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  • richardmitnick 10:14 pm on November 18, 2014 Permalink | Reply
    Tags: Astrobiology, , , , , ,   

    From JPL: “Second Time Through, Mars Rover Examines Chosen Rocks” 


    November 18, 2014
    Guy Webster
    Jet Propulsion Laboratory, Pasadena, Calif.

    NASA’s Curiosity Mars rover has completed a reconnaissance “walkabout” of the first outcrop it reached at the base of the mission’s destination mountain and has begun a second pass examining selected rocks in the outcrop in more detail.

    NASA Mars Curiosity Rover

    This small ridge, about 3 feet (1 meter) long, appears to resist wind erosion more than the flatter plates around it. Such differences are among the rock characteristics that NASA’s Curiosity Mars rover is examining at selected targets at the base of Mount Sharp.

    The ridge pictured here, called “Pink Cliffs,” is within the “Pahrump Hills” outcrop forming part of the basal layer of the mountain. This view is a mosaic of exposures acquired by Curiosity’s Mast Camera (Mastcam) shortly before a two-week walkabout up the outcrop, scouting to select which targets to examine in greater detail during a second pass.

    Pink Cliffs is one of the targets chosen for closer inspection. This image combines several frames taken with the Mastcam on Oct. 7, 2014, the 771st Martian day, or sol of Curiosity’s work on Mars. The color has been approximately white-balanced to resemble how the scene would appear under daytime lighting conditions on Earth.

    Exposed layers on the lower portion of Mount Sharp are expected to hold evidence about dramatic changes in the environmental evolution of Mars. That was a major reason NASA chose this area of Mars for this mission. The lowermost of these slices of time ascending the mountain includes a pale outcrop called “Pahrump Hills.” It bears layers of diverse textures that the mission has been studying since Curiosity acquired a drilled sample from the outcrop in September.

    In its first pass up this outcrop, Curiosity drove about 360 feet (110 meters), and scouted sites ranging about 30 feet (9 meters) in elevation. It evaluated potential study targets from a distance with mast-mounted cameras and a laser-firing spectrometer.

    “We see a diversity of textures in this outcrop — some parts finely layered and fine-grained, others more blocky with erosion-resistant ledges,” said Curiosity Deputy Project Scientist Ashwin Vasavada of NASA’s Jet Propulsion Laboratory, Pasadena, California. “Overlaid on that structure are compositional variations. Some of those variations were detected with our spectrometer. Others show themselves as apparent differences in cementation or as mineral veins. There’s a lot to study here.”

    During a second pass up the outrcrop, the mission is using a close-up camera and spectrometer on the rover’s arm to examine selected targets in more detail. The second-pass findings will feed into decisions about whether to drill into some target rocks during a third pass, to collect sample material for onboard laboratory analysis.

    “The variations we’ve seen so far tell us that the environment was changing over time, both as the sediments were laid down and also after they hardened into bedrock,” Vasavada said. “We have selected targets that we think give us the best chance of answering questions about how the sediments were deposited — in standing water? flowing water? sand blowing in the wind? — and about the composition during deposition and later changes.”

    The first target in the second pass is called “Pelona,” a fine-grained, finely layered rock close to the September drilling target at the base of Pahrump Hills outcrop. The second is a more erosion-resistant ledge called “Pink Cliffs.”

    Before examining Pelona, researchers used Curiosity’s wheels as a tool to expose a cross section of a nearby windblown ripple of dust and sand. One motive for this experiment was to learn why some ripples that Curiosity drove into earlier this year were more difficult to cross than anticipated.

    While using the rover to investigate targets in Pahrump Hills, the rover team is also developing a work-around for possible loss of use of a device used for focusing the telescope on Curiosity’s Chemistry and Camera (ChemCam) instrument, the laser-firing spectrometer.

    Diagnostic data from ChemCam suggest weakening of the instrument’s smaller laser. This is a continuous wave laser used for focusing the telescope before the more powerful laser is fired. The main laser induces a spark on the target it hits; light from the spark is received though the telescope and analyzed with spectrometers to identify chemical elements in the target. If the smaller laser has become too weak to continue using, the ChemCam team plans to test an alternative method: firing a few shots from the main laser while focusing the telescope, before performing the analysis. This would take advantage of more than 2,000 autofocus sequences ChemCam has completed on Mars, providing calibration points for the new procedure.

    Curiosity landed on Mars in August 2012, but before beginning the drive toward Mount Sharp, the rover spent much of the mission’s first year productively studying an area much closer to the landing site, but in the opposite direction. The mission accomplished its science goals in that Yellowknife Bay area. Analysis of drilled rocks there disclosed an ancient lakebed environment that, more than three billion years ago, offered ingredients and a chemical energy gradient favorable for microbes, if any existed there.

    Curiosity spent its second year driving more than 5 miles (8 kilometers) from Yellowknife Bay to the base of Mount Sharp, with pauses at a few science waypoints.

    NASA’s Mars Science Laboratory Project is using Curiosity to assess ancient habitable environments and major changes in Martian environmental conditions. JPL, a division of the California Institute of Technology in Pasadena, built the rover and manages the project for NASA’s Science Mission Directorate in Washington.

    For more information about Curiosity, visit:



    You can follow the mission on Facebook and Twitter at:



    See the full article here.

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    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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  • richardmitnick 9:31 pm on November 18, 2014 Permalink | Reply
    Tags: Astrobiology, , , , ,   

    From BBC- “Comet landing: Organic molecules detected by Philae” 


    18 November 2014
    Paul Rincon

    The Philae lander has detected organic molecules on the surface of its comet, scientists have confirmed.


    Carbon-containing “organics” are the basis of life on Earth and may give clues to chemical ingredients delivered to our planet early in its history.

    The compounds were picked up by a German-built instrument designed to “sniff” the comet’s thin atmosphere.

    Other analyses suggest the comet’s surface is largely water-ice covered with a thin dust layer.

    The European Space Agency (ESA) craft touched down on the Comet 67P on 12 November after a 10-year journey.

    Dr Fred Goessmann, principal investigator on the Cosac instrument, which made the organics detection, confirmed the find to BBC News. But he added that the team was still trying to interpret the results.

    Cosac instrument from Max Planck Institute for Solar System Research

    It has not been disclosed which molecules have been found, or how complex they are.

    But the results are likely to provide insights into the possible role of comets in contributing some of the chemical building blocks to the primordial mix from which life evolved on the early Earth.

    Preliminary results from the Mupus instrument, which deployed a hammer to the comet after Philae’s landing, suggest there is a layer of dust 10-20cm thick on the surface with very hard water-ice underneath.

    Mupus instrument from DLR Institute of Planetary Research

    The ice would be frozen solid at temperatures encountered in the outer Solar System – Mupus data suggest this layer has a tensile strength similar to sandstone.

    “It’s within a very broad spectrum of ice models. It was harder than expected at that location, but it’s still within bounds,” said Prof Mark McCaughrean, senior science adviser to ESA, told BBC News.

    Philae has gone into standby because of low power.

    He explained: “You can’t rule out rock, but if you look at the global story, we know the overall density of the comet is 0.4g/cubic cm. There’s no way the thing’s made of rock.

    “It’s more likely there’s sintered ice at the surface with more porous material lower down that hasn’t been exposed to the Sun in the same way.”

    After bouncing off the surface at least twice, Philae came to a stop in some sort of high-walled trap.

    “The fact that we landed up against something may actually be in our favour. If we’d landed on the main surface, the dust layer may have been even thicker and it’s possible we might not have gone down [to the ice],” said Prof McCaughrean.

    Scientists had to race to perform as many key tests as they could before Philae’s battery life ran out at the weekend.

    On re-charge

    A key objective was to drill a sample of “soil” and analyse it in Cosac’s oven. But, disappointingly, the latest information suggest no soil was delivered to the instrument.

    Prof McCaughrean explained: “We didn’t necessarily see many organics in the signal. That could be because we didn’t manage to pick up a sample. But what we know is that the drill went down to its full extent and came back up again.”

    “But there’s no independent way to say: This is what the sample looks like before you put it in there.”

    Scientists are hopeful however that as Comet 67P/Churyumov-Gerasimenko approaches the Sun in coming months, Philae’s solar panels will see sunlight again. This might allow the batteries to re-charge, and enable the lander to perform science once more.

    “There’s a trade off – once it gets too hot, Philae will die as well. There is a sweet spot,” said Prof McCaughrean.

    He added: “Given the fact that there is a factor of six, seven, eight in solar illumination and the last action we took was to rotate the body of Philae around to get the bigger solar panel in, I think it’s perfectly reasonable to think it may well happen.

    “By being in the shadow of the cliff, it might even help us, that we might not get so hot, even at full solar illumination. But if you don’t get so hot that you don’t overheat, have you got enough solar power to charge the system.”

    The lander’s Alpha Particle X-ray Spectrometer (APXS) , designed to provide information on the elemental composition of the surface, seems to have partially seen a signal from its own lens cover – which could have dropped off at a strange angle because Philae was not lying flat.

    Alpha Particle X-ray Spectrometer (APXS) from NASA/JPL

    See the full article here.

    [I gotta say, I am not sure if the results in the story match the headline. But, hey, I am not a rocket scientist.]

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  • richardmitnick 6:13 pm on November 10, 2014 Permalink | Reply
    Tags: Astrobiology, , , , , ,   

    From astrobio.net: “Preparing for Alien Life” 

    Astrobiology Magazine

    Astrobiology Magazine

    Nov 10, 2014
    Johnny Bontemps

    At a recent event sponsored by NASA and the Library of Congress, a group of scientists and scholars explored how we might prepare for the inevitable discovery of life beyond Earth.

    In 1960, the astronomer Francis Drake pointed a radio telescope located in Green Bank, West Virginia, toward two Sun-like stars 11 light years away. His hope: to pick up a signal that would prove intelligent life might be out there. Fifty years have gone by since Drake’s pioneering SETI experiment, and we’ve yet to hear from the aliens.

    NRAO/Green Bank Radio Telescope

    But thanks to a host of discoveries, the idea that life might exist beyond Earth now seems more plausible than ever. For one, we’ve learned that life can thrive in the most extreme environments here on Earth — from deep-sea methane seep and Antarctic sea ice to acidic rivers and our driest deserts.

    We’ve also found that liquid water isn’t unique to our planet. Saturn’s moon Enceladus and Jupiter’s moons Ganymede and Europa harbor large oceans beneath their icy surfaces. Even Saturn’s largest moon, Titan, could spawn some kind of life in its lakes and rivers of methane-ethane.

    And then there’s the discovery of exoplanets, with more than 1800 alien worlds beyond our Solar System identified so far. In fact, astronomers estimate there may be a trillion planets in our galaxy alone, one-fifth of which may be Earth-like. As Carl Sagan famously said: “The Universe is a pretty big place. If it’s just us, seems like an awful waste of space.”

    NASA Kepler Telescope
    NASA/Kepler exoplanet hunter

    Now some scientists believe the hunt for life beyond Earth may well pay off in our lifetimes. “There have been 10,000 generations of humans before us. Ours could be the first to know,” said SETI astronomer Seth Shostak.

    But what happens once we do? How would we handle the discovery? And what would be its impact on society?

    This artist’s concept illustrates the idea that rocky, terrestrial worlds like the inner planets in our Solar System may be plentiful, and diverse, in the Universe. Image Credit: NASA/JPL–Caltech/

    This was the focus of a conference organized last September by the NASA Astrobiology Program and the Library of Congress. For two days, a group of scientists, historians, philosophers and theologians from around the world explored how we might prepare for the inevitable discovery of life — microbial or intelligent — elsewhere in our Universe.

    The symposium was hosted by Steven J. Dick, the second annual Chair in Astrobiology at the Library of Congress. The video presentations can be viewed here.

    “Three Horse Races”

    Of course, the impact of discovery will depend on the specific scenario. In a talk titled Current Approaches to Finding Life Beyond Earth, and What Happens If We Do, Shostak described three ways — or three “horse races” — for finding life in space.

    First, we could find it nearby, in our Solar System. NASA’s Curiosity Rover is currently surveying the Martian surface for signs of past or present life. And Europa Clipper, a mission to Jupiter’s icy moon, is now under consideration.

    NASA Mars Curiosity Rover

    NASA Europa Clipper
    Europa Clipper schematic

    Second, we could “sniff it out” of the atmosphere of an exoplanet, using telescopes to look for gases such as methane and oxygen that might hint at a biosphere. The James Webb Space Telescope, to be launched in 2018, will be able to carry out that kind of work.

    NASA James Webb Telescope

    And of course we can pursue the kind of SETI work pioneered by Frank Drake, and keep listening for radio signals among the stars.

    This illustration of Europa (foreground), Jupiter (right) and Io (middle) is an artist’s concept. Image credit: NASA/JPL-Caltech

    Finding life in our Solar System, which likely would be microbial, might not have as great an impact as hearing from an intelligent civilization far away. We’d have to worry about issues like contamination. We might also discover some alternative biochemistry, perhaps uncovering new insights about the nature of life. But that kind of discovery wouldn’t affect us as much as the prospect of communicating with intelligent life.

    Then again it’d take hundreds, if not thousands of years for a signal to travel back and forth, Shostak pointed out. So that third scenario would only teach us a very few things right away, such as their location or what kind of star they orbit.

    However, picking a signal might have other tantalizing implications about the nature of alien intelligence.

    Alien Minds & Artificial Intelligence

    Several researchers, including Shostak, put forward the following premise: “That once a society creates the technology that could put them in touch with the cosmos, they are only a few hundred years away from changing their paradigm from biology to artificial intelligence.”

    The idea is based on the so-called “time scale argument” or “short window observation.” Many researchers predict we’ll have developed a strong artificial intelligence by 2050 here on Earth — about a hundred years after the invention of computers, or a hundred and fifty years after the invention of radio communication.

    “The point is that, going from inventing radios to inventing thinking machines is very short — a few centuries at most,” Shostak said. “The dominant intelligence in the cosmos may well be non-biological.”

    In a talk titled Alien Minds, Susan Schneider, a philosophy professor at the University of Connecticut, explored that idea further. The concept of “whole brain emulation” is becoming increasingly popular among certain researchers, she explained. So are other far-fetched sounding ideas like “mind uploading” and “immortally.” So, to her, a civilization capable of radio communication would likely be “super-intelligent” by the time we hear from them.

    According to the “short window observation” idea, a civilization capable of radio communication would likely have developed artificial intelligence by the time we hear from them.
    No image credit

    She also argued that alien super-intelligence would be conscious in principle, since the neural code is akin to a computational code, and thoughts could well be embedded in a silicon-based substrate. A silicon-based intelligence would also have tremendous implications for long distance space travel.

    But again, a recurring theme throughout the conference was to be aware of our anthropocentric tendencies. There’s been a huge gap between microbial life and intelligent life on Earth, and even intelligent life has even evolved on a spectrum.

    Lori Marino, a neuroscientist and current director of the Kimela Center for Animal Advocacy, argued as such in a talked titled The Landscape of Intelligence. We have a lot to learn from other intelligent beings here on Earth (such as dolphins) before even thinking about communicating with aliens.

    Philosophical Impact

    Ultimately, the greatest implications might be philosophical. Whether it turns out to be microbial, complex or intelligent, finding life elsewhere will raise intriguing questions about our place in the cosmos.

    A couple of presentations, by theologian Robin Lovin and Vatican astronomer Guy Consolmagno, even addressed the potential impact on the world’s religions.

    But what if we don’t find anything soon, or even at all?

    The search itself can give us a sense of direction, and help us forge a planetary identity, argued the philosopher Clement Vidal in a talk titled Silent Impact. And if we’re truly alone, then we should start taking better care of life here on Earth, and contemplate our duty of colonization, he added.

    The search itself can help us forge a planetary identity, said philosopher Clement Vidal. Image credit: NASA

    In the meantime, astrobiology can help narrow the gap between the sciences and humanities, as many presenters emphasized. And it can be a step toward integrating our knowledge across a wide range of disciplines.

    So, how do we prepare for something we know so little about? We do so “by continuing to do good science, but also by realizing that science is not metaphysically neutral,” concluded the conference host Steven Dick.

    He added: “We prepare by continuing to question our assumptions about the nature of life and intelligence.”

    See the full article here.


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  • richardmitnick 9:29 pm on November 7, 2014 Permalink | Reply
    Tags: Astrobiology, , , , ,   

    From Daily Galaxy: “”Are We the Only Technologically-Intensive Civilization in the Universe?” -How Long Can It Last Ask Scientists” 

    Daily Galaxy
    The Daily Galaxy

    November 06, 2014
    via University of Rochester

    “We have no idea how long a technological civilization like our own can last,” says University of Rochester astrophysicist Adam Frank. “Is it 200 years, 500 years or 50,000 years? Answering this question is at the root of all our concerns about the sustainability of human society. Are we the first and only technologically-intensive civilization in the entire history of the universe? If not, shouldn’t we stand to learn something from the past successes and failures of other species?”
    Human-caused climate change, ocean acidification and species extinctions may eventually threaten the collapse of civilization, according to some scientists, while other people argue that for political or economic reasons we should allow industrial development to continue without restrictions. In a new paper, two astrophysicists argue that these questions may soon be resolvable scientifically, thanks to new data about the Earth and about other planets in our galaxy, and by combining the earth-based science of sustainability with astrobiology.


    In their paper, which appears in the journal Anthropocene, Frank and co-author Woodruff Sullivan call for creation of a new research program to answer questions about humanity’s future in the broadest astronomical context. The authors explain: “The point is to see that our current situation may, in some sense, be natural or at least a natural and generic consequence of certain evolutionary pathways.”

    To frame these questions, Frank and Sullivan begin with the famous Drake equation* , a straightforward formula used to estimate the number of intelligent societies in the universe. In their treatment of the equation, the authors concentrate on the average lifetime of a Species with Energy-Intensive Technology (SWEIT). Frank and Sullivan calculate that even if the chances of forming such a “high tech” species are 1 in a 1,000 trillion, there will still have been 1,000 occurrences of a history like own on planets across the “local” region of the Cosmos.

    “That’s enough to start thinking about statistics,” says Frank, “like what is the average lifetime of a species that starts harvesting energy efficiently and uses it to develop high technology.”

    Employing dynamical systems theory, the authors map out a strategy for modeling the trajectories of various SWEITs through their evolution. The authors show how the developmental paths should be strongly tied to interactions between the species and its host planet. As the species’ population grows and its energy harvesting intensifies, for example, the composition of the planet and its atmosphere may become altered for long timescales.

    The image below is a schematic of two classes of trajectories in SWEIT solution space. Red line shows a trajectory representing population collapse whereby development of energy harvesting technologies allows for rapid population growth which then drives increases in planetary forcing. As planetary support systems change state the SWEIT population is unable to maintain its own internal systems and collapses. Blue line shows a trajectory representing sustainability in which population levels and energy use approach levels that do not push planetary systems into unfavorable states.

    Frank and Sullivan show how habitability studies of exoplanets hold important lessons for sustaining the civilization we have developed on Earth. This “astrobiological perspective” casts sustainability as a place-specific subset of habitability, or a planet’s ability to support life. While sustainability is concerned with a particular form of life on a particular planet, astrobiology asks the bigger question: what about any form of life, on any planet, at any time?

    We don’t yet know how these other life forms compare to the ones we are familiar with here on Earth. But for the purposes of modeling average lifetimes, Frank explains, it doesn’t matter.

    “If they use energy to produce work, they’re generating entropy. There’s no way around that, whether their human-looking Star Trek creatures with antenna on their foreheads, or they’re nothing more than single-cell organisms with collective mega-intelligence. And that entropy will almost certainly have strong feedback effects on their planet’s habitability, as we are already beginning to see here on Earth.”

    The image below is a plot of human population, total energy consumption and atmospheric CO2 concentration from 10,000 BCE to today. Note the coupled increase in all 3 quantities over the last century.

    “Maybe everybody runs into this bottleneck,” says Frank, adding that this could be a universal feature of life and planets. “If that’s true, the question becomes whether we can learn anything by modeling the range of evolutionary pathways. Some paths will lead to collapse and others will lead to sustainability. Can we, perhaps, gain some insight into which decisions lead to which kind of path?”

    As Frank and Sullivan show, studying past extinction events and using theoretical tools to model the future evolutionary trajectory of humankind–and of still unknown but plausible alien civilizations–could inform decisions that would lead to a sustainable future.

    See the full article here.

    *Frank Donald Drake (born May 28, 1930) is an American astronomer and astrophysicist. He is most notable as one of the pioneers in the search for extraterrestrial intelligence, including the founding of SETI Institute.

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  • richardmitnick 1:46 pm on November 2, 2014 Permalink | Reply
    Tags: , Astrobiology, ,   

    From astrobio.net: “Lack of oxygen delayed the rise of animals on Earth” 

    Astrobiology Magazine

    Astrobiology Magazine

    Nov 2, 2014
    No Writer Credit

    Geologists are letting the air out of a nagging mystery about the development of animal life on Earth.

    Scientists have long speculated as to why animal species didn’t flourish sooner, once sufficient oxygen covered the Earth’s surface. Animals began to prosper at the end of the Proterozoic period, about 800 million years ago — but what about the billion-year stretch before that, when most researchers think there also was plenty of oxygen?

    Well, it seems the air wasn’t so great then, after all.

    Christopher Reinhard and Noah Planavsky conduct research for the study in China. Credit: Yale University

    In a study published Oct. 30 in Science, Yale researcher Noah Planavsky and his colleagues found that oxygen levels during the “boring billion” period were only 0.1% of what they are today. In other words, Earth’s atmosphere couldn’t have supported a diversity of creatures, no matter what genetic advancements were poised to occur.

    “There is no question that genetic and ecological innovation must ultimately be behind the rise of animals, but it is equally unavoidable that animals need a certain level of oxygen,” said Planavsky, co-lead author of the research along with Christopher Reinhard of the Georgia Institute of Technology. “We’re providing the first evidence that oxygen levels were low enough during this period to potentially prevent the rise of animals.”

    The scientists found their evidence by analyzing chromium (Cr) isotopes in ancient sediments from China, Australia, Canada, and the United States. Chromium is found in the Earth’s continental crust, and chromium oxidation is directly linked to the presence of free oxygen in the atmosphere.

    Specifically, the team studied samples deposited in shallow, iron-rich ocean areas, near the shore. They compared their data with other samples taken from younger locales known to have higher levels of oxygen.

    Oxygen’s role in controlling the first appearance of animals has long vexed scientists. “We were missing the right approach until now,” Planavsky said. “Chromium gave us the proxy.” Previous estimates put the oxygen level at 40% of today’s conditions during pre-animal times, leaving open the possibility that oxygen was already plentiful enough to support animal life.

    In the new study, the researchers acknowledged that oxygen levels were “highly dynamic” in the early atmosphere, with the potential for occasional spikes. However, they said, “It seems clear that there is a first-order difference in the nature of Earth surface Cr cycling” before and after the rise of animals.

    “If we are right, our results will really change how people view the origins of animals and other complex life, and their relationships to the co-evolving environment,” said co-author Tim Lyons of the University of California-Riverside. “This could be a game changer.”

    “There’s a lot of interest right now in a broader discussion surrounding the role that environmental stability played in the evolution of complex life, and we think our results are a significant contribution to that,” Reinhard said.

    See the full article here.


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  • richardmitnick 4:34 am on October 30, 2014 Permalink | Reply
    Tags: Astrobiology, , , , , ,   

    From astrobio.net: “Planetary Atmospheres a Key to Assessing Possibilities for Life” 

    Astrobiology Magazine

    Astrobiology Magazine

    Oct 30, 2014
    No Writer Credit

    A planetary atmosphere is a delicate thing. On Earth, we are familiar with the ozone hole — a tear in our upper atmosphere caused by human-created chemicals that thin away the ozone. Threats to an atmosphere, however, can also come from natural causes.

    Earth’s atmosphere likely changed from a helium-heavy one to the nitrogen and oxygen mix we see today. Credit: NASA

    If a big enough asteroid smacks into a planet, it can strip the atmosphere away. Radiation from a star can also make an atmosphere balloon, causing its lighter elements to escape into space.

    Understanding how permanent an atmosphere is, where it came from, and most importantly what it is made of are key to understanding if a planet outside our solar system is habitable for life. Our instruments aren’t yet sophisticated enough to look at atmospheres surrounding Earth-sized planets, but astronomers are starting to gather data on larger worlds to do comparative studies.

    One such example was recently accepted in the journal Astrophysical Journal and is available now in a preprint version on Arxiv. The astronomers created models of planetary formation and then simulated atmospheric stripping, the process where a young star’s radiation can push lighter elements out into space.

    Next, the team compared their findings to data gathered from NASA’s planet-hunting Kepler Space Telescope. The researchers predict that the atmospheric mass of the planets Kepler found is, in some cases, far greater than the thin veneer of air covering Earth.

    NASA Kepler Telescope

    Co-author Christoph Mordasini, who studies planet and star formation at the Max Planck Institute for Astronomy in Heidelberg, Germany, cautioned there is likely an observational bias with the Kepler data.

    “Kepler systems are so compact, with the planets closer to their star than in our solar system,” said Mordasini.

    Astronomers are still trying to understand why.

    “Maybe some of these objects formed early in their system’s history, in the presence of lots of gas and dust,” he said. “This would have made their atmospheres relatively massive compared to Earth. Our planet probably only formed when the gas was already gone, so it could not form a similar atmosphere.”

    Blowing gas away

    Planetary systems come to be in a cloud of gas and dust, the theory goes. If enough mass gathers in a part of the cloud, that section collapses and creates a star surrounded by a thin disk. When the star ignites, its radiative force will gradually clear the area around it of any debris.

    Over just a few million years, the hydrogen and helium in the disk surrounding the star partially spirals onto the star, while the rest gets pushed farther and farther out into space. Proto-Earth likely had a hydrogen-rich atmosphere at this stage, but over time (with processes such as vulcanism, comet impacts, and biological activity) its atmosphere gradually changed to the nitrogen and oxygen composition we see today.

    Kepler’s data has showed other differences from our own solar system. In our own solar system, there is a vast size difference between Earth and the next-biggest planet, Neptune, which has a radius almost four times that of Earth’s. This means there’s a big dividing line when it comes to size between terrestrial planets and gas giants in our solar system.

    This global view of the surface of Venus is centered at 180 degrees east longitude. Magellan synthetic aperture radar mosaics from the first cycle of Magellan mapping are mapped onto a computer-simulated globe to create this image. Data gaps are filled with Pioneer Venus Orbiter data, or a constant mid-range value. Simulated color is used to enhance small-scale structure. The simulated hues are based on color images recorded by the Soviet Venera 13 and 14 spacecraft. Credit: NASA/JPL

    In Kepler surveys (as well as surveys from other planet-hunting telescopes), scientists have found more of a gradient. There are other planetary systems out there with planets in between Earth’s and Neptune’s sizes, which are sometimes called “super-Earths” or “mini-Neptunes.” Whether planets of this size are habitable is up for debate.

    “The gap between the Earth’s and Uranus’ or Neptune’s size, and also in their composition, doesn’t exist in extrasolar planets. So, what we see in the Solar System is not the rule,” Mordasini said.

    The planets that Kepler has picked up, however, tend to be massive and closer to their star, and are therefore easier to detect. They pass more frequently across the face of their parent star, making them more easily spotted from Earth.

    The size implies that they managed to grab their disk’s primordial hydrogen and helium atmosphere before it got blown away. Hydrogen and helium are light elements, so a star’s radiation would puff up the hydrogen and helium atmosphere far more than what we see on Earth, with its heavier elements.

    What does this mean? The team predicts that in some cases, when astronomers measure the radius of a planet, that measurement also includes a bulky atmosphere. In other words, the planet underneath could be a lot smaller than what Kepler’s measurements could indicate.

    This process assumes that the planet has an iron core and silica mantle, just like the Earth, but orbits its parent star about 10 times closer than we do ours. If the atmosphere is more massive — even 1 percent of the planet’s mass is many thousands of times more massive than Earth’s — it creates more pressure on the surface.

    “It depends, but you can imagine this pressure is comparable to the deepest parts of the Earth’s ocean. Additionally, these atmospheres can be isolating and insulating for heat, so it’s also very hot on the surface,” Mordasini said.

    High temperatures on Earth are known to destroy amino acids, the building blocks of carbon-based life.

    Delicate atmosphere

    The atmosphere may be more massive, but it is also delicate. It wouldn’t take too much of a push to send hydrogen, the lightest element, away from the planet and into space.

    A habitable zone planet, Kepler-69c, in an artist’s impression. The world is probably an inhospitable “super-Venus,” but then again, it might be habitable, depending on the character of its atmosphere. Credit: NASA Ames/JPL-Caltech

    Young stars like the Sun in its youth are especially active in x-rays and ultraviolet radiation. When these forms of light hit a planetary atmosphere, they tend to heat it up. Since heating expands gases, the atmosphere grows. An atmosphere that flows beyond certain heights can get so high that part of it gets “unbounded” from the planet’s gravity and escapes into space.

    In our own solar system, for example, Mars likely lost its hydrogen to space over time while a heavier kind of hydrogen (called deuterium) remained behind. A new NASA orbiting spacecraft called Mars Atmosphere and Volatile Evolution (MAVEN) has just arrived at the Red Planet to study more about atmospheric escape today and researchers will to try to extrapolate that knowledge to space.


    By contrast, the planet Venus is an example of having an exceptionally persistent atmosphere. The mostly carbon dioxide atmosphere is so thick today that the planet is completely shrouded in clouds. Underneath the atmosphere is a hellish environment, one in which the spacecraft that have made it there have only survived a few minutes in the 864 º Fahrenheit (462 º Celsius) heat on the surface. It is widely presumed that atmospheres like that of Venus would be too hot for carbon-based life.

    Why Venus, Mars and Earth are so different in their atmospheric composition and history is among the questions puzzling astronomers today. Understanding atmospheric escape on each of these worlds will be helpful, scientists say.

    “How strong atmospheric escape is depends on fundamental properties such as mass or planetary orbit,” Mordasini said. “We found out for giant planets like Jupiter, the operation is typically not as strong.”

    Future work of the team includes considering atmospheres that are not made of hydrogen or helium, which could bring researchers a step closer to understanding how different types of elements work on planets. Eventually, this could feed into models predicting habitability.

    See the full article here.


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  • richardmitnick 3:24 pm on October 25, 2014 Permalink | Reply
    Tags: , Astrobiology, ,   

    From livesience: “Telltale Signs of Life Could Be Deepest Yet” 


    October 24, 2014
    Becky Oskin

    Telltale signs of life have been discovered in rocks that were once 12 miles (20 kilometers) below Earth’s surface — some of the deepest chemical evidence for life ever found.

    White aragonite veins on Washington’s San Juan Islands may contain evidence of deep microbial life.
    Credit: Philippa Stoddard

    Researchers found carbon isotopes in rocks on Washington state’s South Lopez Island that suggest the minerals grew from fluids flush with microbial methane. Methane from living creatures has distinct levels of carbon isotopes that distinguish it from methane gas that arises from rocks. (Isotopes are atoms of the same element with different numbers of neutrons in their nuclei.)

    In a calcium carbonate mineral called aragonite, the standard mix of carbon isotopes was radically shifted toward lighter carbon isotopes (by about 50 per mil, or parts per thousand). This ratio is characteristic of methane gas made by microorganisms, said Philippa Stoddard, an undergraduate student at Yale University who presented the research Tuesday (Oct. 21) at the Geological Society of America‘s annual meeting in Vancouver, British Columbia. “These really light signals are only observed when you have biological processes,” she told Live Science.

    The pale aragonite veins cut through basalt rocks that sat offshore North America millions of years ago. The veins formed after the basalt was sucked into an ancient subduction zone, one that predated today’s Cascadia subduction zone. Two tectonic plates smash together at subduction zones, and one plate descends under the other, creating deep trenches.

    Methane gas supplied the carbon as aragonite crystallized in cracks in the basalt, and replaced pre-existing limestone. The researchers think that microbes produced the methane gas as a waste product.

    “We reason that you could have life deeper in subduction zones, because you have a lot of water embedded in those rocks, and the rocks stay cold longer as the [plate] comes down,” Stoddard said.

    But the South Lopez Island aragonite suggests the minerals formed under extreme conditions that push the limits of life on Earth. For example, temperatures reached more than 250 degrees Fahrenheit (122 degrees Celsius), above the stability limit for DNA, Stoddard said. However, the researchers think the higher pressures at these depths may have counterbalanced the effects of the heat. The rocks are now visible thanks to faulting, which pushed them back up to the surface.

    Stoddard and her collaborators plan to sample more of the aragonite and other rocks nearby, to gain a better understanding of where the fluids came from and pin down the temperatures at which the rocks formed.

    Methane seeps teeming with million of microbes are found on the seafloor offshore Washington and Oregon along the Cascadia subduction zone. And multicellular life has been documented in the Mariana Trench, the deepest spot on Earth, and in South African mines 0.8 miles (1.3 km) deep. Researchers also have discovered microbes feasting on rocks within the oceanic crust itself.

    See the full article here.

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  • richardmitnick 10:43 am on October 24, 2014 Permalink | Reply
    Tags: , Astrobiology, , , , ,   

    From astrobio.net: “The Abundance of Water in Asteroid Fragments” 

    Astrobiology Magazine

    Astrobiology Magazine

    Oct 24, 2014
    Aaron L. Gronstal

    A new study could provide insights about the abundance of water in fragments from a famous asteroid.

    These colorful images are of thin slices of meteorites viewed through a polarizing microscope. Part of the group classified as HED meteorites for their mineral content (Howardite, Eucrite, Diogenite), they likely fell to Earth from 4 Vesta. Credit: NASA / JPL-Caltech / Hap McSween (Univ. Tennessee), A. Beck and T. McCoy (Smithsonian Inst.)

    The study focused on a mineral called apatite, which can act as a record of the volatiles in materials, including things like magma and lunar rocks. Volatiles are chemical elements with low boiling points (like water), and are usually associated with a celestial bodies’ crust or atmosphere.

    By looking at the apatite in meteorites, the team was able to determine the history of water in these rocks from space.

    The meteorites they chose to study are known as the Howardite-Eucrite-Diogenite (HED) meteorites. These meteorites are a subset of the achondrite meteorites, which are stony meteorites that do not have any chondrites (round grains that were formed from molten droplets of material floating around in space before being incorporated into an asteroid).

    Vesta closeup. Credit: NASA

    Studying the composition of meteorites can provide important clues about how asteroids and other rocky bodies form and evolve. Volatile elements influence processes important to planet formation, such as melting and eruption processes.

    HED meteorites are especially interesting because scientists think they originated from the crust of the asteroid Vesta – a large body in the main asteroid belt that was recently visited by NASA’s Dawn spacecraft. Behind Ceres, Vesta is the second largest object in the asteroid belt and is sometimes referred to as a protoplanet.

    Vesta is a relic of the ancient Solar System and can help astrobiologists understand our system’s formation and evolution. This information provides clues about conditions in the Solar System that led to the formation of a habitable planet – the Earth.

    Interestingly, the team’s results from the HED meteorites are similar to studies on the Earth and Moon, and could support theories that water in all three objects (Vesta, the Earth, and the Moon) came from the same source.

    See the full article here.


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  • richardmitnick 4:42 pm on October 21, 2014 Permalink | Reply
    Tags: Astrobiology, , , ,   

    From astrobio.net: “Scientists create possible precursor to life” 

    Astrobiology Magazine

    Astrobiology Magazine

    Oct 21, 2014
    University of Southern Denmark
    Contact Professor, Head of FLINT Center, Steen Rasmussen. Email: steen@sdu.dk. Mobile: +45 60112507

    How did life originate? And can scientists create life? These questions not only occupy the minds of scientists interested in the origin of life, but also researchers working with technology of the future. If we can create artificial living systems, we may not only understand the origin of life – we can also revolutionize the future of technology.

    Model of a protocell. Image by Janet Iwasa

    Protocells are the simplest, most primitive living systems, you can think of. The oldest ancestor of life on Earth was a protocell, and when we see, what it eventually managed to evolve into, we understand why science is so fascinated with protocells. If science can create an artificial protocell, we get a very basic ingredient for creating more advanced artificial life.

    However, creating an artificial protocell is far from simple, and so far no one has managed to do that. One of the challenges is to create the information strings that can be inherited by cell offspring, including protocells. Such information strings are like modern DNA or RNA strings, and they are needed to control cell metabolism and provide the cell with instructions about how to divide.

    Essential for life

    If one daughter cell after a division has a slightly altered information (maybe it provides a slightly faster metabolism), they may be more fit to survive. Therefore it may be selected and an evolution has started.

    Now researchers from the Center for Fundamental Living Technology (FLINT), Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, describe in the journal Europhysics Letters, how they, in a virtual computer experiment, have discovered information strings with peculiar properties.

    Professor and head of FLINT, Steen Rasmussen, says: “Finding mechanisms to create information strings are essential for researchers working with artificial life.”

    An autocatalytic network is a network of molecules, which catalyze each other’s production. Each molecule can be formed by at least one chemical reaction in the network, and each reaction can be catalyzed by at least one other molecule in the network. This process will create a network that exhibits a primitive form of metabolism and an information system that replicates itself from generation to generation. Credit University of Southern Denmark.

    Steen Rasmussen and his colleagues know they face two problems:

    Firstly long molecular strings are decomposed in water. This means that long information strings “break” quickly in water and turn into many short strings. Thus it is very difficult to maintain a population of long strings over time.

    Secondly, it is difficult to make these molecules replicate without the use of modern enzymes, whereas it is easier to make a so-called ligation. A ligation is to connect any combination of two shorter strings into a longer string, assisted by another matching longer string. Ligation is the mechanism used by the SDU-researchers.

    “In our computer simulation – our virtual molecular laboratory – information strings began to replicate quickly and efficiently as expected. However, we were struck to see that the system quickly developed an equal number of short and long information strings and further that a strong pattern selection on the strings had occurred. We could see that only very specific information patterns on the strings were to be seen in the surviving strings. We were puzzled: How could such a coordinated selection of strings occur, when we knew that we had not programmed it. The explanation had to be found in the way the strings interacted with each other”, explains Steen Rasmussen.

    It is like society

    According to Steen Rasmussen, a so-called self-organizing autocatalytic network was created in the virtual pot, into which he and his colleagues poured the ingredients for information strings.

    “An autocatalytic network works like a community; each molecule is a citizen who interacts with other citizens and together they help create a society”, explains Steen Rasmussen.

    This autocatalytic set quickly evolved into a state where strings of all lengths existed in equal concentrations, which is not what is usually found. Further, the selected strings had strikingly similar patterns, which is also unusual.

    “We might have discovered a process similar to the processes that initially sparked the first life. We of course don’t know if life actually was created this way – but it could have been one of the steps. Perhaps a similar process created sufficiently high concentrations of longer information strings when the first protocell was created”, explains Steen Rasmussen.

    Basis for new technology

    The mechanisms underlying the formation and selection of effective information strings are not only interesting for the researchers who are working to create protocells. They also have value to researchers working with tomorrow’s technology, like they do at the FLINT Center.

    “We seek ways to develop technology that’s based on living and life-like processes. If we succeed, we will have a world where technological devices can repair themselves, develop new properties and be re-used. For example a computer made of biological materials poses very different – and less environmentally stressful – requirements for production and disposal”, says Steen Rasmussen.

    Ref: http://epljournal.edpsciences.org/articles/epl/abs/2014/14/epl16388/epl16388.html

    See the full article here.


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  • richardmitnick 3:29 pm on October 20, 2014 Permalink | Reply
    Tags: Astrobiology, , , , , ,   

    From astrobio.net: ” Exomoons Could Be Abundant Sources Of Habitability” 

    Astrobiology Magazine

    Astrobiology Magazine

    Oct 20, 2014
    Elizabeth Howell

    With about 4,000 planet candidates from the Kepler Space Telescope data to analyze so far, astronomers are busy trying to figure out questions about habitability. What size planet could host life? How far from its star does it need to be? What would its atmosphere need to be made of?

    NASA Kepler Telescope

    Look at our own solar system, however, and there’s a big gap in the information we need. Most of the planets have moons, so surely at least some of the Kepler finds would have them as well. Tracking down these tiny worlds, however, is a challenge.

    Europa is one of the moons in our solar system that could host life. What about beyond the solar system? Credit: NASA/JPL/Ted Stryk

    A new paper in the journal Astrobiology, called Formation, Habitability, and Detection of Extrasolar Moons, goes over this mostly unexplored field of extrasolar research. The scientists do an extensive literature review of what is supposed about moons beyond the Solar System, and they add intriguing new results.

    A wealth of moons exist in our own solar system that could host life. Icy Europa, which is circling Jupiter, was recently discovered to have plumes of water erupting from its surface. Titan, in orbit around Saturn, is the only known moon with an atmosphere, and could have the precursor elements to life in its hydrocarbon seas that are warmed by Saturn’s heat. Other candidates for extraterrestrial hosts include Jupiter’s moons Callisto and Ganymede, as well as Saturn’s satellite Enceladus.

    Lead author René Heller, an astrophysicist at the Origins Institute at McMaster University, in Ontario, Canada, said some exomoons could be even better candidates for life than many exoplanets.

    “Moons have separate energy sources,” he said. “While the habitability of terrestrial planets is mostly determined by stellar illumination, moons also receive reflected stellar light from the planet as well as thermal emission from the planet itself.”

    Moreover, a planet like Jupiter — which hosts most of the moons in the Solar System that could support life — provides even more potential energy sources, he added. The planet is still shrinking and thereby converts gravitational energy into heat, so that it actually emits more light than it receives from the Sun, providing yet more illumination. Besides that, moons orbiting close to a gas giant are flexed by the planet’s gravity, providing potential tidal heating as an internal, geological heat source.

    Triton’s odd, melted appearance hint that the moon was captured and altered by Neptune. Credit: NASA

    Finding the first exomoon

    The first challenge in studying exomoons outside our Solar System is to actually find one. Earlier this year, NASA-funded researchers reported the possible discovery of such a moon, but this claim was ambiguous and can never be confirmed. That’s because it appeared as a one-time event, when one star passed in front of another, acting as a sort of gravitational lens that amplified the background star. Two objects popped out in the gravitational lens in the foreground — either a planet and a star, or a planet and an extremely heavy exomoon.

    For his part, Heller is convinced that exomoons are lurking in the Kepler data, but they have not been discovered yet. Only one project right now is dedicated to searching for exomoons, and is led by David Kipping at the Canadian Space Agency. His group has published several papers investigating 20 Kepler planets and candidates in total. The big restriction to their efforts is computational power, as their simulations require supercomputers.

    Another limiting factor is the number of observatories that can search for exomoons. To detect them, at least a handful of transits of the planet-moon system across their common host star would be required to absolutely make sure that the companion is a moon, Heller said. Also, the planet with the moon would have to be fairly far from its star, and decidedly not those close-in hot Jupiters that take only a few days to make an orbit. In that zone, the gravitational drag of the star would fatally perturb any moon’s orbit.

    Heller estimates that a telescope would need to stare constantly at the same patch of sky for several hundred days, minimum, to pick up an exomoon. Kepler fulfilled that obligation in spades with its four years of data gazing at the same spot in the sky, but astronomers will have to wait again for that opportunity.

    Because two of Kepler’s gyroscopes (pointing devices) have failed, Kepler’s new mission will use the pressure of the Sun to keep it steady. But it can only now point to the same region of the sky for about 80 days at at time because the telescope will periodically need to be moved so as not to risk placing its optics too close to the Sun.

    NASA’s forthcoming Transiting Exoplanet Survey Satellite [TESS} is only expected to look at a given field for 70 days. Further into the future, the European Space Agency’s PLAnetary Transits and Oscillations of stars (PLATO) will launch in 2024 for what is a planned six-year mission looking at several spots in the sky.



    “PLATO is the next step, with a comparable accuracy to Kepler but a much larger field of view and hopefully a longer field of view coverage,” Heller said.

    Clues in our solar system

    Thousands of exoplanets and exoplanet candidates have been discovered, but astronomers are still searching for exomoons. Credit: ESA – C. Carreau

    Heller characterizes moons as an under-appreciated feature of extrasolar planetary systems. Just by looking around us in the Solar System, he says, astronomers have been able to make crucial explanations about how the moons must have formed and evolved together with their planets. Moons thus carry information about the substructure of planet evolution, which is not accessible by planet observations alone.

    The Earth’s moon, for example, was likely formed when a Mars-sized object collided with the proto-Earth and produced a debris disk. Over time, that debris coalesced into our moon.

    While Heller says the literature mostly focuses on collision scenarios between an Earth-sized object and a Mars-sized object, he doesn’t see any reason why crashes on a bigger scale might not happen. Perhaps an Earth-sized object crashed into an object that was five times the mass of Earth, producing an extrasolar Earth-Earth binary planet system, he suggests.

    Another collision scenario likely took place at Uranus. The gas giant’s rotation is tilted about 90 degrees in its orbit around the Sun. In other words, it is rolling on its side. More intriguing, its two dozen moons follow Uranus’ rotational equator, and they do not orbit in the same plane as Uranus’ track around the Sun. This scenario suggests that Uranus was hit multiple times by huge objects instead of just once, Heller said.

    Examining mighty Jupiter’s moons gives astronomers a sense of how high temperatures were in the disk that formed the gas giant and its satellites, Heller added. Ganymede, for example, is an icy moon. Models indicate that beyond Ganymede’s orbit (at about 15 Jupiter radii) it is sufficiently cold for water to pass from the gas to the solid (ice) stage, so the regular moons in these regions are very water-rich compared to the inner, mostly rocky moons Io and Europa.

    “It sounds a bit technical, but we couldn’t have this information about planetary accretion if we did not have the moons today to observe,” Heller said.

    Some moons could also have been captured, such as Neptune’s large moon, Triton. The moon orbits in a direction opposite to other moons in Neptune‘s system (and in fact, opposite to the direction of other large moons in the Solar System.) Plus, its odd terrain suggests that it used to be a free-floating object that was captured by Neptune’s gravity. Neptune is so huge that it raised tides within the moon, reforming its surface.

    Even comparing the different types of moons around planets in the Solar System reveals different timescales of formation. Jupiter includes four moons similar in size to Earth’s moon (Europa, Callisto, Ganymede and Io), while the next largest planet in our solar system, Saturn, only has one large moon called Titan. Astronomers believe Saturn has only one large moon because the gas that formed objects in our solar system was more plentiful in Jupiter’s system to provide material for the moons to form.

    The gas abundance happened as a consequence of the huge gas giant creating a void in the material surrounding our young Sun, pulling the material in for its moons. Saturn was not quite large enough to do this, resulting in fewer large moons.

    More strange situations could exist beyond our solar system’s boundaries, but it will take a dedicated search to find exomoons. Once they are discovered, however, they will allow planet formation and evolution studies on a completely new level.

    This research was supported in part by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Center for Exoplanets and Habitable Worlds, which is supported by the Pennsylvania State University, the Pennsylvania Space Grant Consortium, the National Science Foundation (NSF) the NASA Astrobiology Institute.

    See the full article here.


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