in Western Australia, when it was being used by Curtin University Honors student Tyrone O'Doherty. The team has been using the telescope to map radio waves in the universe.
"This object was appearing and disappearing over a few hours during our observations," said Dr. Natasha Hurley-Walker, an astronomer with the Curtin University node of the International Centre for Radio Astronomy Research and co-author of the paper. "That was completely unexpected. It was kind of spooky for an astronomer because there's nothing known in the sky that does that."
Notably, the object is about 4,000 light-years away — which, as Hurley-Walker noted, is "in our galactic backyard." For comparison, our galaxy, the Milky Way, is around 100,000 light-years across, and the nearest neighboring galaxy, Andromeda, is 2.5 million light years away from us.
The research team credits the telescope's wide field of view and extreme sensitivity for being able to pick up this strange radio object. The object was super bright in the radio spectrum — though not in the visible spectrum, meaning it can't be seen with the naked eye. Scientists suspect that its strong radio emissions be a result of the object having a very strong magnetic field, which fits the profile for it possibly being the hypothetical "'ultra-long period magnetar."
"It's a type of slowly spinning neutron star that has been predicted to exist theoretically," Hurley-Walker said. "But nobody expected to directly detect one like this because we didn't expect them to be so bright. Somehow it's converting magnetic energy to radio waves much more effectively than anything we've seen before."[...]
The object belongs to a caste of astronomical events called "transients," which are by nature short-lived and in flux. When astronomers are observing transients in the universe, they are generally observing the unusual activity of a massive star, or the behavior of the remnants that star has left behind. Pulsars, which sometimes emit a bright flash over a period of second or milliseconds, are known as fast transients. Slow transients, such as a supernovae, become extremely luminous over days or months. And then there are fast-radio bursts, or FRBs for short, which are very brief yet incredibly powerful bursts of radio wave energy that appear to be coming from all corners of the universe, yet whose origins are still ill-understood.
Now, astronomers have discovered a new, unknown kind of transient in our galaxy that flashes three times an hour — about every 18 minutes. This transient object has become one of the brightest radio objects in the sky, and its flash lasts between a half of a second to a minute. This slow timeframe, compounded with extreme brightness, makes it a peculiar discovery, according to a paper published in Nature.
"The emission is highly linearly polarized, bright, persists for 30–60 [seconds] on each occurrence and is visible across a broad frequency range," the scientists explain in the paper. "At times, the pulses comprise short-duration (<0.5 [second]) bursts; at others, a smoother profile is observed."
The co-authors add: "By measuring the dispersion of the radio pulses with respect to frequency, we have localized the source to within our own Galaxy and suggest that it could be an ultra-long-period magnetar."
A magnetar is a specific type of neutron star with a very strong magnetic field; neutron stars are the collapsed remnants of much-larger stars. They are formed when a large star becomes so dense in its core that gravity collapses it in on itself, resulting in a chain reaction that smushes negative electrons and positive protons together into neutral neutrons, releasing huge amounts of energy in the process. Essentially huge balls of neutrons, neutron stars have the density of atomic nuclei, the mass of suns, yet are small — typically the width of human cities. Their density is legendary; a commonly quoted and true statistic is that a teaspoon of neutron star material would weigh around one billion tons.
Neutron stars generally spin fast on their axes, and the energetic processes which take place within release powerful radio waves from their poles. The radio emissions from such stars were initially believed to be aliens when such signals were first detected in 1967.
The reason that neutron stars generally rotate so fast is the same reason that a swivel chair spins faster if you extend your arms and bring them in as you start to spin. Because of conservation of angular momentum, a physics principle, any object that is spinning will spin faster if it suddenly shrinks in width. For instance, Earth's sun spins about once every 22 days, though if the sun were to suddenly contract into a tiny neutron star, it would spin thousands of times per second.
This is partly what makes this new discovery so unusual. Unlike many neutron stars, which spin hundreds or thousands of times per second, this theoretical ultra-long period magnetar is spinning much more slowly than any other one observed.
Astronomers made the discovery of this likely ultra-long period magnetar by using the Murchison Widefield Array (MWA) telescope, a low-frequency radio telescope in Western Australia, when it was being used by Curtin University Honors student Tyrone O'Doherty. The team has been using the telescope to map radio waves in the universe.
"This object was appearing and disappearing over a few hours during our observations," said Dr. Natasha Hurley-Walker, an astronomer with the Curtin University node of the International Centre for Radio Astronomy Research and co-author of the paper. "That was completely unexpected. It was kind of spooky for an astronomer because there's nothing known in the sky that does that."
Notably, the object is about 4,000 light-years away — which, as Hurley-Walker noted, is "in our galactic backyard." For comparison, our galaxy, the Milky Way, is around 100,000 light-years across, and the nearest neighboring galaxy, Andromeda, is 2.5 million light years away from us.
The research team credits the telescope's wide field of view and extreme sensitivity for being able to pick up this strange radio object. The object was super bright in the radio spectrum — though not in the visible spectrum, meaning it can't be seen with the naked eye. Scientists suspect that its strong radio emissions be a result of the object having a very strong magnetic field, which fits the profile for it possibly being the hypothetical "'ultra-long period magnetar."
"It's a type of slowly spinning neutron star that has been predicted to exist theoretically," Hurley-Walker said. "But nobody expected to directly detect one like this because we didn't expect them to be so bright. Somehow it's converting magnetic energy to radio waves much more effectively than anything we've seen before."[...]
The moon has an icy secret
The moon has carbon dioxide "traps" that astronauts could use to make fuel and grow plants
If solid carbon dioxide is confirmed, the resource could be used for self-sufficient lunar habitats
By NICOLE KARLIS - SALON
PUBLISHED NOVEMBER 16, 2021 3:28PM (EST)
Though the moon was long considered a barren, inhospitable rocky world, researchers over the past few decades have found that the moon has many of the amenities that humans would need to build a self-sufficient habitat. Indeed, recent discoveries of plentiful water ice pockets on the moon tantalized scientists and space agencies. Now, a new finding suggests that there is plentiful carbon dioxide on the moon as well.
According to new research published in the AGU journal Geophysical Research Letter, scientists have confirmed the existence of lunar carbon dioxide "cold traps," a geological anomaly in which carbon dioxide could collect for long periods and settle. This discovery will likely have a significant impact on future space exploration as humans — or robots — could use carbon dioxide or other organic materials in the cold traps as fuel, convert it to oxygen, or use it in lunar greenhouses for growing plants.
In astronomy, a cold trap refers to a pocket on the surface of a solid body in which volatile gases can accrue and remain still for long periods, often millions of years. Because many planets and bodies in the solar system, the moon included, lack a significant atmosphere, any unlit area can remain at frigid temperatures for thousands or even millions of years. In that span, gases like carbon dioxide can accumulate and sometimes freeze in sufficient quantities, hence the term "cold trap." Carbon dioxide freezes at -109° Fahrenheit or -78° Celsius; the temperature on the Moon in the shade or at night is cooler than that, around -298° F (or -183° C) or even colder in some regions.
While the presence of carbon dioxide in these cold traps is confirmed, scientists are unclear as to whether the molecules are solid or gaseous. But the presence of the cold traps is telling, as carbon dioxide molecules are apt to freeze and remain in solid form even during high temperatures in the lunar summer.
The discovery comes amid decades of uncertainty and speculation in the scientific community around cold traps on the Moon.
"I think when I started this, the question was, 'Can we confidently say there are carbon dioxide cold traps on the Moon or not?'" said Norbert Schörghofer, a planetary scientist at the Planetary Science Institute and lead author on the study. "My surprise was that they're actually, definitely there. It could have been that we can't establish their existence, [they might have been] one pixel on a map... so I think the surprise was that we really found contiguous regions which are cold enough, beyond doubt."
The new report shows that there are several cold trap pockets scattered around the Moon's south pole, in an area that totals 204 square kilometers. These carbon dioxide traps appear to be most concentrated in an area called the Amundsen Crater, which appears to host 82 square kilometers of cold traps. In these areas, temperatures remain at negative 352 degrees Fahrenheit.
"These should be high-priority sites to target for future landed missions," said Paul Hayne, a planetary scientist at the University of Colorado, Boulder who was not involved in the study. "This sort of pinpoints where you might go on the lunar surface to answer some of these big questions about volatiles on the Moon and their delivery from elsewhere in the solar system."
Such cold traps are useful to engineers in a number of ways. If there is solid carbon dioxide in these cold traps, it could help with the production of fuel, steel and other biomaterials on the Moon. Nation-states like China and Russia are already planning to build a research station on the Moon, and taking advantage of the resources in these cold traps could be key to self-sufficiency.
Studying carbon dioxide on the moon could also help scientists better understand the origin of water on the Moon. In 2020, a pair of studies published in the journal Nature Astronomy confirmed that there is a large amount of water on the Moon's sunlit regions.
"We had indications that H₂O – the familiar water we know – might be present on the sunlit side of the Moon," Paul Hertz, director of the Astrophysics Division in the Science Mission Directorate at NASA Headquarters in Washington, previously said in a statement. "Now we know it is there. This discovery challenges our understanding of the lunar surface and raises intriguing questions about resources relevant for deep space exploration."
NASA used the Stratospheric Observatory for Infrared Astronomy (SOFIA), an infrared observatory mounted on a Boeing 747 airplane, to take air observations from the air and confirm the presence of water on the Moon's southern polar region. One study estimated this region could hold nearly 40,000 square kilometers of lunar surface with water ice.
The presence of water ice caught NASA's attention. In 2019, the space agency announced it was planning to send American astronauts to the surface of the Moon within five years, setting their sights on the southern pole.
"We know the South Pole region contains ice and may be rich in other resources based on our observations from orbit, but, otherwise, it's a completely unexplored world," said Steven Clarke, deputy associate administrator of the Science Mission Directorate at NASA Headquarters in Washington. "The South Pole is far from the Apollo landing sites clustered around the equator, so it will offer us a new challenge and a new environment to explore as we build our capabilities to travel farther into space."
According to new research published in the AGU journal Geophysical Research Letter, scientists have confirmed the existence of lunar carbon dioxide "cold traps," a geological anomaly in which carbon dioxide could collect for long periods and settle. This discovery will likely have a significant impact on future space exploration as humans — or robots — could use carbon dioxide or other organic materials in the cold traps as fuel, convert it to oxygen, or use it in lunar greenhouses for growing plants.
In astronomy, a cold trap refers to a pocket on the surface of a solid body in which volatile gases can accrue and remain still for long periods, often millions of years. Because many planets and bodies in the solar system, the moon included, lack a significant atmosphere, any unlit area can remain at frigid temperatures for thousands or even millions of years. In that span, gases like carbon dioxide can accumulate and sometimes freeze in sufficient quantities, hence the term "cold trap." Carbon dioxide freezes at -109° Fahrenheit or -78° Celsius; the temperature on the Moon in the shade or at night is cooler than that, around -298° F (or -183° C) or even colder in some regions.
While the presence of carbon dioxide in these cold traps is confirmed, scientists are unclear as to whether the molecules are solid or gaseous. But the presence of the cold traps is telling, as carbon dioxide molecules are apt to freeze and remain in solid form even during high temperatures in the lunar summer.
The discovery comes amid decades of uncertainty and speculation in the scientific community around cold traps on the Moon.
"I think when I started this, the question was, 'Can we confidently say there are carbon dioxide cold traps on the Moon or not?'" said Norbert Schörghofer, a planetary scientist at the Planetary Science Institute and lead author on the study. "My surprise was that they're actually, definitely there. It could have been that we can't establish their existence, [they might have been] one pixel on a map... so I think the surprise was that we really found contiguous regions which are cold enough, beyond doubt."
The new report shows that there are several cold trap pockets scattered around the Moon's south pole, in an area that totals 204 square kilometers. These carbon dioxide traps appear to be most concentrated in an area called the Amundsen Crater, which appears to host 82 square kilometers of cold traps. In these areas, temperatures remain at negative 352 degrees Fahrenheit.
"These should be high-priority sites to target for future landed missions," said Paul Hayne, a planetary scientist at the University of Colorado, Boulder who was not involved in the study. "This sort of pinpoints where you might go on the lunar surface to answer some of these big questions about volatiles on the Moon and their delivery from elsewhere in the solar system."
Such cold traps are useful to engineers in a number of ways. If there is solid carbon dioxide in these cold traps, it could help with the production of fuel, steel and other biomaterials on the Moon. Nation-states like China and Russia are already planning to build a research station on the Moon, and taking advantage of the resources in these cold traps could be key to self-sufficiency.
Studying carbon dioxide on the moon could also help scientists better understand the origin of water on the Moon. In 2020, a pair of studies published in the journal Nature Astronomy confirmed that there is a large amount of water on the Moon's sunlit regions.
"We had indications that H₂O – the familiar water we know – might be present on the sunlit side of the Moon," Paul Hertz, director of the Astrophysics Division in the Science Mission Directorate at NASA Headquarters in Washington, previously said in a statement. "Now we know it is there. This discovery challenges our understanding of the lunar surface and raises intriguing questions about resources relevant for deep space exploration."
NASA used the Stratospheric Observatory for Infrared Astronomy (SOFIA), an infrared observatory mounted on a Boeing 747 airplane, to take air observations from the air and confirm the presence of water on the Moon's southern polar region. One study estimated this region could hold nearly 40,000 square kilometers of lunar surface with water ice.
The presence of water ice caught NASA's attention. In 2019, the space agency announced it was planning to send American astronauts to the surface of the Moon within five years, setting their sights on the southern pole.
"We know the South Pole region contains ice and may be rich in other resources based on our observations from orbit, but, otherwise, it's a completely unexplored world," said Steven Clarke, deputy associate administrator of the Science Mission Directorate at NASA Headquarters in Washington. "The South Pole is far from the Apollo landing sites clustered around the equator, so it will offer us a new challenge and a new environment to explore as we build our capabilities to travel farther into space."
Astronomy
Scientists identify 29 planets where aliens could observe Earth
Astronomers estimate 29 habitable planets are positioned to see Earth transit and intercept human broadcasts
Ian Sample Science editor
the guardian
Wed 23 Jun 2021 11.00 EDT
For centuries, Earthlings have gazed at the heavens and wondered about life among the stars. But as humans hunted for little green men, the extraterrestrials might have been watching us back.
In new research, astronomers have drawn up a shortlist of nearby star systems where any inquisitive inhabitants on orbiting planets would be well placed to spot life on Earth.
The scientists identified 1,715 star systems in our cosmic neighbourhood where alien observers could have discovered Earth in the past 5,000 years by watching it “transit” across the face of the sun.
Among those in the right position to observe an Earth transit, 46 star systems are close enough for their planets to intercept a clear signal of human existence – the radio and TV broadcasts which started about 100 years ago.
The researchers estimate that 29 potentially habitable planets are well positioned to witness an Earth transit, and eavesdrop on human radio and television transmissions, allowing any observers to infer perhaps a modicum of intelligence. Whether the broadcasts would compel an advanced civilisation to make contact is a moot point.
“One way we find planets is if they block out part of the light from their host star,” said Lisa Kaltenegger, professor of astronomy and director of the Carl Sagan Institute at Cornell University in New York. “We asked, ‘Who would we be the aliens for if somebody else was looking?’ There is this tiny sliver in the sky where other star systems have a cosmic front seat to find Earth as a transiting planet.”
Earthly astronomers have detected thousands of planets beyond the solar system. About 70% are spotted when alien worlds pass in front of their host stars and block some of the light that reaches scientists’ telescopes. Future observatories, such as Nasa’s James Webb Space Telescope due to launch this year, will look for signs of life on “exoplanets” by analysing the composition of their atmospheres.
To work out which nearby star systems are well placed to observe an Earth transit, Kaltenegger and Dr Jackie Faherty, an astrophysicist at the American Museum of Natural History, turned to the European Space Agency’s Gaia catalogue of star positions and motions. From this they identified 2,034 star systems within 100 parsecs (326 light years) that could spot an Earth transit any time from 5,000 years ago to 5,000 years in the future.
One star known as Ross 128, a red dwarf in the Virgo constellation, is about 11 light years away – close enough to receive Earth broadcasts – and has a planet nearly twice the size of Earth. Any suitably equipped life on the planet could have spotted an Earth transit for more than 2,000 years, but lost the vantage point 900 years ago. If there is intelligent life on any of the two known planets orbiting Teegarden’s star, 12.5 light years away, it will be in a prime position to watch Earth transits in 29 years’ time.
At 45 light years away, another star called Trappist-1 is also close enough to eavesdrop on human broadcasts. The star hosts at least seven planets, four of them in the temperate, habitable zone, but they will not be in position to witness an Earth transit for another 1,642 years, the scientists write in Nature.
The findings come as the US government prepares to publish a hotly anticipated report on unidentified flying objects (UFOs). The report from the Pentagon’s Unidentified Aerial Phenomena Task Force, which was set up to gain insights into the nature and origins of unknown aircraft, is not expected to reveal evidence of alien antics, or rule it out.
Prof Beth Biller at Edinburgh University’s Institute for Astronomy, who was not involved in the Nature study, said the work could change how scientists approach Seti, the search for extraterrestrial life. “What was striking to me was how few of the stars within 100 parsecs could have viewed a transiting Earth,” she said.
“The transit method requires a very precise alignment between the transiting planet, its star, and the sun for a given planet to be detectable, so this result is not surprising. Now I am curious about what fraction of the stars in the Gaia catalogue of nearby stars have the right vantage point to detect the Earth via other exoplanet detection methods, such as the radial velocity method or direct imaging!”
In new research, astronomers have drawn up a shortlist of nearby star systems where any inquisitive inhabitants on orbiting planets would be well placed to spot life on Earth.
The scientists identified 1,715 star systems in our cosmic neighbourhood where alien observers could have discovered Earth in the past 5,000 years by watching it “transit” across the face of the sun.
Among those in the right position to observe an Earth transit, 46 star systems are close enough for their planets to intercept a clear signal of human existence – the radio and TV broadcasts which started about 100 years ago.
The researchers estimate that 29 potentially habitable planets are well positioned to witness an Earth transit, and eavesdrop on human radio and television transmissions, allowing any observers to infer perhaps a modicum of intelligence. Whether the broadcasts would compel an advanced civilisation to make contact is a moot point.
“One way we find planets is if they block out part of the light from their host star,” said Lisa Kaltenegger, professor of astronomy and director of the Carl Sagan Institute at Cornell University in New York. “We asked, ‘Who would we be the aliens for if somebody else was looking?’ There is this tiny sliver in the sky where other star systems have a cosmic front seat to find Earth as a transiting planet.”
Earthly astronomers have detected thousands of planets beyond the solar system. About 70% are spotted when alien worlds pass in front of their host stars and block some of the light that reaches scientists’ telescopes. Future observatories, such as Nasa’s James Webb Space Telescope due to launch this year, will look for signs of life on “exoplanets” by analysing the composition of their atmospheres.
To work out which nearby star systems are well placed to observe an Earth transit, Kaltenegger and Dr Jackie Faherty, an astrophysicist at the American Museum of Natural History, turned to the European Space Agency’s Gaia catalogue of star positions and motions. From this they identified 2,034 star systems within 100 parsecs (326 light years) that could spot an Earth transit any time from 5,000 years ago to 5,000 years in the future.
One star known as Ross 128, a red dwarf in the Virgo constellation, is about 11 light years away – close enough to receive Earth broadcasts – and has a planet nearly twice the size of Earth. Any suitably equipped life on the planet could have spotted an Earth transit for more than 2,000 years, but lost the vantage point 900 years ago. If there is intelligent life on any of the two known planets orbiting Teegarden’s star, 12.5 light years away, it will be in a prime position to watch Earth transits in 29 years’ time.
At 45 light years away, another star called Trappist-1 is also close enough to eavesdrop on human broadcasts. The star hosts at least seven planets, four of them in the temperate, habitable zone, but they will not be in position to witness an Earth transit for another 1,642 years, the scientists write in Nature.
The findings come as the US government prepares to publish a hotly anticipated report on unidentified flying objects (UFOs). The report from the Pentagon’s Unidentified Aerial Phenomena Task Force, which was set up to gain insights into the nature and origins of unknown aircraft, is not expected to reveal evidence of alien antics, or rule it out.
Prof Beth Biller at Edinburgh University’s Institute for Astronomy, who was not involved in the Nature study, said the work could change how scientists approach Seti, the search for extraterrestrial life. “What was striking to me was how few of the stars within 100 parsecs could have viewed a transiting Earth,” she said.
“The transit method requires a very precise alignment between the transiting planet, its star, and the sun for a given planet to be detectable, so this result is not surprising. Now I am curious about what fraction of the stars in the Gaia catalogue of nearby stars have the right vantage point to detect the Earth via other exoplanet detection methods, such as the radial velocity method or direct imaging!”
Two newly-approved Venus missions will get us closer to knowing if Venus has cloud-based life
Before 2030, DAVINCI+ and VERITAS are expected to depart for the second planet
By NICOLE KARLIS - salon
PUBLISHED JUNE 8, 2021 6:30AM (EDT)
Future historians may remember 2021 as the year that Earthlings were fixated on Mars. Ingenuity, the little Martian 'chopper that could, successfully took flight, marking the first powered-controlled flight on another planet. The Ingenuity helicopter hitched a ride with the rover Perseverance, which successfully landed on Mars with it and which is currently scouring the surface for signs of past microbial life. Meanwhile, two other nation-states, the United Arab Emirates and China, had their own Mars missions in 2021 — an orbiter and a rover, respectively.
But Mars' moment as the star planet of the solar system may not last. By the end of the decade, all eyes will be on Venus, as the second planet from the Sun becomes a new scientific focus for humanity.
Last week, the National Aeronautics and Space Administration (NASA) announced that the agency has approved two new missions to the second planet from the Sun. One of them will be the first U.S.-led mission into Venus' atmosphere since 1978. Both are expected to launch between 2028 and 2030.
The first mission is called DAVINCI+, an acronym for Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging Plus. DAVINCI+'s primary purpose is to measure the composition of Venus' atmosphere. Scientists hope this mission will help them better understand how the planet formed, in addition to determining whether Venus ever had an ocean or not. Indeed, for decades, scientists have been curious to know Venus evolved to have an atmosphere that traps so much of the Sun's heat, resulting in surface temperatures higher than 880 degrees Fahrenheit — very different than conditions here on its sister planet, Earth. In order to study Venus' atmosphere, scientists will build a "descent sphere" that will plunge through Venus' thick atmosphere as it makes precise measurements of gases.
Studying Venus' atmosphere could also help scientists better understand whether or not there is floating, cloud-based life in the upper atmosphere. In September 2020, a group of international astronomers published a paper in Nature Astronomy explaining how they detected phosphine (PH₃), a gaseous molecule composed of one phosphorus and three hydrogen atoms, in the upper atmosphere of Venus. Researchers saw phosphine's signal in spectrograms from two radio telescopes they used to capture the data, and estimated there were 20 parts per billion of the compound in Venus' clouds.
The astronomers stated that the discovery was a "promising" sign of life, as phosphine on Earth is created in the gaseous emanations of anaerobic life. Astrobiologists speculated that little microbes could be floating in Venus' atmosphere, living their lives entirely high up in Venus' temperate cloud layers, where temperatures can be as balmy as a Mediterranean climate. As Salon reported, not too long after astronomers published the initial paper, more research papers followed questioning the observation of phosphine. At the time, DAVINCI+ was merely a proposal for a mission to study the upper atmosphere of Venus.
In 2020, Therese Encrenaz, an astrophysicist at LESIA, Paris Observator, told Salon via email that she was convinced that "there are still many open questions regarding the photochemistry and meteorology of its atmosphere."
"Venus has been forgotten for too long, relative to the space exploration of Mars," Encrenaz said. "There is no need for phosphine to be interested in Venus."[...]
But Mars' moment as the star planet of the solar system may not last. By the end of the decade, all eyes will be on Venus, as the second planet from the Sun becomes a new scientific focus for humanity.
Last week, the National Aeronautics and Space Administration (NASA) announced that the agency has approved two new missions to the second planet from the Sun. One of them will be the first U.S.-led mission into Venus' atmosphere since 1978. Both are expected to launch between 2028 and 2030.
The first mission is called DAVINCI+, an acronym for Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging Plus. DAVINCI+'s primary purpose is to measure the composition of Venus' atmosphere. Scientists hope this mission will help them better understand how the planet formed, in addition to determining whether Venus ever had an ocean or not. Indeed, for decades, scientists have been curious to know Venus evolved to have an atmosphere that traps so much of the Sun's heat, resulting in surface temperatures higher than 880 degrees Fahrenheit — very different than conditions here on its sister planet, Earth. In order to study Venus' atmosphere, scientists will build a "descent sphere" that will plunge through Venus' thick atmosphere as it makes precise measurements of gases.
Studying Venus' atmosphere could also help scientists better understand whether or not there is floating, cloud-based life in the upper atmosphere. In September 2020, a group of international astronomers published a paper in Nature Astronomy explaining how they detected phosphine (PH₃), a gaseous molecule composed of one phosphorus and three hydrogen atoms, in the upper atmosphere of Venus. Researchers saw phosphine's signal in spectrograms from two radio telescopes they used to capture the data, and estimated there were 20 parts per billion of the compound in Venus' clouds.
The astronomers stated that the discovery was a "promising" sign of life, as phosphine on Earth is created in the gaseous emanations of anaerobic life. Astrobiologists speculated that little microbes could be floating in Venus' atmosphere, living their lives entirely high up in Venus' temperate cloud layers, where temperatures can be as balmy as a Mediterranean climate. As Salon reported, not too long after astronomers published the initial paper, more research papers followed questioning the observation of phosphine. At the time, DAVINCI+ was merely a proposal for a mission to study the upper atmosphere of Venus.
In 2020, Therese Encrenaz, an astrophysicist at LESIA, Paris Observator, told Salon via email that she was convinced that "there are still many open questions regarding the photochemistry and meteorology of its atmosphere."
"Venus has been forgotten for too long, relative to the space exploration of Mars," Encrenaz said. "There is no need for phosphine to be interested in Venus."[...]
The mysteries of Uranus' oceans
A study recreating chemical reactions in the deep waters of ice giants has big implications for exoplanet research
Why studying Uranus and Neptune could help us find habitable planets in other solar systems
A study recreating chemical reactions in the deep waters of ice giants has big implications for exoplanet research
By NICOLE KARLIS - salon
PUBLISHED MAY 20, 2021 8:10PM (UTC)
Astronomers have long predicted that deep beneath Neptune's thick blue clouds lies a super-hot body of water that, despite its high temperature, never boils because of its incredibly high-pressure atmosphere. Uranus, another planet in the outer solar system of similar size and composition, is also believed to have a similar water-rich interior. Unfortunately, due to their distances from Earth, it is hard to directly probe these two planets to test our assumption. But scientists have found novel ways of testing their theories about these ice giants from Earth.
As described in a newly-published study from Nature Astronomy, scientists recreated the pressure and temperature of the interiors of Neptune and Uranus in a lab. The aim of the experiments was to test hypotheses about the chemistry of the deep water within these planets. But the study could have additional implications for what we know about potentially habitable planets in other solar systems.
"We were seeking to extend our knowledge of the deep interior of ice giants and determine what water-rock interactions at extreme conditions might exist," said lead author Taehyun Kim, of Yonsei University in South Korea. "Ice giants and some exoplanets have very deep water layers, unlike terrestrial planets. We proposed the possibility of an atomic-scale mixing of two of the planet-building materials (water and rock) in the interiors of ice giants."
To replicate the conditions, scientists dipped rock-forming minerals — including olivine and ferropericlase — into water, and then compressed the sample in a diamond-anvil to very high pressures. From there, they took x-ray measurements while a laser heated the sample to extremely high temperatures, then measured the reaction. They found that the chemical reaction led to high concentrations of magnesium in the water, leading the team to conclude that oceans on planets like Neptune and Uranus might have similar chemical properties as oceans here on Earth.
Indeed, part of the intrigue of these two planets is the presence of magnesium within their water. Early Earth is believed to have had magnesium-rich waters, which likely played a role in the evolution of early life.
The study's co-author, Sang-Heon Dan Shim of Arizona State University's School of Earth and Space Exploration, explained during a phone interview that the differences in pressure between planets like Earth and Neptune and Uranus can cause "completely different types of chemical reactions" at the bottom of these oceans.
"If you have thick oceans interfacing with rock at the bottom, what happens to that?" Shim said. "And we found that magnesium, which doesn't dissolve a lot in the water at low pressure, begins to sort of dissolve a lot in the ocean, or liquid water, to the degree that you would expect for solubility of salt in water at low pressure."
The study has interesting implications for the study of exoplanets, meaning planets that exist in other solar systems. As Shim explained, their study implies that the oceans of Neptune-like exoplanets may have different chemistry.
Typically, the presence of water on an exoplanet perks up the ears of astronomers and astrobiologists, as anywhere with water implies the potential for either life or habitability. Given the super-hot temperatures in the deep oceans of Neptune and Uranus, Shim said life is unlikely to exist in these planets, despite the rich presence of magnesium.
"The temperature is expected to be like thousands of degrees in those oceans, so it would be a very difficult environment for us to expect life," Shim said. "But that's probably a different story for the exoplanets, the sub-Neptunes outside of the solar system."
Shim noted that some Neptune-like exoplanets do exist in their stars' habitable zones. "In those type of cases, this magnesium-rich water will be very interesting to think about in terms of how it's going to change the way life develops and represent itself there."
As described in a newly-published study from Nature Astronomy, scientists recreated the pressure and temperature of the interiors of Neptune and Uranus in a lab. The aim of the experiments was to test hypotheses about the chemistry of the deep water within these planets. But the study could have additional implications for what we know about potentially habitable planets in other solar systems.
"We were seeking to extend our knowledge of the deep interior of ice giants and determine what water-rock interactions at extreme conditions might exist," said lead author Taehyun Kim, of Yonsei University in South Korea. "Ice giants and some exoplanets have very deep water layers, unlike terrestrial planets. We proposed the possibility of an atomic-scale mixing of two of the planet-building materials (water and rock) in the interiors of ice giants."
To replicate the conditions, scientists dipped rock-forming minerals — including olivine and ferropericlase — into water, and then compressed the sample in a diamond-anvil to very high pressures. From there, they took x-ray measurements while a laser heated the sample to extremely high temperatures, then measured the reaction. They found that the chemical reaction led to high concentrations of magnesium in the water, leading the team to conclude that oceans on planets like Neptune and Uranus might have similar chemical properties as oceans here on Earth.
Indeed, part of the intrigue of these two planets is the presence of magnesium within their water. Early Earth is believed to have had magnesium-rich waters, which likely played a role in the evolution of early life.
The study's co-author, Sang-Heon Dan Shim of Arizona State University's School of Earth and Space Exploration, explained during a phone interview that the differences in pressure between planets like Earth and Neptune and Uranus can cause "completely different types of chemical reactions" at the bottom of these oceans.
"If you have thick oceans interfacing with rock at the bottom, what happens to that?" Shim said. "And we found that magnesium, which doesn't dissolve a lot in the water at low pressure, begins to sort of dissolve a lot in the ocean, or liquid water, to the degree that you would expect for solubility of salt in water at low pressure."
The study has interesting implications for the study of exoplanets, meaning planets that exist in other solar systems. As Shim explained, their study implies that the oceans of Neptune-like exoplanets may have different chemistry.
Typically, the presence of water on an exoplanet perks up the ears of astronomers and astrobiologists, as anywhere with water implies the potential for either life or habitability. Given the super-hot temperatures in the deep oceans of Neptune and Uranus, Shim said life is unlikely to exist in these planets, despite the rich presence of magnesium.
"The temperature is expected to be like thousands of degrees in those oceans, so it would be a very difficult environment for us to expect life," Shim said. "But that's probably a different story for the exoplanets, the sub-Neptunes outside of the solar system."
Shim noted that some Neptune-like exoplanets do exist in their stars' habitable zones. "In those type of cases, this magnesium-rich water will be very interesting to think about in terms of how it's going to change the way life develops and represent itself there."
Neutron stars are very, very weird — and we just learned a fascinating new detail about them
Neutron stars are the densest objects in the universe, created from massive stars that have collapsed
By MATTHEW ROZSA - salon
APRIL 30, 2021 12:00PM (UTC)
Imagine that a massive star, one far bigger than our own sun, has died. First there is a spectacular explosion, followed by whatever remains. Sometimes it is a black hole, which can be fascinating in its own right, and on other occasions we are left with a super-dense collapsed core of the formerly magnificent star. Those objects are known as neutron stars — and scientists believe they may have just figured out a way to learn more about these extremely weird, distant bodies.
To do that, though, they examined something very, very small: The nucleus of atoms, or the smallest unit of ordinary matter that can form a chemical element. Like the solar system itself, atoms contain a massive center with smaller objects rotating around it. In the case of our solar system, the center is the sun and the smaller objects are various planets and other celestial bodies. In the case of an atom, the center is a nucleus composed of parts known as protons and neutrons, which are in turn surrounded by rotating electrons.
"If you go back to when we first started looking at [atomic] nuclei, we used electrons to map out the size of the nucleus," Dr. Kent Paschke, a professor of experimental nuclear and particle physics at the University of Virginia and co-author of the new study, told Salon. "We sort of made a new picture of the nucleus to explain not just where the protons are, but where all the matter in the nucleus is. What we've learned is the average density inside the lead nucleus. What that tells us is a detail about nuclear structure that we never had before, which is how hard it is to create dense, neutron rich matter."
How does this relate to neutron stars? Simply put, this new information could help us learn more about their size and physical properties.
"Fundamentally the physics is the same," Paschke explained. "The kinds of interactions are the same. We think we can translate from the situation inside the tiny nucleus to the situation inside the star. And that's something physicists like to do; they like to have a general rule that applies to a lot of different systems."
He added that what they have learned, specifically, is "the thickness of the neutron skin of the lead nucleus. And so it's a different system than a neutron star. And we're talking about where the neutrons are in the lead nucleus, and then the implications for the total size of the neutron star."
It is important to note that neutron stars are unlike anything we can imagine here on Earth. According to Dr. Jorge Piekarewicz, a physicist at Florida State University who co-authored a companion study to the neutron star research, they originate from stars very different from our sun. Stars like our sun create energy through thermonuclear reactions and, when they die, become "white dwarf" stars. A neutron star, by contrast, is created when a star much, much larger than the sun dies out.
"As the name indicates, neutron stars are made mostly of neutrons, unlike our sun which is largely made of primordial hydrogen created during the Big Bang," Piekarewicz told Salon by email. "Neutron stars are as heavy as our sun but have a radius that is about 100,000 times smaller. As such, they are the densest objects in the universe. A sugar cube of neutron star material weighs as much as the entire population of the world."
Piekarewicz added that neutron stars are unusual — to those of us on Earth, that is — because they contain materials which cannot be made on our planet, have magnetic fields that are exponentially stronger than our planet's magnetic field and are also exponentially denser than water.
"The study is remarkable because it connects objects as small as the atomic nucleus (with sizes of a few femtometers) with astronomical objects as large as a neutron star (with dimensions of about 10 kilometers)," Piekarewicz explained. "The study suggests that neutron stars are larger than anticipated, a fact that is fully consistent with recent observations by the NICER mission onboard the International Space Station. Thus, the study establishes a compelling link between terrestrial experiments and astronomical observations — a partnership that will become even stronger in the new era of gravitational-wave astronomy."
To do that, though, they examined something very, very small: The nucleus of atoms, or the smallest unit of ordinary matter that can form a chemical element. Like the solar system itself, atoms contain a massive center with smaller objects rotating around it. In the case of our solar system, the center is the sun and the smaller objects are various planets and other celestial bodies. In the case of an atom, the center is a nucleus composed of parts known as protons and neutrons, which are in turn surrounded by rotating electrons.
"If you go back to when we first started looking at [atomic] nuclei, we used electrons to map out the size of the nucleus," Dr. Kent Paschke, a professor of experimental nuclear and particle physics at the University of Virginia and co-author of the new study, told Salon. "We sort of made a new picture of the nucleus to explain not just where the protons are, but where all the matter in the nucleus is. What we've learned is the average density inside the lead nucleus. What that tells us is a detail about nuclear structure that we never had before, which is how hard it is to create dense, neutron rich matter."
How does this relate to neutron stars? Simply put, this new information could help us learn more about their size and physical properties.
"Fundamentally the physics is the same," Paschke explained. "The kinds of interactions are the same. We think we can translate from the situation inside the tiny nucleus to the situation inside the star. And that's something physicists like to do; they like to have a general rule that applies to a lot of different systems."
He added that what they have learned, specifically, is "the thickness of the neutron skin of the lead nucleus. And so it's a different system than a neutron star. And we're talking about where the neutrons are in the lead nucleus, and then the implications for the total size of the neutron star."
It is important to note that neutron stars are unlike anything we can imagine here on Earth. According to Dr. Jorge Piekarewicz, a physicist at Florida State University who co-authored a companion study to the neutron star research, they originate from stars very different from our sun. Stars like our sun create energy through thermonuclear reactions and, when they die, become "white dwarf" stars. A neutron star, by contrast, is created when a star much, much larger than the sun dies out.
"As the name indicates, neutron stars are made mostly of neutrons, unlike our sun which is largely made of primordial hydrogen created during the Big Bang," Piekarewicz told Salon by email. "Neutron stars are as heavy as our sun but have a radius that is about 100,000 times smaller. As such, they are the densest objects in the universe. A sugar cube of neutron star material weighs as much as the entire population of the world."
Piekarewicz added that neutron stars are unusual — to those of us on Earth, that is — because they contain materials which cannot be made on our planet, have magnetic fields that are exponentially stronger than our planet's magnetic field and are also exponentially denser than water.
"The study is remarkable because it connects objects as small as the atomic nucleus (with sizes of a few femtometers) with astronomical objects as large as a neutron star (with dimensions of about 10 kilometers)," Piekarewicz explained. "The study suggests that neutron stars are larger than anticipated, a fact that is fully consistent with recent observations by the NICER mission onboard the International Space Station. Thus, the study establishes a compelling link between terrestrial experiments and astronomical observations — a partnership that will become even stronger in the new era of gravitational-wave astronomy."
Astronomers hope to use a quasar as a "flashlight" to see into the universe's dark past
The powerful radio jets of a distant quasar can show us the universe as it existed 13 billion years ago
By NICOLE KARLIS - salon
MARCH 12, 2021 11:00PM (UTC)
This artist’s impression shows how the distant quasar P172+18 and its radio jets may have looked. To date (early 2021), this is the most distant quasar with radio jets ever found and it was studied with the help of ESO’s Very Large Telescope. It is so distant that light from it has travelled for about 13 billion years to reach us: we see it as it was when the Universe was only about 780 million years old. (ESO/M. Kornmesser)
At the center of the most distant galaxies in our universe sits a very bright object powered by a supermassive black hole a billion times as massive as our sun. These objects are called quasars — short for quasi-stellar object — and sometimes they shine so bright that they can obscure nearby galaxies. From a telescope, quasars appear as stars, and thus astronomers can readily observe these celestial objects despite their vast distances. But sometimes, they shine bright not in visible light but in the invisible radio spectrum, like a great glowing cell phone in the sky.
Such is the case with a newly discovered quasar dubbed P172+18. Thanks to the European Southern Observatory's Very Large Telescope (ESO's VLT), astronomers spotted this, one of the most distant quasars ever, and its powerful, prominent radio jets, which only about ten percent of quasars have.
P172+18 is so distant that light from it has travelled for about 13 billion years to reach us. That means that we are able to see it as it was when the universe was just around 780 million years old. Technically, more distant quasars have been identified, but this is the first time one has been observed sporting radio jets this early on in the history of the universe. That's throwing astronomers' working model of the universe's evolution for a spin.
The findings were presented in a study published in The Astrophysical Journal last week.
Chiara Mazzucchelli, who co-led the discovery, told Salon via email that the quasar is significant because it will help astronomers advance their understanding of the early universe — and particularly of the first massive galaxies and black holes that formed during that time.
"Quasars with powerful radio jets are quite rare," Mazzucchelli said. "These radio jets are important because theories suggest that they can trigger mechanisms of very fast growth of the central black holes, and indeed the black hole at the center of P172+18 is accreting at a very high pace — it is amongst the fastest in the universe that we know so far."
Mazzucchelli said astronomers usually expect to find quasars with radio jets in a certain kind of galactic environment — "surrounded by overdensities of galaxies that will evolve in the clusters of galaxies that we see nowadays." Our galactic neighborhood likely formed from an object that looked similar.
"We do not have the data to confirm or discard this in our case yet, but we might be observing one of the most dense regions in the early universe," Mazzucchelli said.
Crucially, astronomers can use this quasar as a "flashlight" for "the state of the universe at that time," Mazzucchelli explained — meaning one can observe how the light from the quasar interacts with nearby matter, and deduce what the nature of the universe was back then.
Indeed, this period — around 1 billion years after the universe formed — is still ill-understood.
"Around 1 billion years after the Big Bang we have 'transition phase,' in which the first stars and galaxies start to form, shine, and ionize the precedent neutral medium permeating the universe before," Mazzucchelli said. "In practice, the first stars and galaxies turn on and the universe becomes then 'transparent' to light, while before it was only filled by neutral gas."
This transition phase, as Mazzucchellii said, is called the epoch of reionization (EoR).
"In practice, we still do not precisely know how/when/how fast this transition happens," Mazzucchelli said. "P172+18 can help us constraining how 'transparent' the region around the quasar was at time, and so constrain the epoch of reionization."
In other words, the quasar can function as a so-called flashlight, one which we can use, in a sense, to observe how transparent the universe looked 13 billion years ago. In a sense, this massive quasar belching out radio waves is helping human astronomers clear the fog of the early universe.
Such is the case with a newly discovered quasar dubbed P172+18. Thanks to the European Southern Observatory's Very Large Telescope (ESO's VLT), astronomers spotted this, one of the most distant quasars ever, and its powerful, prominent radio jets, which only about ten percent of quasars have.
P172+18 is so distant that light from it has travelled for about 13 billion years to reach us. That means that we are able to see it as it was when the universe was just around 780 million years old. Technically, more distant quasars have been identified, but this is the first time one has been observed sporting radio jets this early on in the history of the universe. That's throwing astronomers' working model of the universe's evolution for a spin.
The findings were presented in a study published in The Astrophysical Journal last week.
Chiara Mazzucchelli, who co-led the discovery, told Salon via email that the quasar is significant because it will help astronomers advance their understanding of the early universe — and particularly of the first massive galaxies and black holes that formed during that time.
"Quasars with powerful radio jets are quite rare," Mazzucchelli said. "These radio jets are important because theories suggest that they can trigger mechanisms of very fast growth of the central black holes, and indeed the black hole at the center of P172+18 is accreting at a very high pace — it is amongst the fastest in the universe that we know so far."
Mazzucchelli said astronomers usually expect to find quasars with radio jets in a certain kind of galactic environment — "surrounded by overdensities of galaxies that will evolve in the clusters of galaxies that we see nowadays." Our galactic neighborhood likely formed from an object that looked similar.
"We do not have the data to confirm or discard this in our case yet, but we might be observing one of the most dense regions in the early universe," Mazzucchelli said.
Crucially, astronomers can use this quasar as a "flashlight" for "the state of the universe at that time," Mazzucchelli explained — meaning one can observe how the light from the quasar interacts with nearby matter, and deduce what the nature of the universe was back then.
Indeed, this period — around 1 billion years after the universe formed — is still ill-understood.
"Around 1 billion years after the Big Bang we have 'transition phase,' in which the first stars and galaxies start to form, shine, and ionize the precedent neutral medium permeating the universe before," Mazzucchelli said. "In practice, the first stars and galaxies turn on and the universe becomes then 'transparent' to light, while before it was only filled by neutral gas."
This transition phase, as Mazzucchellii said, is called the epoch of reionization (EoR).
"In practice, we still do not precisely know how/when/how fast this transition happens," Mazzucchelli said. "P172+18 can help us constraining how 'transparent' the region around the quasar was at time, and so constrain the epoch of reionization."
In other words, the quasar can function as a so-called flashlight, one which we can use, in a sense, to observe how transparent the universe looked 13 billion years ago. In a sense, this massive quasar belching out radio waves is helping human astronomers clear the fog of the early universe.
Astronomers home in on a precise date for the universe's birthday
Here's how astronomers were able to make a new, definitive estimate for the age of the universe
By MATTHEW ROZSA - SALON
JANUARY 5, 2021 12:00AM (UTC)
How old is the universe? Astronomers have been homing in on an increasingly precise estimate for its age for decades. Now, a new research paper based on observational data gives of the most precise estimations yet: 13.77 billion years old, give or take some chronological chump change of 40 million years.
The research, which was published in the Journal of Cosmology and Astroparticle Physics, analyzed the oldest light sources in the universe based on data from the Chilean National Science Foundation's Atacama Cosmology Telescope (ACT). Researchers looked at data from the same light sources that came from the European Space Agency's space-based Planck satellite, which gathered its own information about remnants from the Big Bang between 2009 and 2013. The authors pledged to publicly release all of the data that they used to form the basis for their conclusions.
This study comes amidst a fierce debate among scientists about the age of the universe, much of which remains unresolved. For one thing, there is the so-called "Methuselah star" that seemed to be roughly 16 billion years old, which presented a problem for scientists who at that time believed the Big Bang had occurred between 12 billion and 14 billion years ago. By 2013 scientists had revised its age to 14.5 billion years, based on new data, which could peg the star at roughly the same age as the universe itself.
In July, scientists published an article in the Astronomical Journal suggesting that the universe could actually be as young as 12.6 billion years old.
Now, this new study seems to coincide with the results from the Planck satellite, which is good news in terms of trying to reach a scientific consensus.
"Now we've come up with an answer where Planck and ACT agree," Simone Aiola, a researcher at the Flatiron Institute's Center for Computational Astrophysics and first author of one of two papers, told Cornell University. "It speaks to the fact that these difficult measurements are reliable."
The Big Bang model, which was first proposed by Belgian physicist and astronomer Georges Lemaître in 1927, proposes that the universe existed as an extremely dense and hot single point in space before expanding at the speed of light (and initially, faster). There is ample evidence pointing to this theory, including the observation that all gravitationally unbound objects in space are moving away from all other objects as they would in an expanding universe; likewise, more distant objects are moving away faster.
Our solar system is believed to have been created roughly 4.6 billion years ago, meaning that even by the most generous estimations it is far still less than half the age of the universe itself.
Although the use of the word "bang" may imply an explosion, scientists believe that the universe has really been in a state of ongoing expansion. The "bang" is believed to have been a sudden burst of expansion, or inflation, doubling in size at least 90 times as it continued to grow exponentially. As these things happened, the universe emitted considerable amounts of light and microwave radiation, much of which continues to exist in the universe today. This cosmic microwave background is visible to microwave detectors, and as such allows scientists to learn more about the early periods in the history of our universe.
The research, which was published in the Journal of Cosmology and Astroparticle Physics, analyzed the oldest light sources in the universe based on data from the Chilean National Science Foundation's Atacama Cosmology Telescope (ACT). Researchers looked at data from the same light sources that came from the European Space Agency's space-based Planck satellite, which gathered its own information about remnants from the Big Bang between 2009 and 2013. The authors pledged to publicly release all of the data that they used to form the basis for their conclusions.
This study comes amidst a fierce debate among scientists about the age of the universe, much of which remains unresolved. For one thing, there is the so-called "Methuselah star" that seemed to be roughly 16 billion years old, which presented a problem for scientists who at that time believed the Big Bang had occurred between 12 billion and 14 billion years ago. By 2013 scientists had revised its age to 14.5 billion years, based on new data, which could peg the star at roughly the same age as the universe itself.
In July, scientists published an article in the Astronomical Journal suggesting that the universe could actually be as young as 12.6 billion years old.
Now, this new study seems to coincide with the results from the Planck satellite, which is good news in terms of trying to reach a scientific consensus.
"Now we've come up with an answer where Planck and ACT agree," Simone Aiola, a researcher at the Flatiron Institute's Center for Computational Astrophysics and first author of one of two papers, told Cornell University. "It speaks to the fact that these difficult measurements are reliable."
The Big Bang model, which was first proposed by Belgian physicist and astronomer Georges Lemaître in 1927, proposes that the universe existed as an extremely dense and hot single point in space before expanding at the speed of light (and initially, faster). There is ample evidence pointing to this theory, including the observation that all gravitationally unbound objects in space are moving away from all other objects as they would in an expanding universe; likewise, more distant objects are moving away faster.
Our solar system is believed to have been created roughly 4.6 billion years ago, meaning that even by the most generous estimations it is far still less than half the age of the universe itself.
Although the use of the word "bang" may imply an explosion, scientists believe that the universe has really been in a state of ongoing expansion. The "bang" is believed to have been a sudden burst of expansion, or inflation, doubling in size at least 90 times as it continued to grow exponentially. As these things happened, the universe emitted considerable amounts of light and microwave radiation, much of which continues to exist in the universe today. This cosmic microwave background is visible to microwave detectors, and as such allows scientists to learn more about the early periods in the history of our universe.
The most distant galaxy is upending our model of the universe's history
A new study confirms GN-z11 is the oldest and most distant galaxy humans have ever sighted
By NICOLE KARLIS - salon
DECEMBER 27, 2020 1:00PM (UTC)
Looking out into the universe with a telescope means looking back in time, as the speed of light is so slow that even the light of nearby stars in our own galaxy takes years or millennia to reach us. As such, the very distant galaxies also offer humans a peek into the universe's past — which is what makes the discovery of the most distant galaxy ever found also the most ancient.
According to a new study published Dec. 14 in the journal Nature Astronomy, astronomers have confirmed the most distant galaxy in our universe. Named GN-z11, the galaxy is so distant that it is believed to make up the boundary of the universe at 13.4 billion light years, or 134 nonillion kilometers, from Earth, meaning that the light we see from it left 13.4 billion years ago — only 400 million years after the Big Bang.
Nobunari Kashikawa of the School of Science at University of Tokyo, a co-author of the study, explained to Salon that the current designation for GN-z11 as the "oldest" galaxy might be short-lived, as telescopes continually scan the skies.
"GN-z11 is the most distant galaxy we know today, so far, and maybe tomorrow we'll find a more distant galaxy," Kashikawa wrote via email.
Though the distant galaxy was originally spotted by the Hubble Space Telescope in 2016, Kashikawa and his team used the Keck I telescope in Hawaii to confirm its age and distance. At the time of its discovery, astronomers estimated that it was 13.4 billion light years away, based on the discovery of what appeared to be a break, known as the "Lyman break," in the "spectrum characteristic of distant galaxies," Kashikawa explained.
Trying to spot such a distant, faint galaxy pushed the Hubble Space Telescope to its technological limit.
"Our spectroscopic observations reveal the galaxy to be even farther away than we had originally thought, right at the distance limit of what Hubble can observe," Gabriel Brammer, author of the 2016 study, said in a statement.
Astronomers measure the distance of a galaxy by determining its redshift, which is a measurement of how fast it is moving away from Earth. Since the universe is expanding, every object in the sky that is not gravitationally bound to our own galaxy is receding from Earth; as they do so, these objects' light stretches into longer and therefore redder wavelengths. The farther the galaxy, the greater the redshift.
To determine how far GN-z11 was from Earth, Kashikawa's team studied its spectral features, since examining the observations made by the Hubble Space Telescope were limited.
"Even the Hubble cannot resolve ultraviolet emission lines to the degree we needed," Kashikawa said in a statement. "So we turned to a more up-to-date ground-based spectrograph, an instrument to measure emission lines, called MOSFIRE, which is mounted to the Keck I telescope in Hawaii."
Kashikawa told Salon it was "difficult" to determine if there was really a break in the spectrum or not. Specifically, the team pivoted to look at ultraviolet light to find the redshifted chemical signatures. What it boiled down to was having the right equipment to confirm and identify the spectral break.
"Since its wavelength cannot be measured accurately, the accuracy of determining the distance to the galaxy was uncertain," Kashikawa told Salon via email. "Once we believe that the carbon and oxygen emission lines we detected at this time are real, it is not so difficult to calculate the distance from them."
Even though this galaxy is far, far away, astronomers are hopeful that it holds information that we can learn about our own galaxy and the universe.
"The detected light of carbon and oxygen suggests special physical conditions not found in present-day galaxies," Kashikawa told Salon. "The age of GN-z11 is estimated to be only 70 million years and the estimated mass of a billion times that of the Sun (the stellar component) suggests that this young galaxy was born and grew rapidly."
Kashikawa added: "The fact that carbon and oxygen were found in GN-z11 indicates that this galaxy is not the first (metal-free) galaxy in the universe." Since elements heavier than hydrogen and helium are only forged in massive stars, the presence of heavier elements like carbon indicate that the stars in the galaxy are at least second-generation, meaning one generation of large suns has already lived and died, expelling their metals into the galaxy.
This means, Kashikawa said, that the first galaxies in the universe are still "in a more distant universe unknown to mankind."
Next year will be a big year for astronomy, especially in terms of how we better understand the universe.
"The frontier of the farthest reaches of space is expected to expand dramatically," Kashikawa said.
And that's in part because the James Webb Space Telescope is scheduled to launch on October 31, 2021, from French Guiana, and will build on the legacy of the Hubble telescope. Specifically, it will observe the infrared universe and detect light from distant, old galaxies. Infrared light cannot be detected well from Earth due to interference from the atmosphere, and thus probing the universe in infrared requires a space-based telescope.
"The [James Webb Space Telescope] observatory will detect light from the first generation of galaxies that formed in the early universe after the big bang and study the atmospheres of nearby exoplanets for possible signs of habitability," Eric Smith, NASA Webb's program scientist at the agency's headquarters, said in a statement previously.
According to a new study published Dec. 14 in the journal Nature Astronomy, astronomers have confirmed the most distant galaxy in our universe. Named GN-z11, the galaxy is so distant that it is believed to make up the boundary of the universe at 13.4 billion light years, or 134 nonillion kilometers, from Earth, meaning that the light we see from it left 13.4 billion years ago — only 400 million years after the Big Bang.
Nobunari Kashikawa of the School of Science at University of Tokyo, a co-author of the study, explained to Salon that the current designation for GN-z11 as the "oldest" galaxy might be short-lived, as telescopes continually scan the skies.
"GN-z11 is the most distant galaxy we know today, so far, and maybe tomorrow we'll find a more distant galaxy," Kashikawa wrote via email.
Though the distant galaxy was originally spotted by the Hubble Space Telescope in 2016, Kashikawa and his team used the Keck I telescope in Hawaii to confirm its age and distance. At the time of its discovery, astronomers estimated that it was 13.4 billion light years away, based on the discovery of what appeared to be a break, known as the "Lyman break," in the "spectrum characteristic of distant galaxies," Kashikawa explained.
Trying to spot such a distant, faint galaxy pushed the Hubble Space Telescope to its technological limit.
"Our spectroscopic observations reveal the galaxy to be even farther away than we had originally thought, right at the distance limit of what Hubble can observe," Gabriel Brammer, author of the 2016 study, said in a statement.
Astronomers measure the distance of a galaxy by determining its redshift, which is a measurement of how fast it is moving away from Earth. Since the universe is expanding, every object in the sky that is not gravitationally bound to our own galaxy is receding from Earth; as they do so, these objects' light stretches into longer and therefore redder wavelengths. The farther the galaxy, the greater the redshift.
To determine how far GN-z11 was from Earth, Kashikawa's team studied its spectral features, since examining the observations made by the Hubble Space Telescope were limited.
"Even the Hubble cannot resolve ultraviolet emission lines to the degree we needed," Kashikawa said in a statement. "So we turned to a more up-to-date ground-based spectrograph, an instrument to measure emission lines, called MOSFIRE, which is mounted to the Keck I telescope in Hawaii."
Kashikawa told Salon it was "difficult" to determine if there was really a break in the spectrum or not. Specifically, the team pivoted to look at ultraviolet light to find the redshifted chemical signatures. What it boiled down to was having the right equipment to confirm and identify the spectral break.
"Since its wavelength cannot be measured accurately, the accuracy of determining the distance to the galaxy was uncertain," Kashikawa told Salon via email. "Once we believe that the carbon and oxygen emission lines we detected at this time are real, it is not so difficult to calculate the distance from them."
Even though this galaxy is far, far away, astronomers are hopeful that it holds information that we can learn about our own galaxy and the universe.
"The detected light of carbon and oxygen suggests special physical conditions not found in present-day galaxies," Kashikawa told Salon. "The age of GN-z11 is estimated to be only 70 million years and the estimated mass of a billion times that of the Sun (the stellar component) suggests that this young galaxy was born and grew rapidly."
Kashikawa added: "The fact that carbon and oxygen were found in GN-z11 indicates that this galaxy is not the first (metal-free) galaxy in the universe." Since elements heavier than hydrogen and helium are only forged in massive stars, the presence of heavier elements like carbon indicate that the stars in the galaxy are at least second-generation, meaning one generation of large suns has already lived and died, expelling their metals into the galaxy.
This means, Kashikawa said, that the first galaxies in the universe are still "in a more distant universe unknown to mankind."
Next year will be a big year for astronomy, especially in terms of how we better understand the universe.
"The frontier of the farthest reaches of space is expected to expand dramatically," Kashikawa said.
And that's in part because the James Webb Space Telescope is scheduled to launch on October 31, 2021, from French Guiana, and will build on the legacy of the Hubble telescope. Specifically, it will observe the infrared universe and detect light from distant, old galaxies. Infrared light cannot be detected well from Earth due to interference from the atmosphere, and thus probing the universe in infrared requires a space-based telescope.
"The [James Webb Space Telescope] observatory will detect light from the first generation of galaxies that formed in the early universe after the big bang and study the atmospheres of nearby exoplanets for possible signs of habitability," Eric Smith, NASA Webb's program scientist at the agency's headquarters, said in a statement previously.
Scientists discovered a radio signal from the nearest star and want to know if it's from aliens
The signal is consistent with a radio wave originating from a planet orbiting Proxima Centauri
By MATTHEW ROZSA - SALON
DECEMBER 23, 2020 11:54PM (UTC)
Scientists at an Australian observatory have been studying a radio signal that appears to originate in Proxima Centauri, the star closest to the sun, to see if it may be a sign of intelligent life.
A narrow beam of radio waves was detected over a period of 30 hours in April and May 2019 by the Parkes telescope in Australia, according to The Guardian. The researchers studying the wave emission have not yet been able to identify any Earthly origin, whether a satellite in or something on the ground. As a result, scientists at the Breakthrough Listen project — an organization based at the University of California, Berkeley that searches for radio signals from intelligent extraterrestrial life forms in the universe — believe that the radio signal could originate from extraterrestrial intelligent life.
The beam, known as BLC1, is also attractive to E.T.-hunters because its frequency shifts in a way that is consistent with the movement of a planet. It resembles the kind of radio waves that humans would send into space and appears to come from the direction of the red dwarf star Proxima Centauri.
Spokespeople for the Breakthrough Listen project said that this radio beam is, therefore, "the first serious candidate since the 'Wow! signal'" that intelligent aliens may have sent a radio signal into space that was picked up by humans. The "Wow! signal" was a narrowband radio signal detected by Ohio observatory in 1977, and was given its name because astronomer Jerry Ehman wrote "Wow!" next to the data, noting the great degree of magnitude with which the signal was stronger than background noise. While the origin of the Wow! signal has never been definitively determined, recent theories suggest it resulted from a quickly-moving comet, not aliens.
Likewise, the jury is still out on the origin of the 2019 signal from Proxima Centauri. "It has some particular properties that caused it to pass many of our checks, and we cannot yet explain it," Andrew Siemion from the University of California, Berkeley, told Scientific American about the signal. He also pointed to the fact that the signal is in a very narrow band of the radio spectrum, 982 megahertz, which usually does not include transmissions from human-made spacecraft and satellites. "We don't know of any natural way to compress electromagnetic energy into a single bin in frequency," Siemion told the magazine.
As with all news about the potential discovery of intelligent life elsewhere in the universe, there are reasons to be skeptical. There may be an as-of-yet unexplained human cause for the radio signal, and even if it does originate in space, there could be a scientific explanation that does not involve extraterrestrial life. For scientists to learn more about whether this proves aliens exist, they will need to publish their full research and then other astronomers will have to spend an extended period of time analyzing it.
2020 has been a signal year for sensational stories about extraterrestrial life. The most scientifically robust story involved the purported discovery of trace amounts of phosphine — a gas emitted by anaerobic bacteria on Earth — in the atmosphere of Venus. After the initial excitement surrounding that paper's publication, however, two subsequent scientific investigations were not able to replicate the original study's results, throwing cold water on the original flame of excitement.
Similarly, there was much buzz over videos of purported "UFOs" that were recorded by American military pilots, which the Pentagon announced in August it was going to investigate. While those videos do indeed show aircraft that have not been identified, there is no evidence that the crafts are of alien origin, and the objects move in a manner consistent with human technological capabilities. Indeed, mundane explanations range from the possibility of technology being developed by another country or a corporation that did not disclose its work to the US military.
The most out-there piece of 2020 E.T. news involved Haim Eshed, an Israeli official who used to lead the Israeli Defense Ministry's space directorate, and who claimed that a "galactic federation" had contacted human governments, that there is an "underground base in the depths of Mars" where American astronauts and extraterrestrials interact and that President Donald Trump knows these things but was convinced to keep them secret to avoid "mass hysteria." There is no evidence to support his claims.
A narrow beam of radio waves was detected over a period of 30 hours in April and May 2019 by the Parkes telescope in Australia, according to The Guardian. The researchers studying the wave emission have not yet been able to identify any Earthly origin, whether a satellite in or something on the ground. As a result, scientists at the Breakthrough Listen project — an organization based at the University of California, Berkeley that searches for radio signals from intelligent extraterrestrial life forms in the universe — believe that the radio signal could originate from extraterrestrial intelligent life.
The beam, known as BLC1, is also attractive to E.T.-hunters because its frequency shifts in a way that is consistent with the movement of a planet. It resembles the kind of radio waves that humans would send into space and appears to come from the direction of the red dwarf star Proxima Centauri.
Spokespeople for the Breakthrough Listen project said that this radio beam is, therefore, "the first serious candidate since the 'Wow! signal'" that intelligent aliens may have sent a radio signal into space that was picked up by humans. The "Wow! signal" was a narrowband radio signal detected by Ohio observatory in 1977, and was given its name because astronomer Jerry Ehman wrote "Wow!" next to the data, noting the great degree of magnitude with which the signal was stronger than background noise. While the origin of the Wow! signal has never been definitively determined, recent theories suggest it resulted from a quickly-moving comet, not aliens.
Likewise, the jury is still out on the origin of the 2019 signal from Proxima Centauri. "It has some particular properties that caused it to pass many of our checks, and we cannot yet explain it," Andrew Siemion from the University of California, Berkeley, told Scientific American about the signal. He also pointed to the fact that the signal is in a very narrow band of the radio spectrum, 982 megahertz, which usually does not include transmissions from human-made spacecraft and satellites. "We don't know of any natural way to compress electromagnetic energy into a single bin in frequency," Siemion told the magazine.
As with all news about the potential discovery of intelligent life elsewhere in the universe, there are reasons to be skeptical. There may be an as-of-yet unexplained human cause for the radio signal, and even if it does originate in space, there could be a scientific explanation that does not involve extraterrestrial life. For scientists to learn more about whether this proves aliens exist, they will need to publish their full research and then other astronomers will have to spend an extended period of time analyzing it.
2020 has been a signal year for sensational stories about extraterrestrial life. The most scientifically robust story involved the purported discovery of trace amounts of phosphine — a gas emitted by anaerobic bacteria on Earth — in the atmosphere of Venus. After the initial excitement surrounding that paper's publication, however, two subsequent scientific investigations were not able to replicate the original study's results, throwing cold water on the original flame of excitement.
Similarly, there was much buzz over videos of purported "UFOs" that were recorded by American military pilots, which the Pentagon announced in August it was going to investigate. While those videos do indeed show aircraft that have not been identified, there is no evidence that the crafts are of alien origin, and the objects move in a manner consistent with human technological capabilities. Indeed, mundane explanations range from the possibility of technology being developed by another country or a corporation that did not disclose its work to the US military.
The most out-there piece of 2020 E.T. news involved Haim Eshed, an Israeli official who used to lead the Israeli Defense Ministry's space directorate, and who claimed that a "galactic federation" had contacted human governments, that there is an "underground base in the depths of Mars" where American astronauts and extraterrestrials interact and that President Donald Trump knows these things but was convinced to keep them secret to avoid "mass hysteria." There is no evidence to support his claims.
Astronomers discover a "twin" planet to the mysterious, long-predicted Planet Nine
An exotic planet far from its parent star has all the same properties that we hypothesize for Planet Nine
By NICOLE KARLIS - salon
DECEMBER 13, 2020 3:00PM (UTC)
The 11-Jupiter-mass exoplanet called HD 106906 b, shown in this artist's illustration, occupies an unlikely orbit around a double star 336 light-years away. It may be offering clues to something that might be much closer to home: a hypothesized distant member of our solar system dubbed "Planet Nine." This is the first time that astronomers have been able to measure the motion of a massive Jupiter-like planet that is orbiting very far away from its host stars and visible debris disk. ( NASA/M. Kornmesser/ESA/Hubble)
Of all the planets that humans have discovered in other solar systems, most of them orbit close and tight to their parent star. That's partially due to the selection effect: the easiest-to-spot exoplanets (meaning a planet outside of our solar system) are those that are close enough to their star (or stars).
Hence, finding a planet that orbits really, really far from its parent star is a rare occurrence — so rare, in fact, that it's hard to do even in our own solar system. Indeed, there is much evidence that points to the existence of a massive planet far beyond Pluto's orbit, the theoretical Planet Nine; the problem is that it's been nigh-impossible to find.
This week, the discovery of a massive exoplanet 336 light-years away, one that's 11 times the mass of Jupiter, is renewing interest in finding Planet Nine and could hold some clues to its discovery. That's because the existence of this exoplanet, named HD106906 b, proves that the positioning of distant, massive planets in a solar system is not just possible, but provides hints as to how it might happen.
In a paper published this week, astronomers examined years of data collected by the Hubble Space Telescope on an exoplanet called HD106906 b. Astronomers first discovered the exoplanet in 2013 with the Magellan Telescopes at the Las Campanas Observatory in Chile's Atacama Desert. At the time, astronomers didn't know about the planet's orbit or its size.
According to the new paper, the exoplanet orbits its host stars (yes, that's plural — it's a binary star system) once every 15,000 human years. Hence, it also sits extremely far away from its host twin stars, 730 times the distance between the Earth and the sun. That's about 18 times further than Pluto is from our sun.
Another oddity about the exoplanet is how tilted it is in its orbit. To put in context: the sun and all planets in our solar system (and most solar systems) emerged from the same protoplanetary nebula, a swirling, disk-shaped gas and dust bubble, billions of years ago. Because they all formed from the same stuff moving in the same way, the planets in our solar system orbit on the same plane. (Imagine spinning a clay blob on a pottery wheel, and watching it spread out flat into a plate; that's roughly analogous to happens in solar systems as they form from nebulae.) Thus, you could look at the solar system edge-on, and everything lines up.
But HD106906 b doesn't follow that rule. Indeed, it has an "extreme orbit" that is very inclined and elliptical.
"To highlight why this is weird, we can just look at our own Solar System and see that all of the planets lie roughly in the same plane," Meiji Nguyen of the University of California-Berkeley, who led the study, said in a statement. "It would be bizarre if, say, Jupiter just happened to be inclined 30 degrees relative to the plane that every other planet orbits in."
Its bizarre placement in its own solar system raises many questions, but also could provide answers to the hypothetical Planet Nine in our solar system.
As I've previously explained, so-called Planet Nine is a hot topic in the astronomy community. In the past decade, many astronomers have proposed that perturbations in Uranus and Neptunes' orbits mean the existence of a world that has yet to be observed, or possibly some small, heavy exotic object like a micro-black hole. (Such a scenario would not be unprecedented: Neptune was discovered not through direct observation, but because astronomer Alexis Bouvard observed perturbations in Uranus' orbit and predicted the existence of an unknown planet, which turned out to be Neptune.) But according to the new paper on exoplanet HD106906 b, the scenario behind its strange orbit could provide an explanation behind Planet Nine.
"Despite the lack of detection of Planet Nine to date, the orbit of the planet can be inferred based on its effect on the various objects in the outer Solar System," Robert De Rosa of the European Southern Observatory in Santiago, Chile who led the study's analysis, said in a statement. "This suggests that if a planet was indeed responsible for what we observe in the orbits of trans-Neptunian objects it should have an eccentric orbit inclined relative to the plane of the Solar System."
"This prediction of the orbit of Planet Nine is similar to what we are seeing with HD 106906 b," De Rosa explained.
It's possible that Planet Nine was created in the inner solar system and then Jupiter kicked it out far beyond Pluto—but this is just a theory.
"The planet's orbit is very inclined, elongated and external to a dusty debris disc that surrounds it's host stars," Avi Loeb, chair of Harvard's astronomy department, told Salon via email. "In that sense, it resembles the orbit postulated for Planet 9 in the Solar system."
In a recent paper with his student, Amir Siraj, they suggest that a hypothetical Planet Nine could be the result of star clusters.
"They can capture planets that formed around other stars, especially if they have a companion star with them," Loeb said. "The captured planets would then be found on distant and highly inclined orbits, as exhibited by HD106906 b in this exo-planetary system and the putative Planet Nine in the solar system.
HD 106906 b's origins are still unclear: how did it get so far from its parent stars, and why is its orbit so tilted?
"We do not conclusively know where or how the planet formed," De Rosa said, referring to the exoplanet. "Although we have made the first measurement of orbital motion, there are still large uncertainties on the various orbital parameters. It is likely that both observers and theorists alike will be studying HD 106906 for years to come, unraveling the many mysteries of this remarkable planetary system."
Hence, finding a planet that orbits really, really far from its parent star is a rare occurrence — so rare, in fact, that it's hard to do even in our own solar system. Indeed, there is much evidence that points to the existence of a massive planet far beyond Pluto's orbit, the theoretical Planet Nine; the problem is that it's been nigh-impossible to find.
This week, the discovery of a massive exoplanet 336 light-years away, one that's 11 times the mass of Jupiter, is renewing interest in finding Planet Nine and could hold some clues to its discovery. That's because the existence of this exoplanet, named HD106906 b, proves that the positioning of distant, massive planets in a solar system is not just possible, but provides hints as to how it might happen.
In a paper published this week, astronomers examined years of data collected by the Hubble Space Telescope on an exoplanet called HD106906 b. Astronomers first discovered the exoplanet in 2013 with the Magellan Telescopes at the Las Campanas Observatory in Chile's Atacama Desert. At the time, astronomers didn't know about the planet's orbit or its size.
According to the new paper, the exoplanet orbits its host stars (yes, that's plural — it's a binary star system) once every 15,000 human years. Hence, it also sits extremely far away from its host twin stars, 730 times the distance between the Earth and the sun. That's about 18 times further than Pluto is from our sun.
Another oddity about the exoplanet is how tilted it is in its orbit. To put in context: the sun and all planets in our solar system (and most solar systems) emerged from the same protoplanetary nebula, a swirling, disk-shaped gas and dust bubble, billions of years ago. Because they all formed from the same stuff moving in the same way, the planets in our solar system orbit on the same plane. (Imagine spinning a clay blob on a pottery wheel, and watching it spread out flat into a plate; that's roughly analogous to happens in solar systems as they form from nebulae.) Thus, you could look at the solar system edge-on, and everything lines up.
But HD106906 b doesn't follow that rule. Indeed, it has an "extreme orbit" that is very inclined and elliptical.
"To highlight why this is weird, we can just look at our own Solar System and see that all of the planets lie roughly in the same plane," Meiji Nguyen of the University of California-Berkeley, who led the study, said in a statement. "It would be bizarre if, say, Jupiter just happened to be inclined 30 degrees relative to the plane that every other planet orbits in."
Its bizarre placement in its own solar system raises many questions, but also could provide answers to the hypothetical Planet Nine in our solar system.
As I've previously explained, so-called Planet Nine is a hot topic in the astronomy community. In the past decade, many astronomers have proposed that perturbations in Uranus and Neptunes' orbits mean the existence of a world that has yet to be observed, or possibly some small, heavy exotic object like a micro-black hole. (Such a scenario would not be unprecedented: Neptune was discovered not through direct observation, but because astronomer Alexis Bouvard observed perturbations in Uranus' orbit and predicted the existence of an unknown planet, which turned out to be Neptune.) But according to the new paper on exoplanet HD106906 b, the scenario behind its strange orbit could provide an explanation behind Planet Nine.
"Despite the lack of detection of Planet Nine to date, the orbit of the planet can be inferred based on its effect on the various objects in the outer Solar System," Robert De Rosa of the European Southern Observatory in Santiago, Chile who led the study's analysis, said in a statement. "This suggests that if a planet was indeed responsible for what we observe in the orbits of trans-Neptunian objects it should have an eccentric orbit inclined relative to the plane of the Solar System."
"This prediction of the orbit of Planet Nine is similar to what we are seeing with HD 106906 b," De Rosa explained.
It's possible that Planet Nine was created in the inner solar system and then Jupiter kicked it out far beyond Pluto—but this is just a theory.
"The planet's orbit is very inclined, elongated and external to a dusty debris disc that surrounds it's host stars," Avi Loeb, chair of Harvard's astronomy department, told Salon via email. "In that sense, it resembles the orbit postulated for Planet 9 in the Solar system."
In a recent paper with his student, Amir Siraj, they suggest that a hypothetical Planet Nine could be the result of star clusters.
"They can capture planets that formed around other stars, especially if they have a companion star with them," Loeb said. "The captured planets would then be found on distant and highly inclined orbits, as exhibited by HD106906 b in this exo-planetary system and the putative Planet Nine in the solar system.
HD 106906 b's origins are still unclear: how did it get so far from its parent stars, and why is its orbit so tilted?
"We do not conclusively know where or how the planet formed," De Rosa said, referring to the exoplanet. "Although we have made the first measurement of orbital motion, there are still large uncertainties on the various orbital parameters. It is likely that both observers and theorists alike will be studying HD 106906 for years to come, unraveling the many mysteries of this remarkable planetary system."
Why physics Nobelist Roger Penrose believes there are black holes left over from previous universes
Physics Nobelist Sir Roger Penrose has an odd theory about the universe — and there's even evidence for it
MATTHEW ROZSA - SALON
OCTOBER 18, 2020 11:30PM (UTC)
University of Oxford mathematical physicist Sir Roger Penrose won a Nobel Prize earlier this month for a lifetime of work studying black holes, singularities from which not even light can escape. Yet he is also behind a provocative and controversial theory about the formation of the universe — namely, that the Big Bang did not mark the beginning of the universe as we know it, but merely started the next iteration of our universe. In his theory, known as conformal cyclic cosmology, our current conception of the universe is merely one of a series of infinite universes that came before it and which will come after, too.
Cosmology, of course, is full of theories of assorted degrees of harebrainedness, and many of the most famous ones — such as string theory — lack any observational evidence. But Penrose's prediction is different, as there is some evidence in observations of the cosmic background radiation — meaning the average background temperature of the entire night sky, in which one can see remnant heat from the Big Bang and differentiate bright patches in the sky. As pictured in the featured photo on this story, some of those "bright spots" could be, as Penrose believes, radiation emanations from ancient black holes that predate this universe.
"The idea of Roger's 'conformal cyclic cosmology' [CCC], is based on three facts," Pawel Nurowski, a scientist at the Center for Theoretical Physics at the Polish Academy of Sciences, explained to Salon by email. Specifically, Nurowski says, in order for Penrose's theory to make sense, one would have to observe a universe that has a positive cosmological constant (meaning the mysterious, constant repulsive force that pushes everything in the universe which is not gravitationally bound away from everything else), as well as a universe that would look similar at its end as it did in its beginning. Observations of our universe suggest that it will end in a disordered, empty state, with all matter converted to stray photons that never interact with each other.
Nurowski concluded, "We believe that every possible universe will have all these three features," that "we have an infinite sequence of universes (eons)" and that "Penrose considers this sequence of conformally glued eons as the full physical Universe."
"In this picture, our standard cosmology Universe is only one of the eons," Nurowski added. "So the main difference between 'conformal cyclic cosmology' and the standard cosmology is that our Universe is only a part of Penrose's universe," whereas adherents to the traditional idea of a Big Bang believe that that specific event began our current universe.
This brings us to the recent discovery that may support Penrose's CCC hypothesis. According to a paper co-authored by Penrose, Nurowski and two other scientists, unexpected hot spots that have been discovered in the cosmic microwave background of the universe suggest that there are "anomalous regions," perhaps enormous black holes left over from previous universes that have yet to decay. These regions are known as "Hawking Points," after Stephen Hawking, who first came up with the theory that black holes would very slowly decay over unimaginably long timescales, emitting what is called Hawking radiation in his honor. The discovery of these Hawking points suggests that Penrose's cosmological model is accurate.
"The existence of such anomalous regions, resulting from point-like sources at the conformally stretched-out big bang, is a predicted consequence of conformal cyclic cosmology (CCC)," the paper explains, adding that these so-called Hawking points would be caused by radiation emanating from "supermassive black holes in a cosmic aeon prior to our own."
It must be emphasized that Penrose's Nobel Prize was not awarded because of his theory of a conformal cyclical cosmology. Harvard astrophysicist Avi Loeb clarified in an email to Salon: "In 1939, Albert Einstein wrote a paper in Annals of Mathematics doubting that black holes exist in nature. Roger Penrose demonstrated that black holes are a robust prediction of Einstein's general theory of relativity and in doing so invented a new mathematical tool to depict spacetimes, called Penrose diagrams."
Loeb added, "He also showed that it is possible to extract energy from a spinning black hole as if it was a flywheel, through the so-called Penrose Process."
Loeb says that Penrose's belief that the hot spots prove that the black holes in question came from previous universes is controversial.
"The particular theory advocated by Penrose, Conformal Cyclic Cosmology, asserts that the Big Bang expansion repeats in succession of cycles of expansion, implying that one can see through our current Big Bang into past Big Bangs, giving rise to patterns in cosmic microwave background," Loeb explained. "Penrose made the controversial claim that such patterns are seen in data, but it was shown by others that the patterns he identified are not statistically significant.... and so his claim is controversial."
There are skeptics in the astrophysics community. Ethan Siegel, an astrophysicist who pens a science blog that is published in Forbes magazine, was very critical of Penrose's theory. Last week, he penned an article titled "No, Roger Penrose, We See No Evidence Of A 'Universe Before The Big Bang.'"
"The predictions that [Penrose] has made are refuted by the data, and his claims to see these effects are only reproducible if one analyzes the data in a scientifically unsound and illegitimate fashion," Dr. Siegel wrote. "Hundreds of scientists have pointed this out to Penrose — repeatedly and consistently over a period of more than 10 years — who continues to ignore the field and plow ahead with his contentions."
Nurowski and Loeb both pushed back against Siegel's claims.
"The person that wrote this article seems to never read our recent Monthly Notices paper," Nurowski wrote to Salon, linking to his and Penrose's article showing evidence for Hawking points. "[Siegel] also seems not to read our three other papers. He gives a quote of a picture from an old paper with Penrose and Gurzadyan. He has not a single argument against our newest MNRAS [Monthly Notices of the Royal Astronomical Society] paper.... I stress that the statistical analysis in our paper is at the highest astronomical standards."
He added, "I am happy to answer any critics, provided that I hear a single argument against this what we have written, and not the repetition of this what the standard cosmology says. Either we are talking about facts or beliefs. Our paper is about facts. But to talk about them, one has to read the paper first."
Loeb seemed to echo this view, despite his own skepticism about CCC.
"My problem with Penrose's theory is that it is not fully worked out and that there is no statistically irrefutable evidence to support the patterns that he claims to have identified in the cosmic microwave background, but we should remain open minded to new ideas on what preceded the Big Bang," Loeb explained. "This is the story of where we came from, our cosmic roots. The simple picture we have now is clearly incomplete and requires more scientific work. Not more bullying of any new idea."
Cosmology, of course, is full of theories of assorted degrees of harebrainedness, and many of the most famous ones — such as string theory — lack any observational evidence. But Penrose's prediction is different, as there is some evidence in observations of the cosmic background radiation — meaning the average background temperature of the entire night sky, in which one can see remnant heat from the Big Bang and differentiate bright patches in the sky. As pictured in the featured photo on this story, some of those "bright spots" could be, as Penrose believes, radiation emanations from ancient black holes that predate this universe.
"The idea of Roger's 'conformal cyclic cosmology' [CCC], is based on three facts," Pawel Nurowski, a scientist at the Center for Theoretical Physics at the Polish Academy of Sciences, explained to Salon by email. Specifically, Nurowski says, in order for Penrose's theory to make sense, one would have to observe a universe that has a positive cosmological constant (meaning the mysterious, constant repulsive force that pushes everything in the universe which is not gravitationally bound away from everything else), as well as a universe that would look similar at its end as it did in its beginning. Observations of our universe suggest that it will end in a disordered, empty state, with all matter converted to stray photons that never interact with each other.
Nurowski concluded, "We believe that every possible universe will have all these three features," that "we have an infinite sequence of universes (eons)" and that "Penrose considers this sequence of conformally glued eons as the full physical Universe."
"In this picture, our standard cosmology Universe is only one of the eons," Nurowski added. "So the main difference between 'conformal cyclic cosmology' and the standard cosmology is that our Universe is only a part of Penrose's universe," whereas adherents to the traditional idea of a Big Bang believe that that specific event began our current universe.
This brings us to the recent discovery that may support Penrose's CCC hypothesis. According to a paper co-authored by Penrose, Nurowski and two other scientists, unexpected hot spots that have been discovered in the cosmic microwave background of the universe suggest that there are "anomalous regions," perhaps enormous black holes left over from previous universes that have yet to decay. These regions are known as "Hawking Points," after Stephen Hawking, who first came up with the theory that black holes would very slowly decay over unimaginably long timescales, emitting what is called Hawking radiation in his honor. The discovery of these Hawking points suggests that Penrose's cosmological model is accurate.
"The existence of such anomalous regions, resulting from point-like sources at the conformally stretched-out big bang, is a predicted consequence of conformal cyclic cosmology (CCC)," the paper explains, adding that these so-called Hawking points would be caused by radiation emanating from "supermassive black holes in a cosmic aeon prior to our own."
It must be emphasized that Penrose's Nobel Prize was not awarded because of his theory of a conformal cyclical cosmology. Harvard astrophysicist Avi Loeb clarified in an email to Salon: "In 1939, Albert Einstein wrote a paper in Annals of Mathematics doubting that black holes exist in nature. Roger Penrose demonstrated that black holes are a robust prediction of Einstein's general theory of relativity and in doing so invented a new mathematical tool to depict spacetimes, called Penrose diagrams."
Loeb added, "He also showed that it is possible to extract energy from a spinning black hole as if it was a flywheel, through the so-called Penrose Process."
Loeb says that Penrose's belief that the hot spots prove that the black holes in question came from previous universes is controversial.
"The particular theory advocated by Penrose, Conformal Cyclic Cosmology, asserts that the Big Bang expansion repeats in succession of cycles of expansion, implying that one can see through our current Big Bang into past Big Bangs, giving rise to patterns in cosmic microwave background," Loeb explained. "Penrose made the controversial claim that such patterns are seen in data, but it was shown by others that the patterns he identified are not statistically significant.... and so his claim is controversial."
There are skeptics in the astrophysics community. Ethan Siegel, an astrophysicist who pens a science blog that is published in Forbes magazine, was very critical of Penrose's theory. Last week, he penned an article titled "No, Roger Penrose, We See No Evidence Of A 'Universe Before The Big Bang.'"
"The predictions that [Penrose] has made are refuted by the data, and his claims to see these effects are only reproducible if one analyzes the data in a scientifically unsound and illegitimate fashion," Dr. Siegel wrote. "Hundreds of scientists have pointed this out to Penrose — repeatedly and consistently over a period of more than 10 years — who continues to ignore the field and plow ahead with his contentions."
Nurowski and Loeb both pushed back against Siegel's claims.
"The person that wrote this article seems to never read our recent Monthly Notices paper," Nurowski wrote to Salon, linking to his and Penrose's article showing evidence for Hawking points. "[Siegel] also seems not to read our three other papers. He gives a quote of a picture from an old paper with Penrose and Gurzadyan. He has not a single argument against our newest MNRAS [Monthly Notices of the Royal Astronomical Society] paper.... I stress that the statistical analysis in our paper is at the highest astronomical standards."
He added, "I am happy to answer any critics, provided that I hear a single argument against this what we have written, and not the repetition of this what the standard cosmology says. Either we are talking about facts or beliefs. Our paper is about facts. But to talk about them, one has to read the paper first."
Loeb seemed to echo this view, despite his own skepticism about CCC.
"My problem with Penrose's theory is that it is not fully worked out and that there is no statistically irrefutable evidence to support the patterns that he claims to have identified in the cosmic microwave background, but we should remain open minded to new ideas on what preceded the Big Bang," Loeb explained. "This is the story of where we came from, our cosmic roots. The simple picture we have now is clearly incomplete and requires more scientific work. Not more bullying of any new idea."
Giant black hole discovered at centre of cosmic ‘spider’s web’
October 1, 2020
By Agence France-Presse - raw story
Astronomers have discovered six galaxies ensnared in the cosmic “spider’s web” of a supermassive black hole soon after the Big Bang, according to research published Thursday that could help explain the development of these enigmatic monsters.
Black holes that emerged early in the history of the Universe are thought to have formed from the collapse of the first stars, but astronomers have puzzled over how they expanded into giants.
The newly discovered black hole — which dates from when the Universe was not even a billion years old — weighs in at one billion times the mass of our Sun and was spotted by the European Southern Observatory (ESO).
Scientists said the finding helps provide an explanation for how supermassive black holes such as the one at the centre of our Milky Way may have developed.
This is because astronomers believe the filaments trapping the cluster of galaxies are carrying enough gas to “feed” the black hole, enabling it to grow.
“The cosmic web filaments are like spider’s web threads,” said Marco Mignoli, an astronomer at the National Institute for Astrophysics (INAF) in Bologna who led the research, which was published in the journal Astronomy & Astrophysics.
“The galaxies stand and grow where the filaments cross, and streams of gas — available to fuel both the galaxies and the central supermassive black hole — can flow along the filaments.”
Mignoli said that until now there had been “no good explanation” for the existence of such huge early black holes.
– ‘Tip of the iceberg’ –
Researchers said the web structure may have formed with the help of dark matter — thought to attract huge amounts of gas in the early Universe.
“Our finding lends support to the idea that the most distant and massive black holes form and grow within massive dark matter halos in large-scale structures, and that the absence of earlier detections of such structures was likely due to observational limitations,” said co-author Colin Norman of Johns Hopkins University.
The entire web is over 300 times the size of the Milky Way, according to a statement from ESO.
But it said the galaxies are also some of the faintest that current telescopes can spot, adding the discovery was only possible using the largest optical telescopes available, including ESO’s Very Large Telescope in Chile’s Atacama Desert.
“We believe we have just seen the tip of the iceberg, and that the few galaxies discovered so far around this supermassive black hole are only the brightest ones,” said co-author Barbara Balmaverde, an astronomer at INAF in Torino, Italy.
The research is the latest to try and illuminate the mysterious formation of these cosmic monsters, which are so dense that not even light can escape their gravitational pull.
In September, two consortiums of some 1,500 scientists reported the discovery of GW190521, formed by the collision of two smaller black holes.
What scientists observed were gravitational waves produced more than seven billion years ago when they smashed together, releasing eight solar masses worth of energy and creating one of the most powerful events in the Universe since the Big Bang.
At 142 solar masses, GW190521 was the first “intermediate mass” black hole ever observed.
Scientists said the finding challenges current theories on the formation of supermassive black holes, suggesting it could be through the repeated merger of these mid-sized bodies.
Black holes that emerged early in the history of the Universe are thought to have formed from the collapse of the first stars, but astronomers have puzzled over how they expanded into giants.
The newly discovered black hole — which dates from when the Universe was not even a billion years old — weighs in at one billion times the mass of our Sun and was spotted by the European Southern Observatory (ESO).
Scientists said the finding helps provide an explanation for how supermassive black holes such as the one at the centre of our Milky Way may have developed.
This is because astronomers believe the filaments trapping the cluster of galaxies are carrying enough gas to “feed” the black hole, enabling it to grow.
“The cosmic web filaments are like spider’s web threads,” said Marco Mignoli, an astronomer at the National Institute for Astrophysics (INAF) in Bologna who led the research, which was published in the journal Astronomy & Astrophysics.
“The galaxies stand and grow where the filaments cross, and streams of gas — available to fuel both the galaxies and the central supermassive black hole — can flow along the filaments.”
Mignoli said that until now there had been “no good explanation” for the existence of such huge early black holes.
– ‘Tip of the iceberg’ –
Researchers said the web structure may have formed with the help of dark matter — thought to attract huge amounts of gas in the early Universe.
“Our finding lends support to the idea that the most distant and massive black holes form and grow within massive dark matter halos in large-scale structures, and that the absence of earlier detections of such structures was likely due to observational limitations,” said co-author Colin Norman of Johns Hopkins University.
The entire web is over 300 times the size of the Milky Way, according to a statement from ESO.
But it said the galaxies are also some of the faintest that current telescopes can spot, adding the discovery was only possible using the largest optical telescopes available, including ESO’s Very Large Telescope in Chile’s Atacama Desert.
“We believe we have just seen the tip of the iceberg, and that the few galaxies discovered so far around this supermassive black hole are only the brightest ones,” said co-author Barbara Balmaverde, an astronomer at INAF in Torino, Italy.
The research is the latest to try and illuminate the mysterious formation of these cosmic monsters, which are so dense that not even light can escape their gravitational pull.
In September, two consortiums of some 1,500 scientists reported the discovery of GW190521, formed by the collision of two smaller black holes.
What scientists observed were gravitational waves produced more than seven billion years ago when they smashed together, releasing eight solar masses worth of energy and creating one of the most powerful events in the Universe since the Big Bang.
At 142 solar masses, GW190521 was the first “intermediate mass” black hole ever observed.
Scientists said the finding challenges current theories on the formation of supermassive black holes, suggesting it could be through the repeated merger of these mid-sized bodies.
Alien life
Scientists find gas linked to life in atmosphere of Venus
Phosphine, released by microbes in oxygen-starved environments, was present in quantities larger than expected
Ian Sample Science editor
the guardian
Mon 14 Sep 2020 11.00 EDT
Traces of a pungent gas that waft through the clouds of Venus may be emanations from aerial organisms – microbial life, but not as we know it.
Astronomers detected phosphine 30 miles up in the planet’s atmosphere and have failed to identify a process other than life that could account for its presence.
The discovery raises the possibility that life gained a foothold on Earth’s inner neighbour and remnants clung on – or floated on, at least – as Venus suffered runaway global warming that made the planet hellish.
For 2bn years, Venus was temperate and harboured an ocean. But today, a dense carbon dioxide atmosphere blankets a near-waterless surface where temperatures top 450C. The clouds in the sky are hardly inviting, containing droplets of 90% sulphuric acid.
The conditions on Venus are so deeply unpleasant that many scientists believe the planet is dead. Rather than coming from floating Venusians, they suspect phosphine arises from more mundane processes.
“It’s completely startling to say life could survive surrounded by so much sulphuric acid,” said Prof Jane Greaves, an astronomer at Cardiff University, leader of the team who made the discovery. “But all the geological and photochemical routes we can think of are far too underproductive to make the phosphine we see.”
On Earth, phosphine gas is released by microbes in oxygen-starved environments, such as lake sediments and animals’ innards. Other production routes are so extreme – the bellies of Jupiter and Saturn – that on rocky planets, phosphine is considered a marker for life.
As a test-run for searching for life beyond Earth, Greaves observed Venus in 2017 with the James Clerk Maxwell telescope in Hawaii, and in 2019 with the Alma telescope in Chile. Both revealed the signature of phosphine in the upper cloud deck of Venus.
Greaves first spotted the phosphine signal late one day in December 2018 as she was about to leave work. “There wasn’t anyone to talk to and I remember thinking the best way to celebrate was to make a curry, so I drove off to Sainsbury’s,” she said.
The observations point to trace levels of phosphine, about 20 molecules per billion, at least 30 miles high in the Venusian sky. Most appears at the mid-latitudes with none detected at the poles, the scientists report in Nature Astronomy.
While the phosphine may come from a mysterious new source, the researchers’ calculations rule out known chemistry and show that volcanoes, lightning and micrometeorites would all create too little. “The rates of production are so small, and the rates of destruction great enough, that you’d have 1,000 times too little,” said Paul Rimmer, an astrochemist on the team at the University of Cambridge.
To generate the amount of phosphine observed, Earth microbes would need to work at only 10% of their maximum productivity, the scientists say.
Sara Seager, a planetary scientist on the study at MIT in the US, called the finding “mind-boggling”. She hypothesises a lifecycle for Venusian microbes that rain down, dry out and are swept back up to more temperate altitudes by currents in the atmosphere.
Charles Cockell, an astrobiologist at the University of Edinburgh, said that, rather than hinting at life on Venus, the work raises questions about phosphine as a “biomarker”.
“A biological explanation should always be the explanation of last resort and there are good reasons to think the Venusian clouds are dead. The concentrations of sulphuric acid in those clouds are more extreme than any known habitat on Earth,” he said.
Lewis Dartnell, an astrobiologist at the University of Westminster, said the findings would spur more work. “This is a huge opportunity for follow-on observations from Earth-based telescopes, and ideally to scrutinise these droplets in the Venusian atmosphere with a balloon probe drifting through the acidic clouds.”
Astronomers detected phosphine 30 miles up in the planet’s atmosphere and have failed to identify a process other than life that could account for its presence.
The discovery raises the possibility that life gained a foothold on Earth’s inner neighbour and remnants clung on – or floated on, at least – as Venus suffered runaway global warming that made the planet hellish.
For 2bn years, Venus was temperate and harboured an ocean. But today, a dense carbon dioxide atmosphere blankets a near-waterless surface where temperatures top 450C. The clouds in the sky are hardly inviting, containing droplets of 90% sulphuric acid.
The conditions on Venus are so deeply unpleasant that many scientists believe the planet is dead. Rather than coming from floating Venusians, they suspect phosphine arises from more mundane processes.
“It’s completely startling to say life could survive surrounded by so much sulphuric acid,” said Prof Jane Greaves, an astronomer at Cardiff University, leader of the team who made the discovery. “But all the geological and photochemical routes we can think of are far too underproductive to make the phosphine we see.”
On Earth, phosphine gas is released by microbes in oxygen-starved environments, such as lake sediments and animals’ innards. Other production routes are so extreme – the bellies of Jupiter and Saturn – that on rocky planets, phosphine is considered a marker for life.
As a test-run for searching for life beyond Earth, Greaves observed Venus in 2017 with the James Clerk Maxwell telescope in Hawaii, and in 2019 with the Alma telescope in Chile. Both revealed the signature of phosphine in the upper cloud deck of Venus.
Greaves first spotted the phosphine signal late one day in December 2018 as she was about to leave work. “There wasn’t anyone to talk to and I remember thinking the best way to celebrate was to make a curry, so I drove off to Sainsbury’s,” she said.
The observations point to trace levels of phosphine, about 20 molecules per billion, at least 30 miles high in the Venusian sky. Most appears at the mid-latitudes with none detected at the poles, the scientists report in Nature Astronomy.
While the phosphine may come from a mysterious new source, the researchers’ calculations rule out known chemistry and show that volcanoes, lightning and micrometeorites would all create too little. “The rates of production are so small, and the rates of destruction great enough, that you’d have 1,000 times too little,” said Paul Rimmer, an astrochemist on the team at the University of Cambridge.
To generate the amount of phosphine observed, Earth microbes would need to work at only 10% of their maximum productivity, the scientists say.
Sara Seager, a planetary scientist on the study at MIT in the US, called the finding “mind-boggling”. She hypothesises a lifecycle for Venusian microbes that rain down, dry out and are swept back up to more temperate altitudes by currents in the atmosphere.
Charles Cockell, an astrobiologist at the University of Edinburgh, said that, rather than hinting at life on Venus, the work raises questions about phosphine as a “biomarker”.
“A biological explanation should always be the explanation of last resort and there are good reasons to think the Venusian clouds are dead. The concentrations of sulphuric acid in those clouds are more extreme than any known habitat on Earth,” he said.
Lewis Dartnell, an astrobiologist at the University of Westminster, said the findings would spur more work. “This is a huge opportunity for follow-on observations from Earth-based telescopes, and ideally to scrutinise these droplets in the Venusian atmosphere with a balloon probe drifting through the acidic clouds.”
Astrophysicists discover new insights from a rare supernova that gave us the calcium in our bones
Scientists studied the emissions from the stellar event, which was discovered a mere 10 hours after exploding
NICOLE KARLIS - salon
AUGUST 5, 2020 11:24PM (UTC)
...On Wednesday, a paper published in The Astrophysical Journal surfaced new, direct insights into the true nature of the rare events that are thought to produce half of the calcium in our universe, including the calcium in our very own human bodies: calcium-rich supernovae.
Astrophysicists have long struggled to study these rare stellar explosions. But in April 2019, an amateur astronomer named Joel Shepherd spotted a bright burst, which was then dubbed SN 2019ehk, while stargazing in Seattle, Washington. Shepherd reported the discovery to the astronomical community, which is when a global collaboration began, and moved fast enough for astrophysicists to confirm that that bright spot was in fact a supernova happening in Messier 100 (M100), a spiral galaxy located 55 million light years from Earth. With observations from NASA's Swift Satellite, W.M. Keck Observatory in Hawaii, the Lick Observatory in California, and Las Cumbres Observatory, scientists were able to observe the supernova as early as 10 hours after the explosion.
According to the paper, SN 2019ehk emitted the most calcium ever observed in one astrophysical event. Wynn Jacobson-Galan, a first-year Northwestern graduate student who led the study, explained to Salon that SN 2019ehk is just one of the "calcium-rich supernovae that is responsible for contributing to that universal calcium fraction (~50%)."
"Calcium-rich supernovae in general are thought to produce half of the calcium in our universe," Jacobson-Galan said in an email. "They are rare, relative to other types of stellar explosions, but actually these supernovae occur all over the universe."
However, just because these stellar events are rare doesn't mean they have less of an influence on the universe. In fact, it's the opposite.
Jacobson-Galan said, "Calcium-rich supernovae (as well as stellar explosions in general) are powerful enough to create luminosity, which is comparable to their host galaxies i.e., they outshine their galaxies." This is partly how such an explosion can travel through galaxies and be part of creating life here on Earth.
"So with such a powerful explosion capable of releasing so much energy, the supernovae can eject calcium at tremendous speeds (comparable to the speed of light) out into space, and over time the calcium will be recycled into creating new stars, planets, et cetera," Jacobson-Galan said. "Also, multiple calcium-rich supernovae can occur in the same galaxy, so over a long time, with enough explosions happening, the galaxy can become abundant with calcium that can then be used to create stars, et cetera.
"The calcium produced in these explosions is (and was) fundamental in creating our planet and as a result, organic matter like dinosaurs and humans," he added.
The new findings revealed that a calcium-rich supernova is a compact star shedding its outer layer of gas as it nears the end of its life. When the star dies, which occurs through an explosion, its matter barrels into the loose material from the outer shell and emits bright X-rays. A combination of high pressure and hot temperatures drives a nuclear fusion that creates the calcium.
Jacobson-Galan said this revelation happened thanks to how early scientists discovered the explosion.
"We had no idea that this type of stellar explosion was capable of producing high energy emission such as X-rays so this was a 'game changing' result in terms of studying the origins of these unique explosions," Jacobson-Galan said.
He added that this research is opening up "new avenues of study."
"We unlocked a whole new way to study these explosions, which in turn told us that they not only produce bright X-rays but also that they likely arise from the explosion of a compact star that shedded its outer layers right before death," he said. "With this knowledge, we can now search for new calcium-rich supernovae and try to observe the moments after the explosion, which will allow us to really understand where they come from."
Astrophysicists have long struggled to study these rare stellar explosions. But in April 2019, an amateur astronomer named Joel Shepherd spotted a bright burst, which was then dubbed SN 2019ehk, while stargazing in Seattle, Washington. Shepherd reported the discovery to the astronomical community, which is when a global collaboration began, and moved fast enough for astrophysicists to confirm that that bright spot was in fact a supernova happening in Messier 100 (M100), a spiral galaxy located 55 million light years from Earth. With observations from NASA's Swift Satellite, W.M. Keck Observatory in Hawaii, the Lick Observatory in California, and Las Cumbres Observatory, scientists were able to observe the supernova as early as 10 hours after the explosion.
According to the paper, SN 2019ehk emitted the most calcium ever observed in one astrophysical event. Wynn Jacobson-Galan, a first-year Northwestern graduate student who led the study, explained to Salon that SN 2019ehk is just one of the "calcium-rich supernovae that is responsible for contributing to that universal calcium fraction (~50%)."
"Calcium-rich supernovae in general are thought to produce half of the calcium in our universe," Jacobson-Galan said in an email. "They are rare, relative to other types of stellar explosions, but actually these supernovae occur all over the universe."
However, just because these stellar events are rare doesn't mean they have less of an influence on the universe. In fact, it's the opposite.
Jacobson-Galan said, "Calcium-rich supernovae (as well as stellar explosions in general) are powerful enough to create luminosity, which is comparable to their host galaxies i.e., they outshine their galaxies." This is partly how such an explosion can travel through galaxies and be part of creating life here on Earth.
"So with such a powerful explosion capable of releasing so much energy, the supernovae can eject calcium at tremendous speeds (comparable to the speed of light) out into space, and over time the calcium will be recycled into creating new stars, planets, et cetera," Jacobson-Galan said. "Also, multiple calcium-rich supernovae can occur in the same galaxy, so over a long time, with enough explosions happening, the galaxy can become abundant with calcium that can then be used to create stars, et cetera.
"The calcium produced in these explosions is (and was) fundamental in creating our planet and as a result, organic matter like dinosaurs and humans," he added.
The new findings revealed that a calcium-rich supernova is a compact star shedding its outer layer of gas as it nears the end of its life. When the star dies, which occurs through an explosion, its matter barrels into the loose material from the outer shell and emits bright X-rays. A combination of high pressure and hot temperatures drives a nuclear fusion that creates the calcium.
Jacobson-Galan said this revelation happened thanks to how early scientists discovered the explosion.
"We had no idea that this type of stellar explosion was capable of producing high energy emission such as X-rays so this was a 'game changing' result in terms of studying the origins of these unique explosions," Jacobson-Galan said.
He added that this research is opening up "new avenues of study."
"We unlocked a whole new way to study these explosions, which in turn told us that they not only produce bright X-rays but also that they likely arise from the explosion of a compact star that shedded its outer layers right before death," he said. "With this knowledge, we can now search for new calcium-rich supernovae and try to observe the moments after the explosion, which will allow us to really understand where they come from."
Astronomers perplexed by "Odd Radio Circles," a newly discovered, very rare space phenomenon
Invisible except in the radio wave portion of the spectrum, only four Odd Radio Circles have been discovered
NICOLE KARLIS - salon
JULY 13, 2020 11:46PM (UTC)
Astronomers believe they have discovered a new, bizarre type of cosmic object that is invisible to all wavelengths of light except radio.
The strange circular objects in question have been unofficially dubbed "Odd Radio Circles" (ORCs); three of them were discovered in a recent data accumulated during a preliminary survey by the Australian Square Kilometre Array Pathfinder, a radio telescope array in Western Australia. A fourth Odd Radio Circle was discovered when researchers sifted through old data from 2013.
The new phenomenon is the focus of a new paper published on the preprint website arXiv, which was submitted to Nature Astronomy by a group of international astronomers. It is yet to be peer-reviewed.
"Here we report the discovery of a class of circular feature in radio images that do not seem to correspond to any of these known types of object or artefact, but rather appear to be a new class of astronomical object," the authors of the paper write.
The ORCs are mostly circular in shape, with the exception of one shaped like a disc, and they cannot be seen with infrared, optical, or X-ray telescopes. Three of them are brighter around the edges.
The circular nature of the ORCs has led to some curiosity over their true nature. "Circular features are well-known in radio astronomical images, and usually represent a spherical object such as a supernova remnant, a planetary nebula, a circumstellar shell, or a face-on disc such as a protoplanetary disc or a star-forming galaxy," the researchers write.
Astronomers initially believed the ORCs may have been a telescope glitch — which is why the discovery of the fourth ORC, from data that was gathered in 2013 by the Giant MetreWave Radio Telescope in India, was key to the finding. That observation ruled out the possibility that the phenomenon was merely an artifact of the specific Australian radiotelescope array.
So what could these strange, circular radio objects be? In the paper, the researchers suggest a list of scenarios. First, they rule out that ORCs could be remnants of a supernova, mainly because of how rare ORCs are. Galactic planetary nebulas are ruled out, too, for the same reason. "[I]f the ORCs are [supernova remnants], which they strongly resemble, then this implies a population of SNRs [supernova remnants] in the Galaxy some 50 times larger than the currently accepted figure, or else a new class of SNR which has not previously been reported," the researchers explain.
Instead, they suspect the ORCs are a circular wave that appeared after some sort of extra-galactic "transient" event—like fast-radio bursts, another mysterious but far better documented astronomical phenomena.
"The edge-brightening in some ORCs suggests that this circular image may represent a spherical object, which in turn suggests a spherical wave from some transient event," the researchers write. "Several such classes of transient events, capable of producing a spherical shock wave, have recently been discovered, such as fast radio bursts, gamma-ray bursts, and neutron star mergers."
The researchers add that because of the "large angular size" the transient event in question "would have taken place in the distant past."
Avi Loeb, chair of Harvard's astronomy department, told Salon via email that he thinks the ORCs are "likely the result of radio emission from a spherical shock that resulted from an energy source at their center."
"They have a characteristic diameter of about an arcminute, corresponding to a physical length of ten light years (a few parsec) at our distance from most stars in the Milky Way or ten million light years (a few mega-parsecs) at our distance from most galaxies in the visible universe," Loeb said. "The former is a reasonable length scale for a supernova remnant, whereas the latter is a reasonable scale for the reach of the jets produced by the most powerful quasars."
However, since the distance to the source of the event is unknown, it remains unclear which interpretation is more likely.
Loeb added that the most likely explanation is that the ORCs are "the result of outflows from galaxies."
"We know that galaxies have powerful winds, driven by supernova explosions and quasar activity in their cores," Loeb said. "The collision of these outflows with the intergalactic medium is predicted to produce radio shells on the scale of the distance between galaxies, which is a few million light years, exactly as needed at a cosmological distance."
Two decades ago, Loeb co-authored two papers theoretically predicting these "radio halos."
"Perhaps this is an indication that they exist," he added.
The strange circular objects in question have been unofficially dubbed "Odd Radio Circles" (ORCs); three of them were discovered in a recent data accumulated during a preliminary survey by the Australian Square Kilometre Array Pathfinder, a radio telescope array in Western Australia. A fourth Odd Radio Circle was discovered when researchers sifted through old data from 2013.
The new phenomenon is the focus of a new paper published on the preprint website arXiv, which was submitted to Nature Astronomy by a group of international astronomers. It is yet to be peer-reviewed.
"Here we report the discovery of a class of circular feature in radio images that do not seem to correspond to any of these known types of object or artefact, but rather appear to be a new class of astronomical object," the authors of the paper write.
The ORCs are mostly circular in shape, with the exception of one shaped like a disc, and they cannot be seen with infrared, optical, or X-ray telescopes. Three of them are brighter around the edges.
The circular nature of the ORCs has led to some curiosity over their true nature. "Circular features are well-known in radio astronomical images, and usually represent a spherical object such as a supernova remnant, a planetary nebula, a circumstellar shell, or a face-on disc such as a protoplanetary disc or a star-forming galaxy," the researchers write.
Astronomers initially believed the ORCs may have been a telescope glitch — which is why the discovery of the fourth ORC, from data that was gathered in 2013 by the Giant MetreWave Radio Telescope in India, was key to the finding. That observation ruled out the possibility that the phenomenon was merely an artifact of the specific Australian radiotelescope array.
So what could these strange, circular radio objects be? In the paper, the researchers suggest a list of scenarios. First, they rule out that ORCs could be remnants of a supernova, mainly because of how rare ORCs are. Galactic planetary nebulas are ruled out, too, for the same reason. "[I]f the ORCs are [supernova remnants], which they strongly resemble, then this implies a population of SNRs [supernova remnants] in the Galaxy some 50 times larger than the currently accepted figure, or else a new class of SNR which has not previously been reported," the researchers explain.
Instead, they suspect the ORCs are a circular wave that appeared after some sort of extra-galactic "transient" event—like fast-radio bursts, another mysterious but far better documented astronomical phenomena.
"The edge-brightening in some ORCs suggests that this circular image may represent a spherical object, which in turn suggests a spherical wave from some transient event," the researchers write. "Several such classes of transient events, capable of producing a spherical shock wave, have recently been discovered, such as fast radio bursts, gamma-ray bursts, and neutron star mergers."
The researchers add that because of the "large angular size" the transient event in question "would have taken place in the distant past."
Avi Loeb, chair of Harvard's astronomy department, told Salon via email that he thinks the ORCs are "likely the result of radio emission from a spherical shock that resulted from an energy source at their center."
"They have a characteristic diameter of about an arcminute, corresponding to a physical length of ten light years (a few parsec) at our distance from most stars in the Milky Way or ten million light years (a few mega-parsecs) at our distance from most galaxies in the visible universe," Loeb said. "The former is a reasonable length scale for a supernova remnant, whereas the latter is a reasonable scale for the reach of the jets produced by the most powerful quasars."
However, since the distance to the source of the event is unknown, it remains unclear which interpretation is more likely.
Loeb added that the most likely explanation is that the ORCs are "the result of outflows from galaxies."
"We know that galaxies have powerful winds, driven by supernova explosions and quasar activity in their cores," Loeb said. "The collision of these outflows with the intergalactic medium is predicted to produce radio shells on the scale of the distance between galaxies, which is a few million light years, exactly as needed at a cosmological distance."
Two decades ago, Loeb co-authored two papers theoretically predicting these "radio halos."
"Perhaps this is an indication that they exist," he added.
Scientists puzzled by massive star that vanished without a trace
Astronomers have theories as to what could explain the rare and sudden disappearance of a very massive star
NICOLE KARLIS - salon
JULY 2, 2020 12:10AM (UTC)
Since 2001, astronomers have been aware of a massive star in the Kinman Dwarf galaxy, which is about 75 million light-years away from Earth in the constellation of Aquarius. Then, one day in 2019, it disappeared suddenly and mysteriously.
That left many scientists scratching their heads. How did Mother Nature manage to hide such a bright, enormous star, without leaving so much as a poof of smoke in its wake?
In a paper published in Monthly Notices of the Royal Astronomical Society this week, astronomers raised two possible theories as to why the massive luminous blue variable (LBV) star has gone missing.
"One possibility is that we are seeing the end of an LBV eruption of a surviving star, with a mild drop in luminosity, a shift to hotter effective temperatures, and some dust obscuration," the authors write. "Alternatively, the LBV could have collapsed to a massive black hole without the production of a bright supernova."
If the latter is true, it would be an extraordinarily rare event, and maybe the first detection of such a massive star ending its life like this, according to the astronomers who made the observations using the European Southern Observatory's Very Large Telescope (VLT). Stars usually end their lives with a radiant explosion, also known as a supernova, which in many cases leaves a new black hole behind.
"It is extremely rare to find a star right before the end of its life," Jose Groh, a professor of astrophysics at Trinity College in Dublin and co-author of the paper, explained to Salon in an email.
Groh added that such an event has only been observed once in the past.
"In the galaxy NGC 6946, where a smaller massive star seemed to disappear without a bright supernova explosion," Groh said. "In our case, the star is much more massive and is located in a small galaxy, which makes the finding unique and could hold important clues as to how stars could collapse to a black hole without producing a bright supernova."
These kinds of fizzled-out stars are extremely rare. Avi Loeb, chair of Harvard's astronomy department, told Salon via email that this rare class of stars are called "failed supernovae."
"A survey for such stars was initiated twelve years ago by a team of astronomers at Ohio State University and an example was reported by Gerke et al in 2015 and confirmed by Adams et al. (2017)," Loeb said, pointing Salon to a paper on ArXiv.
In general, luminous blue variable stars are known to experience giant outbursts of matter throughout their life. Such outbursts cause the stars' rate of mass loss and luminosity to increase.
The star in question, according to computer simulations, is really big — or was. Its mass was somewhere between 85 and 120 times the mass of our sun, and its volume was vast too — "between 50 and 400 times the size of the Sun," Groh explained. "So it is a supergiant star."
How could a giant star disappear so fast?
"The end of the life of a star proceeds really fast," Groh said. "This massive star spends millions of years burning hydrogen, then another million years burning helium, and towards the end the timescales become shorter and shorter; It burns silicon in a week, and then oxygen in just about a day."
Loeb added that "if gravity is too strong, the star implodes altogether and transforms into a black hole with no visible explosion." In other words, a "failed supernova."
While it would likely leave behind some sort of X-ray Burst, Groh said that usually only lasts for a few days.
"So we need to observe the star using an X-ray telescope in space at that precise moment," Groh explained. "Because we cannot tell when the star will disappear exactly, it is difficult to do these kinds of observations."
"We would need to know beforehand the date and time when the star would form the black hole," Groh added. "Also, in our case the star is located in a distant galaxy, so it is faint."
That left many scientists scratching their heads. How did Mother Nature manage to hide such a bright, enormous star, without leaving so much as a poof of smoke in its wake?
In a paper published in Monthly Notices of the Royal Astronomical Society this week, astronomers raised two possible theories as to why the massive luminous blue variable (LBV) star has gone missing.
"One possibility is that we are seeing the end of an LBV eruption of a surviving star, with a mild drop in luminosity, a shift to hotter effective temperatures, and some dust obscuration," the authors write. "Alternatively, the LBV could have collapsed to a massive black hole without the production of a bright supernova."
If the latter is true, it would be an extraordinarily rare event, and maybe the first detection of such a massive star ending its life like this, according to the astronomers who made the observations using the European Southern Observatory's Very Large Telescope (VLT). Stars usually end their lives with a radiant explosion, also known as a supernova, which in many cases leaves a new black hole behind.
"It is extremely rare to find a star right before the end of its life," Jose Groh, a professor of astrophysics at Trinity College in Dublin and co-author of the paper, explained to Salon in an email.
Groh added that such an event has only been observed once in the past.
"In the galaxy NGC 6946, where a smaller massive star seemed to disappear without a bright supernova explosion," Groh said. "In our case, the star is much more massive and is located in a small galaxy, which makes the finding unique and could hold important clues as to how stars could collapse to a black hole without producing a bright supernova."
These kinds of fizzled-out stars are extremely rare. Avi Loeb, chair of Harvard's astronomy department, told Salon via email that this rare class of stars are called "failed supernovae."
"A survey for such stars was initiated twelve years ago by a team of astronomers at Ohio State University and an example was reported by Gerke et al in 2015 and confirmed by Adams et al. (2017)," Loeb said, pointing Salon to a paper on ArXiv.
In general, luminous blue variable stars are known to experience giant outbursts of matter throughout their life. Such outbursts cause the stars' rate of mass loss and luminosity to increase.
The star in question, according to computer simulations, is really big — or was. Its mass was somewhere between 85 and 120 times the mass of our sun, and its volume was vast too — "between 50 and 400 times the size of the Sun," Groh explained. "So it is a supergiant star."
How could a giant star disappear so fast?
"The end of the life of a star proceeds really fast," Groh said. "This massive star spends millions of years burning hydrogen, then another million years burning helium, and towards the end the timescales become shorter and shorter; It burns silicon in a week, and then oxygen in just about a day."
Loeb added that "if gravity is too strong, the star implodes altogether and transforms into a black hole with no visible explosion." In other words, a "failed supernova."
While it would likely leave behind some sort of X-ray Burst, Groh said that usually only lasts for a few days.
"So we need to observe the star using an X-ray telescope in space at that precise moment," Groh explained. "Because we cannot tell when the star will disappear exactly, it is difficult to do these kinds of observations."
"We would need to know beforehand the date and time when the star would form the black hole," Groh added. "Also, in our case the star is located in a distant galaxy, so it is faint."
Alien life
Scientists say most likely number of contactable alien civilisations is 36
New calculations come up with estimate for worlds capable of communicating with others
Nicola Davis
the guardian
Mon 15 Jun 2020 07.58 EDT
They may not be little green men. They may not arrive in a vast spaceship. But according to new calculations there could be more than 30 intelligent civilisations in our galaxy today capable of communicating with others.
Experts say the work not only offers insights into the chances of life beyond Earth but could shed light on our own future and place in the cosmos.
“I think it is extremely important and exciting because for the first time we really have an estimate for this number of active intelligent, communicating civilisations that we potentially could contact and find out there is other life in the universe – something that has been a question for thousands of years and is still not answered,” said Christopher Conselice, a professor of astrophysics at the University of Nottingham and a co-author of the research.
In 1961 the astronomer Frank Drake proposed what became known as the Drake equation, setting out seven factors that would need to be known to come up with an estimate for the number of intelligent civilisations out there. These factors ranged from the the average number of stars that form each year in the galaxy through to the timespan over which a civilisation would be expected to be sending out detectable signals.
But few of the factors are measurable. “Drake equation estimates have ranged from zero to a few billion [civilisations] – it is more like a tool for thinking about questions rather than something that has actually been solved,” said Conselice.
Now Conselice and colleagues report in the Astrophysical Journal how they refined the equation with new data and assumptions to come up with their estimates.
“Basically, we made the assumption that intelligent life would form on other [Earth-like] planets like it has on Earth, so within a few billion years life would automatically form as a natural part of evolution,” said Conselice.
The assumption, known as the Astrobiological Copernican Principle, is fair as everything from chemical reactions to star formation is known to occur if the conditions are right, he said. “[If intelligent life forms] in a scientific way, not just a random way or just a very unique way, then you would expect at least this many civilisations within our galaxy,” he said.
He added that, while it is a speculative theory, he believes alien life would have similarities in appearance to life on Earth. “We wouldn’t be super shocked by seeing them,” he said.
Under the strictest set of assumptions – where, as on Earth, life forms between 4.5bn and 5.5bn years after star formation – there are likely between four and 211 civilisations in the Milky Way today capable of communicating with others, with 36 the most likely figure. But Conselice noted that this figure is conservative, not least as it is based on how long our own civilisation has been sending out signals into space – a period of just 100 years so far.
The team add that our civilisation would need to survive at least another 6,120 years for two-way communication. “They would be quite far away … 17,000 light years is our calculation for the closest one,” said Conselice. “If we do find things closer … then that would be a good indication that the lifespan of [communicating] civilisations is much longer than a hundred or a few hundred years, that an intelligent civilisation can last for thousands or millions of years. The more we find nearby, the better it looks for the long-term survival of our own civilisation.”
Dr Oliver Shorttle, an expert in extrasolar planets at the University of Cambridge who was not involved in the research, said several as yet poorly understood factors needed to be unpicked to make such estimates, including how life on Earth began and how many Earth-like planets considered habitable could truly support life.
Dr Patricia Sanchez-Baracaldo, an expert on how Earth became habitable, from the University of Bristol, was more upbeat, despite emphasising that many developments were needed on Earth for conditions for complex life to exist, including photosynthesis. “But, yes if we evolved in this planet, it is possible that intelligent life evolved in another part of the universe,” she said.
Prof Andrew Coates, of the Mullard Space Science Laboratory at University College London, said the assumptions made by Conselice and colleagues were reasonable, but the quest to find life was likely to take place closer to home for now.
“[The new estimate] is an interesting result, but one which it will be impossible to test using current techniques,” he said. “In the meantime, research on whether we are alone in the universe will include visiting likely objects within our own solar system, for example with our Rosalind Franklin Exomars 2022 rover to Mars, and future missions to Europa, Enceladus and Titan [moons of Jupiter and Saturn]. It’s a fascinating time in the search for life elsewhere.”
Experts say the work not only offers insights into the chances of life beyond Earth but could shed light on our own future and place in the cosmos.
“I think it is extremely important and exciting because for the first time we really have an estimate for this number of active intelligent, communicating civilisations that we potentially could contact and find out there is other life in the universe – something that has been a question for thousands of years and is still not answered,” said Christopher Conselice, a professor of astrophysics at the University of Nottingham and a co-author of the research.
In 1961 the astronomer Frank Drake proposed what became known as the Drake equation, setting out seven factors that would need to be known to come up with an estimate for the number of intelligent civilisations out there. These factors ranged from the the average number of stars that form each year in the galaxy through to the timespan over which a civilisation would be expected to be sending out detectable signals.
But few of the factors are measurable. “Drake equation estimates have ranged from zero to a few billion [civilisations] – it is more like a tool for thinking about questions rather than something that has actually been solved,” said Conselice.
Now Conselice and colleagues report in the Astrophysical Journal how they refined the equation with new data and assumptions to come up with their estimates.
“Basically, we made the assumption that intelligent life would form on other [Earth-like] planets like it has on Earth, so within a few billion years life would automatically form as a natural part of evolution,” said Conselice.
The assumption, known as the Astrobiological Copernican Principle, is fair as everything from chemical reactions to star formation is known to occur if the conditions are right, he said. “[If intelligent life forms] in a scientific way, not just a random way or just a very unique way, then you would expect at least this many civilisations within our galaxy,” he said.
He added that, while it is a speculative theory, he believes alien life would have similarities in appearance to life on Earth. “We wouldn’t be super shocked by seeing them,” he said.
Under the strictest set of assumptions – where, as on Earth, life forms between 4.5bn and 5.5bn years after star formation – there are likely between four and 211 civilisations in the Milky Way today capable of communicating with others, with 36 the most likely figure. But Conselice noted that this figure is conservative, not least as it is based on how long our own civilisation has been sending out signals into space – a period of just 100 years so far.
The team add that our civilisation would need to survive at least another 6,120 years for two-way communication. “They would be quite far away … 17,000 light years is our calculation for the closest one,” said Conselice. “If we do find things closer … then that would be a good indication that the lifespan of [communicating] civilisations is much longer than a hundred or a few hundred years, that an intelligent civilisation can last for thousands or millions of years. The more we find nearby, the better it looks for the long-term survival of our own civilisation.”
Dr Oliver Shorttle, an expert in extrasolar planets at the University of Cambridge who was not involved in the research, said several as yet poorly understood factors needed to be unpicked to make such estimates, including how life on Earth began and how many Earth-like planets considered habitable could truly support life.
Dr Patricia Sanchez-Baracaldo, an expert on how Earth became habitable, from the University of Bristol, was more upbeat, despite emphasising that many developments were needed on Earth for conditions for complex life to exist, including photosynthesis. “But, yes if we evolved in this planet, it is possible that intelligent life evolved in another part of the universe,” she said.
Prof Andrew Coates, of the Mullard Space Science Laboratory at University College London, said the assumptions made by Conselice and colleagues were reasonable, but the quest to find life was likely to take place closer to home for now.
“[The new estimate] is an interesting result, but one which it will be impossible to test using current techniques,” he said. “In the meantime, research on whether we are alone in the universe will include visiting likely objects within our own solar system, for example with our Rosalind Franklin Exomars 2022 rover to Mars, and future missions to Europa, Enceladus and Titan [moons of Jupiter and Saturn]. It’s a fascinating time in the search for life elsewhere.”
How Europe’s CHEOPS satellite will improve the hunt for exoplanets
May 28, 2020
By The Conversation - raw story
While the planet has been on lockdown the last two months, a new space telescope called CHEOPS opened its eyes, took its first pictures of the heavens and is now open for business.
The CHEOPS mission adds a unique twist in the science that the public normally associates with planet discovery missions like Kepler and TESS. Kepler and TESS produced many groundbreaking discoveries and brought the number of known exoplanets into the thousands – so many that we’ve only scratched the surface of what we can learn from them. Consequently, rather than simply finding more planets, the primary objective of CHEOPS is to better understand the planets that we’ve already found.
I have been in the exoplanet field for the better part of two decades. For most of that time I had the good fortune to work on NASA’s Kepler mission. Among Kepler’s major discoveries is the baffling array of planets that it found. Two prime examples are the thousands of planets whose sizes fall in the gap between Earth and Neptune. Kepler also found planets with orbits that are only a few hours long. None of these planets has counterparts in the solar system. What these planets are like, how they form and how they arrived at their current state are matters of ongoing research. To better understand these planets, we need to have better measurements of their properties – their sizes, masses, composition and atmospheres. Astronomers will turn to CHEOPS to fill these gaps in our knowledge.
CHEOPS mission overview
A joint Swiss-ESA mission, CHEOPS, the “Characterizing Exoplanet Satellite,” will make key measurements of the size and albedo (reflectivity) of planets that orbit distant stars. CHEOPS launched in December of 2019 from the northern coast of South America, hitching a ride as a secondary passenger on a big Soyuz rocket.
The challenge with most of the planets discovered by the Kepler mission is that they orbit faint stars, making them difficult to observe with any telescope other than Kepler itself (which has finished its work and is no longer operating). CHEOPS, on the other hand, will observe planets orbiting bright stars that haven’t been studied with the level of detail once provided by Kepler, and that CHEOPS is now able to provide. These planets are more amenable to the wide variety of complementary observations from instruments on other telescopes – giving new insights into the nature of these recently discovered planets.
CHEOPS was placed in a “Sun-synchronous” orbit where it stays constantly above the Earth’s terminator – the line on the Earth that separates day from night. The satellite observes planets as they transit in front of their host stars using a 32-centimeter mirror. The telescope is 10 times smaller than Kepler, but since it will observe brighter stars, it can achieve a precision similar to Kepler – a fact demonstrated during its commissioning stage. And instead of continuously (and simultaneously) observing a hundred thousand stars in order to discover new planets, CHEOPS looks at individual targets when and where the planet is known to be there.
Science from the CHEOPS mission
For the brightest Sun-like stars, CHEOPS can measure the sizes of planets as small as the Earth by seeing the fraction of the starlight that is blocked by the planet as it passes in front of the star. The improved measurements of planet sizes allow scientists to determine a planet’s density, giving insights into its composition and interior structure. They also establish the key relationship between planetary sizes and their masses, which tells us more about the traits shared by planets across many systems.
In addition to planet sizes, CHEOPS can measure a planet’s “phase curve,” the variation in brightness due to the changing profile of the planet as it orbits its host star (like the changing phases of the Moon). The phase curve tells us how much light is reflected by the planet and, therefore, some of the properties of its surface, atmosphere and clouds. This information, in turn, can tell us more about the conditions that might exist under the cloud tops and at a planet’s surface. Finally, since CHEOPS targets are bright, they are good candidates for detailed observations of their atmospheres using large ground-based and space-based telescopes (like the Extremely Large Telescope and the James Webb Space Telescope).
Ultimately, by better understanding the properties of planets orbiting other stars, astronomers can better understand the nature of the planets in our own solar system. We will better see how our planetary siblings fit into the broader context of planets in the galaxy and how our formation and history is similar to, or different from, these alien worlds.
The CHEOPS mission adds a unique twist in the science that the public normally associates with planet discovery missions like Kepler and TESS. Kepler and TESS produced many groundbreaking discoveries and brought the number of known exoplanets into the thousands – so many that we’ve only scratched the surface of what we can learn from them. Consequently, rather than simply finding more planets, the primary objective of CHEOPS is to better understand the planets that we’ve already found.
I have been in the exoplanet field for the better part of two decades. For most of that time I had the good fortune to work on NASA’s Kepler mission. Among Kepler’s major discoveries is the baffling array of planets that it found. Two prime examples are the thousands of planets whose sizes fall in the gap between Earth and Neptune. Kepler also found planets with orbits that are only a few hours long. None of these planets has counterparts in the solar system. What these planets are like, how they form and how they arrived at their current state are matters of ongoing research. To better understand these planets, we need to have better measurements of their properties – their sizes, masses, composition and atmospheres. Astronomers will turn to CHEOPS to fill these gaps in our knowledge.
CHEOPS mission overview
A joint Swiss-ESA mission, CHEOPS, the “Characterizing Exoplanet Satellite,” will make key measurements of the size and albedo (reflectivity) of planets that orbit distant stars. CHEOPS launched in December of 2019 from the northern coast of South America, hitching a ride as a secondary passenger on a big Soyuz rocket.
The challenge with most of the planets discovered by the Kepler mission is that they orbit faint stars, making them difficult to observe with any telescope other than Kepler itself (which has finished its work and is no longer operating). CHEOPS, on the other hand, will observe planets orbiting bright stars that haven’t been studied with the level of detail once provided by Kepler, and that CHEOPS is now able to provide. These planets are more amenable to the wide variety of complementary observations from instruments on other telescopes – giving new insights into the nature of these recently discovered planets.
CHEOPS was placed in a “Sun-synchronous” orbit where it stays constantly above the Earth’s terminator – the line on the Earth that separates day from night. The satellite observes planets as they transit in front of their host stars using a 32-centimeter mirror. The telescope is 10 times smaller than Kepler, but since it will observe brighter stars, it can achieve a precision similar to Kepler – a fact demonstrated during its commissioning stage. And instead of continuously (and simultaneously) observing a hundred thousand stars in order to discover new planets, CHEOPS looks at individual targets when and where the planet is known to be there.
Science from the CHEOPS mission
For the brightest Sun-like stars, CHEOPS can measure the sizes of planets as small as the Earth by seeing the fraction of the starlight that is blocked by the planet as it passes in front of the star. The improved measurements of planet sizes allow scientists to determine a planet’s density, giving insights into its composition and interior structure. They also establish the key relationship between planetary sizes and their masses, which tells us more about the traits shared by planets across many systems.
In addition to planet sizes, CHEOPS can measure a planet’s “phase curve,” the variation in brightness due to the changing profile of the planet as it orbits its host star (like the changing phases of the Moon). The phase curve tells us how much light is reflected by the planet and, therefore, some of the properties of its surface, atmosphere and clouds. This information, in turn, can tell us more about the conditions that might exist under the cloud tops and at a planet’s surface. Finally, since CHEOPS targets are bright, they are good candidates for detailed observations of their atmospheres using large ground-based and space-based telescopes (like the Extremely Large Telescope and the James Webb Space Telescope).
Ultimately, by better understanding the properties of planets orbiting other stars, astronomers can better understand the nature of the planets in our own solar system. We will better see how our planetary siblings fit into the broader context of planets in the galaxy and how our formation and history is similar to, or different from, these alien worlds.
Astronomers discover a new super-Earth thanks to a gravitational miracle
The stars quite literally aligned to make the gravitational microlensing of an exoplanet possible
NICOLE KARLIS - salon
MAY 20, 2020 11:20PM (UTC)
It is only human to look to the cosmos and ponder if there is another Earth out there. Fortunately, while many members of our species have had our heads pointed towards the ground amid the pandemic, astronomers are looking up at the sky — and lo and behold, they've found a new "super-Earth," the designation for rocky planets more massive than ours, yet with similar conditions otherwise. The finding is one of only a handful of super-Earths discovered to date.
Astronomers at the University of Canterbury in New Zealand came across what the lead author Dr. Herrera Martin describes as a rare planet which has a similar size and orbit to our Earth. The planet has been dubbed OGLE-2018-BLG-0677Lb. Their findings were published in the Astronomical Journal earlier this month.
According to the astronomers' data, this super-Earth's year lasts about 617 days. It travels around a single star that is estimated to be 10 percent less massive than our sun, although its parent star is significantly dimmer; researchers say it could be a dim dwarf star or a "failed star." The planet itself is estimated to be four times Earth's mass, and is located near the Milky Way's central bulge of stars.
One of the most peculiar aspects of this exoplanet's discovery is the way that it was made. The majority of exoplanets that have been discovered so far were found via the "transit method," in which an exoplanet's plane of orbit around their parent star was parallel with our view from Earth. In these cases, the orbiting exoplanet periodically transits in front of its parent star, briefly dimming it from the perspective of us on Earth. Such periodic occlusions can be tracked to determine a planet's mass and size.
Yet OGLE-2018-BLG-0677Lb was discovered via a different means known as gravitational microlensing. In his General Theory of Relativity, Albert Einstein predicted that objects of large mass, things like black holes or stars, would distort space-time. Hence, light bends and distorts around these massive objects. Occasionally this is to the advantage of astronomers, as objects that are generally too distant or dim to observe directly can be briefly magnified by passing massive astrophysical bodies from the perspective of us on Earth. Such observations are known as gravitational microlensing events, and they are rarely so fortuitous: only 2% of discovered exoplanets have been found via microlensing.
"The combined gravity of the planet and its host star caused the light from a more distant background star to be magnified in a particular way," Dr Herrera Martin explained in a press statement. "We used telescopes distributed around the world to measure the light-bending effect."
The microlensing effect is rare, too: an estimated one in a million stars in the galaxy can be affected by it at any given time. Moreover, astronomers say that this kind of observation rarely repeats itself, and the probability of catching a microlensing planet are very low; usually single stars are observed through the lens. In other words, this observation was a bit of a miracle.
"These experiments detect around 3,000 microlensing events each year, the majority of which are due to lensing by single stars," Dr. Albrow, the paper's co-author, said.
This microlensing event was detected in 2018 by the Optical Gravitational Lensing Experiment (OGLE) using a telescope in Chile, and the Korea Microlensing Telescope Network (KMTNet). Analyzing the data took years.
Though this super-Earth likely does not have optimal conditions for life, such discoveries help give insight into the nature of planetary and solar system development. "In the study of astronomical bodies, the search for extra-solar planets is of particular interest as their characterization not only allows us to infer the similarities or differences in the mechanisms of their formation, but it also helps us to better understand our own solar system," the researchers write in their paper.
As mentioned earlier, there are a small number of super-Earths in the galaxy that we know of so far. In 2016, researchers discovered Proxima Centauri b, an exoplanet in the nearest star system to Earth, Alpha Centauri. Proxima Centauri b is believed to have a similar mass to Earth, yet has a short orbital period of only 11 days. While it is within Proxima Centauri's habitable zone, it is tidally locked, which means only one side of the planet faces its sun. Tidally locked planets are less likely to be hospitable to life, as one side of these worlds would be very hot and the other extremely cold. However, some theorists believe that there may be a "ring" of habitability at the boundary between the hot and cold side, where the sky would appear to be in perpetual twilight, and within which life could theoretically thrive.
Astronomers at the University of Canterbury in New Zealand came across what the lead author Dr. Herrera Martin describes as a rare planet which has a similar size and orbit to our Earth. The planet has been dubbed OGLE-2018-BLG-0677Lb. Their findings were published in the Astronomical Journal earlier this month.
According to the astronomers' data, this super-Earth's year lasts about 617 days. It travels around a single star that is estimated to be 10 percent less massive than our sun, although its parent star is significantly dimmer; researchers say it could be a dim dwarf star or a "failed star." The planet itself is estimated to be four times Earth's mass, and is located near the Milky Way's central bulge of stars.
One of the most peculiar aspects of this exoplanet's discovery is the way that it was made. The majority of exoplanets that have been discovered so far were found via the "transit method," in which an exoplanet's plane of orbit around their parent star was parallel with our view from Earth. In these cases, the orbiting exoplanet periodically transits in front of its parent star, briefly dimming it from the perspective of us on Earth. Such periodic occlusions can be tracked to determine a planet's mass and size.
Yet OGLE-2018-BLG-0677Lb was discovered via a different means known as gravitational microlensing. In his General Theory of Relativity, Albert Einstein predicted that objects of large mass, things like black holes or stars, would distort space-time. Hence, light bends and distorts around these massive objects. Occasionally this is to the advantage of astronomers, as objects that are generally too distant or dim to observe directly can be briefly magnified by passing massive astrophysical bodies from the perspective of us on Earth. Such observations are known as gravitational microlensing events, and they are rarely so fortuitous: only 2% of discovered exoplanets have been found via microlensing.
"The combined gravity of the planet and its host star caused the light from a more distant background star to be magnified in a particular way," Dr Herrera Martin explained in a press statement. "We used telescopes distributed around the world to measure the light-bending effect."
The microlensing effect is rare, too: an estimated one in a million stars in the galaxy can be affected by it at any given time. Moreover, astronomers say that this kind of observation rarely repeats itself, and the probability of catching a microlensing planet are very low; usually single stars are observed through the lens. In other words, this observation was a bit of a miracle.
"These experiments detect around 3,000 microlensing events each year, the majority of which are due to lensing by single stars," Dr. Albrow, the paper's co-author, said.
This microlensing event was detected in 2018 by the Optical Gravitational Lensing Experiment (OGLE) using a telescope in Chile, and the Korea Microlensing Telescope Network (KMTNet). Analyzing the data took years.
Though this super-Earth likely does not have optimal conditions for life, such discoveries help give insight into the nature of planetary and solar system development. "In the study of astronomical bodies, the search for extra-solar planets is of particular interest as their characterization not only allows us to infer the similarities or differences in the mechanisms of their formation, but it also helps us to better understand our own solar system," the researchers write in their paper.
As mentioned earlier, there are a small number of super-Earths in the galaxy that we know of so far. In 2016, researchers discovered Proxima Centauri b, an exoplanet in the nearest star system to Earth, Alpha Centauri. Proxima Centauri b is believed to have a similar mass to Earth, yet has a short orbital period of only 11 days. While it is within Proxima Centauri's habitable zone, it is tidally locked, which means only one side of the planet faces its sun. Tidally locked planets are less likely to be hospitable to life, as one side of these worlds would be very hot and the other extremely cold. However, some theorists believe that there may be a "ring" of habitability at the boundary between the hot and cold side, where the sky would appear to be in perpetual twilight, and within which life could theoretically thrive.
NASA human spaceflight chief Doug Loverro resigns on eve of historic SpaceX launch
By Mike Wall - space.com
5/19/2020
Doug Loverro, NASA's chief of human spaceflight, resigned from his post Monday (May 18) after less than a year on the job, the agency announced today (May 19).
Loverro's resignation as Associate Administrator for NASA's Human Exploration and Operations (HEO) Mission Directorate is a stunning development, as the agency counts down to the first orbital crew launch from U.S. soil in nearly a decade, which will take place on May 27.
Loverro's former deputy, former NASA astronaut Ken Bowersox, has taken over HEO in an acting capacity and will therefore oversee Demo-2, the first crewed mission of SpaceX's Crew Dragon capsule. Demo-2, which will send NASA astronauts Bob Behnken and Doug Hurley to the International Space Station (ISS), is scheduled to lift off atop a SpaceX Falcon 9 rocket from Kennedy Space Center in Florida next week.
No crewed mission has launched to orbit from the United States since NASA retired its space shuttle fleet in 2011. Since then, the space agency has relied completely on Russian Soyuz rockets and spacecraft to get its astronauts to and from the ISS.
The HEO leadership change comes just days ahead of a critical flight readiness review for Demo-2, which Loverro would have overseen. NASA Associate Administrator Steve Jurczyk will oversee that meeting in Loverro's place, agency officials told Space.com.
If all goes well with Demo-2, SpaceX will be clear to start flying operational missions to and from the orbiting lab for NASA. Elon Musk's company holds a $2.6 billion contract with the agency's Commercial Crew Program for six such operational flights.
Though NASA described Loverro's departure as a resignation, Politico reports that there may be more to the story. Two industry sources told the outlet that Loverro was actually pushed out over disagreements with NASA Administrator Jim Bridenstine. Bridenstine made no mention of the shakeup today in remarks to the National Space Council, which is led by Vice President Mike Pence.
Loverro's departure continues a string of recent shakeups at the top of HEO.
The division's longtime leader, Bill Gersteinmaier, was reassigned in July 2019. Bowersox then took over as acting HEO chief until Loverro was announced as the successor in October.
The top HEO job obviously comes with high expectations and a lot of pressure, especially these days. NASA is working to land two astronauts near the moon's south pole in 2024, a tight timeline laid out by the administration of President Donald Trump just last year.[...]
RELATED:
Loverro's resignation as Associate Administrator for NASA's Human Exploration and Operations (HEO) Mission Directorate is a stunning development, as the agency counts down to the first orbital crew launch from U.S. soil in nearly a decade, which will take place on May 27.
Loverro's former deputy, former NASA astronaut Ken Bowersox, has taken over HEO in an acting capacity and will therefore oversee Demo-2, the first crewed mission of SpaceX's Crew Dragon capsule. Demo-2, which will send NASA astronauts Bob Behnken and Doug Hurley to the International Space Station (ISS), is scheduled to lift off atop a SpaceX Falcon 9 rocket from Kennedy Space Center in Florida next week.
No crewed mission has launched to orbit from the United States since NASA retired its space shuttle fleet in 2011. Since then, the space agency has relied completely on Russian Soyuz rockets and spacecraft to get its astronauts to and from the ISS.
The HEO leadership change comes just days ahead of a critical flight readiness review for Demo-2, which Loverro would have overseen. NASA Associate Administrator Steve Jurczyk will oversee that meeting in Loverro's place, agency officials told Space.com.
If all goes well with Demo-2, SpaceX will be clear to start flying operational missions to and from the orbiting lab for NASA. Elon Musk's company holds a $2.6 billion contract with the agency's Commercial Crew Program for six such operational flights.
Though NASA described Loverro's departure as a resignation, Politico reports that there may be more to the story. Two industry sources told the outlet that Loverro was actually pushed out over disagreements with NASA Administrator Jim Bridenstine. Bridenstine made no mention of the shakeup today in remarks to the National Space Council, which is led by Vice President Mike Pence.
Loverro's departure continues a string of recent shakeups at the top of HEO.
The division's longtime leader, Bill Gersteinmaier, was reassigned in July 2019. Bowersox then took over as acting HEO chief until Loverro was announced as the successor in October.
The top HEO job obviously comes with high expectations and a lot of pressure, especially these days. NASA is working to land two astronauts near the moon's south pole in 2024, a tight timeline laid out by the administration of President Donald Trump just last year.[...]
RELATED:
Black holes
Black hole found 1,000 light years from Earth
Object found in HR 6819 system is the closest to Earth yet known – and is unusually dark
Nicola Davis
the guardian
Wed 6 May 2020 08.00 EDT
Astronomers say they have discovered a black hole on our doorstep, just 1,000 light years from Earth.
It was found in a system called HR 6819, in the constellation Telescopium.
The system appears through a telescope as a single bright star, but telltale signs in the light emitted have previously revealed there to be two stars present.
Now experts say they have further analysed the data to discover there is another body within the system: a black hole with a mass over four times that of our sun, and the closest to Earth found so far.
“We realised that one could not describe what we saw with just two stars,” said Dietrich Baade, an emeritus astronomer at European Southern Observatory (ESO) and a co-author of the study.
“One of the stars is moving periodically, with a period of 40 days,” he said. “And the only way to understand that period and the very large [velocity] of 60km per second with a mass five times that of the sun was to infer that there is another very massive body which, however, is not visible.”
In other words, a black hole – an object typically formed from the gravitational collapse of a massive star.
The upshot, said Baade, is a so-called “hierarchical triple system”, which he explained by reference to a child’s mobile.
“On the one branch of the mobile you have two stars hanging, one of which is not visible, which is black – that is the black hole. And these two objects are orbiting each other,” he said. “And the other branch of the mobile you have one star which is much farther away from the other two.”
The black hole is unusual. “The hallmark of this black hole is that it is truly black,” he said. “Almost all the other black holes that we know are in the Milky Way – and there are only two dozen of them – shine very brightly in X-rays.”
Baade said the other black holes each had a companion star that feeds them with gas. However, this does not appear to be the case for the newly discovered black hole and its nearby star.
“This star is not so massive that it loses a lot of gas and therefore the black hole is starving and that makes it so dark.”
He said only a handful of similar black holes had been found previously, and they merited further scrutiny. “It may also be the first ever [black hole of this kind],” he said.
Baade added that HR 6819 – or rather, its stars – can be seen by the naked eye. “If you want to see it really overhead, you need to be at the southern tip of South America,” he said.
The new work, which is published in the journal Astronomy & Astrophysics, is based on data collected using telescopes at ESO’s La Silla Observatory in Chile.
“Theoretical models suggest that in the Milky Way there are between 100m and 1bn black holes,” said Baade. “We are finding a tip of an iceberg.”
The discovery could shed light on an unusual system in the constellation Gemini called LB-1. This system has previously been suggested to be composed of a star and a tremendously massive black hole – a finding that has foxed experts. Baade noted LB-1 appears to be very similar to HR 6819.
He said that suggests LB-1 could be a triple system, meaning its “dark object” would be a black hole of a more normal mass, or possibly a neutron star.
Dr Ziri Younsi, an expert on black holes at University College London, who was not involved with the research, said: “It’s remarkable that a black hole has been found so close to Earth,” noting for context that the centre of our galaxy is about 25,000 light years from Earth.
“This new study hints at the exciting prospect of a whole population of stellar-mass black holes lurking in our Galaxy,” Younsi said. “It also offers a potential new means to detect many more systems comprising such quiescent black holes in our galactic neighbourhood in the near future.”
It was found in a system called HR 6819, in the constellation Telescopium.
The system appears through a telescope as a single bright star, but telltale signs in the light emitted have previously revealed there to be two stars present.
Now experts say they have further analysed the data to discover there is another body within the system: a black hole with a mass over four times that of our sun, and the closest to Earth found so far.
“We realised that one could not describe what we saw with just two stars,” said Dietrich Baade, an emeritus astronomer at European Southern Observatory (ESO) and a co-author of the study.
“One of the stars is moving periodically, with a period of 40 days,” he said. “And the only way to understand that period and the very large [velocity] of 60km per second with a mass five times that of the sun was to infer that there is another very massive body which, however, is not visible.”
In other words, a black hole – an object typically formed from the gravitational collapse of a massive star.
The upshot, said Baade, is a so-called “hierarchical triple system”, which he explained by reference to a child’s mobile.
“On the one branch of the mobile you have two stars hanging, one of which is not visible, which is black – that is the black hole. And these two objects are orbiting each other,” he said. “And the other branch of the mobile you have one star which is much farther away from the other two.”
The black hole is unusual. “The hallmark of this black hole is that it is truly black,” he said. “Almost all the other black holes that we know are in the Milky Way – and there are only two dozen of them – shine very brightly in X-rays.”
Baade said the other black holes each had a companion star that feeds them with gas. However, this does not appear to be the case for the newly discovered black hole and its nearby star.
“This star is not so massive that it loses a lot of gas and therefore the black hole is starving and that makes it so dark.”
He said only a handful of similar black holes had been found previously, and they merited further scrutiny. “It may also be the first ever [black hole of this kind],” he said.
Baade added that HR 6819 – or rather, its stars – can be seen by the naked eye. “If you want to see it really overhead, you need to be at the southern tip of South America,” he said.
The new work, which is published in the journal Astronomy & Astrophysics, is based on data collected using telescopes at ESO’s La Silla Observatory in Chile.
“Theoretical models suggest that in the Milky Way there are between 100m and 1bn black holes,” said Baade. “We are finding a tip of an iceberg.”
The discovery could shed light on an unusual system in the constellation Gemini called LB-1. This system has previously been suggested to be composed of a star and a tremendously massive black hole – a finding that has foxed experts. Baade noted LB-1 appears to be very similar to HR 6819.
He said that suggests LB-1 could be a triple system, meaning its “dark object” would be a black hole of a more normal mass, or possibly a neutron star.
Dr Ziri Younsi, an expert on black holes at University College London, who was not involved with the research, said: “It’s remarkable that a black hole has been found so close to Earth,” noting for context that the centre of our galaxy is about 25,000 light years from Earth.
“This new study hints at the exciting prospect of a whole population of stellar-mass black holes lurking in our Galaxy,” Younsi said. “It also offers a potential new means to detect many more systems comprising such quiescent black holes in our galactic neighbourhood in the near future.”
Scientists identify rain of molten iron on distant exoplanet
Conditions on Wasp-76b in Pisces include temperatures of 2,400C and 10,000mph winds
Hannah Devlin
the guardian
Wed 11 Mar 2020 12.00 EDT
Wasp-76b is what astronomers call an exoplanet, one that orbits a star outside our solar system. Scientists have discovered that the local weather conditions include 2,400C temperatures, winds in excess of 10,000mph and a steady pelting of iron rain.
The observations of the distant planet’s unusually hostile climate are the first results from a new instrument on the Very Large Telescope in Chile, which astronomers say will transform our view of worlds far from beyond our own solar system.
Wasp-76b, which is 640 light years away in the constellation of Pisces, is an ultra-hot gas giant. It orbits its star at about 3% of the distance between the Earth and the Sun, resulting in scorching surface temperatures and the weird phenomenon of molten iron falling from the sky.
“It’s a kind of world we can’t imagine easily because we don’t have anything like that in our solar system,” said Christophe Lovis, an exoplanet researcher at the University of Geneva and co-author of the paper.
Because the planet is so close in, it is “tidally locked” (like the Moon’s orbit about Earth) and only only ever shows one face, its day side, to its parent star, while its cooler night side remains in perpetual darkness.
On the day side, which is 1,000 degrees hotter, molecules separate into atoms, and iron evaporates into the atmosphere to form metallic clouds. The extreme temperature difference between the day and night sides produces ferocious winds that carry the iron vapour to the cooler night side, where temperatures decrease to about 1,500C and the iron condenses and falls as rain that constantly peppers the planet’s gas surface and vanishes beneath it.
“One could say that this planet gets rainy in the evening, except it rains iron,” said David Ehrenreich, a professor at the University of Geneva in Switzerland and lead author.
The observations came from a new instrument, the Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (Espresso) that was originally designed to hunt for Earth-like planets around Sun-like stars. It does this by spotting the dip in starlight that occurs as a planet sails across the face of the star.
For giant planets that are very close to their home star, detecting these transits is an easier task as they block out more light. Scientists have now moved on to more refined observations that look not only at the dip in intensity but how the spectrum of the light is shifted, which can reveal what gases are present in the planet’s atmosphere.
The latest observations go one step further still and compare the gases present in the leading edge of the planet as it passes across the face of the star and the trailing edge.
For Wasp-76b, this revealed iron vapour at the leading edge, where the prevailing 10,000mph wind would be blowing from the day side into the night side. But the signal was absent from the trailing edge, suggesting that all the iron had rained down on the night side by the time the circulating wind came back around.
The findings, published in the journal Nature, are the latest to give new insights into the enormous diversity of planets beyond our own solar system. More than 4,000 exoplanets have now been confirmed and powerful new ground-based observatories under construction, such as the Extremely Large Telescope, and the James Webb Space Telescope, scheduled to launch next year, are expected to bring astronomers closer to answering whether any of these have the necessary conditions to support extraterrestrial life.
The observations of the distant planet’s unusually hostile climate are the first results from a new instrument on the Very Large Telescope in Chile, which astronomers say will transform our view of worlds far from beyond our own solar system.
Wasp-76b, which is 640 light years away in the constellation of Pisces, is an ultra-hot gas giant. It orbits its star at about 3% of the distance between the Earth and the Sun, resulting in scorching surface temperatures and the weird phenomenon of molten iron falling from the sky.
“It’s a kind of world we can’t imagine easily because we don’t have anything like that in our solar system,” said Christophe Lovis, an exoplanet researcher at the University of Geneva and co-author of the paper.
Because the planet is so close in, it is “tidally locked” (like the Moon’s orbit about Earth) and only only ever shows one face, its day side, to its parent star, while its cooler night side remains in perpetual darkness.
On the day side, which is 1,000 degrees hotter, molecules separate into atoms, and iron evaporates into the atmosphere to form metallic clouds. The extreme temperature difference between the day and night sides produces ferocious winds that carry the iron vapour to the cooler night side, where temperatures decrease to about 1,500C and the iron condenses and falls as rain that constantly peppers the planet’s gas surface and vanishes beneath it.
“One could say that this planet gets rainy in the evening, except it rains iron,” said David Ehrenreich, a professor at the University of Geneva in Switzerland and lead author.
The observations came from a new instrument, the Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (Espresso) that was originally designed to hunt for Earth-like planets around Sun-like stars. It does this by spotting the dip in starlight that occurs as a planet sails across the face of the star.
For giant planets that are very close to their home star, detecting these transits is an easier task as they block out more light. Scientists have now moved on to more refined observations that look not only at the dip in intensity but how the spectrum of the light is shifted, which can reveal what gases are present in the planet’s atmosphere.
The latest observations go one step further still and compare the gases present in the leading edge of the planet as it passes across the face of the star and the trailing edge.
For Wasp-76b, this revealed iron vapour at the leading edge, where the prevailing 10,000mph wind would be blowing from the day side into the night side. But the signal was absent from the trailing edge, suggesting that all the iron had rained down on the night side by the time the circulating wind came back around.
The findings, published in the journal Nature, are the latest to give new insights into the enormous diversity of planets beyond our own solar system. More than 4,000 exoplanets have now been confirmed and powerful new ground-based observatories under construction, such as the Extremely Large Telescope, and the James Webb Space Telescope, scheduled to launch next year, are expected to bring astronomers closer to answering whether any of these have the necessary conditions to support extraterrestrial life.
NASA REVEALS BIZARRE PICTURE OF MYSTERIOUS HOLE ON SLOPES OF MASSIVE MARTIAN VOLCANO
BY ARISTOS GEORGIOU - hewsweek
ON 3/4/20 AT 6:45 AM EST
NASA has posted an image of an unusual hole on the slopes of a giant Martian volcano known as Pavonis Mons.
In the photo,which was snapped in 2011 by the space agency's Mars Reconnaissance Orbiter (MRO), a circular crater can be seen with very steep walls. At the center of this crater is an opening measuring around 115 feet across, which is the entrance to an underground cavern.
Much of the material that once filled the crater has sunk through the hole forming a pile of debris inside the cavern, according to the University of Arizona's Lunar & Planetary Laboratory (LPL.)
Using a digital model of the terrain around the hole, researchers have estimated that this debris pile is at least 203 feet tall. Furthermore, the top of the pile lies about 92 feet below the rim of the central opening, indicating that the underground cavity was once 295 feet deep, before the material from the crater fell inside.
This is intriguing from a geological perspective because it means the void is larger than most caves on Earth, according to the LPL. The caves on our planet that are larger than the Martian void were all formed through the process of water dissolving underground limestone. This process is unlikely to occur on Mars because these substances are not found in anywhere near the same quantities as they are on Earth.
Researchers think that on Mars, caverns like this could be the result of ancient volcanic activity. Pavonis Mons, which stands higher than Everest at 46,000 feet tall, is a shield volcano, which was formed by successive lava flows cooling and stacking on top of each other.
When hot lava flowed on the surface after eruptions, it would have cooled and hardened. In some cases, this may have insulated the lava below, allowing it to continue flowing. When this underground lava drained away, it may have left behind so-called "lava tube" caves.
These lava tubes are found on Earth in volcanic hotspots such as Hawaii, Iceland, and the Galapagos Islands. There are several potential candidates of lava tubes on both the moon and Mars.
Research presented by a team of scientists at the European Planetary Science Congress 2017 suggested these potential lava tube caves could have an important role to play in future space missions.
The team, led by Riccardo Pozzobon from the University of Padova, Italy, carried out the first comparison of lava tube caves on Earth and candidate lava tube caves on the moon and Mars. They found these caverns could potentially house human space settlements or even be promising places to search for signs of life, on Mars at least.
"The comparison of terrestrial, lunar and Martian examples shows that, as you might expect, gravity has a big effect on the size of lava tubes," Pozzobon said in a press release at the time. "On Earth, they can be up to 30 meters [98 feet] across. In the lower gravity environment of Mars, we see evidence for lava tubes that are 250 meters [820 feet] in width. On the Moon, these tunnels could be a kilometer [0.6 miles] or more across and many hundreds of kilometers in length."
He continued: "These results have important implications for habitability and human exploration of the moon but also for the search for extra-terrestrial life on Mars.
"Lava tubes are environments shielded from cosmic radiation and protected from micrometeorites, potentially providing safe habitats for future human missions. They are also, potentially, large enough for quite significant human settlements."
In the photo,which was snapped in 2011 by the space agency's Mars Reconnaissance Orbiter (MRO), a circular crater can be seen with very steep walls. At the center of this crater is an opening measuring around 115 feet across, which is the entrance to an underground cavern.
Much of the material that once filled the crater has sunk through the hole forming a pile of debris inside the cavern, according to the University of Arizona's Lunar & Planetary Laboratory (LPL.)
Using a digital model of the terrain around the hole, researchers have estimated that this debris pile is at least 203 feet tall. Furthermore, the top of the pile lies about 92 feet below the rim of the central opening, indicating that the underground cavity was once 295 feet deep, before the material from the crater fell inside.
This is intriguing from a geological perspective because it means the void is larger than most caves on Earth, according to the LPL. The caves on our planet that are larger than the Martian void were all formed through the process of water dissolving underground limestone. This process is unlikely to occur on Mars because these substances are not found in anywhere near the same quantities as they are on Earth.
Researchers think that on Mars, caverns like this could be the result of ancient volcanic activity. Pavonis Mons, which stands higher than Everest at 46,000 feet tall, is a shield volcano, which was formed by successive lava flows cooling and stacking on top of each other.
When hot lava flowed on the surface after eruptions, it would have cooled and hardened. In some cases, this may have insulated the lava below, allowing it to continue flowing. When this underground lava drained away, it may have left behind so-called "lava tube" caves.
These lava tubes are found on Earth in volcanic hotspots such as Hawaii, Iceland, and the Galapagos Islands. There are several potential candidates of lava tubes on both the moon and Mars.
Research presented by a team of scientists at the European Planetary Science Congress 2017 suggested these potential lava tube caves could have an important role to play in future space missions.
The team, led by Riccardo Pozzobon from the University of Padova, Italy, carried out the first comparison of lava tube caves on Earth and candidate lava tube caves on the moon and Mars. They found these caverns could potentially house human space settlements or even be promising places to search for signs of life, on Mars at least.
"The comparison of terrestrial, lunar and Martian examples shows that, as you might expect, gravity has a big effect on the size of lava tubes," Pozzobon said in a press release at the time. "On Earth, they can be up to 30 meters [98 feet] across. In the lower gravity environment of Mars, we see evidence for lava tubes that are 250 meters [820 feet] in width. On the Moon, these tunnels could be a kilometer [0.6 miles] or more across and many hundreds of kilometers in length."
He continued: "These results have important implications for habitability and human exploration of the moon but also for the search for extra-terrestrial life on Mars.
"Lava tubes are environments shielded from cosmic radiation and protected from micrometeorites, potentially providing safe habitats for future human missions. They are also, potentially, large enough for quite significant human settlements."
Scientists pinpoint mysterious repeating radio signal from outside our galaxy
Only two fast radio bursts have been detected that actually repeat. What they are is still unknown
NICOLE KARLIS - salon
FEBRUARY 10, 2020 11:03PM (UTC)
Nearly 500 million light years away, a mysterious radio signal is repeating itself.
It's a new piece in the puzzle of fast radio bursts (FRBs) — short bursts of radio waves that are so powerful that scientists are able to detect them on Earth, despite their extragalactic origins. Fast radio bursts are hard to study because of how brief they are, meaning telescopes can't often focus on them in time to get a good look.
Hence, the new discovery of a fast radio burst that repeats once every 16 days is a major clue, and marks the first time scientists have documented a predictable pattern among these mysterious repeating signals that are originating deep in space.
"We conclude that this is the first detected periodicity of any kind in an FRB source," the researchers said in the paper. "The discovery of a 16.35-day periodicity in a repeating FRB source is an important clue to the nature of this object." The repeating FRB has been dubbed FRB 180916.J0158+65.
The specific astrophysical event that causes FRBs is still unknown, although all observed FRBs are from galaxies outside our own. Such signals were first spotted in 2007. It was previously thought that such pulses were random, but according to the aforementioned paper published on the server arXiv in late January, researchers studying FRBs discovered that FRB 180916.J0158+65 is a "repeater," meaning it emits bursts repeatedly and follows a regular pattern.
Scientists have only discovered two repeating FRBs, including the one mentioned above. FRB 180916.J0158+65 was probed using the Canadian Hydrogen Intensity Mapping Experiment (CHIME radio telescope) in British Columbia. Using CHIME, researchers found that between September 2018 and October 2019, FRB 180916.J0158+65's bursts clustered into a period of four days, and then stopped for the next 12 days, before emitting a signal again on the 16th day. The authors of the paper posit one possible explanation could be orbital motion, meaning when an object is moving forward while being pulled by gravity toward another object at the same time.
"Given the source's location in the outskirts of a massive spiral galaxy, a supermassive black hole companion seems unlikely, although lower-mass black holes are viable," the researchers further explained. "Future observations, both intensity and polarimetric, and at all wavebands, could distinguish among models and are strongly encouraged, as are searches for periodicities in other repeaters, to see if the phenomenon is generic."
Up until this observation, FRBs seemed to be random. Overall, less than 70 FRBs have been documented.
There are competing theories as to what FRBs could be. One explanation posits that that FRBs are the result of a binary system containing a massive star and a neutron star, according to a separate paper published on arXiv that looked at the same data from FRB 180916.J0158+65. In this theory, the neutron star could be emitting radio bursts which are sometimes blocked by an opaque wind.
These latest findings are indicative of how humans may be closer to understanding these cosmic puzzles.
Though our civilization communicates frequently with radio waves, these mysterious signals are probably not coming from an alien civilization, as Salon has previously reported.
"It is unlikely that all FRBs are from alien civilizations due to the power requirements at cosmological distances, but possible," Avi Loeb, chair of Harvard's astronomy department, previously told Salon. "We worked out the numbers in a paper with my postdoc, Manasvi Lingam, two years ago."
"One needs to use all the power intercepted by the Earth from the Sun" to create an FRB of comparable intensity to the ones we've detected on Earth, Loeb said. However, Loeb did posit that "a small fraction of nearby FRBs could be artificial radio beams sweeping across the sky."
It's a new piece in the puzzle of fast radio bursts (FRBs) — short bursts of radio waves that are so powerful that scientists are able to detect them on Earth, despite their extragalactic origins. Fast radio bursts are hard to study because of how brief they are, meaning telescopes can't often focus on them in time to get a good look.
Hence, the new discovery of a fast radio burst that repeats once every 16 days is a major clue, and marks the first time scientists have documented a predictable pattern among these mysterious repeating signals that are originating deep in space.
"We conclude that this is the first detected periodicity of any kind in an FRB source," the researchers said in the paper. "The discovery of a 16.35-day periodicity in a repeating FRB source is an important clue to the nature of this object." The repeating FRB has been dubbed FRB 180916.J0158+65.
The specific astrophysical event that causes FRBs is still unknown, although all observed FRBs are from galaxies outside our own. Such signals were first spotted in 2007. It was previously thought that such pulses were random, but according to the aforementioned paper published on the server arXiv in late January, researchers studying FRBs discovered that FRB 180916.J0158+65 is a "repeater," meaning it emits bursts repeatedly and follows a regular pattern.
Scientists have only discovered two repeating FRBs, including the one mentioned above. FRB 180916.J0158+65 was probed using the Canadian Hydrogen Intensity Mapping Experiment (CHIME radio telescope) in British Columbia. Using CHIME, researchers found that between September 2018 and October 2019, FRB 180916.J0158+65's bursts clustered into a period of four days, and then stopped for the next 12 days, before emitting a signal again on the 16th day. The authors of the paper posit one possible explanation could be orbital motion, meaning when an object is moving forward while being pulled by gravity toward another object at the same time.
"Given the source's location in the outskirts of a massive spiral galaxy, a supermassive black hole companion seems unlikely, although lower-mass black holes are viable," the researchers further explained. "Future observations, both intensity and polarimetric, and at all wavebands, could distinguish among models and are strongly encouraged, as are searches for periodicities in other repeaters, to see if the phenomenon is generic."
Up until this observation, FRBs seemed to be random. Overall, less than 70 FRBs have been documented.
There are competing theories as to what FRBs could be. One explanation posits that that FRBs are the result of a binary system containing a massive star and a neutron star, according to a separate paper published on arXiv that looked at the same data from FRB 180916.J0158+65. In this theory, the neutron star could be emitting radio bursts which are sometimes blocked by an opaque wind.
These latest findings are indicative of how humans may be closer to understanding these cosmic puzzles.
Though our civilization communicates frequently with radio waves, these mysterious signals are probably not coming from an alien civilization, as Salon has previously reported.
"It is unlikely that all FRBs are from alien civilizations due to the power requirements at cosmological distances, but possible," Avi Loeb, chair of Harvard's astronomy department, previously told Salon. "We worked out the numbers in a paper with my postdoc, Manasvi Lingam, two years ago."
"One needs to use all the power intercepted by the Earth from the Sun" to create an FRB of comparable intensity to the ones we've detected on Earth, Loeb said. However, Loeb did posit that "a small fraction of nearby FRBs could be artificial radio beams sweeping across the sky."
Solar Orbiter spacecraft will capture the sun's north and south poles
Hannah Devlin Science correspondent
the guardian
Fri 7 Feb 2020 06.10 EST
The sun’s uncharted north and south poles are set to be revealed for the first time by an ambitious mission that will fly above our home star and beam back images.
The Solar Orbiter spacecraft, a joint Nasa and European Space Agency (ESA) mission, is set to be launched from Cape Canaveral just after 4am UK time on Monday morning, and will reach its vantage point above the planetary plane by the end of 2021.
From Earth, the sun looks like a perfectly uniform fiery ball, but scientists say that its extremities could look unfamiliar, possibly featuring gaping dark holes or angular geometric structures.
“There’s no rational reasons why the poles shouldn’t be different”, said Mark McCaughrean, senior advisor for science & exploration at ESA. “Be prepared for surprises.”
The only previous mission to have flown above the sun’s poles was Nasa’s Ulysses probe, launched in 1990, but while it took measurements of the sun’s magnetic field and solar wind, it did not have a camera.
Over the next year, the Solar Orbiter will conduct several flybys of Venus and one of the Earth, using the planets’ gravity to slingshot into a tilted elliptical orbit. By the end of 2021, its orbit will have an inclination of 17° – high enough to take images of the sun’s extremities – and if the mission is extended it could reach an inclination of 33°.
Computational models and magnetic field measurements suggest that the sun’s poles could be dominated by huge coronal holes – areas of the surface that are less dense than their surroundings and will show up as ominous dark pools.
“These coronal holes are enormous at the poles. We’ll be able to peer over the edges … and see how it grows and shrinks with solar activity”, said Nicola Fox, director of Nasa’s heliophysics division. “It’s something we’ve never been able to do before.”
Striking geometric features are also a possibility, according to McCaughrean. The first images of Jupiter’s north pole surprised astronomers with an octagonal arrangement of storms twirling like cogs around a central vortex, while Saturn’s north pole features a vast hexagonal cloud structure.
The $1.3bn mission will run parallel to Nasa’s Parker Solar Probe, launched 18 months ago, which has flown closer to the sun than any spacecraft, and the Inouye solar telescope, which has acquired the highest resolution images of the solar surface since it began observations in December.
At just 3.83 million miles from the solar surface – technically inside the sun’s atmosphere – Parker will be seven times closer to the Sun than Solar Orbiter. But, McCaughrean points out, Parker will not be taking any direct images because if it looked at the sun, it would melt. From its slightly less scorching vantage point, Solar Orbiter will be able to make long-range observations of surface features such as sun spots as well as detecting the solar wind streaming past.
“We always wanted to make this seeing and feeling connection. The stuff that you can see at the surface you can feel going past a few days later”, said McCaughrean. “Parker is out there going ‘Ooh, I’m feeling stuff but I’ve got no idea where it came from’.”
Solar Orbiter’s camera and other instruments are housed behind a heat shield, peering out through shuttered peepholes that close whenever the probe’s interior gets too hot. The titanium shield is coated in a substance called SolarBlack, made from charred animal bones, something Esa concluded was uniquely well-suited to keeping the craft at a stable temperature throughout the mission.
The probe’s orbit, which at times will move almost in synch with the sun’s own rotation, will allow it to track sun spots on the solar surface as they appear and vanish, and will investigate the origins of the solar wind as it streams off the sun.
The mission will also use helioseismology – measurements of small and large scale oscillations at the sun’s surface – to try and unravel the sun’s internal structure. The sun’s acoustic “ringing” can also reveal sun spots bubbling up from the interior days before they appear as darkened patches on the surface.
Solar Orbiter is scheduled to begin making science measurements in May, with full operations starting in November 2021, when the probe’s telescopes switch on.
“It will capture the imagination like science fiction does and inspire the next generation of scientists and space explorers,” said Yannis Zouganelis, Esa’s deputy project scientist for Solar Orbiter.
The Solar Orbiter spacecraft, a joint Nasa and European Space Agency (ESA) mission, is set to be launched from Cape Canaveral just after 4am UK time on Monday morning, and will reach its vantage point above the planetary plane by the end of 2021.
From Earth, the sun looks like a perfectly uniform fiery ball, but scientists say that its extremities could look unfamiliar, possibly featuring gaping dark holes or angular geometric structures.
“There’s no rational reasons why the poles shouldn’t be different”, said Mark McCaughrean, senior advisor for science & exploration at ESA. “Be prepared for surprises.”
The only previous mission to have flown above the sun’s poles was Nasa’s Ulysses probe, launched in 1990, but while it took measurements of the sun’s magnetic field and solar wind, it did not have a camera.
Over the next year, the Solar Orbiter will conduct several flybys of Venus and one of the Earth, using the planets’ gravity to slingshot into a tilted elliptical orbit. By the end of 2021, its orbit will have an inclination of 17° – high enough to take images of the sun’s extremities – and if the mission is extended it could reach an inclination of 33°.
Computational models and magnetic field measurements suggest that the sun’s poles could be dominated by huge coronal holes – areas of the surface that are less dense than their surroundings and will show up as ominous dark pools.
“These coronal holes are enormous at the poles. We’ll be able to peer over the edges … and see how it grows and shrinks with solar activity”, said Nicola Fox, director of Nasa’s heliophysics division. “It’s something we’ve never been able to do before.”
Striking geometric features are also a possibility, according to McCaughrean. The first images of Jupiter’s north pole surprised astronomers with an octagonal arrangement of storms twirling like cogs around a central vortex, while Saturn’s north pole features a vast hexagonal cloud structure.
The $1.3bn mission will run parallel to Nasa’s Parker Solar Probe, launched 18 months ago, which has flown closer to the sun than any spacecraft, and the Inouye solar telescope, which has acquired the highest resolution images of the solar surface since it began observations in December.
At just 3.83 million miles from the solar surface – technically inside the sun’s atmosphere – Parker will be seven times closer to the Sun than Solar Orbiter. But, McCaughrean points out, Parker will not be taking any direct images because if it looked at the sun, it would melt. From its slightly less scorching vantage point, Solar Orbiter will be able to make long-range observations of surface features such as sun spots as well as detecting the solar wind streaming past.
“We always wanted to make this seeing and feeling connection. The stuff that you can see at the surface you can feel going past a few days later”, said McCaughrean. “Parker is out there going ‘Ooh, I’m feeling stuff but I’ve got no idea where it came from’.”
Solar Orbiter’s camera and other instruments are housed behind a heat shield, peering out through shuttered peepholes that close whenever the probe’s interior gets too hot. The titanium shield is coated in a substance called SolarBlack, made from charred animal bones, something Esa concluded was uniquely well-suited to keeping the craft at a stable temperature throughout the mission.
The probe’s orbit, which at times will move almost in synch with the sun’s own rotation, will allow it to track sun spots on the solar surface as they appear and vanish, and will investigate the origins of the solar wind as it streams off the sun.
The mission will also use helioseismology – measurements of small and large scale oscillations at the sun’s surface – to try and unravel the sun’s internal structure. The sun’s acoustic “ringing” can also reveal sun spots bubbling up from the interior days before they appear as darkened patches on the surface.
Solar Orbiter is scheduled to begin making science measurements in May, with full operations starting in November 2021, when the probe’s telescopes switch on.
“It will capture the imagination like science fiction does and inspire the next generation of scientists and space explorers,” said Yannis Zouganelis, Esa’s deputy project scientist for Solar Orbiter.
CHINA'S ENORMOUS ALIEN-HUNTING TELESCOPE IS NOW FULLY OPERATIONAL
BY ARISTOS GEORGIOU - newsweek
ON 1/22/20 AT 1:17 PM EST
The world's largest and most sensitive radio telescope has now begun formal operations.
Known as the Five-hundred-Meter Aperture Spherical radio Telescope (FAST), the facility, located in a deep depression in southwest China's Guizhou province, will help astronomers to shed new light on the evolution of the universe, and even search for extraterrestrial intelligence.
FAST began trial operations in September 2016, but will now gradually become available for use by astronomers from around the world, Chinese state media Xinhua reported.
The telescope consists of a single dish, which has a diameter of 500 meters (1,640 feet) and an area equivalent to 30 football fields. According to Chinese officials, FAST is around 2.5 times more sensitive than the previous largest telescope in the world—the Arecibo Observatory in Puerto Rico—and can process up to 38 gigabytes of information every second.
"Arecibo and FAST are the only two radio telescopes of their type, i.e., built into large depressions in the local terrain and pointed straight up all the time," Rick Steinberg, a spokesperson from the American Astronomical Society, told Newsweek.
"Arecibo is 300 meters, whereas FAST is 500, so it's quite a bit bigger. But the technology, as far as I'm aware, is much the same in the two places, since Arecibo's receivers have been updated several times over the decades," he said.
In total, FAST —whose nickname "Tianyan" means "Eye of the Sky or "Eye of Heaven"—has expanded the range of space that telescopes can investigate, providing unprecedented opportunities to study astronomical phenomena, Li Kejia from the Kavli Institute for Astronomy and Astrophysics at Peking University told Xinhua.
Among the phenomena FAST will be studying over the coming years are pulsars—incredibly dense, relatively small stars with powerful magnetic fields that can rotate hundreds of times per second and shoot out intense beams of radiation.
In fact, FAST has already identified 102 new pulsars over the past two years during its trial period, according to Xinhua. Part of the research at FAST will also be focused on is looking for potential extraterrestrial signals.
"In the process of observing signals from celestial bodies, we also collect signals that might be emitted by humans or extraterrestrial intelligence," Zhu Ming from FAST told Chinese state TV network CCTV.
"However, this is a huge amount of work, since most signals we see—99 percent of them—are various noises, so we need to take our time to identify the signals we want in the noises," Zhu said.
The construction of FAST was completed in 2016, around two decades after it was first proposed by Chinese astronomers. Altogether, the project cost 1.2 billion yuan, which is equivalent to around $174 million.
Known as the Five-hundred-Meter Aperture Spherical radio Telescope (FAST), the facility, located in a deep depression in southwest China's Guizhou province, will help astronomers to shed new light on the evolution of the universe, and even search for extraterrestrial intelligence.
FAST began trial operations in September 2016, but will now gradually become available for use by astronomers from around the world, Chinese state media Xinhua reported.
The telescope consists of a single dish, which has a diameter of 500 meters (1,640 feet) and an area equivalent to 30 football fields. According to Chinese officials, FAST is around 2.5 times more sensitive than the previous largest telescope in the world—the Arecibo Observatory in Puerto Rico—and can process up to 38 gigabytes of information every second.
"Arecibo and FAST are the only two radio telescopes of their type, i.e., built into large depressions in the local terrain and pointed straight up all the time," Rick Steinberg, a spokesperson from the American Astronomical Society, told Newsweek.
"Arecibo is 300 meters, whereas FAST is 500, so it's quite a bit bigger. But the technology, as far as I'm aware, is much the same in the two places, since Arecibo's receivers have been updated several times over the decades," he said.
In total, FAST —whose nickname "Tianyan" means "Eye of the Sky or "Eye of Heaven"—has expanded the range of space that telescopes can investigate, providing unprecedented opportunities to study astronomical phenomena, Li Kejia from the Kavli Institute for Astronomy and Astrophysics at Peking University told Xinhua.
Among the phenomena FAST will be studying over the coming years are pulsars—incredibly dense, relatively small stars with powerful magnetic fields that can rotate hundreds of times per second and shoot out intense beams of radiation.
In fact, FAST has already identified 102 new pulsars over the past two years during its trial period, according to Xinhua. Part of the research at FAST will also be focused on is looking for potential extraterrestrial signals.
"In the process of observing signals from celestial bodies, we also collect signals that might be emitted by humans or extraterrestrial intelligence," Zhu Ming from FAST told Chinese state TV network CCTV.
"However, this is a huge amount of work, since most signals we see—99 percent of them—are various noises, so we need to take our time to identify the signals we want in the noises," Zhu said.
The construction of FAST was completed in 2016, around two decades after it was first proposed by Chinese astronomers. Altogether, the project cost 1.2 billion yuan, which is equivalent to around $174 million.
SECRETS OF BIZARRE 'COTTON CANDY' EXOPLANETS WHICH HAVE STRANGELY LOW DENSITIES REVEALED BY HUBBLE TELESCOPE
BY ARISTOS GEORGIOU - newsweek
ON 12/20/19 AT 7:08 AM EST
Astronomers have uncovered fascinating new insights into a bizarre set of "super-puff" exoplanets which are similar in density to cotton candy.
The three planets—which were discovered in 2012 orbiting the Sun-like star Kepler 51 around 2,400 light-years away—have the lowest densities of any known exoplanets.
"They're very bizarre," said Libby-Roberts from the University of Colorado Boulder, leader of a new study looking into the properties of the planets that's set to be published in the Astronomical Journal.
When scientists first determined the extraordinarily low densities of the planets in 2014, many were surprised by the results.
Now, Libby-Roberts and colleagues have come up with new estimates for the mass and densities of the three planets using observations with the Hubble Space Telescope, independently confirming their "puffy" nature.
These planets are roughly the size of Jupiter, however, they are around a hundred times lighter with masses only several times that of the Earth's. In fact, the team worked out that the planets had densities of less than 0.1 grams per cubic centimeter of volume—which is almost the same as that of cotton candy, according to Libby-Roberts.
"We knew they were low density," she said. "But when you picture a Jupiter-sized ball of cotton candy—that's really low density."
The team suggest that the planets are likely made up of hydrogen and helium although they are surrounded by a thick haze of methane. This atmosphere may be similar to that of Saturn's moon Titan, according to the researchers.
Finally, the astronomers say that the the planets appear to be evaporating at a rapid pace because they are located close to their star, meaning they could shrink significantly over the next billion years.
Super-puff planets are extremely rare—less than 15 have been documented so far—and nothing like them exists in our solar system.
"This is an extreme example of what's so cool about exoplanets in general," Zachory Berta-Thompson, a co-author of the research, said in a statement. "They give us an opportunity to study worlds that are very different than ours, but they also place the planets in our own solar system into a larger context."
The researchers suggest that the planets may represent a brief transitory phase in planet evolution—a consequence of the young age of the Kepler 51 star system, which is only around 500 million years old compared to our 4.6-billion-year-old sun.
"A good bit of their weirdness is coming from the fact that we're seeing them at a time in their development where we've rarely gotten the chance to observe planets," Berta Thompson said.
The three planets—which were discovered in 2012 orbiting the Sun-like star Kepler 51 around 2,400 light-years away—have the lowest densities of any known exoplanets.
"They're very bizarre," said Libby-Roberts from the University of Colorado Boulder, leader of a new study looking into the properties of the planets that's set to be published in the Astronomical Journal.
When scientists first determined the extraordinarily low densities of the planets in 2014, many were surprised by the results.
Now, Libby-Roberts and colleagues have come up with new estimates for the mass and densities of the three planets using observations with the Hubble Space Telescope, independently confirming their "puffy" nature.
These planets are roughly the size of Jupiter, however, they are around a hundred times lighter with masses only several times that of the Earth's. In fact, the team worked out that the planets had densities of less than 0.1 grams per cubic centimeter of volume—which is almost the same as that of cotton candy, according to Libby-Roberts.
"We knew they were low density," she said. "But when you picture a Jupiter-sized ball of cotton candy—that's really low density."
The team suggest that the planets are likely made up of hydrogen and helium although they are surrounded by a thick haze of methane. This atmosphere may be similar to that of Saturn's moon Titan, according to the researchers.
Finally, the astronomers say that the the planets appear to be evaporating at a rapid pace because they are located close to their star, meaning they could shrink significantly over the next billion years.
Super-puff planets are extremely rare—less than 15 have been documented so far—and nothing like them exists in our solar system.
"This is an extreme example of what's so cool about exoplanets in general," Zachory Berta-Thompson, a co-author of the research, said in a statement. "They give us an opportunity to study worlds that are very different than ours, but they also place the planets in our own solar system into a larger context."
The researchers suggest that the planets may represent a brief transitory phase in planet evolution—a consequence of the young age of the Kepler 51 star system, which is only around 500 million years old compared to our 4.6-billion-year-old sun.
"A good bit of their weirdness is coming from the fact that we're seeing them at a time in their development where we've rarely gotten the chance to observe planets," Berta Thompson said.
NASA MISSION TO 'TOUCH THE SUN' REVEALS BIZARRE MAGNETIC FIELDS AND 'ROGUE WAVES' IN CORONA
BY HANNAH OSBORNE - newsweek
ON 12/4/19 AT 1:01 PM EST
NASA has released the first results from its mission to "touch the sun" with the Parker Solar Probe, which launched from Earth just over two years ago.
Initial results show bizarre behavior of the sun's magnetic field, including reversals that took just seconds. They also found thousands of "giant rogue waves," and that when these passed the spacecraft, the solar wind sped up to over 310,000 miles per hour.
The first findings from the mission have been published across four scientific papers in the journal Nature. NASA is also holding a press conference with senior members of the mission to discuss the results. This begins at 1.30 p.m. ET and can be watched on the space agency's website here.
Despite the sun being a key factor in the existence of life on Earth, there are huge gaps in our understanding of it. For example, the corona—the outermost part of the atmosphere—is far hotter than the sun's surface, reaching about one million degrees Celsius compared to 5,500 C. The reason for this is unknown.
Ads by scrollerads.comThe sun also produces the solar wind, which is constantly bombarding Earth's magnetic field. When the sun produces strong outbursts, this can get through our protective shield and affect satellite and communication systems, as well as energy grids on the ground. Having a better grasp of how the solar wind is produced could help researchers find ways to better protect the planet from solar storms in the future.
The Parker Solar Probe has come closer to the sun than any other man-made object. During its final three flybys, scheduled for 2024 and 2025, it will come within 3.83 million miles of the sun's surface. The initial flybys that have now been completed saw the Parker Solar Probe orbit the sun at a distance of around 15 million miles at its closest point.
Justin Kasper, from the University of Michigan, is principal investigator of the Solar Wind Electrons Alphas and Protons (SWEAP) instrument onboard the spaceship. The first measurements taken relate to the sun's corona and its magnetic fields. The corona is what produces the solar wind, but how it does this was not known. It is also unclear why the solar wind is accelerated as it leaves the corona.
With the new observations the team has found that while the 'fast' solar wind, which can reach between 300 and 620 miles per second, comes from large holes in the corona at the sun's north and south poles, the 'slow' solar wind comes from smaller holes in the corona at the equator. The fastest solar wind recorded was traveling at 1.3 million miles an hour.
"In space when we look at the solar wind we see many waves in the wind," Kasper told Newsweek. "They are waves of both the particles and the magnetic field and they carry energy. We wondered if these waves could be heating the corona and if they would be stronger closer to the sun. Think of being in the ocean watching waves flow by and wondering where they came from. To our surprise when we got closer to the sun, not only were the little waves stronger but we also saw giant 'rogue waves' just like in the ocean. When a rogue wave passed by the spacecraft the speed of the wind could jump more than 500,000 kilometers [310,685 miles] per hour in seconds.
"There were thousands of these rogue waves seen in the ten days we were near the sun. We wonder if the rogue waves are what heated the corona."
Kasper said findings also showed that the wind rotates around the sun between ten and 20 times faster than models had predicted. "We are discovering that our standard models of the sun are missing some very fundamental physics and in this mission Parker Solar Probe has a great chance of revealing what is really happening."
Results from the mission also showed unexpected and strange changes to the magnetic field. Researchers found magnetic fields could be traced back to coronal holes and that they would sometimes flip suddenly, reversing by as much as 180 degrees, before flipping back again in the space of a few seconds to a few hours.
The Parker Solar Probe continues to orbit the sun, getting a little closer on each round trip. Activity on the sun increases and decreases on an 11-year cycle. At present, it is in the 'solar minimum' with fewer sunspots than normal appearing. Over the coming years, activity is going to pick up until it reaches the 'solar maximum' around 2024—towards the end of the mission.
"This is working out very nicely," Kasper said. "Right now we're nearing the deepest part of solar minimum, so the sun is nice and stable. It has a well-defined north and south magnetic pole just like Earth and the orientation of the magnetic field flips in a belt that goes around the sun's equator. This makes it a lot easier for us to compare the initial encounters and to try and connect what we see flying around the spacecraft to specific structures in the Sun's atmosphere.
"This is good practice because as the mission proceeds over the next five years and we get closer to the sun, the sun will get more active, with lots of sunspots popping up and a much more complicated magnetic field. It's almost like we get to start with the training wheels on our bike before getting closer to a more complex active sun."
Parker Solar Probe's next encounter with the sun will start in January. At this point, the team will be looking to see if their initial findings are repeated and if spikes in these rogue waves get even stronger as the spacecraft gets closer to the surface.
In a statement, Stuart Bale, from the University of California, Berkeley, and principal investigator on the probe's FIELDS instrument, said: "We have been working nearly around the clock for a decade on this thing, so to see the data...it is just a pleasure. It is a big case of delayed gratification, but it is terrific stuff."
Initial results show bizarre behavior of the sun's magnetic field, including reversals that took just seconds. They also found thousands of "giant rogue waves," and that when these passed the spacecraft, the solar wind sped up to over 310,000 miles per hour.
The first findings from the mission have been published across four scientific papers in the journal Nature. NASA is also holding a press conference with senior members of the mission to discuss the results. This begins at 1.30 p.m. ET and can be watched on the space agency's website here.
Despite the sun being a key factor in the existence of life on Earth, there are huge gaps in our understanding of it. For example, the corona—the outermost part of the atmosphere—is far hotter than the sun's surface, reaching about one million degrees Celsius compared to 5,500 C. The reason for this is unknown.
Ads by scrollerads.comThe sun also produces the solar wind, which is constantly bombarding Earth's magnetic field. When the sun produces strong outbursts, this can get through our protective shield and affect satellite and communication systems, as well as energy grids on the ground. Having a better grasp of how the solar wind is produced could help researchers find ways to better protect the planet from solar storms in the future.
The Parker Solar Probe has come closer to the sun than any other man-made object. During its final three flybys, scheduled for 2024 and 2025, it will come within 3.83 million miles of the sun's surface. The initial flybys that have now been completed saw the Parker Solar Probe orbit the sun at a distance of around 15 million miles at its closest point.
Justin Kasper, from the University of Michigan, is principal investigator of the Solar Wind Electrons Alphas and Protons (SWEAP) instrument onboard the spaceship. The first measurements taken relate to the sun's corona and its magnetic fields. The corona is what produces the solar wind, but how it does this was not known. It is also unclear why the solar wind is accelerated as it leaves the corona.
With the new observations the team has found that while the 'fast' solar wind, which can reach between 300 and 620 miles per second, comes from large holes in the corona at the sun's north and south poles, the 'slow' solar wind comes from smaller holes in the corona at the equator. The fastest solar wind recorded was traveling at 1.3 million miles an hour.
"In space when we look at the solar wind we see many waves in the wind," Kasper told Newsweek. "They are waves of both the particles and the magnetic field and they carry energy. We wondered if these waves could be heating the corona and if they would be stronger closer to the sun. Think of being in the ocean watching waves flow by and wondering where they came from. To our surprise when we got closer to the sun, not only were the little waves stronger but we also saw giant 'rogue waves' just like in the ocean. When a rogue wave passed by the spacecraft the speed of the wind could jump more than 500,000 kilometers [310,685 miles] per hour in seconds.
"There were thousands of these rogue waves seen in the ten days we were near the sun. We wonder if the rogue waves are what heated the corona."
Kasper said findings also showed that the wind rotates around the sun between ten and 20 times faster than models had predicted. "We are discovering that our standard models of the sun are missing some very fundamental physics and in this mission Parker Solar Probe has a great chance of revealing what is really happening."
Results from the mission also showed unexpected and strange changes to the magnetic field. Researchers found magnetic fields could be traced back to coronal holes and that they would sometimes flip suddenly, reversing by as much as 180 degrees, before flipping back again in the space of a few seconds to a few hours.
The Parker Solar Probe continues to orbit the sun, getting a little closer on each round trip. Activity on the sun increases and decreases on an 11-year cycle. At present, it is in the 'solar minimum' with fewer sunspots than normal appearing. Over the coming years, activity is going to pick up until it reaches the 'solar maximum' around 2024—towards the end of the mission.
"This is working out very nicely," Kasper said. "Right now we're nearing the deepest part of solar minimum, so the sun is nice and stable. It has a well-defined north and south magnetic pole just like Earth and the orientation of the magnetic field flips in a belt that goes around the sun's equator. This makes it a lot easier for us to compare the initial encounters and to try and connect what we see flying around the spacecraft to specific structures in the Sun's atmosphere.
"This is good practice because as the mission proceeds over the next five years and we get closer to the sun, the sun will get more active, with lots of sunspots popping up and a much more complicated magnetic field. It's almost like we get to start with the training wheels on our bike before getting closer to a more complex active sun."
Parker Solar Probe's next encounter with the sun will start in January. At this point, the team will be looking to see if their initial findings are repeated and if spikes in these rogue waves get even stronger as the spacecraft gets closer to the surface.
In a statement, Stuart Bale, from the University of California, Berkeley, and principal investigator on the probe's FIELDS instrument, said: "We have been working nearly around the clock for a decade on this thing, so to see the data...it is just a pleasure. It is a big case of delayed gratification, but it is terrific stuff."
Scientists spot black hole so huge it ‘shouldn’t even exist’ in our galaxy
November 27, 2019
By Agence France-Presse - raw story
Astronomers have discovered a black hole in the Milky Way so huge that it challenges existing models of how stars evolve, researchers said Thursday.
LB-1 is 15,000 light years from Earth and has a mass 70 times greater than the Sun, according to the journal Nature.
The Milky Way is estimated to contain 100 million stellar black holes but LB-1 is twice as massive as anything scientists thought possible, said Liu Jifeng, a National Astronomical Observatory of China professor who led the research.
“Black holes of such mass should not even exist in our galaxy, according to most of the current models of stellar evolution,” he added.
Scientists generally believe that there are two types of black holes.
The more common stellar black holes — up to 20 times more massive than the Sun — form when the centre of a very big star collapses in on itself.
Supermassive black holes are at least a million times bigger than the Sun and their origins are uncertain.
But researchers believed that typical stars in the Milky Way shed most of their gas through stellar winds, preventing the emergence of a black hole the size of LB-1, Liu said.
“Now theorists will have to take up the challenge of explaining its formation,” he said in a statement.
Astronomers are still only beginning to grasp “the abundance of black holes and the mechanisms by which they form,” David Reitze, a physicist at the California Institute of Technology who was not involved in the discovery, told AFP.
Stellar black holes are usually formed in the aftermath of supernova explosions, a phenomenon that occurs when extremely large stars burn out at the end of their lives.
“LB-1’s large mass falls into a range “known as the ‘pair instability gap’ where supernovae should not have produced it,” Reitze said.
“That means that this is a new kind a black hole, formed by another physical mechanism!”
LB-1 was discovered by an international team of scientists using China’s sophisticated LAMOST telescope.
Additional images from two of the world’s largest optical telescopes — Spain’s Gran Telescopio Canarias and the Keck I telescope in the United States — confirmed that the size of LB-1, which the National Astronomical Observatory of China said was “nothing short of fantastic”.
LB-1 is 15,000 light years from Earth and has a mass 70 times greater than the Sun, according to the journal Nature.
The Milky Way is estimated to contain 100 million stellar black holes but LB-1 is twice as massive as anything scientists thought possible, said Liu Jifeng, a National Astronomical Observatory of China professor who led the research.
“Black holes of such mass should not even exist in our galaxy, according to most of the current models of stellar evolution,” he added.
Scientists generally believe that there are two types of black holes.
The more common stellar black holes — up to 20 times more massive than the Sun — form when the centre of a very big star collapses in on itself.
Supermassive black holes are at least a million times bigger than the Sun and their origins are uncertain.
But researchers believed that typical stars in the Milky Way shed most of their gas through stellar winds, preventing the emergence of a black hole the size of LB-1, Liu said.
“Now theorists will have to take up the challenge of explaining its formation,” he said in a statement.
Astronomers are still only beginning to grasp “the abundance of black holes and the mechanisms by which they form,” David Reitze, a physicist at the California Institute of Technology who was not involved in the discovery, told AFP.
Stellar black holes are usually formed in the aftermath of supernova explosions, a phenomenon that occurs when extremely large stars burn out at the end of their lives.
“LB-1’s large mass falls into a range “known as the ‘pair instability gap’ where supernovae should not have produced it,” Reitze said.
“That means that this is a new kind a black hole, formed by another physical mechanism!”
LB-1 was discovered by an international team of scientists using China’s sophisticated LAMOST telescope.
Additional images from two of the world’s largest optical telescopes — Spain’s Gran Telescopio Canarias and the Keck I telescope in the United States — confirmed that the size of LB-1, which the National Astronomical Observatory of China said was “nothing short of fantastic”.
NASA’s TESS spacecraft is finding hundreds of exoplanets – and is poised to find thousands more
November 5, 2019
By The Conversation - raw story
Within just 50 light-years from Earth, there are about 1,560 stars, likely orbited by several thousand planets. About a thousand of these extrasolar planets – known as exoplanets – may be rocky and have a composition similar to Earth’s. Some may even harbor life. Over 99% of these alien worlds remain undiscovered — but this is about to change.
With NASA’s new exoplanet-hunter space telescope TESS, the all-sky search is on for possibly habitable planets close to our solar system. TESS — orbiting Earth every 13.7 days — and ground-based telescopes are poised to find hundreds of planets over the next few years. This could transform astronomers’ understanding of alien worlds around us and provide targets to scan with next-generation telescopes for signatures of life. In just over a year, TESS has identified more than 1,200 planetary candidates, 29 of which astronomers have already confirmed as planets. Given TESS’s unique ability to simultaneously search tens of thousands of stars for planets, the mission is expected to yield over 10,000 new worlds.
These are exciting times for astronomers and, especially, for those of us exploring exoplanets. We are members of the planet-hunting Project EDEN, which also supports TESS’s work. We use telescopes on the ground and in space to find exoplanets to understand their properties and potential for harboring life.
Undiscovered worlds all around us
Worlds around us await discovery. Take, for example, Proxima Centauri, an unassuming, faint red star, invisible without a telescope. It is one of over a hundred billion or so such stars within our galaxy, unremarkable except for its status as our next-door neighbor. Orbiting Proxima is a fascinating but mysterious world, called Proxmia b, discovered only in 2016.
Scientists know surprisingly little about Proxima b. Astronomers name the first planet discovered in a system “b”. This planet has never been seen with human eyes or by a telescope. But we know it exists due to its gravitational pull on its host star, which makes the star wobble ever so slightly. This slight wobble was found in measurements collected by a large, international group of astronomers from data taken with multiple ground-based telescopes. Proxima b very likely has a rocky composition similar to Earth’s, but higher mass. It receives about the same amount of heat as Earth receives from the Sun.
And that is what makes this planet so exciting: It lies in the “habitable” zone and just might have properties similar to Earth’s, like a surface, liquid water, and — who knows? — maybe even an atmosphere bearing the telltale chemical signs of life.
NASA’s TESS mission launched in April 2018 to hunt for other broadly Earth-sized planets, but with a different method. TESS is looking for rare dimming events that happen when planets pass in front of their host stars, blocking some starlight. These transit events indicate not only the presence of the planets, but also their sizes and orbits.
Finding a new transiting exoplanet is a big deal for astronomers like us because, unlike those found through stellar wobbles, worlds seen transiting can be studied further to determine their densities and atmospheric compositions.
Red dwarf suns
For us, the most exciting exoplanets are the smallest ones, which TESS can detect when they orbit small stars called red dwarfs – stars with masses less than half the mass of our Sun.
Each of these systems is unique. For example, LP 791-18 is a red dwarf star 86 light-years from Earth around which TESS found two worlds. The first is a “super-Earth,” a planet larger than Earth but probably still mostly rocky, and the second is a “mini-Neptune,” a planet smaller than Neptune but gas- and ice-rich. Neither of these planets have counterparts in our solar system.
Among astronomers’ current favorites of the new broadly Earth-sized planets is LHS 3884b, a scorching “hot Earth” that orbits its sun so quickly that on it you could celebrate your birthday every 11 hours.
No Earth-like worlds yet
But how Earth-like are Earth-sized planets? The promise of finding nearby worlds for detailed studies is already paying off. A team of astronomers observed the hot super-Earth LHS 3884b with the Hubble Space Telescope and found the planet to be a horrible vacation spot, without even an atmosphere. It is just a bare rock with temperatures ranging from over 700 C (1300 Fahrenheit) at noon to near absolute zero (-460 Fahrenheit) at midnight.
The TESS mission was initially funded for two years. But the spacecraft is in excellent shape and NASA recently extended the mission through 2022, doubling the time TESS will have to scan nearby, bright stars for transits.
However, finding exoplanets around the coolest stars — those with temperatures less than about 2700 C (4900 F) — will still be a challenge due to their extreme faintness. Since ultracool dwarfs provide our best opportunity to find and study exoplanets with sizes and temperatures similar to Earth’s, other focused planet searches are picking up where TESS leaves off.
The worlds TESS can’t find
In May 2016, a Belgian-led group announced the discovery of a planetary system around the ultracool dwarf they christened TRAPPIST-1. The discovery of the seven transiting Earth-sized exoplanets in the TRAPPIST-1 system was groundbreaking.
It also demonstrated how small telescopes — relative to the powerful behemoths of our age — can still make transformational discoveries. With patience and persistence, the TRAPPIST telescope scanned nearby faint, red dwarf stars from its high-mountain perch in the Atacama desert for small, telltale dips in their brightnesses. Eventually, it spotted transits in the data for the red dwarf TRAPPIST-1, which — although just 41 light-years away — is too faint for TESS’s four 10-cm (4-inch) diameter lenses. Its Earth-sized worlds would have remained undiscovered had the TRAPPIST team’s larger telescope not found them.
Two projects have upped up the game in the search for exo-Earth candidates around nearby red dwarfs. The SPECULOOS team installed four robotic telescopes – also in the Atacama desert – and one in the Northern Hemisphere. Our Exoearth Discovery and Exploration Network – Project EDEN – uses nine telescopes in Arizona, Italy, Spain and Taiwan to observe red dwarf stars continuously.
The SPECULOOS and EDEN telescopes are much larger than TESS’s small lenses and can find planets around stars too faint for TESS to study, including some of the transiting Earth-sized planets closest to us.
The decade of new worlds
The next decade is likely to be remembered as the time when we opened our eyes to the incredible diversity of other worlds. TESS is likely to find between 10,000 and 15,000 exoplanet candidates by 2025. By 2030, the European Space Agency’s GAIA and PLATO missions are expected to find another 20,000-35,000 planets. GAIA will look for stellar wobbles introduced by planets, while PLATO will search for planetary transits as TESS does.
However, even among the thousands of planets that will soon be found, the exoplanets closest to our solar system will remain special. Many of these worlds can be studied in great detail – including the search for signs of life. Discoveries of the nearest worlds also represent major steps in humanity’s progress in exploring the universe we live in. After mapping our own planet and then the solar system, we now turn to nearby planetary systems. Perhaps one day Proxima b or another nearby world astronomers have yet to find will be the target for interstellar probes, like Project Starshot, or even crewed starships. But first we’ve got to put these worlds on the map.
With NASA’s new exoplanet-hunter space telescope TESS, the all-sky search is on for possibly habitable planets close to our solar system. TESS — orbiting Earth every 13.7 days — and ground-based telescopes are poised to find hundreds of planets over the next few years. This could transform astronomers’ understanding of alien worlds around us and provide targets to scan with next-generation telescopes for signatures of life. In just over a year, TESS has identified more than 1,200 planetary candidates, 29 of which astronomers have already confirmed as planets. Given TESS’s unique ability to simultaneously search tens of thousands of stars for planets, the mission is expected to yield over 10,000 new worlds.
These are exciting times for astronomers and, especially, for those of us exploring exoplanets. We are members of the planet-hunting Project EDEN, which also supports TESS’s work. We use telescopes on the ground and in space to find exoplanets to understand their properties and potential for harboring life.
Undiscovered worlds all around us
Worlds around us await discovery. Take, for example, Proxima Centauri, an unassuming, faint red star, invisible without a telescope. It is one of over a hundred billion or so such stars within our galaxy, unremarkable except for its status as our next-door neighbor. Orbiting Proxima is a fascinating but mysterious world, called Proxmia b, discovered only in 2016.
Scientists know surprisingly little about Proxima b. Astronomers name the first planet discovered in a system “b”. This planet has never been seen with human eyes or by a telescope. But we know it exists due to its gravitational pull on its host star, which makes the star wobble ever so slightly. This slight wobble was found in measurements collected by a large, international group of astronomers from data taken with multiple ground-based telescopes. Proxima b very likely has a rocky composition similar to Earth’s, but higher mass. It receives about the same amount of heat as Earth receives from the Sun.
And that is what makes this planet so exciting: It lies in the “habitable” zone and just might have properties similar to Earth’s, like a surface, liquid water, and — who knows? — maybe even an atmosphere bearing the telltale chemical signs of life.
NASA’s TESS mission launched in April 2018 to hunt for other broadly Earth-sized planets, but with a different method. TESS is looking for rare dimming events that happen when planets pass in front of their host stars, blocking some starlight. These transit events indicate not only the presence of the planets, but also their sizes and orbits.
Finding a new transiting exoplanet is a big deal for astronomers like us because, unlike those found through stellar wobbles, worlds seen transiting can be studied further to determine their densities and atmospheric compositions.
Red dwarf suns
For us, the most exciting exoplanets are the smallest ones, which TESS can detect when they orbit small stars called red dwarfs – stars with masses less than half the mass of our Sun.
Each of these systems is unique. For example, LP 791-18 is a red dwarf star 86 light-years from Earth around which TESS found two worlds. The first is a “super-Earth,” a planet larger than Earth but probably still mostly rocky, and the second is a “mini-Neptune,” a planet smaller than Neptune but gas- and ice-rich. Neither of these planets have counterparts in our solar system.
Among astronomers’ current favorites of the new broadly Earth-sized planets is LHS 3884b, a scorching “hot Earth” that orbits its sun so quickly that on it you could celebrate your birthday every 11 hours.
No Earth-like worlds yet
But how Earth-like are Earth-sized planets? The promise of finding nearby worlds for detailed studies is already paying off. A team of astronomers observed the hot super-Earth LHS 3884b with the Hubble Space Telescope and found the planet to be a horrible vacation spot, without even an atmosphere. It is just a bare rock with temperatures ranging from over 700 C (1300 Fahrenheit) at noon to near absolute zero (-460 Fahrenheit) at midnight.
The TESS mission was initially funded for two years. But the spacecraft is in excellent shape and NASA recently extended the mission through 2022, doubling the time TESS will have to scan nearby, bright stars for transits.
However, finding exoplanets around the coolest stars — those with temperatures less than about 2700 C (4900 F) — will still be a challenge due to their extreme faintness. Since ultracool dwarfs provide our best opportunity to find and study exoplanets with sizes and temperatures similar to Earth’s, other focused planet searches are picking up where TESS leaves off.
The worlds TESS can’t find
In May 2016, a Belgian-led group announced the discovery of a planetary system around the ultracool dwarf they christened TRAPPIST-1. The discovery of the seven transiting Earth-sized exoplanets in the TRAPPIST-1 system was groundbreaking.
It also demonstrated how small telescopes — relative to the powerful behemoths of our age — can still make transformational discoveries. With patience and persistence, the TRAPPIST telescope scanned nearby faint, red dwarf stars from its high-mountain perch in the Atacama desert for small, telltale dips in their brightnesses. Eventually, it spotted transits in the data for the red dwarf TRAPPIST-1, which — although just 41 light-years away — is too faint for TESS’s four 10-cm (4-inch) diameter lenses. Its Earth-sized worlds would have remained undiscovered had the TRAPPIST team’s larger telescope not found them.
Two projects have upped up the game in the search for exo-Earth candidates around nearby red dwarfs. The SPECULOOS team installed four robotic telescopes – also in the Atacama desert – and one in the Northern Hemisphere. Our Exoearth Discovery and Exploration Network – Project EDEN – uses nine telescopes in Arizona, Italy, Spain and Taiwan to observe red dwarf stars continuously.
The SPECULOOS and EDEN telescopes are much larger than TESS’s small lenses and can find planets around stars too faint for TESS to study, including some of the transiting Earth-sized planets closest to us.
The decade of new worlds
The next decade is likely to be remembered as the time when we opened our eyes to the incredible diversity of other worlds. TESS is likely to find between 10,000 and 15,000 exoplanet candidates by 2025. By 2030, the European Space Agency’s GAIA and PLATO missions are expected to find another 20,000-35,000 planets. GAIA will look for stellar wobbles introduced by planets, while PLATO will search for planetary transits as TESS does.
However, even among the thousands of planets that will soon be found, the exoplanets closest to our solar system will remain special. Many of these worlds can be studied in great detail – including the search for signs of life. Discoveries of the nearest worlds also represent major steps in humanity’s progress in exploring the universe we live in. After mapping our own planet and then the solar system, we now turn to nearby planetary systems. Perhaps one day Proxima b or another nearby world astronomers have yet to find will be the target for interstellar probes, like Project Starshot, or even crewed starships. But first we’ve got to put these worlds on the map.
‘A protocluster is a rare and special system’: Scientists discover oldest galaxy cluster
September 27, 2019
By Agence France-Presse - raw story
Astronomers have discovered a 13-billion-year-old galaxy cluster that is the earliest ever observed, according to a paper released Friday, a finding that may hold clues about how the universe developed.
Such an early-stage cluster — called a protocluster — is “not easy to find”, Yuichi Harikane, a researcher at the National Astronomical Observatory of Japan who led the international team, said in a press release.
“A protocluster is a rare and special system with an extremely high density,” Harikane said, adding that the researchers used the wide viewing field of the Subaru telescope in Hawaii to “map a large area of the sky” in their search.
The discovery of the protocluster, a collection of 12 galaxies, suggests that large cosmic structures were present in the very early stages of the universe, which scientists believe was born 13.8 billion years ago.
One of the 12 galaxies is known as Himiko, a giant gas cloud found in 2009 by using the same telescope.
“It is reasonable to find a protocluster near a massive object, such as Himiko. However, we’re surprised to see that Himiko was located… on the edge 500 million light-years away from the center,” the paper’s co-author Masami Ouchi said.
“It is still not understood why Himiko is not located in the center,” he said.
“These results will be key for understanding the relationship between clusters and massive galaxies.”
The team included scientists from Imperial College London and the study is published in Friday’s Astrophysical Journal.
Such an early-stage cluster — called a protocluster — is “not easy to find”, Yuichi Harikane, a researcher at the National Astronomical Observatory of Japan who led the international team, said in a press release.
“A protocluster is a rare and special system with an extremely high density,” Harikane said, adding that the researchers used the wide viewing field of the Subaru telescope in Hawaii to “map a large area of the sky” in their search.
The discovery of the protocluster, a collection of 12 galaxies, suggests that large cosmic structures were present in the very early stages of the universe, which scientists believe was born 13.8 billion years ago.
One of the 12 galaxies is known as Himiko, a giant gas cloud found in 2009 by using the same telescope.
“It is reasonable to find a protocluster near a massive object, such as Himiko. However, we’re surprised to see that Himiko was located… on the edge 500 million light-years away from the center,” the paper’s co-author Masami Ouchi said.
“It is still not understood why Himiko is not located in the center,” he said.
“These results will be key for understanding the relationship between clusters and massive galaxies.”
The team included scientists from Imperial College London and the study is published in Friday’s Astrophysical Journal.
The Milky Way Has Giant Bubbles at Its Center
Astronomers have found radio-emitting structures jutting out from our galaxy’s black hole.
MARINA KOREN - the atlantic
8:00 AM ET
Farhad Yusef-Zadeh was observing the center of the Milky Way galaxy in radio waves, looking for the presence of faint stars, when he saw it: a spindly structure giving off its own radio emissions. The filament-like feature was probably a glitch in the telescope, or something clouding the field of view, he decided. It shouldn’t be here, he thought, and stripped it out of his data.
But the mystery filament kept showing up, and soon Yusef-Zadeh found others. What the astronomer had mistaken for an imperfection turned out to be an entire population of cosmic structures at the heart of the galaxy.
More than 100 filaments have been detected since Yusef-Zadeh’s first encounter in the early 1980s. Astronomers can’t completely explain them, but they have given them familiar labels, naming them after the earthly things they resemble: the pelican, the mouse, the snake. The menagerie of filaments is clustered around the supermassive black hole at the center of our galaxy. “They haven’t been found elsewhere,” says Yusef-Zadeh, a physics and astronomy professor at Northwestern University.
Their origins remained a mystery, too, until now.
New observations of the galactic center have revealed a pair of giant bubbles at the center of the Milky Way that give off radio emissions, according to recent research published in Nature. The bubbles stretch outward from the black hole and extend into space in opposite directions. The billowy lobes resemble the two halves of an hourglass, with the black hole nestled at its waist. And the filaments that Yusef-Zadeh discovered all those years ago are encased within.
These bubbles are big. Top to bottom, the cosmic hourglass measures 1,400 light-years, a distance that, if converted into miles, comprises of a dizzying number of zeros; one light-year—the distance that light covers in an Earth year—is about 6 trillion miles. The black hole, by comparison, is a pinprick of light.
The discovery suggests that the sinuous filaments arose as part of a larger structure. “We’ve long thought that this was the case, but we haven’t been able to image the proof,” says Cornelia Lang, an astronomer at the University of Iowa who studies these filaments, and who was not involved in the bubble research.
The new observations come from the MeerKAT telescope in South Africa, an array of dozens of dishes that work together to generate a large field of view. The facility, which began operations last year, is located in one of the best places on the planet to study the heart of the Milky Way; the galactic center passes right overhead and remains observable for hours.
But it’s not a straight shot. Our solar system resides near one of the Milky Way’s shimmery spirals, and there’s about 25,000 light-years of gas, dust, and other cosmic matter sitting between us and the galactic center. To observe that faraway place, astronomers must observe in forms of electromagnetic radiation other than visible light, like radio. “We have to piece together a picture of the center of the galaxy using wavelengths that are not the kind that our eye sees,” Lang says.
The astronomers behind the bubble discovery looked for a specific kind of radio emission generated in turbulent regions of space, where electrons move at close to the speed of light and bounce around magnetic fields. As the charged particles zoom, they give off radio waves that can illuminate cosmic structures in the vicinity. By capturing this radiation, astronomers have illuminated the contours of the bulbs and the structures they contain.
The bubbles look like a carefully spun, delicate work of interstellar art. But they are the aftermath of a violent, cosmic cataclysm that unfolded millions of years ago.
“Something happened, in a very short period of time, a few million years ago at the center of the galaxy,” says Fernando Camilo, the chief scientist at the South African Radio Astronomy Observatory and one of the members of the international team responsible for the discovery.
Camilo and other astronomers are considering a couple of explanations. A flurry of dying stars at the center of the galaxy might have infused the medium with enormous amounts of energy as they exploded. Or it could be that the black hole experienced a flare-up, as black holes around the universe have been known to do. Sometimes, black holes consume nearby stellar material so quickly that they end up regurgitating some of it. The result is two luminous jets of radiation that can outshine entire galaxies. Our supermassive black hole is in a quiet chapter of its life, but astronomers suspect that it has previously experienced this active phase.
Whatever happened, it was powerful enough to create a burst of energy that, as the researchers put it, literally punched through the interstellar medium. “As it punches through the medium, it’s sweeping the material of the medium with it,” says Yusef-Zadeh, one of the members of the team. “Eventually, it reaches a point where it stalls.”
The ancient explosion inflated the bubbles and, as they expanded, excited the electrons that, together with nearby magnetic fields, produce radio emissions we can detect all the way from here. “This is the most exquisite radio map of the galactic center that has ever been published,” says Grant Tremblay, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, who was not involved in the work.
The heart of the galaxy is home to other bubbles, recorded in other wavelengths. The Fermi bubbles, named for the 20th-century scientist who studied high-energy physics, are even larger, stretching about 25,000 light-years above and below the galactic center. Astronomers discovered them nearly a decade ago with a space telescope designed to detect gamma rays. And they’re still trying to understand them. Camilo speculates that perhaps the Fermi bubbles might be the dumping grounds of eons of many cosmic explosions—a larger, older version of the radio-emitting bubbles his team found.
There may be more bubbles, more pelican-shaped mysteries, lurking in this panoramic view of the center of the galaxy. As telescopes collect more data—if new, more advanced facilities come online—the portrait will become sharper. And astronomers should be prepared to find something so strange that they’re tempted to chuck them out of the data. “I remember vividly that I spent quite a bit of time to get rid of things that I would not have really done if I knew these structures existed,” Yusef-Zadeh says. “It was just so weird.”
But the mystery filament kept showing up, and soon Yusef-Zadeh found others. What the astronomer had mistaken for an imperfection turned out to be an entire population of cosmic structures at the heart of the galaxy.
More than 100 filaments have been detected since Yusef-Zadeh’s first encounter in the early 1980s. Astronomers can’t completely explain them, but they have given them familiar labels, naming them after the earthly things they resemble: the pelican, the mouse, the snake. The menagerie of filaments is clustered around the supermassive black hole at the center of our galaxy. “They haven’t been found elsewhere,” says Yusef-Zadeh, a physics and astronomy professor at Northwestern University.
Their origins remained a mystery, too, until now.
New observations of the galactic center have revealed a pair of giant bubbles at the center of the Milky Way that give off radio emissions, according to recent research published in Nature. The bubbles stretch outward from the black hole and extend into space in opposite directions. The billowy lobes resemble the two halves of an hourglass, with the black hole nestled at its waist. And the filaments that Yusef-Zadeh discovered all those years ago are encased within.
These bubbles are big. Top to bottom, the cosmic hourglass measures 1,400 light-years, a distance that, if converted into miles, comprises of a dizzying number of zeros; one light-year—the distance that light covers in an Earth year—is about 6 trillion miles. The black hole, by comparison, is a pinprick of light.
The discovery suggests that the sinuous filaments arose as part of a larger structure. “We’ve long thought that this was the case, but we haven’t been able to image the proof,” says Cornelia Lang, an astronomer at the University of Iowa who studies these filaments, and who was not involved in the bubble research.
The new observations come from the MeerKAT telescope in South Africa, an array of dozens of dishes that work together to generate a large field of view. The facility, which began operations last year, is located in one of the best places on the planet to study the heart of the Milky Way; the galactic center passes right overhead and remains observable for hours.
But it’s not a straight shot. Our solar system resides near one of the Milky Way’s shimmery spirals, and there’s about 25,000 light-years of gas, dust, and other cosmic matter sitting between us and the galactic center. To observe that faraway place, astronomers must observe in forms of electromagnetic radiation other than visible light, like radio. “We have to piece together a picture of the center of the galaxy using wavelengths that are not the kind that our eye sees,” Lang says.
The astronomers behind the bubble discovery looked for a specific kind of radio emission generated in turbulent regions of space, where electrons move at close to the speed of light and bounce around magnetic fields. As the charged particles zoom, they give off radio waves that can illuminate cosmic structures in the vicinity. By capturing this radiation, astronomers have illuminated the contours of the bulbs and the structures they contain.
The bubbles look like a carefully spun, delicate work of interstellar art. But they are the aftermath of a violent, cosmic cataclysm that unfolded millions of years ago.
“Something happened, in a very short period of time, a few million years ago at the center of the galaxy,” says Fernando Camilo, the chief scientist at the South African Radio Astronomy Observatory and one of the members of the international team responsible for the discovery.
Camilo and other astronomers are considering a couple of explanations. A flurry of dying stars at the center of the galaxy might have infused the medium with enormous amounts of energy as they exploded. Or it could be that the black hole experienced a flare-up, as black holes around the universe have been known to do. Sometimes, black holes consume nearby stellar material so quickly that they end up regurgitating some of it. The result is two luminous jets of radiation that can outshine entire galaxies. Our supermassive black hole is in a quiet chapter of its life, but astronomers suspect that it has previously experienced this active phase.
Whatever happened, it was powerful enough to create a burst of energy that, as the researchers put it, literally punched through the interstellar medium. “As it punches through the medium, it’s sweeping the material of the medium with it,” says Yusef-Zadeh, one of the members of the team. “Eventually, it reaches a point where it stalls.”
The ancient explosion inflated the bubbles and, as they expanded, excited the electrons that, together with nearby magnetic fields, produce radio emissions we can detect all the way from here. “This is the most exquisite radio map of the galactic center that has ever been published,” says Grant Tremblay, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, who was not involved in the work.
The heart of the galaxy is home to other bubbles, recorded in other wavelengths. The Fermi bubbles, named for the 20th-century scientist who studied high-energy physics, are even larger, stretching about 25,000 light-years above and below the galactic center. Astronomers discovered them nearly a decade ago with a space telescope designed to detect gamma rays. And they’re still trying to understand them. Camilo speculates that perhaps the Fermi bubbles might be the dumping grounds of eons of many cosmic explosions—a larger, older version of the radio-emitting bubbles his team found.
There may be more bubbles, more pelican-shaped mysteries, lurking in this panoramic view of the center of the galaxy. As telescopes collect more data—if new, more advanced facilities come online—the portrait will become sharper. And astronomers should be prepared to find something so strange that they’re tempted to chuck them out of the data. “I remember vividly that I spent quite a bit of time to get rid of things that I would not have really done if I knew these structures existed,” Yusef-Zadeh says. “It was just so weird.”
Water discovered for first time in atmosphere of habitable exoplanet
September 11, 2019
By Agence France-Presse - raw story
Water has been discovered for the first time in the atmosphere of an exoplanet with Earth-like temperatures that could support life as we know it, scientists revealed Wednesday.
Eight times the mass of Earth and twice as big, K2-18b orbits in its star’s “habitable zone” at a distance — neither too far nor too close — where water can exist in liquid form, they reported in the journal Nature Astronomy.
“This planet is the best candidate we have outside our solar system” in the search for signs of life, co-author Giovanna Tinetti, an astronomer at University College London, told AFP.
“We cannot assume that it has oceans on the surface but it is a real possibility.”
Of the more than 4,000 exoplanets detected to date, this is the first known to combine a rocky surface and an atmosphere with water.
Most exoplanets with atmospheres are giant balls of gas, and the handful of rocky planets for which data is available seem to have no atmosphere at all.
Even if they did, most Earth-like planets are too far from their stars to have liquid water or so close that any H2O has evaporated.
Discovered in 2015, K2-18b is one of hundreds of so-called “super-Earths” — planets with less than ten times the mass of ours — spotted by NASA’s Kepler spacecraft.
Future space missions are expected to detect hundreds more in the coming decades.
– ‘Is Earth unique?’ –
“Finding water in a potentially habitable world other than Earth is incredibly exciting,” said lead-author Angelos Tsiaras, also from UCL.
“K2-18b is not ‘Earth 2.0’,” he said. “However, it brings us closer to answering the fundamental question: is the Earth unique?”
Working with spectroscopic data captured in 2016 and 2017 by the Hubble Space Telescope, Tsiaras and his team used open-source algorithms to analyse the starlight filtered through K2-18b’s atmosphere.
They found the unmistakable signature of water vapour. Exactly how much remains uncertain, but computer modelling suggested concentrations between 0.1 and 50 percent.
By comparison, the percentage of water vapour in Earth’s atmosphere varies between 0.2 percent above the poles, and up to four percent in the tropics.
There was also evidence of hydrogen and helium as well. Nitrogen and methane may also be present but with current technology remain undetectable, the study said.
Further research will be able to determine the extent of cloud coverage and the percentage of water in the atmosphere.
– First of many –
Water is crucial in the search for life, in part because it carries oxygen.
“Life as we know is based on water,” said Tinetti.
K2-18b orbits a red dwarf star about 110 light years distant — a million billion kilometres — in the Leo constellation of the Milky Way, and is probably bombarded by more destructive radiation than Earth.
“It is likely that this is the first of many discoveries of potentially habitable planets,” said UCL astronomer Ingo Waldmann, also a co-author.
“This is not only because super-Earths like K2-18b are the most common planets in our galaxy, but also because red dwarfs — stars smaller than our Sun — are the most common stars.”
The new generation of space-based star gazing instruments led by the James Webb Space Telescope and the European Space Agency’s ARIEL mission will be able to describe exoplanet atmospheres in far greater detail.
ARIEL, slated for a 2028 launch, will canvas some 1,000 planets, a large enough sampling to look for patterns and identify outliers.
“Over 4,000 exoplanets have been detected but we don’t know much about their composition and nature,” said Tinetti. “By observing a large sample of planets, we hope to reveal secrets about their chemistry, formation and evolution.”
Eight times the mass of Earth and twice as big, K2-18b orbits in its star’s “habitable zone” at a distance — neither too far nor too close — where water can exist in liquid form, they reported in the journal Nature Astronomy.
“This planet is the best candidate we have outside our solar system” in the search for signs of life, co-author Giovanna Tinetti, an astronomer at University College London, told AFP.
“We cannot assume that it has oceans on the surface but it is a real possibility.”
Of the more than 4,000 exoplanets detected to date, this is the first known to combine a rocky surface and an atmosphere with water.
Most exoplanets with atmospheres are giant balls of gas, and the handful of rocky planets for which data is available seem to have no atmosphere at all.
Even if they did, most Earth-like planets are too far from their stars to have liquid water or so close that any H2O has evaporated.
Discovered in 2015, K2-18b is one of hundreds of so-called “super-Earths” — planets with less than ten times the mass of ours — spotted by NASA’s Kepler spacecraft.
Future space missions are expected to detect hundreds more in the coming decades.
– ‘Is Earth unique?’ –
“Finding water in a potentially habitable world other than Earth is incredibly exciting,” said lead-author Angelos Tsiaras, also from UCL.
“K2-18b is not ‘Earth 2.0’,” he said. “However, it brings us closer to answering the fundamental question: is the Earth unique?”
Working with spectroscopic data captured in 2016 and 2017 by the Hubble Space Telescope, Tsiaras and his team used open-source algorithms to analyse the starlight filtered through K2-18b’s atmosphere.
They found the unmistakable signature of water vapour. Exactly how much remains uncertain, but computer modelling suggested concentrations between 0.1 and 50 percent.
By comparison, the percentage of water vapour in Earth’s atmosphere varies between 0.2 percent above the poles, and up to four percent in the tropics.
There was also evidence of hydrogen and helium as well. Nitrogen and methane may also be present but with current technology remain undetectable, the study said.
Further research will be able to determine the extent of cloud coverage and the percentage of water in the atmosphere.
– First of many –
Water is crucial in the search for life, in part because it carries oxygen.
“Life as we know is based on water,” said Tinetti.
K2-18b orbits a red dwarf star about 110 light years distant — a million billion kilometres — in the Leo constellation of the Milky Way, and is probably bombarded by more destructive radiation than Earth.
“It is likely that this is the first of many discoveries of potentially habitable planets,” said UCL astronomer Ingo Waldmann, also a co-author.
“This is not only because super-Earths like K2-18b are the most common planets in our galaxy, but also because red dwarfs — stars smaller than our Sun — are the most common stars.”
The new generation of space-based star gazing instruments led by the James Webb Space Telescope and the European Space Agency’s ARIEL mission will be able to describe exoplanet atmospheres in far greater detail.
ARIEL, slated for a 2028 launch, will canvas some 1,000 planets, a large enough sampling to look for patterns and identify outliers.
“Over 4,000 exoplanets have been detected but we don’t know much about their composition and nature,” said Tinetti. “By observing a large sample of planets, we hope to reveal secrets about their chemistry, formation and evolution.”
space facts
Light from a distant quasar passes through intervening gas clouds in galaxies and in intergalactic space. These clouds of primeval hydrogen subtract specific colors from the beam. The resulting ‘absorption spectrum’ can help determine the distances and chemical composition of the invisible clouds. NASA/STScI
New Horizons is past Pluto, but it is not forgotten, and not done beaming back fascinating science. In January 2019 it will blaze past and image an example of the mysterious Trans-Neptunian Objects (TNO) that litter the outer edge of the solar system by the millions. It is these objects which have suggested the presence of an unseen Planet Nine.
The Universe has two trillion more galaxies than astronomers thought
Hubble telescope images from deep space were collected over 20 years to solve the puzzle the cosmos harbors
From The Guardian: There are a dizzying two trillion galaxies in the Universe, up to 20 times more than previously thought, astronomers reported on Thursday.
The surprising find, based on 3D modeling of images collected over 20 years by the Hubble Space Telescope, was published in the Astronomical Journal.
Scientists have puzzled over how many galaxies the cosmos harbors at least since US astronomer Edwin Hubble showed in 1924 that Andromeda, a neighboring galaxy, was not part of our own Milky Way.
But even in the era of modern astronomy, getting an accurate tally has proven difficult.
To begin with, there is only part of the cosmos where light given off by distant objects has had time to reach Earth.
The rest is effectively beyond our reach.
And even within this “observable Universe”, current technology only allows us to glimpse 10% of what is out there, according to the new findings.
“It boggles the mind that over 90% of the galaxies in the Universe have yet to be studied,” commented Christopher Conselice of the University of Nottingham, who led the study.
“Who knows what interesting properties we will find when we observe these galaxies with the next generation of telescopes,” he said in a statement.
Using deep space images from Hubble, Conselice and his team painstakingly converted them into 3D to measure the number of galaxies at different times in the history of the Universe.
The analysis reached back more than 13bn years – very near the time of the “Big Bang” thought to have given birth to the Universe.
A galaxy is a system of millions or billions or stars, held together by gravity, with planetary systems within them.
Using new mathematical models, the astronomers were able to infer the number of “invisible” galaxies beyond the reach of telescopes, leading to the surprising realization that the vast majority are too faint and far away to be seen.
When the Universe was only a few billion years old, there were ten times as many galaxies in a given volume of space than there are today, the findings suggest.
This in turn suggests that “significant evolution must have occurred to reduce their number through extensive merging of systems”.
The surprising find, based on 3D modeling of images collected over 20 years by the Hubble Space Telescope, was published in the Astronomical Journal.
Scientists have puzzled over how many galaxies the cosmos harbors at least since US astronomer Edwin Hubble showed in 1924 that Andromeda, a neighboring galaxy, was not part of our own Milky Way.
But even in the era of modern astronomy, getting an accurate tally has proven difficult.
To begin with, there is only part of the cosmos where light given off by distant objects has had time to reach Earth.
The rest is effectively beyond our reach.
And even within this “observable Universe”, current technology only allows us to glimpse 10% of what is out there, according to the new findings.
“It boggles the mind that over 90% of the galaxies in the Universe have yet to be studied,” commented Christopher Conselice of the University of Nottingham, who led the study.
“Who knows what interesting properties we will find when we observe these galaxies with the next generation of telescopes,” he said in a statement.
Using deep space images from Hubble, Conselice and his team painstakingly converted them into 3D to measure the number of galaxies at different times in the history of the Universe.
The analysis reached back more than 13bn years – very near the time of the “Big Bang” thought to have given birth to the Universe.
A galaxy is a system of millions or billions or stars, held together by gravity, with planetary systems within them.
Using new mathematical models, the astronomers were able to infer the number of “invisible” galaxies beyond the reach of telescopes, leading to the surprising realization that the vast majority are too faint and far away to be seen.
When the Universe was only a few billion years old, there were ten times as many galaxies in a given volume of space than there are today, the findings suggest.
This in turn suggests that “significant evolution must have occurred to reduce their number through extensive merging of systems”.
Kepler Finds 1,284 New Exoplanets
From NY Times: Planets keep falling out of the sky for Kepler.
Astronomers operating NASA’s planet-finding spacecraft announced on Tuesday that they had validated the planethood of 1,284 new candidates from Kepler’s voluminous catalog of potential exoplanets, bringing the total of planets Kepler has discovered to more than 2,000.
All of them orbit stars in a patch of sky on the Cygnus-Lyra border, where Kepler, launched in 2009, spent four years staring at 150,00 stars looking for the characteristic dimming when planets crossed their faces. About two dozen of the planets found so far occupy the so-called Goldilocks zones of their stars where liquid surface water and perhaps “Life as We Think We Know It” could exist.
Extrapolating these results to the entire galaxy, Natalie Batalha, a Kepler mission scientist from Ames Research Center, said there could be 10 billion roughly Earth-size stars in the galaxy within their stars’ habitable zones. The nearest habitable planet, she estimated, could be as close as 11 light-years.
The Kepler team, she said, is now approaching in the next year or two the closeout of their mission to determine the frequency of Earth-size planets in the universe. They will be passing the baton to future missions like NASA’s TESS, which will search for planets around nearby bright stars, starting in 2017.
Astronomers operating NASA’s planet-finding spacecraft announced on Tuesday that they had validated the planethood of 1,284 new candidates from Kepler’s voluminous catalog of potential exoplanets, bringing the total of planets Kepler has discovered to more than 2,000.
All of them orbit stars in a patch of sky on the Cygnus-Lyra border, where Kepler, launched in 2009, spent four years staring at 150,00 stars looking for the characteristic dimming when planets crossed their faces. About two dozen of the planets found so far occupy the so-called Goldilocks zones of their stars where liquid surface water and perhaps “Life as We Think We Know It” could exist.
Extrapolating these results to the entire galaxy, Natalie Batalha, a Kepler mission scientist from Ames Research Center, said there could be 10 billion roughly Earth-size stars in the galaxy within their stars’ habitable zones. The nearest habitable planet, she estimated, could be as close as 11 light-years.
The Kepler team, she said, is now approaching in the next year or two the closeout of their mission to determine the frequency of Earth-size planets in the universe. They will be passing the baton to future missions like NASA’s TESS, which will search for planets around nearby bright stars, starting in 2017.
Astronomers discover distant dwarf planet beyond Neptune
Currently designated 2015 RR245, the giant ball of ice and rock lies nine billion kilometres away in the the most distant reaches of the solar system
From The Guardian: A dwarf planet half the size of Britain has been found tumbling through space in the most distant reaches of the solar system.
The giant ball of rock and ice lies nine billion kilometres away on an orbit that swings far beyond the realm of Neptune, the most remote of the fully-fledged planets in our cosmic vicinity.
Astronomers first noticed the new world when it appeared as a bright spot moving slowly across a sequence of images taken in September 2015 by a telescope on Mauna Kea in Hawaii for the Outer Solar System Origins Survey (OSSOS).
“It was really remarkable to see how bright this object was,” said Michele Bannister, an astronomer on the team at the University of Victoria, Canada. “It’s far brighter than the objects we normally find.”
In a formal note released on Monday, the International Astronomical Union (IAU) designated the dwarf planet 2015 RR245. The name will be replaced when astronomers come up with a better one.
While discussions have begun about possible names for the object, Bannister said it was too early to share them. The scientists can propose a name only when the dwarf planet’s orbit has been observed for several years and its trajectory more clearly defined. The name will then be voted on by an IAU committee. “As long as the proposal is reasonable and a bit mythological, it’s generally fine,” Bannister said.
In an act of linguistic gymnastics, the IAU created the term “dwarf planet” in 2006 to describe heavenly bodies that it decided were not proper planets. Pluto became the first dwarf planet that year, when IAU members voted to demote it from full planetary status. A dwarf planet must circle the sun and be large enough to be rendered spherical by its own gravity.
The giant ball of rock and ice lies nine billion kilometres away on an orbit that swings far beyond the realm of Neptune, the most remote of the fully-fledged planets in our cosmic vicinity.
Astronomers first noticed the new world when it appeared as a bright spot moving slowly across a sequence of images taken in September 2015 by a telescope on Mauna Kea in Hawaii for the Outer Solar System Origins Survey (OSSOS).
“It was really remarkable to see how bright this object was,” said Michele Bannister, an astronomer on the team at the University of Victoria, Canada. “It’s far brighter than the objects we normally find.”
In a formal note released on Monday, the International Astronomical Union (IAU) designated the dwarf planet 2015 RR245. The name will be replaced when astronomers come up with a better one.
While discussions have begun about possible names for the object, Bannister said it was too early to share them. The scientists can propose a name only when the dwarf planet’s orbit has been observed for several years and its trajectory more clearly defined. The name will then be voted on by an IAU committee. “As long as the proposal is reasonable and a bit mythological, it’s generally fine,” Bannister said.
In an act of linguistic gymnastics, the IAU created the term “dwarf planet” in 2006 to describe heavenly bodies that it decided were not proper planets. Pluto became the first dwarf planet that year, when IAU members voted to demote it from full planetary status. A dwarf planet must circle the sun and be large enough to be rendered spherical by its own gravity.