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  1. Life in Ancient Oceans Enabled by Erosion from Land


    Aaron Satkoski used the UW-Madison Department of Geoscience's mass spectrometer to measure isotopes in samples collected from South Africa. Image credit: David Tenenbaum Image credit: None
    Aaron Satkoski used the UW-Madison Department of Geoscience's mass spectrometer to measure isotopes in samples collected from South Africa. Image credit: David Tenenbaum

    As scientists continue finding evidence for life in the ocean more than 3 billion years ago, those ancient fossils pose a paradox.

    Organisms, including the single-celled bacteria living in the ocean at that early date, need a steady supply of phosphorus, but “it’s very hard to account for this phosphorus unless it is eroding from the continents,” says Aaron Satkoski, a scientist in the geoscience department at the University of Wisconsin–Madison. “So that makes it really hard to explain the fossils we see at this early era.”

    Satkoski, who is first author of a new report on ocean ...

    Source: [University of Wisconsin-Madison]

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  1. Cementing a Theory About the Sea Creatures of the Ediacara Biota


    Fossil photo from the Ediacara Biota. Source: James Gehling Image credit: None
    Fossil photo from the Ediacara Biota. Source: James Gehling

    Earth’s earliest community of complex sea creatures lived in a warm, slimy, planetary petri dish that nurtured a broad array of exotic species. Yet we likely wouldn’t know about it at all, scientists say, if not for a quirk in the chemistry of ancient oceans.

    A Yale-led research team found that the Ediacara Biota, a collection of marine fossils found in sandstone around the world, record the operation of an unusual mechanism that preserved impressions of the creatures’ soft bodies for hundreds of millions of years. The findings appear in the journal Geology. The research is supported in ...

    Source: [Yale News]

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  1. "False" Biosignatures May Complicate Search for Ancient Life on Earth, Other Planets


    Transmission electron microscopy images of carbon-sulfer structures that form in the presence of yeast extract. Arrows point to carbon shells; the dark areas are filled with sulfur. Source: J. Cosmidis & A. Templeton (via Nature Communications) Image credit: None
    Transmission electron microscopy images of carbon-sulfer structures that form in the presence of yeast extract. Arrows point to carbon shells; the dark areas are filled with sulfur. Source: J. Cosmidis & A. Templeton (via Nature Communications)

    Self-assembling carbon microstructures created in a lab by University of Colorado Boulder researchers could provide new clues – and new cautions – in efforts to identify microbial life preserved in the fossil record, both on Earth and elsewhere in the solar system.

    The geological search for ancient life frequently zeroes in on fossilized organic structures or biominerals that can serve as “biosignatures” that survive in the rock record over extremely long time scales. Mineral elements such as sulfur are often formed through biological activity. Microbes can also produce a variety of telltale extracellular structures that resemble sheaths and stalks.

    However, according to ...

    Source: [University of Colorado, Boulder]

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  1. Habitable Worlds 2017: A System Science Workshop


    Image credit: None

    The Nexus for Exoplanet System Science (NExSS), a NASA research coordination network dedicated to the study of planetary habitability, is pleased to announce a five-day conference on “Habitable Worlds 2017: A System Science Workshop” from Nov 13-17, 2017 in Laramie, WY. The field of exoplanets is currently at the cusp of a watershed moment in finding life on other worlds, propelled by the discoveries of habitable zone terrestrial planets in both ground and space-based surveys, and the potential for future telescopes to characterize the atmospheres of some of these rocky planets. Preparing for such a singular moment needs a diverse ...

    Source: [NExSS]

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  1. The NAI Director's Seminar Series Presents: What We Talk About When We Talk About Earth's Oxygenation


    The NASA Astrobiology Institute (NAI) Director’s Seminar Series presents “What We Talk About When We Talk About Earth’s Oxygenation”

    Presenter: Noah Planavsky, Yale University
    When: October 31, 2016 1PM PDT

    As the possibility of detecting the atmospheric composition of terrestrial exoplanets moves from the realm of science fiction to science we have become increasingly focused on determining what Earth would look like if analyzed remotely over its long history. Beyond just providing a record of Earth’s atmospheric composition, our goal is to determine how biological evolution has shaped surface oxygenation. A better understanding of our own planet’s atmospheric ...

    Source: [NAI Seminars and Workshops]

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  1. Early Career Scientists Receive Honors


    Two early career scientists who are active in the field of astrobiology have received recognition for their achievements.

    Will Ratcliff makes Popular Science's 2016 Brilliant 10 List. Image source: Georgia Tech Image credit: None
    Will Ratcliff makes Popular Science's 2016 Brilliant 10 List. Image source: Georgia Tech

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  1. Understanding Water-Soluble Organic Compounds in Meteorites


    Amines may provide novel insights about the prebiotic origins of meteoritic amino acids. Credit: Dr. Jose Aponte, NASA/GSFC Image credit: None
    Amines may provide novel insights about the prebiotic origins of meteoritic amino acids. Credit: Dr. Jose Aponte, NASA/GSFC

    A new study investigates aliphatic monoamines extracted from five different carbonaceous chondrite meteorites. These water-soluble organic compounds can act as a record of processes that occurred during the formation of our solar system and inside the asteroid parent body, as well as the chemistry that could have played a role in the origin of life on Earth.

    Researchers found that monoamines were less abundant than amino acids in CR2 chondrites, but more abundant in CM2 and CM1/2 chondrites. The study provides insight into the possible pathways in which monoamines form, and the potential common origins they might share with ...

    Source: [Geochimica et Cosmochimica Acta]

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  1. "Promiscuous Enzymes" Lead Bacteria Down New Pathways to Survival


    An image of E. coli. "Promiscuous enzymes" fill in for missing enzymes after the bacteria is genetically altered. Source: NIAID/Flickr (Creative Commons) via Science News Image credit: None
    An image of E. coli. "Promiscuous enzymes" fill in for missing enzymes after the bacteria is genetically altered. Source: NIAID/Flickr (Creative Commons) via Science News

    Biologist Shelley Copley, of the University of Colorado, Boulder and the NASA Astrobiology Institute at MIT and Georgia Tech (formerly the University of Montana), was able to watch a microevolutionary process take place among certain strains of E. coli, when her research team deleted the genes necessary for producing important enzymes and observed how generations of the bacteria developed new ways to survive and replicate.

    As Copley explained during her presentation at the 2nd American Society for Microbiology Conference on Experimental Microbial Evolution, the bacteria adapted by turning to “promiscuous enzymes,” enzymes that can switch from their specialty function to ...

    Source: [Science News]

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  1. Scientists in Astrobiology Awarded 2016 MacArthur Genius Grants


    Two scientists from the California Institute of Technology (Caltech) who are members of the NASA Astrobiology Program have been honored as 2016 MacArthur Fellows.

    Dianne Newman, Microbiologist

    Dianne Newman, a professor of geobiology and biology at Caltech, focuses on the metabolisms of microbes that live in the absence of oxygen, looking at how they are able to produce energy and thrive in low-oxygen environments. Her research has included ancient bacteria able to use iron in place of water to photosynthesize, providing a possible explanation for the appearance of banded iron formations (BIFs), as well as re-identifying possible reasons for ...

    Source: [MacArthur Foundation]

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  1. Methane Muted: How Did Early Earth Stay Warm?


    An artist’s depiction of an ice-covered planet in a distant solar system resembles what the early Earth might have looked like if a mysterious mix of greenhouse gases had not warmed the climate. Photo credit: European Southern Observatory (ESO) via Wikimedia Common. Image credit: None
    An artist’s depiction of an ice-covered planet in a distant solar system resembles what the early Earth might have looked like if a mysterious mix of greenhouse gases had not warmed the climate. Photo credit: European Southern Observatory (ESO) via Wikimedia Common.

    For at least a billion years of the distant past, planet Earth should have been frozen over but wasn’t. Scientists thought they knew why, but a new modeling study from the Alternative Earths team of the NASA Astrobiology Institute has fired the lead actor in that long-accepted scenario.

    Humans worry about greenhouse gases, but between 1.8 billion and 800 million years ago, microscopic ocean dwellers really needed them. The sun was 10 to 15 percent dimmer than it is today—too weak to warm the planet on its own. Earth required a potent mix of heat-trapping gases to ...

    Source: [University of California, Riverside]

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  1. Luis Campos Begins Tenure as Library of Congress Chair in Astrobiology


    Dr. Luis Campos begins his tenure as the fourth Baruch S. Blumberg NASA/Library of Congress Chair in Astrobiology. Image sources: University of New Mexico/Library of Congress Image credit: None
    Dr. Luis Campos begins his tenure as the fourth Baruch S. Blumberg NASA/Library of Congress Chair in Astrobiology. Image sources: University of New Mexico/Library of Congress

    On October 3, 2016, Luis Campos began his twelve month residency at the Kluge Center as the new Baruch S. Blumberg NASA/Library of Congress Chair in Astrobiology.

    Campos plans to use the collection at the Library to explore the connection between astrobiology and synthetic biology. Synthetic biology seeks to engineer novel forms of life; astrobiology seeks to discover novel forms of life. Both are “fields deeply concerned with developing a comprehensive understanding of the full potential of living systems,” says Campos.

    The appointment announcement from the Library of Congress was released on June 28, 2016.

    Luis Campos will be ...

    Source: [Library of Congress]

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  1. Scientists Find Earliest Signs of Eukaryotic Shell-Making


    Fossilized eukaryotes dating roughly 809 million years ago show evidence of creating mineral shells. Credit: P. Cohen Image credit: None
    Fossilized eukaryotes dating roughly 809 million years ago show evidence of creating mineral shells. Credit: P. Cohen

    On September 27, 2016, paleobiologist Phoebe Cohen of the NASA Astrobiology Institute team at MIT presented a talk entitled “The First Appearance of Controlled Eukaryotic Biomineralization in the Neoproterozoic Fossil Record” at the Geological Society of America (GSA) Annual Meeting in Denver Colorado.

    She spoke about the discovery of fossilized eukaryotes from the Fifteenmile Group of Yukon, Canada that showed evidence of an early form of biomineralization, when an organism produces minerals to build or harden structures like bone or tissue. The observed exoskeletal shells were made out of calcium phosphate, and Cohen’s team dated the fossils back to around ...

    Source: [Science News]

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  1. The NAI Director's Seminar Series Presents: Bowling with Astrobiologists: A Twisted Path Toward the Origin of DNA


    On October 3, 2016, the NAI Director’s Seminar Series presented Bowling with Astrobiologists: A Twisted Path Toward the Origin of DNA.

    Presenter: Nathaniel Comfort (NASA/Library of Congress Chair in Astrobiology)

    At the beginning, so runs the Zen saying, one sees mountains as mountains, and rivers as rivers. In 2015, it seemed a straightforward task to document the impact of recent developments such as genomics on origin-of-life research. It was to be—and will be—the first part of a book project on the biological, scientific, and cultural history of DNA. But then, a local conference attended by many luminaries ...

    Source: [NAI Seminars and Workshops]

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  1. The Art of Yellowstone Science


    Image from <i>The Art of Yellowstone Science</i>. Credit: Tom Murphy Image credit: None
    Image from The Art of Yellowstone Science. Credit: Tom Murphy Image from <i>The Art of Yellowstone Science</i>. Credit: Tom Murphy Image credit: None
    Image from The Art of Yellowstone Science. Credit: Tom Murphy

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  1. Astrobiologia - Uma Ciência Emergente


    Published in August 2016 and authored by Douglas Galante, Evandro Pereira Da Silva, Fabio Rodrigues, Jorge Horvath, and Marcio De Avellar, Astrobiologia – Uma Ciência Emergente provides an introduction to astrobiology in Portuguese. The first issue gathers input from experts in different scientific areas and covers topics including research into the origins of life, the potentially habitable moons of our Solar System, and the discoveries of exoplanets.

    More information and a free download of the first issue of Astrobiologia – Uma Ciência Emergente is available at: http://www.tikinet.com.br/iag/.

    The Research Unit in Astrobiology (NAP-Astrobio) is ...

    Image credit: None

    Source: [University of São Paulo NAP-Astrobio]

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