NAI

  1. Greenhouse Gases on Early Earth Helped Keep It Warm


    A team of researchers including members of NAI’s University of Colorado, Boulder Team have provided the first direct field evidence supporting the theory that high concentrations of greenhouse gases could have helped avoid global freezing on the early Earth. They analyzed iron carbonates from 3.75-3.8 billion year old rocks in northern Québec, and conclude that the atmosphere of early Earth contained high levels of CO2. Their paper appears in a recent issue of Earth and Planetary Science Letters.

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  1. Liquid Water on Mars: Is It Still Flowing?


    The scientific strategy of NASA’s Mars exploration can be summarized as “Follow the water.” The habitability of Mars, past or present, is intimately tied to the presence of liquid water. Since the first orbiting spacecraft, Mariner 9, surveyed the planet in the early 1970s, we have known that the Mars polar caps are composed in part of ice, and we have seen large channels cut by water that flowed on the surface billions of years ago. Two of the most important recent discoveries on Mars were “gullies” that indicate much more recent surface flows, less than a million years old, and the evidence from rovers on the surface that shallow ponds or seas of salty water must have once existed, although they may have been transient. However, all these indications of surface water are old – whether the age is measured in millions or billions of years. Now, in what looks to be one of the most important recent discoveries about Mars, we have photographic evidence that flows of liquid water have taken place in the past seven years! The change of perspective from billions or millions of years to something that happened in the twenty-first century could be profound.

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  1. Low Abundance Acidophilic Archea Revealed


    Scientists from NAI’s University of California, Berkeley Team report in this week’s Science on their use of shotgun sequencing to uncover three novel archea present in all biofilms growing in pH 0.5 to 1.5 solutions within the Richmond Mine, California. Their results inform the problem of characterizing microbial communities and lineages which are difficult to cultivate.

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  1. Snowball Earth and the Origin of Photosynthesis


    Using atmospheric chemical models of a Snowball Earth, scientists from NAI’s Alumni Virtual Planetary Laboratory Team show that, during long and severe glacial intervals, a weak hydrological cycle coupled with photochemical reactions involving water vapor would give rise to the sustained production of hydrogen peroxide. The peroxide, upon release from melting ice into the oceans and atmosphere at the end of the snowball event, could mediate global oxidation events. Their results are published in the December 12th issue of PNAS.

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  1. Astrobiology and Stardust


    Carl Sagan once said “We are all star stuff.” But how? What does that really mean? One of the fundamental questions of astrobiology, how does life originate and evolve?, provides a structure in which to examine the relationship between life and the cosmos. Everywhere life has been found on Earth, which is essentially every place in which it has been sought, life’s intimate connection with water has also been found. Within the framework of contemplating life’s cosmic origins, one must also ask about the history of water on Earth. NASA’s Stardust mission has provided the opportunity for astrobiologists to gain deeper insight into this history.

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  1. Found: A Hyperthermophilic Nitrogen Fixer


    Researchers from NAI’s Carnegie Institution of Washington Team have published in Science their findings of a novel archaeon who’s ability to fix nitrogen at 92 degrees Celcius has officially increased the upper limit of biological nitrogen fixation by 28 degrees Celcius. The hyperthermophilic methanogen was isolated from a hydrothermal vent. Thier findings could reveal a broader range of conditions for life in the subseafloor biosphere.

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  1. Stardust Sample Analysis


    A special issue of Science (Dec 15) includes several papers reporting on various aspects of Stardust sample analysis including an organics survey, isotopic and elemental compositions, mineralogy and petrology, and infrared spectroscopy. Many NAI researchers contributed to this comprehensive analytical campaign, including members of NAI’s Teams at the Carnegie Institution of Washington, NASA’s Ames Research Center and Goddard Space Flight Center, and NAI’s Alumni Team at the University of Washington.

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  1. Direct Observation of Magnetic Field on Tau Bootis


    An international team of researchers including NAI Postdoctoral Fellow Evgenya Shkolnik of the University of Hawai’i Team publish their observation in this month’s Royal Astronomical Society Letters of a magnetic field at the surface of star Tau Bootis, which is orbited by a giant planet every three days. The magnetic field’s intensity is similar to that of the Sun, but the star and the planet are tidally locked, possibly producing the observed magnetic knots.

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  1. NAI Researchers Search for Meteorites in Antarctica


    Follow along as scientists from NAI’s University of Hawai’i Team go on expedition with the NSF/NASA – sponsored Antarctic Search for Meteorites (ANSMET) program. View photos, read about the team and their mission, and stay current with regular dispatches from the “Streets of McMurdo.” The ANSMET program enables researchers to collect meteorites in Antarctica first hand for scientific study. Over 75% of meteorites are recovered from Antarctica, and more than 15,000 samples have been supplied to over 400 scientists in 32 countries over the last 30 years.

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  1. Oxygen and Life in the Precambrian


    The December 2006 issue of Geobiology is a collection of papers focusing on the history of Earth’s biogeochemistry, from the earliest sedimentary rocks in Greenland to the late Proterozoic. The rise of atmospheric oxygen provides a thematic link. The papers in this issue, edited by David Catling and Roger Buick of NAI’s University of Washington Alumni Team, grew out of a session of the Earth System Processes 2 conference in Calgary, Canada, 8–11 August 2005, sponsored by the NAI.

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  1. Mineral Surfaces and Life


    Robert Hazen, from NAI’s Carnegie Institution of Washington Team, published his 2005 Presidential Address to the Mineralogical Society of America in this month’s American Mineralogist. The address reviews the role of mineral surfaces on the self-assembly of lipids, the polymerization of amino acids and nucleic acids, and the selective adsorption of organic species, including chiral molecules, onto mineral surfaces.

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  1. Organic Hazes on Early Earth and Titan


    Researchers from NAI’s Unviersity of Colorado, Boulder and University of Arizona Teams have published a new study in PNAS this week about the atmospheres of both present day Titan and early Earth. For Titan, their experiments modeled conditions measured by the Huygens probe from NASA’s Cassini mission, and CO2 was added to model the early Earth conditions. They conclude that organize haze can form over a wide range of methane and carbon dioxide concentrations.

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  1. Earth’s Hidden Biospheres


    Two recent discoveries in astrobiology challenge many of our assumptions about an integrated biological community on Earth. At the microbial level, it seems that there may be previously hidden biospheres that exist on Earth alongside our more familiar neighbors. One such community has been found deeply buried underground, while the other lives in the sea alongside more familiar life forms.

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  1. NASA Study Shows Titan and Early Earth Atmospheres Are Similar


    Organic haze in the atmosphere of Saturn’s moon, Titan, is similar to haze in early Earth’s air — haze that may have helped nourish life on our planet— according to a NASA Astrobiology Institute study released Nov. 6, 2006.

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  1. Astrobiology Primer Published!


    The Astrobiology Primer: An Outline of General Knowledge appears in this month’s issue of Astrobiology. Sponsored by NAI, the Primer was spearheaded by editor-in-chief Lucas Mix, and represents the work of 8 editors, 13 authors, and countless contributors. Intended as a reference tool, it provides information in these 7 topics: Stellar Formation and Evolution, Planetary Formation and Evolution, Astrobiogeochemistry and the Origin of Life, Evolution of Life Through Time, Planet Detection and Characterization, Diversity of Life, and Science in Space. The Primer came about in large part because of NAI support for graduate student research, collaboration, and inclusion as ...

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