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  • richardmitnick 11:32 am on October 7, 2016 Permalink | Reply
    Tags: Alternative Earths project, Astrobiology, , , , NASA Astrobiology Institute (NAI)   

    From Many Worlds: “One Planet, But Many Different Earths” 

    NASA NExSS bloc

    NASA NExSS

    Many Worlds

    Many Words icon

    2016-10-07
    Marc Kaufman

    1
    Artist conception of early Earth. (NASA/JPL-Caltech)

    We all know that life has not been found so far on any planet beyond Earth — at least not yet. This lack of discovery of extraterrestrial life has long been used as a knock on the field of astrobiology and has sometimes been put forward as a measure of Earth’s uniqueness.

    But the more recent explosion in exoplanet discoveries and the next-stage efforts to characterize their atmospheres and determine their habitability has led to rethinking about how to understand the lessons of life of Earth.

    Because when seen from the perspective of scientists working to understand what might constitute an exoplanet that can sustain life, Earth is a frequent model but hardly a stationary or singular one. Rather, our 4.5 billion year history — and especially the almost four billion years when life is believed to have been present — tells many different stories.

    For example, our atmosphere is now oxygen-rich, but for billions of years had very little of that compound most associated with complex life. And yet life existed.

    The same with temperature. Earth went through snowball or slushball periods when most of the planet’s surface was frozen over. Hardly a good candidate for life, and yet the planet remained habitable and inhabited.

    And in its early days, Earth had a very weak magnetic field and was receiving only 70 to 80 percent as much energy from the sun as it does today. Yet it supported life.

    “It’s often said that there’s an N of one in terms of life detected in the universe,” that there is but one example, said Timothy Lyons, a biogeochemist and distinguished professor at University of California, Riverside.

    “But when you look at the conditions on Earth over billion of years, it’s pretty clear that the planet had very different kinds of atmospheres and oceans, very different climate regimes, very different luminosity coming from the sun. Yet we know there was life under all those very different conditions.

    “It’s one planet, but it’s silly to think of it as one planetary regime. Each of our past chapters is a potential exoplanet.”

    2
    A particularly extreme phase of our planet’s history is called the “Snowball Earth” period. During these episodes, the Earth’s surface was entirely or largely covered by ice for millions of years, stretching from the poles to the tropics. One such freezing happened over 700 to 800 million years ago in the Pre-Cambrian, around the time that animals appeared. Others are now thought to have occurred much further back in time. They varied in duration and extent but during a full-on snowball event, life could only survive in ice-free refuges, or where sunlight managed to penetrate through the ice to allow photosynthesis. No image credit.

    Lyons is the principal investigator for one of the newer science teams selected to join the NASA Astrobiology Institute (NAI), an interdisciplinary group hat calls itself “Alternative Earths.”

    Consisting of 23 scientists from 14 institutions, its self-described mission is to address and answer these questions: How has Earth remained persistently inhabited through most of its highly changeable history? How has the presence of very different kinds of lifeforms been manifested in the atmosphere, and simultaneously been captured in what would become the rock record? And how might this approach to early Earth help in the search for life beyond Earth?

    “The idea that early Earth can help us understand other planets and moons, especially in our solar system, is certainly not new,” Lyons said. “Scientists have studied possible Mars analogues and extreme life for years. But we’re taking it to the next level with exoplanets, and pushing hard on the many ways that conditions on early Earth can help us study exoplanet atmospheres and habitability.”

    The importance of this work was apparent at a recent workshop on biosignatures held by NASA’s initiative, the Nexus for Exoplanet System Science (NExSS.) As Earth scientists, Lyons and his group are expert at finding proxy records in ancient rocks that hold information important to exoplanet scientists (among others) want to know.

    Those proxy fingerprints occur as elemental, molecular, and isotopic properties preserved in rocks that correspond to ancient characteristics in the ocean or atmosphere that can no longer be observed directly.

    “We can’t measure the pH in ancient oceans, and we can’t measure the composition of ancient atmospheres,” Lyons said. “So what we have to do is go to the chemistry of ocean and land deposits formed at the same time and look for the chemical fingerprints locked away and preserved.”

    At the exoplanet biosignatures workshop, Lyons was struck by how eager exoplanet modelers were to learn about the proxy chemicals they could profitably put in their models for clues about how distant planet atmospheres might form and behave. It’s clear that no single element or compound will be a silver bullet for understanding whether there’s life on an exoplanet, but a variety of proxy results together can begin to tell an important story.

    2
    The element chromium and its isotopes have become important proxies for the measurement of oxygen levels in the atmosphere of early Earth and have led to some revised theories about when those concentrations jumped. Understanding the potential makeup of early Earth’s atmosphere and oceans is a pathway to understanding exoplanets. No image credit.

    “We told them about the range of things they should be modeling and, wow, they were interested. I was thinking at the time that ‘you guys really need us — and vice versa.’”

    Some of the researchers most intrigued by potentially new geochemical proxies from the University of Washington’s Virtual Planetary Laboratory, They’ve been a pioneer in modeling how different atmospheric, geological, stellar and other factors characterize particular kinds of planets and solar systems and their possibilities for life.

    In keeping with the growing connection between exoplanet and Earth science, Lyons just brought one of the VPL top modellers, Edward Schwieterman, to UC Riverside for a postdoc as part of the Alternative Earths project.

    Among his initial projects will take the new data being generated by the Alternative Earths team about the atmosphere and oceans of early Earth, and model what would happen on a planet with that kind of atmosphere if it was orbiting a very different type of star from our own.

    “It’s a direct use of early Earth research on exoplanet studies, and is exactly the kind of work we plan to do be doing,” Lyons said. “Eddie is the perfect bridge between the lessons learned from early Earth and their implications for exoplanets.”

    3
    Banded iron formations at Karijini National Park, Western Australia. The layers of reddish iron point to an early ocean poor in oxygen and rich in dissolved iron. These formations date most commonly from the periods just before and right after the Great Oxidation Event, which spanned from about 2.4 to 2.0 billion years ago. Their distributions over times and their chemical properties are key proxies for the tempo and fabric of the earliest permanent oxygenation of Earth’s atmosphere. No image credit.

    Lyons, along with colleagues Christopher Reinhard of Georgia Tech and Noah Planavsky of Yale and other members of their Alternative Earths team, are especially focused on an effort to understand Earth’s atmosphere—as tracked in the rock record—over the eons and especially the levels of oxygen present.

    The concentration of oxygen in the atmosphere is now about about 21 percent and, by some estimates, reached as high as 35 percent within the past 500 million years.

    In comparison, early Earth had but trace amounts of oxygen for two billion years before what is called the Great Oxidation Event—when marine O2-producing photosynthesis outpaced reactions that consumed O2 and allowed for the beginnings of its permanent accumulation in the atmosphere. Estimated to have occurred 2.4 billion years ago, it began (or was part of) an oxidizing process that led to ever more complex life forms over the following one to two billion years.

    There is a spirited scientific debate underway now about whether that “Great Oxidation Event” triggered permanently high levels of oxygen in the atmosphere and the oceans, or whether it began an up and down process through which the presence of oxygen was quite unstable and still well below current levels until relatively recent times.

    Lyons and Reinhard are of the “boring billion” school, arguing that oxygen levels did not head continuously upwards after the Oxidation Event, but rather stayed relatively stable and still very low for most of a billion and half years after the Great Oxidation Event and continued to challenge O2-requiring life—for almost a third of Earth history.

    This would be primarily an Earth science issue if not for the fact that oxygen — on its own and in conjunction with other compounds — is among the most prominent and promising biosignatures that exoplanet scientists are looking for.

    In fact, not that long ago, it was widely accepted that a discovery of oxygen and/or ozone in the atmosphere of a planet pretty much proved, or at least strongly suggested, the presence of some sort of biology on the planet below. That view has been modified of late by the identification of ways that free oxygen can be formed abiotically (without the presence of photosynthesis and life), potentially producing false positives for potential life.

    While the field is a long way from an active search for direct, in situ fingerprints of life on exoplanets light years away, oxygen and its relationship with other atmospheric gases remains a lodestar in thinking about what biosignatures to search for. The technology is already in place for characterizing the compositions of very distant atmospheres.

    And this is where, for Lyons, Reinhard and others, things get both interesting and complicated.

    For more than a billion years before the Great Oxidation Event Earth demonstrably supported life. It consisted mostly of anaerobic microbes that did just fine without oxygen, but in many cases needed and produced of methane, an organic compound with one carbon atom and four hydrogen.

    So if an exoplanet scientist from a distant world were to search for life on Earth during that period via the detection of oxygen only, they would entirely miss the presence of an already long history of life. Searching for the large-scale presence of methane might have been more productive, though that is a source of rigorous debate as well.

    4
    An image of a rock with fossilized stromatolites, tiny layered structures from 3.7 billion years ago that are remnants from a community of microbes. Found in a part of Greenland new exposed by melting glaciers, Australian scientists reported in the journal Nature that the stromatolites lived on an ancient seafloor at a time when Earth’s skies were orange and its oceans green. They describe the stromatolites as perhaps the oldest fossil found so far on Earth, although chemical suggestions of life may extend further back in time . (Allen Nutman/University of Wollongong)

    Because both oxygen and methane can be formed without life, a current gold standard for detecting future biosignatures on exoplanets is the presence of the two together. Because of the way the two interact, they would remain in an atmosphere together only if both were being replenished on a substantial, on-going scale. And as far as is now understood, the only way to do that is through biology.

    Yet as described by Reinhard, the most current research suggest that oxygen and methane were probably were in the Earth’s atmosphere together at levels that would be detectable from afar. There was a lot of methane in the very early Earth atmosphere, and there has been a lot of oxygen for the past 600 million years or so, but as one grew in concentration the other declined — and during the “boring billion” both were likely low.

    “So we have a complicated situation here where using the best exoplanet biosignatures we have now, intelligent beings looking at Earth over the past 4.5 billion years would not find a convincing signature of life for most, or maybe all, of that time if they relied only on co-occurrence of oxygen and methane,” Reinhard said. Yet there has been life for at least 3.7 billion years, and those beings studying Earth would have come up with a very false negative.

    Lyons insists this is should not be a source of pessimism in the search for life on exoplanets, instead it is a “call to arms for new and more creative possibilities rather than the lowest hanging fruit.” It’s a challenge “to help us sharpen our thinking in a search that was never going to be easy.”

    And the best test bed available for coming up with different answers, he said, may very well be the many different Earths that have come and gone on our planet.

    See the full article here .

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    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 3:32 pm on September 2, 2016 Permalink | Reply
    Tags: , , Astrobiology, , , Phosphorous, , Schreibersite   

    From astrobio.net via SETI: “Did meteorites bring life’s phosphorus to Earth?” 

    Astrobiology Magazine

    Astrobiology Magazine

    Aug 30, 2016
    Keith Cooper

    1
    An artist’s impression of meteors crashing into water on the young Earth. Did they bring phosphorous with them? Image credit: David A Aguilar (CfA)

    Meteorites that crashed onto Earth billions of years ago may have provided the phosphorous essential to the biological systems of terrestrial life. The meteorites are believed to have contained a phosphorus-bearing mineral called schreibersite, and scientists have recently developed a synthetic version that reacts chemically with organic molecules, showing its potential as a nutrient for life.

    Phosphorus is one of life’s most vital components, but often goes unheralded. It helps form the backbone of the long chains of nucleotides that create RNA and DNA; it is part of the phospholipids in cell membranes; and is a building block of the coenzyme used as an energy carrier in cells, adenosine triphosphate (ATP).

    Yet the majority of phosphorus on Earth is found in the form of inert phosphates that are insoluble in water and are generally unable to react with organic molecules. This appears at odds with phosphorus’ ubiquity in biochemistry, so how did phosphorus end up being critical to life?

    In 2004, Matthew Pasek, an astrobiologist and geochemist from the University of South Florida, developed the idea that schreibersite [(Fe, Ni)3P], which is found in a range of meteorites from chondrites to stony–iron pallasites, could be the original source of life’s phosphorus. Because the phosphorus within schreibersite is a phosphide, which is a compound containing a phosphorus ion bonded to a metal, it behaves in a more reactive fashion than the phosphate typically found on Earth.

    Finding naturally-formed schreibersite to use in laboratory experiments can be time consuming when harvesting from newly-fallen meteorites and expensive when buying from private collectors. Instead, it has become easier to produce schreibersite synthetically for use in the laboratory.

    Natural schreibersite is an alloy of iron, phosphorous and nickel, but the common form of synthetic schreibersite that has typically been used in experiments is made of just iron and phosphorus, and is easily obtainable as a natural byproduct of iron manufacturing. Previous experiments have indicated it reacts with organics to form chemical bonds with oxygen, the first step towards integrating phosphorous into biological systems.

    However, since natural schreibersite also incorporates nickel, some scientific criticism has pointed out that the nickel could potentially alter the chemistry of the mineral, rendering it non-reactive despite the presence phosphides. If this were the case it would mean that the experiments with the iron–phosphorous synthetic schreibersite would not represent the behavior of the mineral in nature.

    Since the natural version incorporates nickel, there has always been the worry that the synthetic version is not representative of how schreibersite actually reacts and that the nickel might somehow hamper those chemical reactions.

    “There was always this criticism that if we did include nickel it might not react as much,” says Pasek.

    Pasek and his colleagues have addressed this criticism by developing a synthetic form of schreibersite that includes nickel.

    2
    This 15cm wide fragment of the Seymchan meteorite found in Russia in 1967 is an iron-nickel pallasite. The long filament of dark grey material in the center is schreibersite. Image credit: University of South Florida.

    Nickel-flavored schreibersite

    In a recent paper published in the journal Physical Chemistry Chemical Physics, Pasek and lead author and geochemist Nikita La Cruz of the University of Michigan show how a form of synthetic schreibersite that includes nickel reacts when exposed to water. As the water evaporates, it creates phosphorus–oxygen (P–O) bonds on the surface of the schreibersite, making the phosphorus bioavailable to life. The findings seem to remove any doubts as to whether meteoritic schreibersite could stimulate organic reactions.

    “Biological systems have a phosphorus atom surrounded by four oxygen atoms, so the first step is to put one oxygen atom and one phosphorous atom together in a single P–O bond,” Pasek explains.

    Terry Kee, a geochemist at the University of Leeds and president of the Astrobiology Society of Britain, has conducted his own extensive work with schreibersite and, along with Pasek, is one of the original champions of the idea that it could be the source of life’s phosphorus.

    “The bottom line of what [La Cruz and Pasek] have done is that it appears that this form of nickel-flavored synthetic schreibersite reacts pretty much the same as the previous synthetic form of schreibersite,” he says.

    This puts to rest any criticism that previous experiments lacked nickel.

    3
    A bubbling hydrothermal pool in the Mývatn area of Iceland. Could such pools have pro-moted P–O bonds on the surfaces of schreibersite meteorites that had fallen into the pools? Image credit: Keith Cooper

    Shallow pools and volcanic vents

    Pasek describes how meteors would have fallen into shallow pools of water on ancient Earth. The pools would then have undergone cycles of evaporation and rehydration, a crucial process for chemical reactions to take place. As the surface of the schreibersite dries, it allows molecules to join into longer chains. Then, when the water returns, these chains become mobile, bumping into other chains. When the pool dries out again, the chains bond and build ever larger structures.

    “The reactions need to lose water in some way in order to build the molecules that make up life,” says Pasek. “If you have a long enough system with enough complex organics then, hypothetically, you could build longer and longer polymers to make bigger pieces of RNA. The idea is that at some point you might have enough RNA to begin to catalyze other reactions, starting a chain reaction that builds up to some sort of primitive biochemistry, but there’s still a lot of steps we don’t understand.”

    Demonstrating that nickel-flavored schreibersite, of the sort contained in meteorites, can produce phosphorus-based chemistry is exciting. However, Kee says further evidence is needed to show that the raw materials of life on Earth came from space.

    “I wouldn’t necessarily say that the meteoric origin of phosphorus is the strongest idea,” he says. “Although it’s certainly one of the more pre-biotically plausible routes.”

    Despite having co-developed much of the theory behind schreibersite with Pasek, Kee points out that hydrothermal vents could rival the meteoritic model. Deep sea volcanic vents are already known to produce iron-nickel alloys such as awaruite and Kee says that the search is now on for the existence of awaruite’s phosphide equivalent in the vents: schreibersite.

    “If it could be shown that schreibersite can be produced in the conditions found in vents — and I think those conditions are highly conducive to forming schreibersite — then you’ve got the potential for a lot of interesting phosphorylation chemistry to take place,” says Kee.

    Pasek agrees that hydrothermal vents could prove a good environment to promote phosphorus chemistry with the heat driving off the water to allow the P–O bonds to form. “Essentially it’s this driving off of water that you’ve got to look for,” he adds.

    Pasek and Kee both agree that it is possible that both mechanisms — the meteorites in the shallow pools and the deep sea hydrothermal vents — could have been at work during the same time period and provided phosphorus for life on the young Earth.

    Meanwhile David Deamer, a biologist from the University of California, Santa Cruz, has gone one step further by merging the two models, describing schreibersite reacting in hydrothermal fields of bubbling shallow pools in volcanic locations similar to those found today in locations such as Iceland or Yellowstone.

    Certainly, La Cruz and Pasek’s results indicate that schreibersite becomes more reactive the warmer the environment in which it exists.

    “Although we see the reaction occurring at room temperature, if you increase the temperature to 60 or 80 degree Celsius, you get increased reactivity,” says Pasek. “So, hypothetically, if you have a warmer Earth you should get more reactivity.”

    One twist to the tale is the possibility that phosphorus could have bonded with oxygen in space, beginning the construction of life’s molecules before ever reaching Earth. Schreibersite-rich grains coated in ice and then heated by shocks in planet-forming disks of gas and dust could potentially have provided conditions suitable for simple biochemistry. While Pasek agrees in principle, he says he has “a hard time seeing bigger things like RNA or DNA forming in space without fluid to promote them.”

    See the full article here .

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  • richardmitnick 11:32 am on April 26, 2016 Permalink | Reply
    Tags: Astrobiology, , , , ,   

    From Many Worlds: “Breaking Down Exoplanet Stovepipes” 

    NASA NExSS bloc

    NASA NExSS

    Many Worlds

    Many Words icon

    2016-04-25
    Marc Kaufman

    1
    The search for life beyond our solar system requires unprecedented cooperation across scientific disciplines. NASA’s NExSS collaboration includes those who study Earth as a life-bearing planet (lower right), those researching the diversity of solar system planets (left), and those on the new frontier, discovering worlds orbiting other stars in the galaxy (upper right). (NASA)

    That fields of science can benefit greatly from cross-fertilization with other disciplines is hardly a new idea. We have, after all, long-standing formal disciplines such as biogeochemistry — a mash-up of many fields that has the potential to tell us more about the natural environment than any single approach. Astrobiology in another field that inherently needs expertise and inputs from a myriad of disciplines, and the NASA Astrobiology Institute was founded (in 1998) to make sure that happened.

    Until fairly recently, the world of exoplanet study was not especially interdisciplinary. Astronomers and astrophysicists searched for distant planets and when they succeeded came away with some measures of planetary masses, their orbits, and sometimes their densities. It was only in recent years, with the advent of a serious search for exoplanets with the potential to support life, that it became apparent that chemists (astrochemists, that is), planetary and stellar scientists, cloud specialists, geoscientists and more were needed at the table.

    Universities were the first to create more wide-ranging exoplanet centers and studies, and by now there are a number of active sites here and abroad. NASA formally weighed in one year ago with the creation of the Nexus for Exoplanet System Science (NExSS) — an initiative which brought together 17 university and research center teams with the goal of supercharging exoplanet studies, or at least to see if a formal, national network could produce otherwise unlikely collaborations and science.

    That network is virtual, unpaid, and comes with no promises to the scientists. Still, NASA leaders point to it as an important experiment, and some interesting collabortions, proposals and workshops have come out of it.

    “A year is a very short time to judge an effort like this,” said Douglas Hudgins, program scientist for NASA’s Exoplanet Exploration Program, and one of the NASA people who helped NExSS come into being.

    “Our attitude was to pull together a group of people, do our best to give them tool to work well together, let them have some time to get to know each other, and see what happens. One year down the road, though, I think NExSS is developing and good ideas are coming out of it.”

    2
    Illustration of what a sunset might look like on a moon orbiting Kepler 47c and its two suns. (Softpedia)

    One collaboration resulted in a “White Paper” on how laboratory work today can prepare researchers to better understand future exoplanet measurements coming from new generation missions. Led by NExSS member Jonathan Fortney of the University of Clalfornia, Santa Cruz, it was the result of discussions at the first NExSS meeting in Washington, and was expanded by others from the broader community.

    Another NExSS collaboration between Steven Desch of Arizona State University and Jason Wright of Penn State led to a proposal to NASA to study a planet being pulled apart by the gravitational force a white dwarf star. The interior of the disintegrating planet could potentially be analyzed as its parts scatter.

    Leaders of NExSS say that other collaborations and proposals are in the works but are not ready for public discussion yet.

    In addition, NExSS — along with the NASA Astrobiology Institute (NAI) and the National Science Foundation (NSF) — sponsored an unusual workshop this winter at Arizona State University focused on a novel way to looking at whether an exoplanet might support life. Astrophysicists and geoscientists spent three days discussing and debating how the field might gather and use information about the formation, evolution and insides of exoplanets to determine whether they might be habitable.

    One participant was Shawn Domogal-Goldman, a research space scientist at the Goddard Space Flight Center and a leader of the NExSS group. He’s an expert in ancient earth as well the astrophysics of exoplanets, and his view is that the Earth provides 4.5 billion years of physical, chemical, climatic and biological dynamics that need to be mined for useful insights about exoplanets.

    When the workshop was over he said: “For me, and I think for others, we’ll look back at this meeting years from now and say to ourselves, ‘We were there at the beginning of something big.”

    NExSS has two more workshops coming up, one on “Biosignatures” July 27 t0 29 in Seattle and another on stellar-exoplanet interactions in November. Reflecting the broad reach of NExSS, the biosignatures program has additional sponsors include the NASA Astrobiology Institute (NAI), NASA’s Exoplanet Exploration Program (ExEP), and international partners, including the European Astrobiology Network Association (EANA) and Japan’s Earth-Life Science Institute (ELSI).

    3
    By looking for signs of life, scientists focus on the potential presence of oxygen, ozone, water, carbon dioxide, methane and nitrous oxide, which could indicate plant or bacterial life. The figure above shows how complex Earth’s spectra is compared to Mars or Venus. This is a reflection of the intricate balance and control of elements needed to support life. The upcoming NExSS workshop will focus on what we know, and need to know, about what future missions and observations should be looking for in terms of exoplanet biosignatures. (ESA)

    The initial idea for NExSS came from Mary Voytek, senior scientist for astrobiology in NASA’s Planetary Sciences Division. Interdisciplinary collaboration and solutions are baked into the DNA of astrobiology, so it is not surprising that an interdisciplinary approach to exoplanets would come from that direction. In addition, as the study of exoplanets increasingly becomes a search for possible life or biosignatures on those planets, it falls very much into the realm of astrobiology.

    Hudgins said that while this dynamic is well understood at NASA headquarters, the structure of the agency does not necessarily reflect the convergence. Exoplanet studies are funded through the Division of Astrophysics while astrobiology is in the Planetary Sciences Division.

    NExSS is a beginning effort to bring the overlapping fields closer together within the agency, and more may be on the way. Said Hudgins: “We could very well see some evolution in how NASA approaches the problem, with more bridges between astrobiology and exoplanets.”

    NExSS is led by Natalie Batalha of NASA’s Ames Research Center in Moffett Field, California; Dawn Gelino with NExScI, the NASA Exoplanet Science Institute at the California Institute of Technology in Pasadena; and Anthony Del Genio of NASA’s Goddard Institute for Space Studies in New York City.

    All three see NExSS as an experiment and work in progress, with some promising accomplishments already. And some clear challenges.

    Del Genio, for instance, described the complex dynamics involved in having a team like his own — climate modelers who have spent years understanding the workings of our planet — determine how their expertise can be useful in better understanding exoplanets.

    These are some of his thoughts:

    “This sounds great, but in practice it is very difficult to do for a number of reasons. First, all the disciplines speak different languages. Jargon from one field has to be learned by people in another field, and unlike when I travel to Europe with a Berlitz phrase book, there is no Earth-to-Astrophysics translation guide to consult.

    “Second, we don’t appreciate what the important questions are in each others’ fields, what the limitations of each field are, etc. We have been trying to address these roadblocks in the first year by having roughly monthly webinars where different people present research that their team is doing. But there are 17 teams, so this takes a while to do, and we are only part way through having all the teams present.

    “Third, NExSS is a combination of teams that proposed to different NASA programs for funding, and we are a combination of big and small teams. We are also a combination of teams in areas whose science is more mature, and teams in areas whose science is not yet very mature (and maybe if you asked all of us you’d get 10 different opinions on whose science is mature and whose isn’t).

    What’s more, he wrote, he sees an inevitable imbalance between the astrophysics teams — which have been thinking about exoplanets for a long time — and teams from other disciplines that have mature models and theories for their own work but are now applying those tools to think about exoplanets for the first time.

    But he sees these issues as challenges rather than show-stoppers, and expects to see important — and unpredictable — progress during the three-year life of the initiative.

    Natalie Batalie said that she became involved with NExSS because “I wanted to help expedite the search for life on exoplanets.”

    “Reaching this goal requires interdisciplinary thinking that’s been difficult to achieve given the divisional boundaries within NASA’s science mission directorate. NExSS is an experiment to see if cooperation between the divisions can lead to cross-fertilization of ideas and a deeper understanding of planetary habitability.”

    She said that in the last year, scientists working on planetary habitability both inside and outside of NExSS — and funded by different science divisions within NASA — have had numerous NExSS-sponsored opportunities to interact, learn from each other and begin collaborations.

    The Fortney et al “White Paper” on experimental data gaps, for example, was conceived during one of these gatherings, as was the need for a biosignatures analysis group to support NASA’s Science & Technology Definition Teams studying the possible flagship missions of the future.

    In full disclosure, Many Worlds is funded by NExSS but represents only the views of the writer.

    See the full article here .

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    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 2:56 pm on March 29, 2016 Permalink | Reply
    Tags: Astrobiology, , , Life's Building Blocks Form In Replicated Deep Sea Vents, ,   

    From SPACE.com: “Life’s Building Blocks Form In Replicated Deep Sea Vents” 

    space-dot-com logo

    SPACE.com

    March 28, 2016
    Charles Q. Choi

    1
    Alkaline hydrothermal vents may have played a role in the origin of life.
    Credit: NOAA

    Chimney-like mineral structures on the seafloor could have helped create the RNA molecules that gave rise to life on Earth and hold promise to the emergence of life on distant planets.

    Scientists think Earth was born roughly 4.54 billion years ago. Life on Earth may be nearly that old with recent findings suggesting that life might have emerged only about 440 million years after the planet formed.

    However, it remains a mystery how life might have first arisen. The main building blocks of life now are DNA, which can store genetic data, and proteins, which include enzymes that can direct chemical reactions. However, DNA requires proteins in order to form, and proteins need DNA to form, raising the chicken-and-egg question of how protein and DNA could have formed without each other.

    To resolve this conundrum, scientists have suggested that life may have first primarily depended on compounds known as RNA. These molecules can store genetic data like DNA, serve as enzymes like proteins, and help create both DNA and proteins. Later DNA and proteins replaced this “RNA world” because they are more efficient at their respective functions, although RNA still exists and serves vital roles in biology.

    However, it remains uncertain how RNA might have arisen from simpler precursors in the primordial soup that existed on Earth before life originated. Like DNA, RNA is complex and made of helix-shaped chains of smaller molecules known as nucleotides.

    One way that RNA might have first formed is with the help of minerals, such as metal hydrides. These minerals can serve as catalysts, helping create small organic compounds from inorganic building blocks. Such minerals are found at alkaline hydrothermal vents on the seafloor.

    Alkaline hydrothermal vents are also home to large chimney-like structures rich in iron and sulfur. Prior studies suggested that ancient counterparts of these chimneys might have isolated and concentrated organic molecules together, spurring the origin of life on Earth.

    To see how well these chimneys support the formation of strings of RNA, researchers synthesized chimneys by slowly injecting solutions containing iron, sulfur and silicon into glass jars. Depending on the concentrations of the different chemicals used to grow these structures, the chimneys were either mounds with single hollow centers or, more often, spires and “chemical gardens” with multiple hollow tubes.

    2
    Chimney-like mineral structures created in the lab created from solutions containing iron, sulfur and silicon under a) low concentrations and b) high concentrations. Structures in a) represent mound (left) and spindle (right) formations, while those in b) represent chemical garden formations.
    Credit: Bradley Burcar et al., Astrobiology.

    “Being able to perform our experiments in chimney structures that looked like something one might encounter in the darker regions of Tolkien’s Middle Earth gave these studies a geologic context that sparked the imagination,” said study co-author Linda McGown, an analytical chemist and astrobiologist at Rensselaer Polytechnic Institute in Troy, N.Y.

    The chimneys were grown in liquids and gases resembling the oceans and atmosphere of early Earth. The liquids were acidic and enriched with iron, while the gases were rich in nitrogen and had no oxygen. The scientists then poked syringes up the chimneys to pump alkaline solutions containing a variety of chemicals into the model oceans. This simulated ancient vent fluid seeping into primordial seas.

    Sometimes the researchers added montmorillonite clay to their glass jars. Clays are produced by interactions between water and rock, and would likely have been common on the early Earth, McGown said.

    The kind of nucleotides making up RNA are known as ribonucleotides, since they are made with the sugar ribose. The scientists found that unmodified ribonuclotides could form strings of two nucleotides. In addition, ribonucleotides “activated” with a compound known as imidazole — a molecule created during chemical reactions that synthesize nucleotides — could form RNA strings or polymers up to four ribonucleotides long.

    “In order to observe significant RNA polymerization on the time scale of laboratory experiments, it is generally necessary to activate the nucleotides,” McGown said. “Imidazole is commonly used for nucleotide activation in these types of experiments.”

    The scientists found that not only was the chemical composition of the chimneys important when it came to forming RNA, but the physical structure of the chimneys was key too. When the researchers mixed iron, sulfur and silicon solutions into their simulated oceans, instead of slowly injecting them into the seawater to form chimneys, the resulting blend could not trigger RNA formation.

    “The chimneys, and not just their constituents, are responsible for the polymerization,” McGown said.

    These experiments for the first time demonstrate that RNAs can form in alkaline hydrothermal chimneys, albeit synthetic ones.

    “Our goal from the start of our RNA polymerization research has been to place the RNA polymerization experiments as closely as possible in the context of the most likely early Earth environments,” McGown said. “Most previous RNA polymerization research has focused on surface environments, and the exploration of deep-ocean hydrothermal vents could yield exciting new possibilities for the emergence of an RNA world.”

    One concern about these findings is that the experiments were performed at room temperature. Hydrothermal vents are much hotter, and such temperatures could destroy RNA. [Video: The Search For Another Earth]

    “Keep in mind, however, that hydrothermal vents are dynamic systems with gradients of chemical and physical conditions, including temperature,” McGown said.

    In principle, cooler sections of hydrothermal vents might have nurtured RNA and its precursor molecules, she said.

    In the future, McGown and her colleagues will perform experiments investigating what effects variables such as pressure, temperature and mineralogy might have on the formation of RNA molecules, focusing primarily on conditions mimicking deep-ocean environments on an early Earth and those that may also have existed on Mars and elsewhere, McGown said.

    The scientists detailed their findings in the July 22 issue of the journal Astrobiology.

    Science team:

    Bradley T. Burcar,1,2 Laura M. Barge,3,4 Dustin Trail,1,5,* E. Bruce Watson,1,5 Michael J. Russell,3,4 and Linda B. McGown1,2
    1 New York Center for Astrobiology, Rensselaer Polytechnic Institute, Troy, New York.
    2 Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, New York.
    3 NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California.
    4 NASA Astrobiology Institute, Icy Worlds.
    5 Department of Earth and Environmental Sciences, Rensselaer Polytechnic Institute School of Science, Troy, New York.

    See the full article here .

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  • richardmitnick 9:33 pm on November 28, 2015 Permalink | Reply
    Tags: Astrobiology, , ,   

    From NASA NExSS: “NExSS Coalition to Lead Search for Life on Distant Worlds” April 2015 but Important 

    NASA NExSS bloc

    NASA NExSS

    Last Updated: July 30, 2015
    Editor: Sarah Loff

    1
    The search for life beyond our solar system requires unprecedented cooperation across scientific disciplines. NASA’s NExSS collaboration includes those who study Earth as a life-bearing planet (lower right), those researching the diversity of solar system planets (left), and those on the new frontier, discovering worlds orbiting other stars in the galaxy (upper right). Credits: NASA

    NASA is bringing together experts spanning a variety of scientific fields for an unprecedented initiative dedicated to the search for life on planets outside our solar system.

    The Nexus for Exoplanet System Science, or “NExSS”, hopes to better understand the various components of an exoplanet, as well as how the planet stars and neighbor planets interact to support life.

    “This interdisciplinary endeavor connects top research teams and provides a synthesized approach in the search for planets with the greatest potential for signs of life,” says Jim Green, NASA’s Director of Planetary Science. “The hunt for exoplanets is not only a priority for astronomers, it’s of keen interest to planetary and climate scientists as well.”

    The study of exoplanets – planets around other stars – is a relatively new field. The discovery of the first exoplanet around a star like our sun was made in 1995. Since the launch of NASA’s Kepler space telescope six years ago, more than 1,000 exoplanets have been found, with thousands of additional candidates waiting to be confirmed.

    NASA Kepler Telescope
    Kepler

    Scientists are developing ways to confirm the habitability of these worlds and search for biosignatures, or signs of life.

    The key to this effort is understanding how biology interacts with the atmosphere, geology, oceans, and interior of a planet, and how these interactions are affected by the host star. This “system science” approach will help scientists better understand how to look for life on exoplanets.

    NExSS will tap into the collective expertise from each of the science communities supported by NASA’s Science Mission Directorate:

    Earth scientists develop a systems science approach by studying our home planet.
    Planetary scientists apply systems science to a wide variety of worlds within our solar system.
    Heliophysicists add another layer to this systems science approach, looking in detail at how the Sun interacts with orbiting planets.
    Astrophysicists provide data on the exoplanets and host stars for the application of this systems science framework.

    NExSS will bring together these prominent research communities in an unprecedented collaboration, to share their perspectives, research results, and approaches in the pursuit of one of humanity’s deepest questions: Are we alone?

    The team will help classify the diversity of worlds being discovered, understand the potential habitability of these worlds, and develop tools and technologies needed in the search for life beyond Earth.

    Dr. Paul Hertz, Director of the Astrophysics Division at NASA notes, “NExSS scientists will not only apply a systems science approach to existing exoplanet data, their work will provide a foundation for interpreting observations of exoplanets from future exoplanet missions such as TESS, JWST, and WFIRST.”

    NASA TESS
    TESS

    NASA Webb Telescope
    JWST

    NASA WFIRST telescope
    WFIRST

    The Transiting Exoplanet Survey Satellite (TESS) is working toward a 2017 launch, with the James Webb Space Telescope (JWST) scheduled for launch in 2018. The Wide-field Infrared Survey Telescope is currently being studied by NASA for a launch in the 2020’s.

    NExSS will be led by Natalie Batalha of NASA’s Ames Research Center, Dawn Gelino with NExScI, the NASA Exoplanet Science Institute, and Anthony del Genio of NASA’s Goddard Institute for Space Studies. The NExSS project will also include team members from 10 different universities and two research institutes. These teams were selected from proposals submitted across NASA’s Science Mission Directorate.

    The Berkeley/Stanford University team is led by James Graham. This “Exoplanets Unveiled” group will focus on this question: “What are the properties of exoplanetary systems, particularly as they relate to their formation, evolution, and potential to harbor life?”

    http://astro.berkeley.edu/p/Berkeley-NExSS

    Daniel Apai leads the Earths in Other Solar Systems team from the University of Arizona. The EOS team will combine astronomical observations of exoplanets and forming planetary systems with powerful computer simulations and cutting-edge microscopic studies of meteorites from the early solar system to understand how Earth-like planets form and how biocritical ingredients — C, H, N, O-containing molecules — are delivered to these worlds.

    http://otherearths.org

    The Arizona State University team will take a similar approach. Led by Steven Desch, this research group will place planetary habitability in a chemical context, with the goal of producing a “periodic table of planets”. Additionally, the outputs from this team will be critical inputs to other teams modeling the atmospheres of other worlds.

    Researchers from Hampton University will be exploring the sources and sinks for volatiles on habitable worlds. The Living, Breathing Planet Team, led by William B. Moore, will study how the loss of hydrogen and other atmospheric compounds to space has profoundly changed the chemistry and surface conditions of planets in the solar system and beyond. This research will help determine the past and present habitability of Mars and even Venus, and will form the basis for identifying habitable and eventually living planets around other stars.

    http://sol.hamptonu.edu/project/the-living-breathing-planet/

    The team centered at NASA’s Goddard Institute for Space Studies will investigate habitability on a more local scale. Led by Tony Del Genio, it will examine the habitability of solar system rocky planets through time, and will use that foundation to inform the detection and characterization of habitable exoplanets in the future.

    http://www.giss.nasa.gov/projects/astrobio/

    The NASA Astrobiology Institute’s Virtual Planetary Laboratory, based at the University of Washington, was founded in 2001 and is a heritage team of the NExSS network. This research group, led by Dr. Victoria Meadows, will combine expertise from Earth observations, Earth system science, planetary science, and astronomy to explore factors likely to affect the habitability of exoplanets, as well as the remote detectability of global signs of habitability and life.

    Five additional teams were chosen from the Planetary Science Division portion of the Exoplanets Research Program (ExRP). Each brings a unique combination of expertise to understand the fundamental origins of exoplanetary systems, through laboratory, observational, and modeling studies.

    A group led by Neal Turner at NASA’s Jet Propulsion Laboratory, California Institute of Technology, will work to understand why so many exoplanets orbit close to their stars. Were they born where we find them, or did they form farther out and spiral inward? The team will investigate how the gas and dust close to young stars interact with planets, using computer modeling to go beyond what can be imaged with today’s telescopes on the ground and in space.

    A team at the University of Wyoming, headed by Hannah Jang-Condell, will explore the evolution of planet formation, modeling disks around young stars that are in the process of forming their planets. Of particular interest are “transitional” disks, which are protostellar disks that appear to have inner holes or regions partially cleared of gas and dust. These inner holes may be caused in part by planets inside or near the holes.

    A Penn State University team, led by Eric Ford, will strive to further understand planetary formation by investigating the bulk properties of small transiting planets and implications for their formation.

    A second Penn State group, with Jason Wright as principal investigator, will study the atmospheres of giant planets that are transiting hot Jupiters with a novel, high-precision technique called diffuser-assisted photometry. This research aims to enable more detailed characterization of the temperatures, pressures, composition, and variability of exoplanet atmospheres.

    http://science.psu.edu/news-and-events/2015-news/FordWright4-2015

    The University of Maryland and NASA’s Goddard Space Flight Center team, with Wade Henning at the helm, will study tidal dynamics and orbital evolution of terrestrial class exoplanets. This effort will explore how intense tidal heating, such as the temporary creation of magma oceans, can actually save Earth-sized planets from being ejected during the orbital chaos of early solar systems.

    Another University of Maryland project, led by Drake Deming, will leverage a statistical analysis of Kepler data to extract the maximum amount of information concerning the atmospheres of Kepler’s planets.

    The group led by Hiroshi Imanaka from the SETI Institute will be conducting laboratory investigation of plausible photochemical haze particles in hot, exoplanetary atmospheres.

    The Yale University team, headed by Debra Fischer, will design new spectrometers with the stability to reach Earth-detecting precision for nearby stars. The team will also make improvements to Planet Hunters, http://www.planethunters.org, a web interface that allows citizen scientists to search for transiting planets in the NASA Kepler public archive data. Citizen scientists have found more than 100 planets not previously detected; many of these planets are in the habitable zones of host stars.

    A group led by Adam Jensen at the University of Nebraska-Kearney will explore the existence and evolution of exospheres around exoplanets, the outer, ‘unbound’ portion of a planet’s atmosphere. This team previously made the first visible light detection of hydrogen absorption from an exoplanet’s exosphere, indicating a source of hot, excited hydrogen around the planet. The existence of such hydrogen can potentially tell us about the long-term evolution of a planet’s atmosphere, including the effects and interactions of stellar winds and planetary magnetic fields.

    From the University of California, Santa Cruz, Jonathan Fortney’s team will investigate how novel statistical methods can be used to extract information from light which is emitted and reflected by planetary atmospheres, in order to understand their atmospheric temperatures and the abundance of molecules.

    See the full article here .

    Please help promote STEM in your local schools.

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    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 10:10 pm on November 12, 2015 Permalink | Reply
    Tags: Astrobiology, , ,   

    From U Hawaii: “UH Researchers Shed New Light on the Origins of Earth’s Water” 

    U Hawaii

    University of Hawaii

    12 November 2015
    Dr. Lydia Hallis
    Lydia.Hallis@glasgow.ac.uk
    cell: +44 (0)7709585622

    Dr. Karen Meech
    meech@ifa.hawaii.edu
    
+1 808-956-6828
    cell: +1 720-231-7048

    Dr. Roy Gal
    Media Contact
    +1 808-956-6235
    cell: +1 301-728-8637
    rgal@ifa.hawaii.edu

    1
    Scanning electron microscope image of a Baffin Island picrite (type of basaltic rock). The mineral olivine, shown as abundant mid-gray color cracked grains (A), hosts glassy melt inclusions (B) containing tiny amounts of water sourced from Earth’s deep mantle. Image by Lydia J. Hallis.

    Water covers more than two-thirds of Earth’s surface, but its exact origins are still something of a mystery. Scientists have long been uncertain whether water was present at the formation of the planet, or if it arrived later, perhaps carried by comets and meteorites.

    Now researchers from the University of Hawaii at Manoa, using advanced ion-microprobe instrumentation, have found that rocks from Baffin Island in Canada contain evidence that Earth’s water was a part of our planet from the beginning. Their research is published in the 13 November issue of the journal Science.

    The research team was led by cosmochemist Dr. Lydia Hallis, then a postdoctoral fellow at the UH NASA Astrobiology Institute (UHNAI) and now Marie Curie Research Fellow at the University of Glasgow, Scotland.

    The ion microprobe allowed researchers to focus on minute pockets of glass inside these scientifically important rocks, and to detect the tiny amounts of water within. The ratio of hydrogen to deuterium in the water provided them with valuable new clues as to its origins.

    Hydrogen has an atomic mass of one, while deuterium, an isotope of hydrogen also known as “heavy hydrogen,” has an atomic mass of two. Scientists have discovered that water from different types of planetary bodies in our solar system have distinct hydrogen to deuterium ratios.

    Dr. Hallis explained, “The Baffin Island rocks were collected back in 1985, and scientists have had a lot of time to analyze them in the intervening years. As a result of their efforts, we know that they contain a component from Earth’s deep mantle.

    “On their way to the surface, these rocks were never affected by sedimentary input from crustal rocks, and previous research shows their source region has remained untouched since Earth’s formation. Essentially, they are some of the most primitive rocks we’ve ever found on Earth’s surface, and so the water they contain gives us an invaluable insight into Earth’s early history and where its water came from.

    “We found that the water had very little deuterium, which strongly suggests that it was not carried to Earth after it had formed and cooled. Instead, water molecules were likely carried on the dust that existed in a disk around our Sun before the planets formed. Over time this water-rich dust was slowly drawn together to form our planet.

    “Even though a good deal of water would have been lost at the surface through evaporation in the heat of the formation process, enough survived to form the world’s water.

    “It’s an exciting discovery, and one which we simply didn’t have the technology to make just a few years ago. We’re looking forward to further research in this area in the future.”

    The paper is entitled Evidence for primordial water in Earth’s deep mantle. UH co-authors are Dr. Gary Huss, Dr. Kazuhide Nagashima, Prof. G. Jeffrey Taylor, Prof. Mike Mottl, and Dr. Karen Meech.

    The research was funded by the University of Hawaii NASA Astrobiology Institute under Cooperative Agreement No. NNA09-DA77A.

    See the full article here .

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    System Overview

    The University of Hawai‘i System includes 10 campuses and dozens of educational, training and research centers across the Hawaiian Islands. As the public system of higher education in Hawai‘i, UH offers opportunities as unique and diverse as our Island home.

    The 10 UH campuses and educational centers on six Hawaiian Islands provide unique opportunities for both learning and recreation.

    UH is the State’s leading engine for economic growth and diversification, stimulating the local economy with jobs, research and skilled workers.

     
  • richardmitnick 9:59 am on October 18, 2015 Permalink | Reply
    Tags: , Astrobiology, , Zircons   

    From astrobio.net: “Study questions dates for cataclysms on early moon, Earth” 

    Astrobiology Magazine

    Astrobiology Magazine

    Oct 18, 2015
    No Writer Credit

    1
    The deformed lunar zircon at center was brought from the moon by Apollo astronauts. The fractures characteristic of meteorite impact are not seen in most lunar zircons, so the ages they record probably reflect heating by molten rock, not impact. Photo: Apollo 17/Nicholas E. Timms

    Phenomenally durable crystals called zircons are used to date some of the earliest and most dramatic cataclysms of the solar system. One is the super-duty collision that ejected material from Earth to form the moon roughly 50 million years after Earth formed. Another is the late heavy bombardment, a wave of impacts that may have created hellish surface conditions on the young Earth, about 4 billion years ago.

    Both events are widely accepted but unproven, so geoscientists are eager for more details and better dates. Many of those dates come from zircons retrieved from the moon during NASA’s Apollo voyages in the 1970s.

    A study of zircons from a gigantic meteorite impact in South Africa, now online in the journal Geology, casts doubt on the methods used to date lunar impacts. The critical problem, says lead author Aaron Cavosie, a visiting professor of geoscience and member of the NASA Astrobiology Institute at the University of Wisconsin-Madison, is the fact that lunar zircons are “ex situ,” meaning removed from the rock in which they formed, which deprives geoscientists of corroborating evidence of impact.

    “While zircon is one of the best isotopic clocks for dating many geological processes,” Cavosie says, “our results show that it is very challenging to use ex situ zircon to date a large impact of known age.”

    Although many of their zircons show evidence of shock, “once separated from host rocks, ex situ shocked zircons lose critical contextual information,” Cavosie says.

    The “clock” in a zircon occurs as lead isotopes accumulate during radioactive decay of uranium. With precise measurements of isotopes scientists can calculate, based on the half life of uranium, how long lead has been accumulating.

    If all lead was driven off during asteroid impact, the clock was reset, and the amount of accumulated lead should record exactly how long ago the impact occurred.

    Studies of lunar zircons have followed this procedure to produce dates from 4.3 billion to 3.9 billion years ago for the late heavy bombardment.

    2
    This highly shocked zircon, from the Vredefort Dome in South Africa, shows thin, red bands that are a hallmark of meteorite impact. Uranium-lead dating from this zircon matched the age of the rocks exposed at Vredefort, not the more recent age of impact (2 billion years). Credit: Aaron Cavosie

    To evaluate the assumption of clock-resetting by impact, Cavosie and colleagues gathered zircons near Earth’s largest impact, located in South Africa and known to have occurred 2 billion years ago. The Vredefort impact structure is deeply eroded, and approximately 90 kilometers across, says Cavosie, who is also in the Department of Applied Geology at Curtin University in Perth, Australia. “The original size, estimated at 300 kilometers diameter, is modeled to result from an impactor 14 kilometers in diameter,” he says.

    1
    Vredefort Dome

    The researchers searched for features within the zircons that are considered evidence of impact, and concluded that most of the ages reflect when the zircons formed in magma. The zircons from South Africa are “out of place grains that contain definitive evidence of shock deformation from the Vredefort impact,” Cavosie says. “However, most of the shocked grains do not record the age of the impact but rather the age of the rocks they formed in, which are about 1 billion years older.”

    The story is different on Earth, says zircon expert John Valley, a professor of geoscience at UW-Madison. “Most zircons on Earth are found in granite, and they formed in the same process that formed the granite. This has led people to assume that all the zircons were reset by impact, so the ages they get from the Moon are impact ages. Aaron is saying to know that, you have to apply strict criteria, and that’s not what people have been doing.”

    The accuracy of zircon dating affects our view of Earth’s early history. The poorly understood late heavy bombardment, for example, likely influenced when life arose, so dating the bombardment topped a priority list of the National Academy of Sciences for lunar studies. Did the giant craters on the moon form during a brief wave or a steady rain of impacts? “It would be nice to know which,” Valley says.

    “The question of what resets the zircon clock has always been very complicated. For a long time people have been saying if zircon is really involved in a major impact shock, its age will be reset, so you can date the impact. Aaron has been saying, ‘Yes, sometimes, but often what people see as a reset age may not really be reset.’ Zircons are the gift that keep on giving, and this will not change that, but we need to be a lot more careful in analyzing what that gift is telling us.”

    See the full article here .

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  • richardmitnick 8:26 am on October 7, 2015 Permalink | Reply
    Tags: , , Astrobiology, , Plant life   

    From astrobio.net: “Ancient alga knew how to survive on land before it left water & evolved into first plant” 

    Astrobiology Magazine

    Astrobiology Magazine

    1
    Closterium strigosum is one of the green algae the scientists analyzed. Credit: Michael Melkonian

    A team of scientists led by Dr Pierre-Marc Delaux (John Innes Centre / University of Wisconsin, Madison) has solved a long-running mystery about the first stages of plant life on earth.

    The team of scientists from the John Innes Centre, the University of Wisconsin – Madison and other international collaborators, has discovered how an ancient alga was able to inhabit land, before it went on to evolve into the world’s first plant and colonise the earth.

    Up until now it had been assumed that the alga evolved the capability to source essential nutrients for its survival after it arrived on land by forming a close association with a beneficial fungi called arbuscular mycorrhiza (AM), which still exists today and which helps plant roots obtain nutrients and water from soil in exchange for carbon.

    The previous discovery of 450 million year old fossilised spores similar to the spores of the AM fungi suggests this fungi would have been present in the environment encountered by the first land plants. Remnants of prehistoric fungi have also been found inside the cells of the oldest plant macro-fossils, reinforcing this idea.

    However, scientists were not clear how the algal ancestor of land plants could have survived long enough to mediate a quid pro quo arrangement with a fungi. This new finding points to the alga developing this crucial capability while still living in the earth’s oceans!

    Dr Delaux and colleagues analysed DNA and RNA of some of the earliest known land plants and green algae and found evidence that their shared algal ancestor living in the Earth’s waters already possessed the set of genes, or symbiotic pathways, it needed to detect and interact with the beneficial AM fungi.

    The team of scientists believes this capability was pivotal in enabling the alga to survive out of the water and to colonise the earth. By working with the fungi to find sustenance, the alga was able to buy time to adapt and evolve in a very different and seemingly infertile environment.

    Dr Delaux said: “At some point 450 million years ago, alga from the earth’s waters splashed up on to barren land. Somehow it survived and took root, a watershed moment that kick-started the evolution of life on earth. Our discovery shows for the first time that the alga already knew how to survive on land while it was still in the water. Without the development of this pre-adapted capability in alga, the earth could be a very different place today.

    “This finding has filled a gap in our collective knowledge about the origins of life on earth. None of this would have been possible without the dedication of a world-wide team of scientists including a tremendous contribution from the 1KP initiative led by Gane KS Wong .”

    Professor Jean-Michel Ané, from the University of Wisconsin said: “The surprise was finding the mechanisms in algae which allow plants to interact with symbiotic fungi. Nobody has studied beneficial associations in these algae.”

    See the full article here .

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  • richardmitnick 6:02 pm on October 1, 2015 Permalink | Reply
    Tags: Astrobiology, , , , , U Kansas   

    From Kansas: “Scientists refine hunt for Mars life by analyzing rock samples in Western U.S” 

    U Kansas bloc

    University of Kansas

    LAWRENCE — The search for life beyond Earth is one of the grandest endeavors in the history of humankind — a quest that could transform our understanding of our universe both scientifically and spiritually.

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    Petrographic thin section made from core sample. This 30 micron thin slice of rock allows a view of the types of features thought to be microbial. Here, the blue layers are an epoxy added in to see void-space in the rock, and the grey is sediment. The morphology of the orange-brown layers are suggestive of microbial activity, such as they way they roll over themselves in the bottom left and smoothly drape over the triangular feature. This type of deposition demonstrates that the sediment had to have a degree of cohesive stickiness, such as that provided by the presence of microbial mats.

    With news coming this week that NASA has confirmed the presence of flowing saltwater on the surface of Mars, the hunt for life on the Red Planet has new momentum.

    “One of the many reasons this is exciting is that life as we currently know it requires water,” said Alison Olcott-Marshall, assistant professor of geology at the University of Kansas. “So the fact that it’s present at Mars means that the most basic and universal requirement for life was fulfilled.”

    In the journal Astrobiology, Olcott-Marshall recently has published an analysis of Eocene rocks found in the Green River Formation, a lake system extending over parts of Colorado, Utah and Wyoming.

    Marshall and co-author Nicholas A. Cestari, a masters student in her lab, found these Green River rocks have features that visually indicate the presence of life, and they argue that probes to Mars should identify similar indicators on that planet and double-check them through chemical analysis.

    “Once something is launched into space, it becomes much harder to do tweaks — not impossible, but much, much harder,” Olcott-Marshall said. “Scientists are still debating the results of some of the life-detection experiments that flew to Mars on the Viking Missions in the late ’70s, in a large part because of how the experiments were designed. Looking at Earth-based analogs lets us get some of these bumps smoothed out here on Earth, when we can revise, replicate and re-run experiments easily.”

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    Petrographic thin section made from core sample. This 30 micron thin slice of rock allows a view of the types of features thought to be microbial, such as the layers that fold over themselves in the middle of the sample marked 2534.8’. This demonstrates that the sediment had to have a degree of cohesive stickiness, such as that provided by the presence of microbial mats.

    The researchers examined cored samples of rock from 50 million years ago that included sections of “microbial mats.”

    “Microbial mats are essentially the microbial world’s version of apartment buildings — they are layered communities of microbes, and each layer represents a different metabolic strategy,” Olcott-Marshall said. “Generally, the photosynthetic microbes are at the top, and then every successive layer makes use of the waste products of the level above. Thus, not only does a microbial mat contain a great deal of biology, but a great number of chemicals, pigments and metabolic products are made, which means lots of potential biosignatures.”

    At times during the Eocene, the Green River Formation’s water chemistry purged fish and other organisms from the lake, providing room for these microbes to thrive.

    “During these times, ‘microbialites’ formed — these are rocks thought to be made by microbial processes, essentially the preserved remnants of microbial mats. The Green River Formation has a wide variety of these structures, and these features are why we went looking in these rocks, as microbialites are one life-detection target on Mars.”

    First, the researchers visually inspected the cored samples for signs of biology by identifying geological signs associated with microbialites — such as “stromatolites.”

    “These are things like finely laminated sediments, where each lamination follows the ones below, or signs of cohesive sediment, things like layers that roll over onto themselves or are at an angle steeper than what gravity would allow,” Olcott-Marshall said. “These are all thought to be signs that microbes are helping hold sediment together.”

    If visual examination pointed to the presence of biology in sections of the rock cores, the researchers looked to confirm the presence of life. They powdered those rock samples in a ball mill, and then used hot organic solvents like methanol to remove any organic carbons that might have been preserved in the rocks. That solvent was then concentrated and analyzed with gas chromatography/mass spectroscopy.

    “GC/MS allows an identification of compounds, including organic molecules, preserved in a rock,” Olcott-Marshall said. “Viking was the first time that a GC/MS was sent to Mars, and there is one up there right now on Curiosity collecting data.”

    NASA Viking 2
    NASA/Viking 2

    NASA Mars Curiosity Rover
    NASA/Mars Curiosity Rover

    Through GC/MS, the researchers determined that rock structures appearing to be biological indeed hosted living organisms millions of years ago: analysis showed the presence of lipid biomarkers.

    “A lipid biomarker is the preserved remnant of a lipid, or a fat, once synthesized by an organism,” Olcott-Marshall said. “These can be simple or very complex. Different organisms make different lipids, so identifying the biomarker can often allow a deeper understanding of the biota or the environment present when a rock was formed. These are a type of biosignature.”

    The researchers said their results could be a powerful guide for sample selection on Mars.

    “There is a GC/MS on Curiosity right now, but there are only nine sample cups dedicated for looking for biomarkers like these,” Olcott-Marshall said. “It’s crucial those nine samples are ones most likely to guarantee success. Additionally, one of the goals of the planned 2020 rover mission is to identify samples for caching for eventual return to Earth. The amount of sample that can be returned is likely very small, thus, once again, doing our best to guarantee success is very important. What this shows is that we can use visual inspection to help us screen for these samples that are likely to be successful for further biosignature analysis.”

    She said microbial and non-microbial rocks are found in similar environments, with identical preservation histories for millions of years, and many of the same chemical parameters, such as amounts of organic carbon preserved in the rocks.

    “The only difference is that one rock is shaped in a way people have associated with biology, and sure enough, those rocks are the ones that seem to preserve the biosignatures, at least in the Green River,” she said.

    See the full article here.

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    U Kansas campus

    Since its founding, the University of Kansas has embodied the aspirations and determination of the abolitionists who settled on the curve of the Kaw River in August 1854. Their first goal was to ensure that the new Kansas Territory entered the union as a free state. Another was to establish a university.

    Nearly 150 years later, KU has become a major public research and teaching institution of 28,000 students and 2,600 faculty on five campuses (Lawrence, Kansas City, Overland Park, Wichita, and Salina). Its diverse elements are united by their mission to educate leaders, build healthy communities, and make discoveries that change the world.

    A member of the prestigious Association of American Universities since 1909, KU consistently earns high rankings for its academic programs. Its faculty and students are supported and strengthened by endowment assets of more than $1.44 billion. It is committed to expanding innovative research and commercialization programs.

    KU has 13 schools, including the only schools of pharmacy and medicine in the state, and offers more than 360 degree programs. Particularly strong are special education, city management, speech-language pathology, rural medicine, clinical child psychology, nursing, occupational therapy, and social welfare. Students, split almost equally between women and men, come from all 50 states and 105 countries and are about 15 percent multicultural. The University Honors Program is nationally recognized, and KU has produced 26 Rhodes Scholars, more than all other Kansas schools combined.

     
  • richardmitnick 2:28 pm on September 22, 2015 Permalink | Reply
    Tags: Astrobiology, , , International Innovation, ,   

    From International Innovation- ” Life in the cosmos: Seth Shostak” 

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    International Innovation

    1

    SETI Seth Shostak
    Seth Shostak

    What is it about astronomy that captivates you?

    I find astronomy captivating, not only because it deals with huge and imposing celestial objects that have existed for billions of years, but it also answers big questions, questions that everybody, no matter where they live, might ask. Where did the Universe come from? Where is it going? What’s out there? For this reason, it’s a privilege to work in this field.

    As the only organisation addressing the full range of disciplines investigating life in the Universe, what is the Search for Extraterrestrial Intelligence (SETI) Institute’s mission?

    The Institute’s mission is to research life in the cosmos; it’s that simple. We’re not only looking for intelligent life forms – which is the purpose of the SETI experiments – we’re also looking for the existence of microbes closer to Earth, for example, on Mars or on some of the moons surrounding Saturn or Jupiter. There are more than half a dozen locations in our own solar system where life could exist, or where it could have once existed, with Mars being one of the favourites.

    Our work also involves investigating how life started on Earth, because this could give us some indication of how it might have started elsewhere, as well as finding exoplanets – planets orbiting other stars – that are possible habitats for life.

    When I joined the SETI Institute in 1991, the majority of its efforts were focused on radio SETI, which was by far its biggest project. However, today, 95 per cent of our scientists are working on what’s called astrobiology, looking for evidence of life on Mars, Jupiter, Saturn’s moons, etc. The Institute’s emphasis has greatly shifted.

    Could you share examples of R&D projects that are currently underway at the SETI Institute?

    In the astrobiology realm, there are around a dozen researchers studying the history of Mars. They are seeking to answer questions such as whatthe planet may have looked like 4 billion years ago and whether there was water on it. Today, Mars is cold and extremely dry – a terrible place for supporting life – but it wasn’t always so. The question is whether it could have supported life at one point. It’s certainly possible that we’ll find microbes there, so there is a lot of hardware roaming around the surface of Mars and orbiting the planet in an attempt to find out more about its history.

    Other researchers here are studying asteroids and meteors to find out whether they brought ingredients for life to Earth. If this is the case, it’s possible the same has happened to other planets. Similarly, a group is researching Jupiter and Saturn’s moons for water, and consequently life. We also have a team working on the New Horizons mission, which has just flown by Pluto. In fact, one of our senior research scientists, Dr Mark Showalter, found two of Pluto’s moons.

    Another important project for our astrobiologists is the search for exoplanets. We’re heavily involved with NASA’s Kepler Mission and that particular effort has found over 4,000 planets orbiting stars, some of which appear to be similar to Earth. We are also planning a large survey of dim stars, which are smaller than the Sun, because these might have habitable planets orbiting them. Finally, we’re making improvements to our equipment; for example, building new radio receivers.

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    As part of a new trend in radio astronomy, the Allen Telescope Array (ATA) uses a large number of small dishes (LNSD) array to simultaneously survey numerous SETI targets. How does the ATA work and what are the key advantages of this approach?

    The ATA uses 42 relatively small antennas, which are 20 feet in diameter. This differs from past approaches in that radio telescopes built in the 1960s and 1970s used the largest possible antennas. While bigger antennas are able to receive more cosmic static and fainter signals, they are far more expensive to build. Thanks to advances in electronics, however, it’s now possible to connect a lot of small antennas together to achieve the same performance as one big antenna, only for a lot less money. Not only that, but small antennas can scan large swathes of the sky much more quickly than large antennas.

    Can you summarise the Institute’s most significant achievements to date?

    Our planetary discoveries have certainly made the headlines. For example, the planet Kepler 452b is 1,400 light-years away and orbits a star that is just like the Sun. This planet could be Earth’s cousin in that it’s a little bit bigger than Earth and its year is 385 days long rather than 365 days. Another planet, which is similar in size to Jupiter, was found by one of our astronomers around a nearby star. This planet was found using a ground-based telescope, which isn’t usually possible.

    Another significant achievement is the New Horizons mission. It took New Horizons almost ten years to arrive at Pluto, and the team working on this project didn’t know whether the spacecraft would actually make it or if there would be any data to collect at the end of its journey. It has been wonderfully successful, however, and we’ll be continuing to receive data for the next year and a half.

    In terms of the ATA, we haven’t found a signal yet, but the speed of our search is continually increasing. I have bet everyone a Starbucks coffee that we’ll find ET within 20 years. I may have to buy a lot of coffee, but there’s hope!

    What are the greatest challenges facing signal detection technology and how can the Center help to overcome these issues?

    One of the biggest challenges we face is funding because this directly affects what we can achieve and the types of equipment we can develop. The astrobiologists benefit from NASA funding but all of the Institute’s SETI experiments are privately funded. There are a number of approaches we could adopt to speed up our research; for example, the technology developed for video games uses specialised hardware that can complete computational tasks very quickly. The technical challenges associated with doing this could certainly be solved. When I bet people a cup of Starbucks coffee that we’re going to find ET, this assumes that we can develop the equipment necessary to greatly speed up our work – and this is possible if we have the funds.

    What more can be done to attract support from funding bodies and further engage the public?

    We get a lot of media attention and the public is interested in what we do. Indeed, we even have the attention of the House Committee on Science, Space & Technology in congress, where I testified about a year ago. I would say the public is aware of what we’re doing but what they don’t know is that we can’t do very much because of funding issues. Communicating that message would enable us to have a decent chance of success; if we can build the right equipment we might be able to find ET.

    Can you reveal what the future holds for the Institute?

    I’m very optimistic about the future because this really is a special time in history. We know so much more about astronomy and the planets orbiting other stars than we did when I was a kid, or even twenty-odd years ago. Now we know what’s out there, we have the ability to build equipment that could, in principle, find proof of life, whether in our solar system or somewhere else in space. This is the first time we can say this.

    I think the public recognises this at some level. Some people will have read about planets orbiting other stars or water on Mars, and it may occur to them that this could be the generation that finds extraterrestrial life. It’s rather like being alive at the end of the 15th Century when people were finally able to build wooden ships that could cross the ocean, and that rapidly changed the world as they knew it.

    http://www.seti.org

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