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Does Pluto Have Buried Oceans

December 7, 2017 by  
Filed under Around The Net

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

Courtesy-Space

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 arXiv.org.)

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.

Courtesy-Space

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 Space.com

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.

Courtesy-Space

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

Courtesy-Space

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 Space.com.Next 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 Space.com. “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.”

Courtesy-Space

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.

Courtesy-Space

 

Astronomers Ponder The Role Of Physics In Life

September 25, 2017 by  
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Understanding the origin of life is arguably one of the most compelling quests for humanity. This quest has inevitably moved beyond the puzzle of life on Earth to whether there’s life elsewhere in the universe. Is life on Earth a fluke? Or is life as natural as the universal laws of physics?

Jeremy England, a biophysicist at the Massachusetts Institute of Technology, is trying to answer these profound questions. In 2013, he formulated a hypothesis that physics may spontaneously trigger chemicals to organize themselves in ways that seed “life-like” qualities.

Now, new research by England and a colleague suggests that physics may naturally produce self-replicating chemical reactions, one of the first steps toward creating life from inanimate substances.

This might be interpreted as life originating directly from the fundamental laws of nature, thereby removing luck from the equation. But that would be jumping the gun.

Life had to have come from something; there wasn’t always biology. Biology is born from the raw and lifeless chemical components that somehow organized themselves into prebiotic compounds, created the building blocks of life, formed basic microbes and then eventually evolved into the spectacular array of creatures that exist on our planet today.  

“Abiogenesis” is when something nonbiological turns into something biological and England thinks thermodynamics might provide the framework that drives life-like behavior in otherwise lifeless chemicals. However, this research doesn’t bridge life-like qualities of a physical system with the biological processes themselves, England said.

“I would not say I have done anything to investigate the ‘origin of life’ per se,” England told Live Science. “I think what’s interesting to me is the proof of principle – what are the physical requirements for the emergence of life-like behaviors?”

Self-organization in physical systems

When energy is applied to a system, the laws of physics dictate how that energy dissipates. If an external heat source is applied to that system, it will dissipate and reach thermal equilibrium with its surroundings, like a cooling cup of coffee left on a desk. Entropy, or the amount of disorder in the system, will increase as heat dissipates. But some physical systems may be  sufficiently out of equilibrium that they “self-organize” to make best use of an external energy source, triggering interesting self-sustaining chemical reactions that prevent the system from reaching thermodynamic equilibrium and thus maintaining an out-of-equilibrium state, England speculates. (It’s as if that cup of coffee spontaneously produces a chemical reaction that sustains a hotspot in the center of the fluid, preventing the coffee from cooling to an equilibrium state.) He calls this situation “dissipation-driven adaptation” and this mechanism is what drives life-like qualities in England’s otherwise lifeless physical system.

A key life-like behavior is self-replication, or (from a biological viewpoint) reproduction. This is the basis for all life: It starts simple, replicates, becomes more complex and replicates again. It just so happens that self-replication is also a very efficient way of dissipating heat and increasing entropy in that system.

In a study published July 18 in the journal Proceedings of the National Academy of Sciences,  England and co-author Jordan Horowitz tested their hypothesis. They carried out computer simulations on a closed system (or a system that doesn’t exchange heat or matter with its surroundings) containing a “soup” of 25 chemicals. Although their setup is very simple, a similar type of soup may have pooled on the surface of a primordial and lifeless Earth. If, say, these chemicals are concentrated and heated by an external source – a hydrothermal vent, for example – the pool of chemicals would need to dissipate that heat in accordance with the second law of thermodynamics. Heat must dissipate and the entropy of the system will inevitably increase.

Under certain initial conditions, he found that these chemicals may optimize the energy applied to the system by self-organizing and undergoing intense reactions to self-replicate. The chemicals fine-tuned themselves naturally. These reactions generate heat that obeys the second law of thermodynamics; entropy will always increase in the system and the chemicals would self-organize and exhibit the life-like behavior of self-replication.

“Essentially, the system tries a bunch of things on a small scale, and once one of them starts experiencing positive feedback, it does not take that long for it to take over the character of organization in the system,” England told Live Science.

This is a very simple model of what goes on in biology: chemical energy is burned in cells that are – by their nature – out of equilibrium, driving the metabolic processes that maintain life. But, as England admits, there’s a big difference between finding life-like qualities in a virtual chemical soup and life itself.

Sara Imari Walker, a theoretical physicist and astrobiologist at Arizona State University who was not involved in the current research, agrees.

“There’s a two-way bridge that needs to be crossed to try to bridge biology and physics; one is to understand how you get life-like qualities from simple physical systems and the other is to understand how physics can give rise to life,” Imari Walker told Live Science. “You need to do both to really understand what properties are unique to life and what properties are characteristic of things that you consider to be almost alive […] like a prebiotic system.”

Emergence of life beyond Earth?

Before we can even begin to answer the big question of whether these simple physical systems may influence the emergence of life elsewhere in the universe, it would be better to understand where these systems exist on Earth first.

“If, when you say ‘life,’ you mean stuff that is as stunningly impressive as a bacterium or anything else with polymerases and DNA, my work doesn’t yet tell us anything about how easy or difficult it is to make something that complex, so I shouldn’t speculate about what we’d be likely to find elsewhere than Earth,”  England said. (Polymerases are proteins that assemble DNA and RNA.)

This research doesn’t specifically identify how biology emerges from nonbiological systems, only that in some complex chemical situations, surprising self-organization occurs. These simulations do not consider other life-like qualities – such as adaptation to environment or reaction to stimuli. Also, this thermodynamics test on a closed system does not consider the role of information reproduction in life’s origins, said Michael Lässig, a statistical physicist and quantitative biologist at the University of Cologne in Germany.

“[This] work is indeed a fascinating result on non-equilibrium chemical networks but it is still a long way from a physics explanation of the origins of life, which requires the reproduction of information,” Lässig, who was not involved in the research, told Live Science.

There’s a critical role for information in living systems, added Imari Walker. Just because there appears to be natural self-organization exhibited by a soup of chemicals, it doesn’t necessarily mean living organization.

“I think there’s a lot of intermediate stages that we have to get through to go from simple ordering to having a full-on information processing architecture like a living cell, which requires something like memory and hereditary,” said Imari Walker. “We can clearly get order in physics and non-equilibrium systems, but that doesn’t necessarily make it life.”

To say England’s work could be the “smoking gun” for the origin of life is premature, and there are many other hypotheses as to how life may have emerged from nothing, experts said. But it is a fascinating insight into how physical systems may self-organize in nature. Now that researchers have a general idea about how this thermodynamic system behaves, it would be a nice next step to identify sufficiently out-of-equilibrium physical systems that naturally occur on Earth, England said.

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Astronomers Find Titanium Oxide On Aline Planet

September 22, 2017 by  
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For the first time ever, titanium oxide has been spotted in an exoplanet’s skies, a new study reports.

Astronomers using the European Southern Observatory’s Very Large Telescope (VLT) in Chile detected the substance in the atmosphere of WASP-19b, a huge, scorching-hot planet located 815 light-years from Earth.

The presence of titanium oxide in the atmosphere of WASP-19b can have substantial effects on the atmospheric temperature structure and circulation,” study co-author Ryan MacDonald, an astronomer at the University of Cambridge in England, said in a statement.  

One possible effect is “thermal inversion.” If enough titanium oxide is present, the stuff can keep heat from entering or exiting an atmosphere, causing upper layers to be hotter than lower layers, researchers said. (This phenomenon occurs in Earth’s stratosphere, but the culprit is ozone, not titanium oxide.)

Artist’s illustration showing the exoplanet WASP-19b, whose atmosphere contains titanium oxide. In large enough quantities, titanium oxide can prevent heat from entering or escaping an atmosphere, leading to a “thermal inversion” in which temperatures are higher in the upper atmosphere than lower down.

WASP-19b is a bizarre world about the mass of Jupiter. The alien planet lies incredibly close to its host star, completing one orbit every 19 hours. As a result, WASP-19b’s atmospheric temperatures are thought to hover around 3,600 degrees Fahrenheit (2,000 degrees Celsius).

The research team — led by Elyar Sedaghati of the European Southern Observatory, the German Aerospace Center and the Technical University of Berlin — studied WASP-19b for more than a year using the VLT’s refurbished FORS2 instrument. These observations allowed them to determine that small amounts of titanium oxide, along with water and wisps of sodium, swirl around in the exoplanet’s blistering air.

“Detecting such molecules is, however, no simple feat,” Sedaghati said in the same statement. “Not only do we need data of exceptional quality, but we also need to perform a sophisticated analysis. We used an algorithm that explores many millions of spectra spanning a wide range of chemical compositions, temperatures, and cloud or haze properties in order to draw our conclusions.”

In addition to shedding new light on WASP-19b, the new study — which was published online today (Sept. 13) in the journal Nature — should improve researchers’ modeling of exoplanet atmospheres in general, team members said.

“To be able to examine exoplanets at this level of detail is promising and very exciting,” said co-author Nikku Madhusudhan, also of the University of Cambridge. 

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With Boron On Mars Prove Life Once Existed

September 21, 2017 by  
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NASA’s Mars rover Curiosity has discovered boron in Gale Crater — new evidence that the Red Planet may have been able to support life on its surface in the ancient past.

Boron is a very interesting element to astrologists; on Earth, it’s thought to stabilize the sugary molecule ribose. Ribose is a key component of ribonucleic acid (RNA), a molecule that’s present in all living cells and drives metabolic processes. But ribose is notoriously unstable, and to form RNA, it is thought that boron is required to stabilize it. When dissolved in water, boron becomes borate, which, in turn, reacts with ribose, making RNA possible.

In a new study published in the journal Geophysical Research Letters, researchers analyzed data gathered by Curiosity’s ChemCam (Chemistry and Camera) instrument, which zaps rocks with a powerful laser to see what minerals they contain. ChemCam detected the chemical fingerprint of boron in calcium-sulfate mineral veins that have been found zigzagging their way through bedrock in Gale Crater, the 96-mile-wide (154 kilometers) crater that the rover is exploring. These veins were formed by the presence of ancient groundwater, meaning the water contained borate.

The find raises exciting possibilities, the researchers said.

“Because borates may play an important role in making RNA — one of the building blocks of life — finding boron on Mars further opens the possibility that life could have once arisen on the planet,” study lead author Patrick Gasda, a postdoctoral researcher at Los Alamos National Laboratory in New Mexico, said in a statement. 

“Borates are one possible bridge from simple organic molecules to RNA,” he added. “Without RNA, you have no life. The presence of boron tells us that, if organics were present on Mars, these chemical reactions could have occurred.”

Scientists have long hypothesized that the earliest “proto-life” on Earth emerged from an “RNA World,” where individual RNA strands containing genetic information had the ability to copy themselves. The replication of information is one of the key requirements for basic lifelike systems. Therefore, the detection of boron on Mars, locked in calcium-sulfate veins that we know were deposited by ancient water, shows that borates were present in water “0 to 60 degrees Celsius (32 to 140 degrees Fahrenheit) and with neutral-to-alkaline pH,” the researchers said.

“We detected borates in a crater on Mars that’s 3.8 billion years old, younger than the likely formation of life on Earth,” Gasda added. “Essentially, this tells us that the conditions from which life could have potentially grown may have existed on ancient Mars, independent from Earth.”

Since landing on Mars in 2012, Curiosity has uncovered compelling evidence that the planet used to be a far wetter place than it is now. For example, the rover has found evidence of a lake-and-stream system inside Gale Crater that lasted for long stretches in the distant past. And, by climbing the slopes of Mount Sharp — the 3.4-mile-high (5.5 km) mountain in the crater’s center — Curiosity has been able to examine various layers of sedimentary minerals that formed in the presence of ancient water. 

These studies are helping scientists gain a better understanding of how long these minerals were dissolved in the water, where they were deposited and, ultimately, how they impacted the habitability of the Red Planet. The detection of boron is another strand of evidence supporting the idea that ancient life might have existed on our neighboring planet.

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Can The James Webb Telescope Find Life In Our Solar System

September 18, 2017 by  
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The soon-to-launch James Webb Space Telescope will turn its powerful eye on two of the solar system’s top candidates for hosting alien life: the icy moons Enceladus and Europa, the agency confirmed in a statement this month.

Both Europa (a moon of Jupiter) and Enceladus (a moon of Saturn) are thought to possess subsurface oceans of liquid water beneath thick outer layers of ice. Both moons have also shown evidence of enormous plumes of liquid shooting up through cracks in the surface ice; these plumes could be caused by subsurface geysers, which could provide a source of heat and nutrients to life-forms there, scientists have said.

“We chose these two moons because of their potential to exhibit chemical signatures of astrobiological interest,” said Heidi Hammel, executive vice president of the Association of Universities for Research in Astronomy (AURA), who is leading an effort to use the telescope to study objects in Earth’s solar system.  

The James Webb Space Telescope, nicknamed “Webb,” will capture infrared light, which can be used to identify objects that generate heat but are not hot enough to radiate light (including humans, which is why many night-vision systems utilize infrared light). Researchers are hoping that Webb can help to identify regions on the surfaces of these moons where geologic activity, such as plume eruptions, are taking place. 

Enceladus’ plumes were studied in detail by the Cassini probe at Saturn. The spacecraft spotted hundreds of plumes, and even flew through some of them and sampled their composition. Europa’s plumes were spotted by the Hubble Space Telescope, and researchers know far less about them than those on Europa.

“Are they made of water ice? Is hot water vapor being released? What is the temperature of the active regions and the emitted water?” Geronimo Villanueva, lead scientist on the Webbobservation of Europa and Enceladus, said in the statement. “Webb telescope’s measurements will allow us to address these questions with unprecedented accuracy and precision.”

Webb’s observations will help pave the way for the Europa Clipper mission, a $2 billion orbital mission to the icy moon. Scheduled to launch in the 2020s, Europa Clipper will search for signs of life on Europa. The observations with Webb could identify areas of interest for the Europa Clipper mission to investigate, according to the statement.

As seen by Webb, the Saturn moon Enceladus will appear about 10 times smaller than Europa, so scientists will not be able to capture high-resolution views of Enceladus’ surface, according to the statement. However, Webb can still analyze the molecular composition of Enceladus’ plumes. 

But it’s also possible that the observations won’t catch a plume erupting from Europa’s surface; scientists don’t know how frequently these geysers erupt, and the limited observing time with Webb may not coincide with one of them. The telescope can detect organics — elements such as carbon that are essential to the formation of life as we know it — in the plumes. However, Villanueva cautioned that Webb does not have the power to directly detect life-forms in the plumes.

Webb is set to launch in 2018 and will orbit the sun at the L2 Lagrange point, which is about one million miles (1.7 million km) farther from the sun than the Earth’s orbit around the sun. The telescope will provide high-resolution views of both the very distant and very nearby universe. Scientists have already begun submitting ideas for objects or regions that should be observed using Webb’s powerful eye, and Europa and Enceladus are among the objects that are now guaranteed observing time.

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Project Blue Telescope Goes CrowdFunding

September 15, 2017 by  
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The private space telescope initiative Project Blue launched a new crowdfunding campaign Sept. 6 in a second attempt to raise money for its mission to directly image Earth-like exoplanets. 

The initiative aims to launch a small space telescope into low-Earth orbit. The telescope will spy on our interstellar neighbor Alpha Centauri and image any Earth-like planets that might orbit the star system.

In support of Project Blue, BoldlyGo Institute and numerous organizations, including the SETI (Search for Extraterrestrial Intelligence) Institute, the University of Massachusetts Lowell and Mission Centaur, launched an IndieGoGo campaign to raise $175,000 over the next two months. The funds will be used to establish mission requirements, design the initial system architecture and test its capability for detecting exoplanets. Project leaders will also begin looking for potential partners who could manufacture parts of the space telescope, representatives said in a statement. 

“We’re very excited to pursue such an impactful space mission and, as a privately-funded effort, to include a global community of explorers and space science advocates in Project Blue from the beginning,” Jon Morse, CEO of BoldlyGo Institute, said in the statement.

Last year, Project Blue organizers attempted to raise $1 million through the crowdfunding platform Kickstarter, but the campaign was canceled after only $335,597 was contributed and Project Blue received none of the funds (as is Kickstarter’s policy). 

With the IndieGoGo campaign, however, the organizers have a more flexible goal and will be able to keep all contributions from supporters, even if the initial goal of $175,000 is not reached. So far, more than $45,000 has been raised through the campaign.

The neighboring star system Alpha Centauri is located only 4.37 light-years from Earth, making it a target for scientific research. Project Blue estimates it will take about $50 million to build the special-purpose telescope, which is planned to launch in 2021. 

The small space telescope will use a specialized coronagraph to block the bright glare of Alpha Centauri’s stars and detect planets that may be orbiting there. One planet, Proxima b, has already been detected around Proxima Centauri. 

However, Proxima b was discovered indirectly, by measuring the planet’s gravitational effect on its host star. Instead, the Project Blue telescope will be designed to directly image Earth-like planets in Alpha Centauri’s neighborhood.

 

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Do Trappist-1 Planets Have Enough Water For Alien Life

September 11, 2017 by  
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The new study looks at how much ultraviolet (UV) radiation is received by each of the planets, because this could affect how much water the worlds could sustain over billions of years, according to the study. Lower-energy UV light can break apart water molecules into hydrogen and oxygen atoms on a planet’s surface, while higher-energy UV light (along with X-rays from the star) can heat a planet’s upper atmosphere and free the separated hydrogen and oxygen atoms into space, according to the study. (It’s also possible that the star’s radiation destroyed the planets’ atmospheres long ago.)

The researchers measured the amount of UV radiation bathing the TRAPPIST-1 planets using NASA’s Hubble Space Telescope, and in their paper they estimate just how much water each of the worlds could have lost in the 8 billion years since the system formed.

It’s possible that the six innermost planets (identified by the letters b, c, d, e, f and g), pelted with the highest levels of UV radiation, could have lost up to 20 Earth-oceans’ worth of water, according to the paper. But it’s also possible that the outermost four planets (e, f, g and h — the first three of which are in the star’s habitable zone) lost less than three Earth-oceans’ worth of water.

If the planets had little or no water to start with, the destruction of water molecules by UV radiation could spell the end of the planets’ habitability. But it’s possible that the planets were initially so rich in liquid water that, even with the water loss caused by UV radiation, they haven’t dried up,  according to one of the study’s authors, Michaël Gillon, an astronomer at the University of Liège in Belgium. Gillon was also lead author on two studies that first identified the seven TRAPPIST-1 planets.

“It is very likely that the planets formed much farther away from the star [than they are now] and migrated inwards during the first 10 million years of the system,” Gillon told Space.com in an email.

Farther away from their parent star, the planets might have formed in an environment rich in water ice, meaning the planets could have initially had very water-rich compositions.

“We’re talking about dozens, and maybe even hundreds of Earth-oceans, so a loss of 20 Earth-oceans wouldn’t matter much,” Gillon said. “What our results show is that even if the outer planets were initially quite water-poor like the original Earth, they could still have some water on their surfaces.”

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Is “Opportunity” The Longest Running Rover On Mars

August 24, 2017 by  
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Opportunity is a rover that has been working on Mars since January 2004. Originally intended to last 90 days, the machine is still trekking after 13 years on the Red Planet. In 2015, it passed a driving milestone, reaching more than a marathon’s worth of distance (26.2 miles, or 42.1 kilometers) – and the rover keeps racking up driving time.

Lately, however, it has been showing its age. In 2014 and early 2015, NASA made several attempts to restore Opportunity’s flash memory capabilities after the rover experienced problems. Flash memory allows the rover to store information even when it is powered off. In 2015, NASA decided to continue most operations with random-access memory instead, which keeps data only when the power in the rover is on. At the time, NASA said the only change to operations will be requiring Opportunity to send high-priority data right away, as it cannot be stored if the rover is turned off. 

That said, the mission has been extremely productive on the Red Planet. Opportunity has explored two large craters — Victoria and Endeavour — among many other locations. Along the way, the rover has found multiple signs of water — while surviving a sand trap and bad dust storm.

Making an orphan’s dream come true

Opportunity and its twin rover, Spirit, received their names from 9-year-old Sofi Collis. She was the winner of a naming contest NASA held (with assistance from the Planetary Society and sponsorship from Lego) to find monikers for the Mars Exploration Rovers. Siberian-born Collis was adopted at age 2 and came to live with her new family in Scottsdale, Arizona.

“I used to live in an orphanage,” Collis wrote in her winning essay. “It was dark and cold and lonely. At night, I looked up at the sparkly sky and felt better. I dreamed I could fly there. In America, I can make all my dreams come true. Thank you for the ‘Spirit’ and the ‘Opportunity.'”

The Mars Exploration Rovers launched in 2003 on a 283-million-mile (455.4 million kilometers) journey to hunt for water on Mars. The $800-million cost for the two of them covered a suite of science instruments. Site survey tools included a panoramic camera, as well as a mini-thermal emission spectrometer that was supposed to search for signs of heat. Each rover also had a small arm with tools such as spectrometers and a microscopic imager.

Cruise to Mars

Opportunity left Earth July 7, 2003, aboard a Delta II rocket en route to a landing site at the Martian equator called Meridiani Planum. NASA was intrigued by a layer of hematite that the orbiting Mars Global Surveyor spotted from above. As hematite (an iron oxide) often forms in a spot that had liquid water, NASA was curious about how the water got there in the first place and where the water went.

The 384-pound rover made its final approach to Mars on Jan. 25, 2004. It plowed through the Martian atmosphere, popped out a parachute and then vaulted to the surface in a cocoon of airbags.

Opportunity rolled to a stop inside a shallow crater just 66 feet (20 meters) across, delighting scientists as the first pictures beamed back from the Red Planet. “We have scored a 300-million mile interplanetary hole-in-one,” quipped Cornell University’s Steve Squyres, principal investigator for the rover’s science instruments, in a press release in the days after the landing.

Early sols of science

Opportunity and Spirit (which had landed successfully three weeks earlier, on Jan. 3, 2004) had a primary goal to “follow the water” during their time on Mars. They would hunt for any environments that showed evidence of water activity, particularly looking for minerals that may have been left behind after water came through.

Both rovers met that goal quickly. In early March, just six weeks after landing, Opportunity identified a rock outcrop that showed evidence of a liquid past. The rocks at “Guadalupe” had sulfates as well as crystals inside of niches, which are both signs of water. Spirit found water evidence of its own that same week.

Two weeks later, Opportunity found hematite inside some small spheres that NASA dubbed “blueberries” because of their size and shape. Using a spectrometer, Opportunity found evidence of iron inside a group of berries when comparing it to the bare, underlying rock.

The month wasn’t yet over when Opportunity discovered more evidence of water, this time from images of a rock outcrop that probably formed from a deposit of saltwater in the ancient past. Chlorine and bromine found in the rocks helped solidify the theory.

It was a positive start to Opportunity’s mission — and it hadn’t even left the crater where it had landed yet. Before Opportunity’s 90-day prime mission was over, the golf-cart size rover clambered out of Eagle Crater and ventured to its next science target about half a mile away: Endurance Crater. It spotted more water signs there in October.

One of Opportunity’s most dangerous moments came in 2005, when the rover was mired in the sand for five weeks. NASA had put the rover into a “blind drive” on April 26, 2005, meaning the rover was not checking for obstacles as it went. Opportunity then plowed into a 12-inch-high (30 cm) sand dune, where the six-wheeled rover initially had trouble getting out.

To save the stranded rover, NASA ran tests on a model of the rover in a simulated Martian “sandbox” at the Jet Propulsion Laboratory. Based on what they learned in the sandbox, the rover drivers then sent a series of commands to Opportunity. It took the rover about 629 feet (191 meters) of wheel rotations before it was able to move forward three feet, but it cut itself free in early June 2005.

NASA chose to move the rover forward in more careful increments, which was especially important because Opportunity lost the full use of its right-front wheel (because of a seized steering motor) just days before it got stuck in the sand. The rover could still move around just fine with its other three steerable wheels, NASA said.

Opportunity’s experience in the sand came in handy in October 2005, when NASA detected unusual traction problems on Sol 603. Just 16 feet into a planned 148-foot drive, a slip check system on board automatically stopped the rover when it went past a programmed limit. Two Martian days later, Opportunity backed itself out of the problem and kept on going.

Victoria Crater

In late September 2006, Opportunity wheeled up to Victoria Crater after 21 months on the road. It circled the rim for a few months snapping pictures and getting a close look at some layered rocks surrounding the crater. NASA then made a gutsy decision in June 2007 to take Opportunity inside the crater. It was a risk to the rover as it might not have been able to climb up again, but NASA said the science was worth it.

“The scientific allure is the chance to examine and investigate the compositions and textures of exposed materials in the crater’s depths for clues about ancient, wet environments,” NASA stated in a press release. “As the rover travels farther down the slope, it will be able to examine increasingly older rocks in the exposed walls of the crater.”

The trek down was interrupted by a severe dust storm in July 2007. Opportunity’s power-generating capabilities dropped by 80 percent in only one week as its solar panels became covered in dust. Late in the month, Opportunity’s power dipped to critical levels. NASA worried the rover would stop working, but Opportunity pulled through.

It wasn’t until late August that the skies cleared enough for Opportunity to resume work and head into the crater. Opportunity spent about a year wandering through Victoria Crater, getting an up-close look at the layers on the bottom and figuring that these were likely shaped by water.

Opportunity climbed out successfully in August 2008 and began a gradual journey to Endeavour, an incredible 13 miles (21 km) away. It took about three years to get there, as the rover was stopping to look at interesting science targets on the way. But Opportunity successfully arrived in August 2011.

Opportunity’s water history examinations continued at Endeavour, with one example being a 2013 probe of a rock called “Esperance.” The rock not only has clay minerals produced by water, but there was enough of the liquid to “flush out ions set loose by those reactions,” stated Opportunity long-term planned Scott McLennan of the State University of New York, at the time.

By mid-year 2014, however, Opportunity was experiencing problems with its aging memory. The rover used Flash memory to store information when it went into hibernation during the Martian nights, which take place about as frequently as they do on Earth. 

Controllers did a remote memory wipe from Earth, but memory issues and resets continued to plague the rover through the end of the year. Eventually, officials elected to stop using Flash memory, move storage over to random access memory (RAM) instead, and find a way to address the problem more thoroughly. In 2015, NASA decided to use RAM in most situations, which requires Opportunity to send high-priority data right away as the information cannot be stored if the rover is off.

Despite these issues, Opportunity continues rolling on the Red Planet. It set an off-world driving record in July 2014 when it successfully passed 25.01 miles (40.2 kilometers), exceeding the distance from the Soviet Union’s remote-controlled lunar Lunokhod 2 rover in 1973. In March 2015, it passed another huge milestone: completing a marathon on Mars.

The rover successfully imaged Comet Siding Spring when the celestial body sped fairly close to Mars in October 2014. In January 2015, Opportunity took pictures from a “high point” on the rim of Endeavour, about 440 feet (134 feet) above the surrounding crater floor. In March 2015, NASA announced that the rover – while overlooking an area nicknamed “Marathon Valley” – had seen some rocks with a composition unlike others studied by Spirit or Opportunity; one of the features was high concentrations of aluminum and silicon. 

After working through a Martian winter, in March 2016, Opportunity tackled its steepest slope ever — reaching a tilt of 32 degrees — while trying to reach a target on “Knudsen Ridge” inside Marathon Valley. As engineers watched the rover’s wheels slip in the sand, they decided (with some reluctance) to skip the target and move to the next thing. 

NASA announced it was wrapping up operations in Marathon Valley in June 2016, and added that Opportunity recently got a close-up look of “red-toned, crumbly material” on the southern slope of the valley. Opportunity scuffed some of this material with a wheel, revealing material with some of the highest sulfur content seen on Mars. NASA said the scuff had strong evidence of magnesium sulfate, a substance expected to precipitate from water. 

As of August 2017, Opportunity was in a location called “Perseverance Valley” on the rim of Endeavour Crater, and the rover had traveled 27.95 miles (44.97 kilometers).

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Will The James Webb Telescope Easily Find Earth Like Planets

August 17, 2017 by  
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The James Webb Space Telescope (JWST), billed as “NASA’s premier observatory of the next decade,” could search for signs of an atmosphere on Proxima b. When it launches next year, JWST will be the most powerful space-based observatory yet, and the largest ever contrcuted. Its 6.5-meter mirror (nearly three times the size of the Hubble Space Telescope’s mirror) is expected to yield insights into the entire universe, ranging from the formation of planets and galaxies to peering at exoplanets in higher resolution than ever before.

There is only so much telescope time for JWST, however, and as with Hubble observations, astronomers will receive access on a competitive basis. Among the many proposals for the telescope that have emerged in recent months following NASA’s solicitation of science projects, a paper accepted for publication in the Astrophysical Journal (a draft version of which is available on Arxiv) suggests using the JWST to probe Proxima b’s atmosphere.

If such observations go forward, the telescope will provide an unparalleled view of Proxima b. JWST is optimized for infrared wavelengths, which can be used to examine a planet’s heat emissions. Because JWST will be orbiting the sun, it won’t be peering through Earth’s atmosphere, whose warmth can interfere with observations.

“Other telescopes are not able to do this,” Ignas Snellan, an astronomy researcher at the University of Leiden in the Netherlands and the paper’s lead author, told Seeker in an email. “Hubble is too small and works in the wrong wavelength range. Current ground-based telescopes cannot touch the mid-infrared because of very high thermal backgrounds, and are in a not enough stable environment, in contrast to JWST, which operates from space.”

The astronomers hope to use JWST to determine whether or not Proxima b has an atmosphere. Snellan said this will be very difficult, because the planet is very faint compared to its parent star. The research team therefore proposes looking for carbon dioxide.

The team’s method “looks for a striking signature that is expected from this molecule at 15 micron, that varies strongly from one wavelength to the next,” Snellan explained. “It will be very challenging, but we think doable.”

Finding carbon dioxide isn’t necessarily a sign of life as we know it. The gas is only found in trace amounts in Earth’s atmosphere (which is mostly made up of nitrogen and oxygen), even though carbon is the primary basis for life on our planet.

But carbon dioxide is a common gas on both Venus, which has a hellishly thick atmosphere, and Mars. Though the Red Planet once had a much thicker atmosphere long ago, today it is very thin. Scientists are still investigating how this atmospheric loss occurred, but suggest that the sun might have pushed light molecules out of Mars’ upper atmosphere that could not be held in by the planet’s gravity. Life may have existed on Mars in the ancient past, but scientists aren’t sure if that was possible then — or even now.

Might Proxima b be hospitable to life? Scientists are eager to look at the exoplanet in more detail, but Snellen notes that even better telescopes will be needed to answer that question. He suggests that the European Extremely Large Telescope could do the job after construction of the massive observatory is completed in the next decade. It would be able to probe for oxygen, which is a more definitive sign of life.

Meanwhile, the Breakthrough Starshot Initiative, which aims to one day send ultra-fast nanoprobes to the Alpha Centauri star system, is planning to soon begin examining the system’s three stars. The initiative recently partnered with the European Southern Observatory’s Very Large Telescope to look for worlds that could be habitable.

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Astronomers Find Stratrosphere On Alien World

August 10, 2017 by  
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A huge, superhot alien planet has a stratrosphere, like Earth does, a new study suggests. 

“This result is exciting because it shows that a common trait of most of the atmospheres in our solar system — a warm stratosphere — also can be found in exoplanet atmospheres,” study co-author Mark Marley, of NASA’s Ames Research Center in California’s Silicon Valley, said in a statement.

“We can now compare processes in exoplanet atmospheres with the same processes that happen under different sets of conditions in our own solar system,” Marley added. [Gallery: The Strangest Alien Planets] 

The research team, led by Thomas Evans of the University of Exeter in England, detected spectral signatures of water molecules in the atmosphere of WASP-121b, a gas giant that lies about 880 light-years from Earth. These signatures indicate that the temperature of the upper layer of the planet’s atmosphere increases with the distance from the planet’s surface. In the bottom layer of the atmosphere, the troposphere, the temperature decreases with altitude, study team members said.

WASP-121b lies incredibly close to its host star, completing one orbit every 1.3 days. The planet is a “hot Jupiter”; temperatures at the top of its atmosphere reach a sizzling 4,500 degrees Fahrenheit (2,500 degrees Celsius), researchers said.

“The question [of] whether stratospheres do or do not form in hot Jupiters has been one of the major outstanding questions in exoplanet research since at least the early 2000s,” Evans told Space.com. “Currently, our understanding of exoplanet atmospheres is pretty basic and limited. Every new piece of information that we are able to get represents a significant step forward.”

The discovery is also significant because it shows that atmospheres of distant exoplanets can be analyzed in detail, said Kevin Heng of the University of Bern in Switzerland, who is not a member of the study team. 

“This is an important technical milestone on the road to a final goal that we all agree on, and the goal is that, in the future, we can apply the very same techniques to study atmospheres of Earth-like exoplanets,” Heng told Space.com. “We would like to measure transits of Earth-like planets. We would like to figure out what type of molecules are in the atmospheres, and after we do that, we would like to take the final very big step, which is to see whether these molecular signatures could indicate the presence of life.”

Available technology does not yet allow such work with small, rocky exoplanets, researchers said. 

“We are focusing on these big gas giants that are heated to very high temperatures due to the close proximity of their stars simply because they are the easiest to study with the current technology,” Evans said. “We are just trying to understand as much about their fundamental properties as possible and refine our knowledge, and, hopefully in the decades to come, we can start pushing towards smaller and cooler planets.”

WASP-121b is nearly twice the size of Jupiter. The exoplanet transits, or crosses the face of, its host star from Earth’s perspective. Evans and his team were able to observe those transits using an infrared spectrograph aboard NASA’s Hubble Space Telescope.

“By looking at the difference in the brightness of the system for when the planet was not behind the star and when it was behind the star, we were able to work out the brightness and the spectrum of the planet itself,” Evans said. “We measured the spectrum of the planet using this method at a wavelength range which is very sensitive to the spectral signature of water molecules.”

The team observed signatures of glowing water molecules, which indicated that WASP-121b’s atmospheric temperatures increase with altitude, Evans said. If the temperature decreased with altitude, infrared radiation would at some point pass through a region of cooler water-gas, which would absorb the part of the spectrum responsible for the glowing effect, he explained. 

There have been hints of stratospheres detected on other hot Jupiters, but the new results are the most convincing such evidence to date, Evans said.

“It’s the first time that it has been done clearly for an exoplanet atmosphere, and that’s why it’s the strongest evidence to date for an exoplanet stratosphere,” he said. 

He added that researchers might be able to move closer to studying more Earth-like planets with the arrival of next-generation observatories such as NASA’s James Webb Space Telescope and big ground-based observatories such as the Giant Magellan Telescope (GMT), the European Extremely Large Telescope (E-ELT) and the Thirty Meter Telescope (TMT). JWST is scheduled to launch late next year, and GMT, E-ELT and TMT are expected to come online in the early to mid-2020s.

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