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Does Pluto Have Buried Oceans

December 7, 2017 by  
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Our solar system may harbor many more potentially habitable worlds than scientists had thought.

Subsurface oceans could still slosh beneath the icy crusts of frigid, faraway worlds such as the dwarf planets Pluto and Eris, kept liquid by the heat-generating tug of orbiting moons, according to a new study. 

“These objects need to be considered as potential reservoirs of water and life,” lead author Prabal Saxena, of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. “If our study is correct, we now may have more places in our solar system that possess some of the critical elements for extraterrestrial life.”  

Underground oceans are known, or strongly suspected, to exist on a number of icy worlds, including the Saturn satellites Titan and Enceladus and the Jovian moons Europa, Callisto and Ganymede. These oceans are kept liquid to this day by “tidal heating”: The powerful gravitational pull of these worlds’ giant parent planets stretches and flexes their interiors, generating heat via friction.

The new study suggests something similar may be going on with Pluto, Eris and other trans-Neptunian objects (TNOs).

Many of the moons around TNOs are thought to have coalesced from material blasted into space when objects slammed into their parent bodies long ago. That’s the perceived origin story for the one known satellite of Eris (called Dysnomia) and for Pluto’s five moons (as well as for Earth’s moon). 

Such impact-generated moons generally begin their lives in relatively chaotic orbits, team members of the new study said. But over time, these moons migrate to more-stable orbits, and as this happens, the satellites and the TNOs tug on each other gravitationally, producing tidal heat.

Saxena and his colleagues modeled the extent to which this heating could warm up the interiors of TNOs — and the researchers got some intriguing results.

“We found that tidal heating can be a tipping point that may have preserved oceans of liquid water beneath the surface of large TNOs like Pluto and Eris to the present day,” study co-author Wade Henning, of NASA Goddard and the University of Maryland, said in the same statement.

As the term “tipping point” implies, there’s another factor in play here as well. It’s been widely recognized that TNOs could harbor buried oceans thanks to the heat produced by the decay of the objects’ radioactive elements. But just how long such oceans could persist has been unclear. This type of heating peters out eventually, as more and more radioactive material decays into stable elements. And the smaller the object, the faster it cools down.

Tidal heating may do more than just lengthen subsurface oceans’ lives, researchers said.Next Up

“Crucially, our study also suggests that tidal heating could make deeply buried oceans more accessible to future observations by moving them closer to the surface,” said study co-author Joe Renaud, of George Mason University in Virginia. “If you have a liquid-water layer, the additional heat from tidal heating would cause the next adjacent layer of ice to melt.” 

The new study was published online last week in the journal Icarus


A Planets Equator May Inhibit Astronomers From Finding Life

December 5, 2017 by  
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Spotting signs of life in an alien planet’s atmosphere may be tougher than scientists had thought.

One prominent such “biosignature” target, ozone, may get trapped near the equators of Proxima b, TRAPPIST-1d and other potentially habitable worlds that orbit close to their host stars, making the gas hard to detect from afar, a new study suggests.

“Absence of traces of ozone in future observations does not have to mean there is no oxygen at all,” study lead author Ludmila Carone, of the Max Planck Institute for Astronomy in Heidelberg, Germany, said in a statement. “It might be found in different places than on Earth, or it might be very well hidden.”

Ozone is an unstable molecule that consists of three oxygen atoms. Here on Earth, the stuff is generally produced in the atmosphere after ultraviolet (UV) radiation from the sun splits “normal” diatomic oxygen (O2). 

The vast majority of Earth’s O2 is generated by living organisms — plants and photosynthetic microbes — so ozone serves as a sort of secondary biomarker, at least for Earth-like life.

Earth’s atmospheric flows distribute most ozone relatively evenly into our planet’s famous ozone layer, which helps shield life from harmful UV radiation. So hypothetical aliens studying Earth from afar with powerful telescopes would have a good chance of detecting the gas.

But the situation is likely different on Proxima b, TRAPPIST-1d and other tidally locked worlds — those that always show the same face to their parent stars, and therefore have a “dayside” and a “nightside” — according to Carone and her colleagues. (Tidal locking is a consequence of a very tight orbit; TRAPPIST-1d and Proxima b complete one lap around their stars every four Earth days and 11 Earth days, respectively.)

Modeling work performed by the researchers indicates that, on planets with orbital periods of 25 Earth days or less, airflows tend to concentrate ozone (and other photochemically produced molecules) in an equatorial band.

“We all knew from the beginning that the hunt for alien life will be a challenge,” Carone said. “As it turns out, we are only just scratching the surface of how difficult it really will be.”

The new results also suggest that worlds like Proxima b don’t have a global ozone layer. That may or may not have a significant negative effect on their habitability, Carone said.

“Proxima b and TRAPPIST-1d orbit red dwarfs, reddish stars that emit very little harmful UV light to begin with,” she said in the statement. (Tidally locked planets pretty much have to orbit dim dwarf stars to be habitable; worlds that orbit so close to sunlike stars are far too hot to host life as we know it.) 

“On the other hand, these stars can be very temperamental, and prone to violent outbursts of harmful radiation, including UV,” she added. “There is still a lot that we don’t know about these red dwarf stars. But I’m confident we will know much more in five years.”

In five years, astronomers will have a lot more data — from telescopes such as NASA’s $8.8 billion James Webb Space Telescope, which is scheduled to launch in early 2019 — to inform their inferences about the habitability of red-dwarf planets. And advances in modeling techniques over this time span should help as well, study team members said.

The new study will appear in the Feb. 1, 2018, issue of the journal Monthly Notices of the Royal Astronomical Society.


Does Space Dust Transport Life Around The Galaxy

November 29, 2017 by  
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It may not take an asteroid strike to transport life from one planet to another.

Fast-moving dust could theoretically knock microbes floating high up in a world’s atmosphere out into space, potentially sending the bugs on a trip to another planet — perhaps even one orbiting a different star, according to a new study.

“The proposition that space-dust collisions could propel organisms over enormous distances between planets raises some exciting prospects of how life and the atmospheres of planets originated,” study author Arjun Berera, a professor in the School of Physics and Astronomy at the University of Edinburgh in Scotland, said in a statement.  

“The streaming of fast space dust is found throughout planetary systems and could be a common factor in proliferating life,” Berera added.

Berera isn’t the first person to propose that organisms could hop from world to world throughout the cosmos. That basic idea, known as panspermia, has been around for thousands of years. It has received renewed interest recently, however, as scientists have demonstrated that some organisms — such as certain bacteria, and micro-animals known as tardigrades — can survive for extended periods in space.

But researchers have generally regarded comet or asteroid impacts as the only viable way to get simple life-forms off a planet and into space, whence they could perhaps blunder their way to a different habitable world. (We won’t consider here the “directed panspermia” idea, which posits that intelligent aliens have seeded the galaxy with life or its building blocks.)

Comet or asteroid impacts do indeed blast rocks from planet to planet. Scientists have found numerous meteorites here on Earth that were once part of Mars — including one known as ALH84001, which some scientists think may preserve signs of ancient Red Planet life.

In the new study, Berera examined what likely happens when bits of interplanetary dust hit molecules and particles in Earth’s atmosphere. This space stuff rains down on us every day, hitting the planet at speeds of between 22,400 mph and 157,000 mph (36,000 to 253,000 km/h).

He calculated that small particles floating at least 93 miles (150 kilometers) above Earth’s surface could theoretically get knocked into space by this wandering dust. It’s unclear if microbes could survive such violent collisions; that’s an area ripe for future research, Berera wrote in the new paper, which has been accepted for publication in the journal Astrobiology. (You can read the study for free at the online preprint site

And even if these micro-impacts are invariably fatal, they could still help life get a foothold on other worlds by sending its building blocks — the complex molecules that make up a microbe corpse, for example — out into space, he added.


Scientist Send Message To Alien Planet To Contact E.T.

November 24, 2017 by  
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If there are any intelligent aliens in the GJ 273 system, they can expect to hear from us about a dozen years from now.

Last month, scientists and artists beamed a message to GJ 273, a red dwarf also known as Luyten’s star that lies 12.36 light-years from Earth, project team members revealed today (Nov. 16). Luyten’s star hosts two known planets, one of which, GJ 273b, may be capable of supporting life as we know it.

Though the message was designed to provoke a response from the hypothetical denizens of GJ 273b, the main goal in sending the communication involved laying a foundation for the future, said team member Douglas Vakoch, president of METI (Messaging Extraterrestrial Intelligence) International, a San Francisco-based nonprofit.

“It is a prototype for what I think we would most likely need to do 100 times, or 1,000 times, or 1 million times,” Vakoch told “To me, the big success of the project will come if, 25 years from now, there’s someone who remembers to look [for a response]. If we could accomplish that, that would be a radical shift of perspective.”

Indeed, humanity’s demonstrable penchant for short-term thinking has prompted some skepticism within the SETI (search for extraterrestrial intelligence) community about METI as a viable strategy, Vakoch said. (METI is also known as “active SETI.” “Traditional” SETI involves listening and looking for signals that could be from E.T.)

METI is controversial for another reason as well. Some critics — most famously, physicist Stephen Hawking — have suggested that the strategy could betray our existence to super-advanced hostile or resource-hungry aliens, with potentially dire consequences for humanity and the rest of the planet. will end in 14 seconds.

But beaming a message to Luyten’s star doesn’t increase the risk of an alien attack, Vakoch said. 

“It’s really hard to imagine a scenario in which a civilization around Luyten’s star could have the capacity to come to Earth and threaten us, and yet they’re not able to pick up our leakage radiation,” he said, referring to the TV and radio signals that have been slipping out into the cosmos from Earth for more than half a century.

The Luyten’s star project, known as “Sónar Calling GJ 273b,” is a collaboration involving METI International; the Institute of Space Studies of Catalonia in Spain; and Sónar, a music, creativity and technology festival in Barcelona, Spain.

“Doing it in partnership with the Sónar festival is a way that we can respect the necessity of incorporating a scientific perspective but also to recognize that doesn’t capture the fullness of the human spirit,” Vakoch said.

Team members crafted a message that includes a scientific and mathematical “tutorial,” as well as 33 short musical compositions by artists in the Sónar community. The team beamed this message out in binary code at two different radio frequencies on Oct. 16, Oct. 17 and Oct. 18, using the 105-foot-wide (32 meters) European Incoherent Scatter Scientific Association (EISCAT) radio antenna in Tromsø, Norway.

Luyten’s star was chosen primarily for its proximity to Earth, which could theoretically lead to a relatively rapid response. The red dwarf is the nearest star visible from the Northern Hemisphere that’s known to host a potentially habitable planet, Vakoch said. (That planet, by the way is a “super-Earth” about three times more massive than our own.”

The ease of conversation has not always factored in to METI campaigns. In 1974, for example, Puerto Rico’s Arecibo Observatory beamed a message devised by Frank Drake, Carl Sagan and other researchers toward the globular cluster M13, which lies 25,000 light-years away from Earth. (This “Arecibo message” began its long space journey 43 years ago today, in fact.)

The October transmissions represented the first phase of “Sónar Calling GJ 273b.” The group also plans to send an “expanded tutorial” to Luyten’s star in April 2018 at several different radio frequencies, turning the EISCAT antenna into something like a musical instrument, team members said.


Astronomers Find New Alien Planet Suitable For Life

November 21, 2017 by  
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A newfound exoplanet may be one of the best bets to host alien life ever discovered — and it’s right in Earth’s backyard, cosmically speaking.

Astronomers have spotted a roughly Earth-mass world circling the small, dim star Ross 128, which lies just 11 light-years from the sun. The planet, known as Ross 128b, may have surface temperatures amenable to life as we know it, the researchers announced in a new study that will appear in the journal Astronomy & Astrophysics.

Ross 128b is 2.6 times more distant from Earth than Proxima b, the potentially habitable planet found in the nearest solar system to the sun. But Proxima b’s parent star, Proxima Centauri, blasts out a lot of powerful flares, potentially bathing that planet in enough radiation to stunt the emergence and evolution of life, scientists have said. [10 Exoplanets That Could Host Alien Life]

Radiation is likely much less of an issue for Ross 128b, because its parent star is not an active flarer, said discovery team leader Xavier Bonfils, of the Institute of Planetology and Astrophysics of Grenoble and the University of Grenoble Alpes in France.

“This is the closest Earth-mass planet potentially in the habitable zone that orbits a quiet star,” Bonfils told

Bonfils and his colleagues found Ross 128b using the High Accuracy Radial velocity Planet Searcher (HARPS), an instrument at the European Southern Observatory’s La Silla Observatory in Chile.

As its name suggests, HARPS employs the “radial velocity” method, noticing the wobbles in a star’s movement induced by the gravitational tugs of orbiting planets. (NASA’s prolific Kepler space telescope, by contrast, uses the “transit” technique, spotting tiny brightness dips caused when a planet crosses its host star’s face from the spacecraft’s perspective.)

The HARPS observations allowed Bonfils and his team to determine that Ross 128b has a minimum mass 1.35 times that of Earth, and that the planet orbits its host star once every 9.9 Earth days.

Such a tight orbit would render Ross 128b uninhabitable in our own solar system. But Ross 128 is much cooler than the sun, so the newfound world is likely temperate, the researchers said. Determining whether  the planet is actually capable of supporting life as we know it, however, would require a better understanding of its atmosphere, Bonfils said.

“Ross 128b receives 1.38 times [more] irradiation than Earth from our sun,” he said. “Some models made by theorists say that a wet Earth-size planet with such irradiation would form high-altitude clouds. Those clouds would reflect back to space a large fraction of the incident light, hence preventing too much greenhouse heating. With those clouds, the surface would remain cool enough to allow liquid water at the surface. Not all models agree, though, and others predict this new planet is rather like Venus.

Though both Ross 128 and Proxima Centauri are red dwarfs — the most common type of star in the Milky Way galaxy — they are very different objects.

“Proxima Centauri is particularly active, with frequent, powerful flares that may sterilize (if not strip out) its atmosphere,” Bonfils said. “Ross 128 is one of the quietest stars of our sample and, although it is a little further away from us (2.6x), it makes for an excellent alternative target.”

And the star may indeed be targeted in the not-too-distant-future — by giant ground-based instruments such as the European Extremely Large Telescope, the Giant Magellan Telescope and the Thirty Meter Telescope, all of which are scheduled to be up and running by the mid-2020s.

Such megascopes should be able to resolve Ross 128b and even search its atmosphere for oxygen, methane and other possible signs of life, Bonfils said. (NASA’s $8.9 billion James Webb Space Telescope, which is scheduled to launch in early 2019, probably won’t be able to perform such a biosignature search, the researchers said in their discovery paper. If Ross 128b transited its host star from Webb’s perspective, it would likely be a different story, they added.)

Earlier this year, by the way, radio astronomers detected a strange signal that seemed to be emanating from Ross 128. But further investigation revealed that the signal most likely came from an Earth-orbiting satellite, not an alien civilization.


Can An Ancient Spiral Galaxy Reveal The Secrets Of The Milky Way

November 13, 2017 by  
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Astronomers have uncovered an ancient cosmic artifact 11 billion light-years from Earth: the oldest spiral galaxy ever seen.

The newly discovered galaxy, known as A1689B11, is an ancestor of modern spiral galaxies like our own Milky Way, which are defined by long tentacles of gas, dust and stars that wrap around the galaxy’s central bulge.

“Spiral galaxies are exceptionally rare in the early universe, and this discovery opens the door to investigating how galaxies transition from highly chaotic, turbulent discs to tranquil, thin discs like those of our own Milky Way galaxy,” Renyue Cen, a co-author of the new paper describing the findings and a senior research astronomer at Princeton University, said in a statement.

Galaxies come in many different shapes and sizes, and researchers think many spiral galaxies form mainly through mergers of smaller elliptical galaxies, although many factors can affect how a galaxy changes its shape over time, according to NASA. Elliptical galaxies are disks that can be mostly circular or very elongated but lack the arm-like features of spiral galaxies.

Astronomer Edwin Hubble was one of the first people to theorize that elliptical galaxies evolved to form spiral galaxies, although he did not fully appreciate the complexity of galaxy evolution, according to the European Space Agency’s Hubble Space Telescope website. Nonetheless, researchers still refer to the time in cosmic history when spiral galaxies began to form from elliptical galaxies as “the Hubble sequence.”

“Studying ancient spirals like A1689B11 is a key to unlocking the mystery of how and when the Hubble sequence emerges,” Cen said in the statement from Swinburne University in Australia (where some of the other co-authors are based). Previously, researchers reported finding spiral galaxies that date back 10.7 billion years.

The newly discovered galaxy is too far away to be observed directly with modern instruments. So the researchers took advantage of a natural phenomenon known as gravitational lensing, in which the gravity of a massive object (like a galaxy or a cluster of galaxies) bends and amplifies the light from an object that lies beyond it (as seen by an observer). In this way, the authors of the new research paper were able to detect light from the very distant spiral galaxy A1689B11 by looking for the effects of gravitational lensing around the edge of a galaxy cluster that is nearer to Earth.

The observations were conducted using an instrument called the Near-infrared Integral Field Spectrograph on the Gemini North telescope, located on Mauna Kea in Hawaii. The researchers were able to “look 11 billion years back in time and directly witness the formation of the first, primitive spiral arms of a galaxy,” Cen said in the statement.

Because light travels at a finite speed, the light from A1689B11 left that galaxy 11 billion years ago, when the universe was less than 3 billion years old. In this way, astronomers can look back in time and learn about the history of the universe through direct observations


Does Proxima b Have Neighbors

November 10, 2017 by  
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The nearest alien planet to Earth may not be an only child.

Astronomers have spotted a dusty ring around the nearby star Proxima Centauri, hinting at the existence of other planets in addition to the famous Proxima b, a new study reports.


“This result suggests that Proxima Centauri may have a multiple-planet system with a rich history of interactions that resulted in the formation of a dust belt,” study lead author Guillem Anglada, an astronomer at the Instituto de Astrofisica de Andalucia in Spain, said in a statement. “Further study may also provide information that might point to the locations of as-yet unidentified additional planets.” [Proxima b: Closest Earth-Like Planet Discovery in Pictures]

Proxima Centauri is a red dwarf that lies about 4.2 light-years from Earth, in the southern constellation of Centaurus (The Centaur). In 2016, researchers spotted Proxima b, an apparently Earth-size world orbiting the star in what seems to be the habitable zone, the region where liquid water could exist on the surface. The star itself is about the same age as the sun. (Coincidentally, the team that discovered Proxima b was led by Guillem Anglada-Escudé of Queen Mary University of London, a part of Anglada’s team but no relation to the author of the new research.)

Anglada and his colleagues studied Proxima Centauri using the Atacama Large millimeter/submillimeter Array (ALMA), a network of telescopes in Chile. The researchers discovered a belt of dusty material containing about 1 percent the mass of Earth. The belt — which lies a few hundred million kilometers from the star, far beyond Proxima b’s orbit — has a temperature of about minus 328 degrees Fahrenheit (minus 230 degrees Celsius), roughly the same temperature of the solar system’s Kuiper Belt, researchers said.

The dusty material might range in size from grains of only a few millimeters to asteroid-like bodies several kilometers across, study team members said. Dust belts like this are thought to be the remains of material that didn’t manage to clump together to form planets, they added.

ALMA also spotted signs of a possible second dust ring, about 10 times farther from the star than the other one, though this feature awaits confirmation. If the outer ring does indeed exist, its material would be very cold, lying so far from a star that is much smaller and dimmer than the sun.

The faint outer belt could prove useful to astronomers: Studying its shape could yield a better understanding of Proxima b’s mass, which is not known very well at the moment, the researchers said.  

And then there’s the exploration angle. The $100 million Breakthrough Starshot project aims to send sail-equipped, laser-driven microprobes zooming past Proxima b in the not-too-distant-future, and mapping out the system’s dust environment could be key to the success of such a mission, study team members said.

“These first results show that ALMA can detect dust structures orbiting around Proxima. Further observations will give us a more detailed description of Proxima’s planetary system,” study co-author Pedro Amado, also from the Instituto de Astrofiscia de Andaluicia, said in the same statement. “What we are seeing now is just the appetizer compared to what is coming!”

The new study has been accepted for publication in Astrophysical Journal Letters.


Planet Star Duo Puzzles Astronomers

November 3, 2017 by  
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A giant planet has been found orbiting an ultracool dwarf star — the largest planet compared to its star ever found — leaving scientists baffled at how the duo could have formed.

The planet NGTS-1b is situated 600 light-years from our solar system, according to a statement from the University of Warwick, and it is a gas giant about the size of Jupiter. Its star, on the other hand, is just half the mass and radius of the sun. The planet orbits its star at 3 percent the distance from the Earth to the sun, and it whips around a full orbit every 2.6 Earth days.

An international collaboration of researchers found the planet using the Next-Generation Transit Survey, an array of 12 telescopes at the Paranal Observatory in northern Chile that searches for a telltale dimming in distant stars that would indicate planets passing by. [7 Ways to Discover Alien Planets]

“The discovery of NGTS-1b was a complete surprise to us — such massive planets were not thought to exist around such small stars,” Daniel Bayliss, lead author on the new work and a researcher at University of Warwick in the United Kingdom, said in the statement. “This is the first exoplanet we have found with our new NGTS facility, and we are already challenging the received wisdom of how planets form.”

The system’s star is a small, dim M-dwarf, which is the most common type of star in the sky. Red dwarfs burn their fuel much more slowly than sun-like stars, so they can have lifetimes of trillions of years. According to the new work, this is the third time a gas giant has been seen orbiting an M-dwarf — but this planet is by far the largest.

While it can be tricky enough just to spot planets orbiting M-dwarfs, researchers are much more used to seeing M-dwarfs orbited by rocky planets, according to a statement from the Royal Astronomical Society. In February, for instance, researchers found seven rocky planets orbiting the small, dim TRAPPIST-1. NGTS-1 is larger than TRAPPIST-1, but researchers are still unsure how the star could have gathered enough material to build a large gas giant during the system’s formation, they said in the statement.

To find NGTS-1b, the Next-Generation Transit Survey monitored certain spots in the sky for months with red-sensitive cameras to catch any changes in brightness to stars in its field of view, according to the statement from the University of Warwick. Researchers saw the particular M-dwarf dipping in brightness every 2.6 days, suggesting it had a planetary companion. Then, they confirmed the planet’s gargantuan size by measuring its radial velocity — how much the star “wobbles” during each orbit from its companion’s gravitational pull. 

“NGTS-1b was difficult to find, despite being a monster of a planet, because its parent star is small and faint,” Bayliss said. “Small stars are actually the most common in the universe, so it is possible that there are many of these giant planets waiting to be found.”

“Our challenge is to now find out how common these types of planets are in the galaxy, and with the new NGTS facility, we are well-placed to do just that,” he added.

The new work, currently available on, has been accepted for publication in the Monthly Notices of the Royal Astronomical Society.


Is Another Mission To Pluto Being Planned

October 31, 2017 by  
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A grassroots movement seeks to build momentum for a second NASA mission to the outer solar system, a generation after a similar effort helped give rise to the first one.

That first mission, of course, was New Horizons, which in July 2015 performed the first-ever flyby of Pluto and is currently cruising toward a January 2019 close encounter with a small object known as 2014 MU69.

New Horizons got its start with letter-writing campaigns in the late 1980s, and the new project hopes to duplicate that success, said campaign co-leader Kelsi Singer, a New Horizons team member who’s based at the Southwest Research Institute (SwRI) in Boulder, Colorado.   

Nearly three dozen scientists have drafted letters in support of a potential return mission to Pluto or to another destination in the Kuiper Belt, the ring of icy bodies beyond Neptune’s orbit, Singer told Up

These letters have been sent to NASA planetary science chief Jim Green, as well as to the chairs of several committees that advise the agency, she added.

“We need the community to realize that people are interested,” Singer said. “We need the community to realize that there are important, unmet goals. And we need the community to realize that this should have a spot somewhere in the Decadal Survey.”

That would be the Planetary Science Decadal Survey, a report published by the National Academy of Sciences that lays out the nation’s top exploration priorities for the coming decade.

“This is the way it normally works,” said New Horizons principal investigator Alan Stern, who’s also based at SwRI.

“First it bubbles up in the community and then, when there’s enough action, the agency starts to get behind it,” Stern, who has been the driving force behind New Horizons since the very beginning, told “Then it lets the Decadal Survey sort things out.”

Stern contributed a letter to the new campaign, and he has voiced support for a dedicated Pluto orbiter. Singer would also be happy if NASA went back to the dwarf planet.

“Pluto just has so much going on,” she said.

But there are other exciting options available as well, Singer said. For example, NASA could do a flyby of a different faraway dwarf planet — Eris, perhaps — to get a better idea of the variety and diversity of these intriguing worlds.

Or the agency could target Kuiper Belt objects (KBOs) that have diameters of a few hundred kilometers or so, she added. New Horizons has flown by one “big” KBO (Pluto) and will soon see a small one — 2014 MU69 is just 20 miles (32 km) or so across — but there are no plans at the moment to study anything of an intermediate size up close.

The last Decadal Survey was put out in 2011, and it covers the years 2013 to 2022. The next one is due out in five years, and it will help map out NASA’s plans for the 2020s and early 2030s. So Singer knows she and her colleagues must be patient, even if their letter-writing campaign ultimately bears fruit.

“I would say 25 years is the longest I think about,” she said, referring to how long it may be before another Kuiper Belt mission gets to its destination. “And I hope it may be more like 15 years.”


Are Other Solvents Outside Of Water Possible For Alien Life

October 18, 2017 by  
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Life on early Earth seems to have begun with a paradox: while life needs water as a solvent, the essential chemical backbones of early life-forming molecules fall apart in water. Our universal solvent, it turns out, can be extremely corrosive.

Some have pointed to this paradox as a sign that life, or the precursor of life, originated elsewhere and was delivered here via comets or meteorites. Others have looked for solvents that could have the necessary qualities of water without that bond-breaking corrosiveness.

In recent years the solvent often put forward as the eligible alternative to water is formamide, a clear and moderately irritating liquid consisting of hydrogen, carbon, nitrogen and oxygen. Unlike water, it does not break down the long-chain molecules needed to form the nucleic acids and proteins that make up life’s key initial instruction manual, RNA. Meanwhile it also converts via other useful reactions into key compounds needed to make nucleic acids in the first place.

Although formamide is common in star-forming regions of space, scientists have struggled to find pathways for it to be prevalent, or even locally concentrated, on early Earth. In fact, it is hardly present on Earth today except as a synthetic chemical for companies.

New research presented by Zachary Adam, an earth scientist at Harvard University, and Masashi Aono, a complex systems scientist at Earth-Life Science Institute (ELSI) at Tokyo Institute of Technology, has produced formamide by way of a surprising and reproducible pathway: bombardment with radioactive particles. 

The two and their colleagues exposed water and a mixture of two chemicals known to have existed on early Earth (hydrogen cyanide and aqueous acetonitrile) to the high-energy particles emitted from a cylinder of cobalt-60, an artificially produced radioactive isotope commonly used in cancer therapy. The result, they report, was the production of substantial amounts of formamide more quickly than earlier attempts by researchers using theoretical models and in laboratory settings. 

It remains unclear whether early Earth had enough radioactive material in the right places to produce the chemical reactions that led to the formation of formamide. And even if the conditions were right, scientists cannot yet conclude that formamide played an important role in the origin of life.

Still, the new research furthers the evidence of the possible role of alternative solvents and presents a differing picture of the basis of life. Furthermore, it is suggestive of processes that might be at work on other exoplanets as well – where solvents other than water could, with energy supplied by radioactive sources, provide the necessary setting for simple compounds to be transformed into far more complex building blocks.

“Imagine that water-based life was preceded by completely unique networks of interacting molecules that approximated, but were distinct from and followed different chemical rules, than life as we know it,” said Adam.

Their work was presented at recent gatherings of the International Society for the Study of the Origin of Life, and the Astrobiology Science Conference.

The team of Adam and Aono are hardly the first to put forward the formamide hypothesis as a solution to the water paradox, and they are also not the first to posit a role for high-energy, radioactive particles in the origin of life. 

An Italian team led by Rafaelle Saladino of Tuscia University recently proposed formamide as a chemical that would supply necessary elements for life and would avoid the “water paradox.” Since the time that Marie Curie described the phenomenon of radioactivity, scientists have proposed innumerable ways that the emission of particle-shedding atomic nuclei might have played roles, either large or small, in initiating life on Earth.

Putting formamide and radioactivty together, as Adam and Aono have done, is a potentially significant step forward, though one that needs deeper study.

“If we have formamide as a solvent, those precursor molecules can be kept stable, a kind of cradle to preserve very interesting products,” said Aono, who has moved to Tokyo-based Keio University while remaining a fellow at ELSI.

The experiment with cobalt-60 did not begin as a search for a way to concentrate the production of formamide. Rather, Adam was looking more generally into the effects of gamma rays on a variety of molecules and solvents, while Aono was exploring radioactive sources for a role in the origin of life.

The two came together somewhat serendipitously at ELSI, an origins-of-life research center created by the Japanese government. ELSI was designed to be a place for scientists from around the world and from many different disciplines to tackle some of the notoriously difficult issues in origins of life research. At ELSI, Adam, who had been unable to secure sites to conduct laboratory tests in the United States, learned from Aono about a sparingly-used (and free) cobalt-60 lab; they promptly began collaborating.

It is well known that the early Earth was bombarded by high-energy cosmic particles and gamma rays. So is the fact that numerous elements (aluminum-26, iron-60, iodine-129) have existed as radioactive isotopes that can emit radiation for minutes to millennium, and that these isotopes were more common on early Earth than today. Indeed, the three listed above are now extinct on Earth, or nearly extinct, in their natural forms.

Less known is the presence of “natural nuclear reactors” as sites where a high concentration of uranium in the presence of water has led to self-sustaining nuclear fission. Only one such spot has been found —in the Oklo region of the African nation of Gabon — where spent radioactive material was identified at 16 sites separate sites. Scientists ultimately concluded widespread natural nuclear reactions occurred in the region some 2 billion years ago.

That time frame would mean that the site would have been active well after life had begun on Earth, but it is a potential proof of concept of what could have existed elsewhere long before.

Adam and Aono remain agnostic about where the formamide-producing radioactive particles came from. But they are convinced that it is entirely possible that such reactions took place and helped produce an environment where each of the backbone precursors of RNA could readily be found in close quarters.

Current scientific thinking about how formamide appeared on Earth focuses on limited arrival via asteroid impacts or through the concentration of the chemical in evaporated water-formamide mixtures in desert-like conditions. Adam acknowledges that the prevailing scientific consensus points to low amounts of formamide on early Earth.

“We are not trying to argue to the contrary,” he said, “but we are trying to say that it may not matter.”

If you have a unique place (or places) on the Earth creating significant amounts of formamide over a long period of time through radiolysis, then an opportunity exists for the onset of some unique chemistry that can support the production of essential precursor compounds for life, Adam said.

“So, the argument then shifts to — how likely was it that this unique place existed? We only need one special location on the entire planet to meet these circumstances,” he said.

After that, the system set into motion would have the ability to bring together the chemical building blocks of life.

“That’s the possibility that we look forward to investigating in the coming years,” Adam said.

James Cleaves, an organic chemist also at ELSI and a co-author of the cobalt-60 paper, said while production of formamide from much simpler compounds represents progress, “there are no silver bullets in origin of life work. We collect facts like these, and then see where they lead.”


Does Proxima Centauri b Have A Shiny Green Tint

October 17, 2017 by  
Filed under Around The Net

A world orbiting the sun’s closest stellar neighbor may have a shiny green tint to it — and not necessarily because it’s covered in leafy plants. 

Researchers have found a way to characterize potential auroras on the nearby exoplanet Proxima Centauri b and found that, if the planet sports oxygen in its atmosphere, the auroras may give the atmosphere a greenish cast. 

“The northern and southern lights [on Proxima Centauri b] would be at least 100 times brighter than on Earth,” Rodrigo Luger, a postdoctoral student at the University of Washington, who led the study of how the planet’s auroras could be spotted from Earth, told by email. Luger said the auroras might be so bright as to be visible with very powerful telescopes.

The active star Proxima Centauri lies only 4.2 light-years from the solar system. A small world orbits in the star’s habitable zone, the region where liquid water could survive on the surface. Its radius remains a mystery. However, scientists know it is about 1.3 times as massive as the Earth, which its initial discovers said suggests a rocky planet. 

Proxima Centauri is a small star, dimmer than Earth’s sun, so its habitable zone is closer to the star than the habitable zone of the sun. As a result, Proxima Centauri b is 20 times closer to its star than Earth is to the sun, and completes an orbit every 11.2 Earth-days. The red dwarf star is more active than Earth’s sun, firing off far more frequent flares that may douse the planet in radiation that could be harmful for potential life. 

Those same flares may help scientists better understand the planet. If Proxima Centauri b has a magnetic field, it may capture the charged particles in the flares and funnel them toward the poles, creating brilliant auroral displays. 

Observing the auroras can help researchers characterize the planet’s atmosphere. On Earth, the different color glow of the northern and southern lights corresponds to reactions with different molecules in the atmosphere. According to Luger, who presented the results at the Astrobiology Science Conference in Mesa, Arizona, in April, if Proxima Centauri b is a terrestrial world with an Earth-like atmosphere and a magnetic field, the green light of the oxygen auroras would grow 100 times stronger than on Earth.

Because of the potential for green light, the researchers dubbed such a world “the pale green dot,” a nod to Carl Sagan’s categorization of Earth as a pale blue dot.

Periods of intense stellar activity could make the auroras even brighter. While coronal mass ejections and flares have the strongest impact on generating auroras, Luger said, they aren’t really predictable in advance.

“But the sun certainly has periodic activity cycles, so if we understand those of Proxima Centauri, we might be able to use that to our advantage,” he said.

He went on to say that the extreme activity of the star may make such knowledge unnecessary — astronomers could simply count on a high likelihood that the star would flare and cause the auroras to brighten.

While several studies have described searches for auroras on gas giant exoplanets that orbit close to their parent stars, none have been spotted on worlds beyond the solar system. But Luger remains confident.

“Proxima Centauri b is optimal for auroral detection,” he said.

He gave several reasons that auroras may be soon spotted on Proxima Centauri b. The planet is nearby — it’s the closest known exoplanet to Earth — making it easier for instruments to collect detailed observations. The extreme magnetic activity of the star, coupled with the planet’s close orbit, means Proxima Centauri b is bombarded with solar particles far more vigorously than Earth. At the same time, the star is faint, so a glowing green planet would show up more easily than it would around a sun-like star. Finally, the short orbit means that the world moves around its sun at a rapid clip; when a light source is moving toward or away from an observer, this motion can be observed through a phenomenon called redshift, or Doppler shift. Luger said the Doppler shift of the auroras’ light waves would be significantly larger than they would be on their own, making lines that would otherwise be hard to see more visible. That would make it easier to identify any oxygen in the atmosphere.

Unfortunately, this “pale green dot” won’t be spotted with current telescopes. NASA’s upcoming powerhouse telescope ― the James Webb Space Telescope ― will hunt for infrared light, so Luger said it won’t be able to detect the green oxygen aurora, which is in the visible light range.

“Our best bet for detection is the [Thirty-Meter Telescope] or similar next-generation extremely large telescopes,” he said.

The Thirty-Meter Telescope (TMT) — so-named because its primary mirror would be 30 meters (98 feet) wide — began construction on Hawaii’s Mauna Kea peak before it was halted in 2015 after protests over the sacred nature of the land. The project remains at a halt today, though some astronomers have lauded the benefits of moving the telescope to Spain’s Canary Islands.

But even TMT would take some time to identify the signature of oxygen from the auroras, with Luger estimating “tens of hours” of observation. The same is true for the Large UV/Opitcal/Infrared Survey (LUVOIR), a proposed design for a telescope with a primary mirror between 9 and 15 meters (30 and 50 feet). With telescope time extremely competitive, it could be hard to study the system so extensively.

In order to produce auroras, a planet must have a magnetic field. Out of the four terrestrial planets in Earth’s solar system, only two have a worldwide field — Earth and Mercury. Mars has a patchy field, and Venus has none. If Proxima Centauri b is similarly lacking, it might not produce auroras.

However, the planet may get a brightness boost from airglow, the faint emission of light from the atmosphere that keeps nighttime on Earth from ever being completely dark.

“The planet is likely also to have strong airglow, which is planetwide,” Luger said. “Airglow is not generated by magnetic fields, and is typically weaker than aurorae, so we did not calculate it. But it should be quite strong on Proxima Centauri b, and could cause the entire planet to glow green.”


Alien Megastructure Around Star May Not Exist

October 13, 2017 by  
Filed under Around The Net

There’s a prosaic explanation for at least some of the weirdness of “Tabby’s star,” it would appear.

The bizarre long-term dimming of Tabby’s star — also known as Boyajian’s star, or, more formally, KIC 8462852 — is likely caused by dust, not a giant network of solar panels or any other “megastructure” built by advanced aliens, a new study suggests.

Astronomers came to this conclusion after noticing that this dimming was more pronounced in ultraviolet (UV) than infrared light. Any object bigger than a dust grain would cause uniform dimming across all wavelengths, study team members said

“This pretty much rules out the alien megastructure theory, as that could not explain the wavelength-dependent dimming,” lead author Huan Meng of the University of Arizona said in a statement. “We suspect, instead, there is a cloud of dust orbiting the star with a roughly 700-day orbital period.”

Strange brightness dips

KIC 8462852, which lies about 1,500 light-years from Earth, has generated a great deal of intrigue and speculation since 2015. That year, a team led by astronomer Tabetha Boyajian (hence the star’s nicknames) reported that KIC 8462852 had dimmed dramatically several times over the past half-decade or so, once by 22 percent.

No orbiting planet could cause such big dips, so researchers began coming up with possible alternative explanations. These included swarms of comets or comet fragments, interstellar dust and the famous (but unlikely) alien-megastructure hypothesis.

The mystery deepened after the initial Boyajian et al. study. For example, other research groups found that, in addition to the occasional short-term brightness dips, Tabby’s star dimmed overall by about 20 percent between 1890 and 1989. In addition, a 2016 paper determined that its brightness decreased by 3 percent from 2009 to 2013.

The new study, which was published online Tuesday (Oct. 3) in The Astrophysical Journal, addresses such longer-term events.

From January 2016 to December 2016, Meng and his colleagues (who include Boyajian) studied Tabby’s star in infrared and UV light using NASA’s Spitzer and Swift space telescopes, respectively. They also observed it in visible light during this period using the 27-inch-wide (68 centimeters) telescope at AstroLAB IRIS, a public observatory near the Belgian village of Zillebeke.

The observed UV dip implicates circumstellar dust — grains large enough to stay in orbit around Tabby’s star despite the radiation pressure but small enough that they don’t block light uniformly in all wavelengths, the researchers said.

The new study does not solve all of KIC 8462852’s mysteries, however. For example, it does not address the short-term 20 percent brightness dips, which were detected by NASA’s planet-hunting Kepler space telescope. (Kepler is now observing a different part of the sky during its K2 extended mission and will not follow up on Tabby’s star for the forseeable future.)

And a different study — led by Joshua Simon of the Observatories of the Carnegie Institution for Science in Pasadena, California — just found that Tabby’s star experienced two brightening spells over the past 11 years. (Simon and his colleagues also determined that the star has dimmed by about 1.5 percent from February 2015 to now.)

“Up until this work, we had thought that the star’s changes in brightness were only occurring in one direction — dimming,” Simon said in a statement. “The realization that the star sometimes gets brighter in addition to periods of dimming is incompatible with most hypotheses to explain its weird behavior.”


Astronomers Discover Water Mystery On Mars

October 9, 2017 by  
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A new examination of old data suggests that there might be ice hiding in the Martian equator, even though scientists previously thought that the substance couldn’t exist there.

Scientists uncovered an unexpected amount of hydrogen when looking at older data from NASA’s Mars Odyssey spacecraft dating back to between 2002 and 2009. At higher latitudes, hydrogen generally indicates buried water ice, but this was not believed possible at the equator, according to a statement from NASA.

If there is indeed water there, this would help with a future human mission to Mars, because it could mean the astronauts wouldn’t need to bring the substance with them for drinking, cooling equipment or watering plants, researchers said in the statement. Instead, the astronauts could live off the land to an extent, reducing the number of resources that need to be trucked (at higher cost) from Earth

Mars Odyssey’s first major discovery, in 2002, was also linked to water; the spacecraft found buried hydrogen at high latitudes, and the 2008 landing of the Phoenix Mars lander confirmed that there was water ice. However, at lower latitudes, measurements of hydrogen were explained as hydrated minerals (which other spacecraft have also observed). Researchers didn’t think water ice was thermodynamically stable in those areas.

For this new study, the researchers analyzed data collected using Mars Odyssey’s neutron spectrometer. The instrument is not designed to directly detect water, but by measuring neutrons, it can detect signatures of hydrogen, which can mark the presence of water or other hydrogen-bearing substances. 

The science team reduced the blurring or “noise” in Odyssey’s data using image-reconstruction techniques based on those used for other spacecraft and for medicine, according to the statement. This improved the spatial resolution of the data to 180 miles (290 kilometers), twice the previous resolution of 320 miles (520 km).

“It was as if we’d cut the spacecraft’s orbital altitude in half, and it gave us a much better view of what’s happening on the surface,” Jack Wilson, the study’s principal investigator and a postdoctoral researcher at the Johns Hopkins University Applied Physics Laboratory.

Their work focused on equatorial areas, particularly in zones around the Medusae Fossae formation, an area that includes material that is easy to erode. Previous observations from NASA’s Mars Reconnaissance Orbiter and the European Space Agency’s Mars Express orbiter suggested there might be volcanic deposits or water ice just below the surface. Scientists, however, were skeptical that it was water ice, because “if the detected hydrogen were buried ice within the top meter [3.3 feet] of the surface, there would be more than would fit into pore space in soil,” Wilson said.

The study’s scientists emphasized that more evidence is needed to conclude that the signature indeed comes from water ice. They’re not too sure how the water was preserved, they said; perhaps ice and dust flowing from the poles moved through the atmosphere when Mars had a steeper axis tilt than today. However, it’s been at least hundreds of thousands of years since those conditions existed, and the water ice deposited back then shouldn’t be around anymore, the researchers said. (This would be true even if, somehow, dust or a crust at the surface trapped the humidity underground, the scientists added.)

“Perhaps the signature could be explained in terms of extensive deposits of hydrated salts, but how these hydrated salts came to be in the formation is also difficult to explain,” Wilson said. “So, for now, the signature remains a mystery worthy of further study, and Mars continues to surprise us.”


Astronomers Discover Prehistoric Lake On Mars Could Have Supported Life

October 6, 2017 by  
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An up-close view of Mars’ rocky deposits by NASA’s Curiosity rover shows a changing climate in the planet’s ancient past that would have left the surface warm and humid enough to support liquid water — and possibly life. Evidence of an ancient lake points to the prospect of two unique habitats within its shores; the lower part of the lake was devoid of oxygen compared to an oxygen-rich upper half. 

In a recent paper published in the journal Science, Redox stratification of an ancient lake in Gale crater,” Stony Brook University geoscientist Joel Hurowitz and his colleagues used more than three years of data retrieved from the rover to paint a picture of ancient conditions at Gale Crater, the lowest point in a thousand kilometers. The site, a 150-mile kilometer crater formed during an impact around 3.8 billion years ago, once flowed with rivers ending in a lake. The sedimentary rocks laid down by these rivers and onto the lakebed tell the story of how the environment changed over time.

Curiosity landed on a group of sedimentary rocks known as the Bradbury group. The rover sampled a part of this group called the Sheepbed mudstones, as well as rocks from the Murray formation at the base of the 5-kilometer high peak at the center of the crater known as Mount Sharp. Both types of rocks were deposited in the ancient lake, but the Sheepbed rocks are older and occur lower in the stratigraphic layers of rocks. Comparing the two types of rocks can lead to interesting revelations about the paleoenvironment. 

Rocks that form at the same time in the same area can nevertheless display differences in composition and other characteristics. These different groupings are known as “facies” and the Murray formation is split into two facies. One is comprised mainly of hematite and phyllosilicate, and given the name HP, while the other is the magnetite-silicate facies, known as MS. 

“The two Murray facies were probably laid down at about the same time within different parts of the lake,” explained Hurowitz. “The former laid down in shallow water, and the latter in deeper water.”

The near-shore HP facies have thicker layers in the rocks compared to the thin layers of the deeper water MS facies. This difference in layer thickness is because the river flowing into the lake would have slowed down and dumped some of its sedimentary material at the lake shore. The flow would then have spread into the lake and dropped finer material into the deeper parts of the lake. 

Curiosity landed on rocks known as the Bradbury group. The Murray formation consist of younger rocks at the base of Mount Sharp. The height is exaggerated in the diagram.

The different mineralogy of the two facies was caused by the lake becoming separated into two layers. Ultraviolet (UV) radiation along with low levels of atmospheric oxygen penetrated the upper part of the lake and acted as oxidants on molecules in the water. These ions of iron (Fe2+) and manganese (Mn2+) were brought to the lake via seepage of groundwater through the lake floor.

When the UV and oxygen interacted with these, they lost electrons, meaning that they had become “oxidized.” The oxidized iron and manganese precipitated into minerals — hematite and manganese oxide — that eventually made up the rocks sampled by Curiosity in the HP facies. However, the UV and oxygen didn’t reach all the way to the lake floor, so the iron and manganese wasn’t oxidized in the deeper part of the lake, and instead became the mineral known as magnetite, making up the MS facies. 

The difference in oxidation of the two facies in the Murray formation due to differences in layers of the lake is known as redox stratification. Identifying redox stratification in the ancient lake shows that there were two completely different types of potential habitat available to any microbial life that might have been present.

The researchers also discovered that the Murray formation has a high concentration of salts, which provide clues relating to evaporation of the lake, and thus the end of the potential habitat. High salinity is a result of water evaporating and leaving salts behind. However, evaporation leaves other tell-tale signs such as desiccation cracks — similar to what you see when mud dries and cracks — and none of these signs appear in the Murray formation. This indicates that the evaporation occurred at a later period of time and that the salts seeped through layers overlying the Murray formation before becoming deposited in the Murray rocks. 

“Curiosity will definitely be able to examine the rocks higher up in the stratigraphy to determine if lake evaporation influenced the rocks deposited in it,” said Hurowitz. “In fact, that’s exactly what the rover is doing as we speak at the area known as Vera Rubin Ridge.”

Once Curiosity examines these rocks, it will be able to confirm that the salts found in the Murray formation came from a later period of evaporation, and therefore no significant evaporation occurred during the time that the Murray formation was deposited, meaning the environment would have been stable enough to support possible life forms.

The inflowing river deposits thicker material (clastics) close to the lake shore, and finer material towards the deeper part of the lake. The incoming UV and O2 oxidizes the iron and manganese in the upper part

Another result of the research is evidence of climate change. The older Sheepbed formation shows very little evidence of chemical weathering compared to the Murray formation. The change to substantial chemical weathering in the younger rocks indicates that the climate likely changed from cold, arid conditions to a warm, wet one. 

“The timing of this climate shift is not something we can tell for sure because we haven’t seen the Sheepbed member and the Murray formation in contact with each other,” said Hurowitz. “If we had, then we might be able to tell if the change in their chemical and mineralogical properties were abrupt (indicating rapid climate change) or gradual. At best, what we can say is that the rocks that we examined were likely deposited over a timespan of tens of thousands of years to as much as around 10 million years.”

The cause of the climate change on Mars is still a matter of debate. If the climate changed in a short period of time, it could have been due to short-term variations or an asteroid impact. A slower change in climate could have been the result of changes in the obliquity cycle of the planet.

The climate change indicated in the rocks shows that the ancient Martian environment would have been warm and humid enough to sustain liquid water on the surface. The redox stratification of the lake as revealed by the different mineralogy in the Murray formation shows that there would have been two different environments within the lake itself. If microbial life was present on Mars at this time, the different potentially habitable niches could have encouraged diversity with anaerobic forms possibly living in the lower depths of the lake. 

“I’m not sure that this was something we would have predicted if we hadn’t had the opportunity to examine Gale’s rock record up close and personal,” adds Hurowitz.



Astronomers Find Carbon Star With Red Glowing Bubble

September 28, 2017 by  
Filed under Around The Net

Gorgeous new imagery shows the enormous, glowing bubble that a strange, dying red star has blown around itself.

The huge star, known as U Antliae, lies about 900 light-years from Earth, in the southern constellation Antlia (the Air Pump). U Antliae has burned all the hydrogen and helium in its core and has therefore moved on to the “asymptotic giant branch” (AGB), the last major step in the life cycle of a sun-like star before it becomes superdense white dwarf. 

AdvertisementA few millennia ago, U Antliae erupted in a spasm of activity that generated a big bubble, a surprisingly thin structure that astronomers have now studied using the European Southern Observatory’s Atacama Large Millimeter/submillimeter Array (ALMA), a network of radio telescopes in northern Chile.

“Around 2,700 years ago, U Antliae went through a short period of rapid mass loss,” ESO officials wrote in a statement. “During this period of only a few hundred years, the material making up the shell seen in the new ALMA data was ejected at high speed. Examination of this shell in further detail also shows some evidence of thin, wispy gas clouds known as filamentary substructures.”

ALMA captured the bubble in multiple wavelengths of light, producing a 3D “data cube” that researchers have mined in detail. For example, the imagery shows gases in the bubble moving toward or away from the observer at different speeds, ESO officials said.

This image was created from ALMA data on the red carbon star U Antliae and its surrounding shell of material. The colors show the motion of the glowing material in the shell along the line of sight to the Earth. Blue material lies between us and the central star, and is moving toward us. Red material around the edge is moving away from the star, but not toward Earth. (For clarity, this view does not include the material on the far side of the star, which is receding from us in a symmetrical manner.)

Analyzing such stellar bubbles could help astronomers better understand the evolution of stars and galaxies, ESO officials added.

“Shells such as the one around U Antliae show a rich variety of chemical compounds based on carbon and other elements,” the officials wrote in the same statement. “They also help to recycle matter and contribute up to 70 percent of the dust between stars.”

The new ALMA imagery is part of a study, led by Franz Kerschbaum of the University of Vienna, that has been accepted for publication in the journal Astronomy & Astrophysics.


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