NAI

  1. Timelines for the Evolution of Cyanobacteria


    Former NAI Principal Investigator, Andy Knoll of Harvard University, and colleagues discuss the evolution of cyanobacteria in their new paper, “The evolutionary diversification of cyanobacteria: Molecular-phylogenetic and paleontological perspectives” in the April 4th issue of PNAS. The evolutionary timeline has implications for the rise of atmospheric oxygen on Earth.

    Image courtesy of Micro*scope

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  1. Imaging the Unseen


    Researchers from NAI’s University of California, Los Angeles Team have pioneered a new imaging technique which allows them to non-destructively produce 3D images of ancient fossils. The technique, combining confocal microscopy and Raman spectroscopy, could be used on samples returned from Mars by future NASA missions. Their work on 650 million year old fossils from Kazakhstan is published in the February, 2006 issue of Astrobiology.

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  1. Modeling Disk-Averaged Spectra of Earth


    To assess the detectability of planetary characteristics in disk-averaged spectra, the NAI Virtual Planetary Laboratory Team has developed a spatially and spectrally resolved model of the Earth. Using infrared observations of the Earth taken by existing instruments orbiting Mars, and ground-based observations of earthshine, the model has been validated, and indicates that several atmospheric species can be identified. Models such as this one will help analyze disk averaged spectra as returned from upcoming NASA and ESA extra-solar planet detection and characterization missions. They published their results in the February issue of Astrobiology.

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  1. Going Deep


    Some of the most arresting images of life on our planet have come from the deep-sea world of hydrothermal vents. Massive chimneys belching superheated fluids, colonies of giant crimson-tipped tubeworms swaying in the current, swarms of tiny shrimp, albino crabs. These ecosystems, although isolated from life on the surface, contain a virtual zoo of creatures, thriving under conditions of heat and pressure so extreme that, until the vent communities were discovered in the late 1970s, scientists did not even imagine that they existed.

    Perhaps even more fascinating – at least to biologists – has been the cataloging of the microbial life that ...

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  1. Hot Rocks From Comet Wild 2


    Scientists are finding surprises from analyzing tiny particles of comet dust collected by the Stardust spacecraft and returned to Earth 8 weeks ago. They had expected mostly “primitive” particles that had condensed under cool conditions in the solar nebula and been preserved in the deep freeze of space. However, some of the comet dust is made of minerals that can only be formed at high temperatures — either close to the Sun or perhaps in other planetary systems that existed before the solar system formed. NAI scientist Don Browlee reports that “In the coldest part of the solar system, we’ve ...

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  1. A Window Into the Subsurface Microbial Population


    A new paper this week in PNAS highlights a collaboration between NAI Lead Teams at Penn State, University of Rhode Island, UCLA, and the Marine Biological Laboratory. Their research reveals that heterotrophic Archea dominate the scene in a variety of biogeochemically distinct sedimentary regions, and may constitute a significant portion of the prokaryotic biomass in Earth’s subsurface. Ecosystem-level carbon budgets suggest that community turnover times are on the order of 100-2,000 years.

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  1. Life in the Deep Subseafloor


    In a new study published in this week’s PNAS, researchers from NAI’s University of Rhode Island Lead Team report the vertical and geographical distribution of microbes in deeply buried marine sediments of the Pacific Ocean Margin. Sediment cores from the Peru and Cascadia Margins were obtained, and thousands of clones were studied to describe the nature of the biomass in areas with and without methane hydrates. The data suggest that prokaryotic communities from methane hydrate-bearing sediment cores are distinct from those in hydrate-free cores. This study is an important step in understanding the role of biology in Earth ...

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  1. Life in the Landscape?


    A review article in Nature this week from scientists on NAI’s University of California, Berkeley Lead Team examines the idea of the influence of life on topography. The authors call for a need to explore how small scale biotic processes can influence an entire landscape, and whether the resulting topography is distinct.

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  1. Habitable Conditions on the Early Earth


    Direct information concerning the first 500 million years of Earth history – the Hadean Eon – is very limited, since practically no crustal rocks from that time have survived. We do know that the Earth collided much more frequently than it does today with asteroids and comets, as witnessed by the heavily cratered highlands of the Moon. Astronomers also tell us that the Sun was about 30 percent fainter then, so that the Earth may have been cold, unless there was a large greenhouse effect to trap the Sun’s heat and raise surface temperatures above the freezing point. Also of special interest is the apparent fact that life arose on Earth either during or shortly after the Hadean Eon.

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  1. Surviving STS-107


    Rocco Mancinelli, PI of NAI’s SETI Institute Lead Team, and member of NAI’s NASA Ames Research Center Lead Team joined researchers from KSC and Ames, as well as NAI’s Former Director, Barry Blumberg, in studying populations of C. Elegans which survived the atmospheric breakup of STS-107 during it’s fatal re-entry. Their results are published in Astrobiology. Five canisters were recovered, and live animals were observed in four of them. This demonstrates not only the ability of the culture medium to support the organisms during spaceflight, but also the ability of the animals to survive a relatively ...

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  1. Theoretical Planets Around M-Dwarfs


    NAI’s Virtual Planetary Laboratory Lead Team has published new findings from their Lab about the observable, biosignature gases of theoretical planets orbiting M-Dwarf stars in this month’s Astrobiology. Their outcomes are positive for designating M-Dwarfs a viable target for future observations involving the search for life.

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  1. Chance to View Stardust Return


    NASA’s Stardust mission is nearing Earth after a four billion kilometer round-trip journey to bring back comet dust samples. Viewers in California, Oregon, and Nevada have a chance to see the fiery entry of the return capsule into Earth’s atmosphere in the early morning of Sunday January 15 (approximately 2 a.m. PST, 3 a.m. MST).

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  1. NAI Discoveries Ranked Among NASA’s Top Science Stories of the Year


    Scientists from NAI’s NASA Goddard Space Flight Center Lead Team and NAI’s Carnegie Institution of Washington Lead Team and their collaborators used the NASA Spitzer Space Telescope to capture the first light ever detected from two planets orbiting stars other than the sun. Spitzer picked up the infrared glow from the Jupiter-sized planets. The findings mark the beginning of a new age of planetary science, in which extrasolar planets can be directly measured and compared.

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  1. Alternative Model for Diagenesis of Meridiani Bedrock


    Tom McCollom of NAI’s University of Colorado Lead Team and his co-author Brian Hynek published the details of their alternative model today in Nature. The scenario does not require prolonged interaction with a standing body of surface water, and describes an environment less favorable to biological activity on Mars.

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  1. Update on the Human-Chimpanzee Divergence


    Researchers from NAI’s Pennsylvania State University Lead Team and their colleagues at Arizona State University published this week in PNAS their research constraining the divergence of humans and chimpanzees. Using the largest data set yet and improved computational methods for the molecular clock calculations, the study narrows the gap from between 3 and 13 million years ago to between 5 and 7 million years ago.

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