NAI

nai


  1. A Simple Bacterium Reveals How Stress Drives Evolution


    E.coli, a common bacteria. Image credit: None
    E.coli, a common bacteria.

    A common bacteria is furthering evidence that evolution is not entirely a blind process, subject to random changes in the genes, but that environmental stressors can also play a role.
    A NASA-funded team is the first group to design a method demonstrating how transposons — DNA sequences that move positions within a genome — jump from place to place.

    The researchers saw that the jumping rate of these transposons, aptly-named “jumping genes,” increases or decreases depending on factors in the environment, such as food supply.

    “This is a new window into how environment can affect evolution rates,” said Nigel Goldenfeld, director ...

    Source: [astrobio.net]

    Read More

  1. Examining Mars Analog Rocks in Northern Ontario


    On August 10, CTV News spotlighted NASA Astrobiology Institute (NAI) scientists testing instruments and examining Mars analog rocks in Timmons, Ontario, Canada. Pablo Sobron and Adrian Brown, both scientists with the team at SETI, are featured in the news story.

    The transcript is available at CTV News.

    Source: [CTV News Northern Ontario]

    Read More

  1. Purple Signs of Life


    Astrobiologists examine purple microorganisms as a possible link to life on early Earth and other planets. Image source: CNN Image credit: None
    Astrobiologists examine purple microorganisms as a possible link to life on early Earth and other planets. Image source: CNN

    A story published in CNN takes a look at the color purple and how astrobiologists are considering the possible connection between purple organisms and the evolution of life on early Earth and other planets.

    The Purple Earth hypothesis, first presented by microbiologist Shil Dassarma at the University of Maryland School of Medicine, suggests that ancient microbes may have relied on retinal rather than chlorophyll to harness energy from sunlight. Retinal is easier to produce in low-oxygen environments and, because it absorbs green light and reflects a combination of red and violet, makes the organism appear purple. The pigment is evident ...

    Source: [CNN]

    Read More

  1. NASA Finds Moon of Saturn Has Chemical That Could Form ‘Membranes’


    This Cassini image from 2012 shows Titan and its host planet Saturn. Image credit: None
    This Cassini image from 2012 shows Titan and its host planet Saturn.

    NASA scientists have definitively detected the chemical acrylonitrile in the atmosphere of Saturn’s moon Titan, a place that has long intrigued scientists investigating the chemical precursors of life.

    On Earth, acrylonitrile, also known as vinyl cyanide, is useful in the manufacture of plastics. Under the harsh conditions of Saturn’s largest moon, this chemical is thought to be capable of forming stable, flexible structures similar to cell membranes. Other researchers have previously suggested that acrylonitrile is an ingredient of Titan’s atmosphere, but they did not report an unambiguous detection of the chemical in the smorgasbord of organic, or ...

    Source: [NASA]

    Read More

  1. An Earth-like Atmosphere May Not Survive Proxima b’s Orbit


    This artist’s impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the solar system. Image credit: None
    This artist’s impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the solar system.

    Proxima b, an Earth-size planet right outside our solar system in the habitable zone of its star, may not be able to keep a grip on its atmosphere, leaving the surface exposed to harmful stellar radiation and reducing its potential for habitability.

    At only four light-years away, Proxima b is our closest known extra-solar neighbor. However, due to the fact that it hasn’t been seen crossing in front of its host star, the exoplanet eludes the usual method for learning about its atmosphere. Instead, scientists must rely on models to understand whether the exoplanet is habitable.

    One such computer model ...

    Source: [NASA]

    Read More

  1. The Great Oxidation Event and the Rubisco Family Tree


    Scientists trace the points in time where Rubisco branched out in diverse forms, before and after the Great Oxidation Event. Source: B. Kacar Image credit: None
    Scientists trace the points in time where Rubisco branched out in diverse forms, before and after the Great Oxidation Event. Source: B. Kacar

    Scientists with the NASA Astrobiology Institute Postdoctoral Program at Harvard University are tracing the evolution of an abundant and important enzyme that jumpstarts a separation between non-living and living.

    Rubisco (ribulose-1,5-biphosphate carboxylase/oxygenase) is the key catalyst for a reaction that converts inorganic carbon to organic carbon. In plant, algae, and certain bacteria cells, Rubisco helps to connect carbon dioxide to ribulose 1,5-biphosphate (RuBP) to create the first stage of the Calvin cycle and the production of sugar; Rubisco can also catalyze RuBP to bind with oxygen in a competing reaction.

    Betul Kacar and her team, using computational ...

    Source: [Geobiology]

    Read More

  1. Watch Talks from AbGradCon 2017


    Participants at the Astrobiology Graduate Conference (AbGradCon) 2017 held in Charlottesville, VA. Image credit: None
    Participants at the Astrobiology Graduate Conference (AbGradCon) 2017 held in Charlottesville, VA.

    The Astrobiology Graduate Conference (AbGradCon) 2017 was held in Charlottesville, VA and hosted by the National Radio Astronomy Observatory. A four-day Proposal Writing Retreat (PWR) at the Green Bank Observatory in Green Bank, WV preceded the conference. During PWR, twenty-nine early career scientists, including four organizers, wrote, presented, and peer-reviewed nine proposals and selected three top proposals to present at AbGradCon immediately following the retreat. AbGradCon included 85 participants who engaged in talks followed by in-depth Q&A, took part in four poster sessions, and mingled over games and refreshments in the evenings.

    You can view recordings of talks from ...

    Source: [AbGradCon 2017]

    Read More

  1. 2017 NASA Astrobiology Postdoctoral Fellowship Program Selections


    Image credit: None

    We are pleased to announce the March 2017 selections for the NASA Astrobiology Program element of the NASA Postdoctoral Program (NPP):

    Peter Conlin
    Advisor: Will Ratcliff, Georgia Institute of Technology (Exobiology; Evolution of Advanced Life)
    Topic: “Experimentally investigating the origin and consequences of fitness decoupling during the transition to multicellularity”

    Juan Rosas Bonilla
    Advisor: Jun Korenaga, Yale University (NAI University of California, Riverside team)
    Topic: “Early Earth Geodynamics and Continental Evolution”

    Jaclyn Saunders
    Advisor: Tanja Bosak (NAI Massachusetts Institute of Technology team)
    Topic: “Arsenic based metabolisms in the open ocean: an unexplored frontier”

    Nicholas Speller
    Advisor: Amanda Stockton, Georgia Institute ...

    Read More

  1. Astrobiology Sessions at GSA 2017


    Image credit: None

    The 2017 Geological Society of America Annual Meeting takes place on October 22-25 in Seattle, Washington. Below is a highlight of sessions co-coordinated by scientists with the Alternative Earths and Virtual Planetary Laboratory (VPL) teams of the NASA Astrobiology Institute.

    GSA is still accepting abstracts for sessions. The deadline to submit an abstract is August 1, 2017.

    T58. Oxygen and Ecosystems from the Proterozoic to the Paleozoic
    Noah J. Planavsky, Devon B. Cole, Christopher T. Reinhard
    Paleontological Research Institution; Paleontological Society; GSA Geobiology & Geomicrobiology Division
    Recently there have been sustained efforts to develop a more comprehensive understanding of coupled ...

    Source: [Geological Society of America]

    Read More

  1. A Bibliometric Analysis of Origins of Life Research


    A network map of Origins of Life-relevant subject categories extracted from published research journals. Source: A. Aydinoglu Image credit: None
    A network map of Origins of Life-relevant subject categories extracted from published research journals. Source: A. Aydinoglu

    A study by Arsev Aydinoglu and Zehra Taşkın explores the growth and degrees of collaboration and interdisciplinarity in Origin(s) of Life (OoL) research using statistical analysis of science publications. The paper, Origins of Life Research: a Bibliometric Approach, is published in Origins of Life and Evolution of Biospheres.

    The authors looked at a body of 126,105 unique publications and broke out a dataset of 5,647 publications tagged with the keywords Origin(s) of Life, astrobiology, exobiology, and prebiotic chemistry. From this data, they identified the most prolific authors, most cited articles, popular journals, and research trends. They ...

    Source: [Origins of Life and Evolution of Biospheres]

    Read More

  1. Weathering of Rocks a Poor Regulator of Global Temperatures


    A river runs through a valley in the Himalayan mountains. New results show the rate for chemical weathering of rocks is not as sensitive to global temperatures as geologists thought. Source: Pixabay (via UW) Image credit: None
    A river runs through a valley in the Himalayan mountains. New results show the rate for chemical weathering of rocks is not as sensitive to global temperatures as geologists thought. Source: Pixabay (via UW)

    A University of Washington study shows that the textbook understanding of global chemical weathering — in which rocks are dissolved, washed down rivers and eventually end up on the ocean floor to begin the process again — does not depend on Earth’s temperature in the way that geologists have believed.

    The study—published in Nature Communications and supported by the NASA Exobiology Program, the NASA Astrobiology Institute, and the NASA Earth and Space Science Fellowship program—looks at a key aspect of carbon cycling, the process by which carbon atoms move between the air, rocks and the oceans. The results call into question ...

    Source: [University of Washington]

    Read More

  1. Fifth Baruch S. Blumberg/Library of Congress Chair in Astrobiology Announced


    Lucianne Walkowicz has been selected as the fifth Library of Congress Chair in Astrobiology. Image source: TED. Image credit: None
    Lucianne Walkowicz has been selected as the fifth Library of Congress Chair in Astrobiology. Image source: TED.

    The fifth Baruch S. Blumberg/Library of Congress Chair in Astrobiology has been announced. Lucianne Walkowicz, astronomer based at the Adler Planetarium, will begin her 12-month residency with the Kluge Center on October 1, 2017.

    As Chair, Walkowicz intends to work on a project entitled “Fear of a Green Planet: Inclusive Systems of Thought for Human Exploration of Mars.” Her project will create an inclusive framework for human exploration of Mars—a vision that encompasses both cutting-edge research on Mars as a place of essential astrobiological significance and weaves in lessons from the diverse histories of exploration on Earth. In addition ...

    Source: [Library of Congress]

    Read More

  1. Emergence of Eukaryotes Traced Back to 2.31 Billion Years Ago


    David Gold with the Summons Lab looked at evidence of sterol biosynthesis and used molecular clock analysis to date the earliest appearance of eukaryotes. Image credit: MIT Image credit: None
    David Gold with the Summons Lab looked at evidence of sterol biosynthesis and used molecular clock analysis to date the earliest appearance of eukaryotes. Image credit: MIT

    David Gold, a member of the NASA Astrobiology Institute at MIT, with researchers at the Summons Lab has published a paper, finding biomarker evidence that suggests eukaryotic organisms were present on Earth as early as 2.31 billion years ago, around the time of the first wide-spread availability of oxygen in the Earth’s atmosphere.

    The paper, “Paleoproterozoic sterol biosynthesis and the rise of oxygen,” is published in Nature.

    Gold and his team used molecular clock analysis, sifting through DNA databases tracing the evolution of genes for encoding enzymes necessary for sterol biosynthesis, and using the age of fossils ...

    Source: [Foundations of Complex Life]

    Read More

  1. Exoplanet Biosignatures Workshop Without Walls Report Now Available


    Image credit: None

    NASA’s Nexus for Exoplanet System Science and the NASA Astrobiology Institute held a series of joint Exoplanet Biosignatures Workshop Without Walls from June to July 2016, including an in-person workshop, in Seattle, WA that brought together the astrobiology, exoplanet, and mission concept communities to review, discuss, debate, and advance the science of biosignatures. A broad range of experts were engaged, merging the interdisciplinary reaches of NExSS, the NAI, NASA’s Exoplanet Exploration Program (ExEP), and international partners, such as the European Astrobiology Network Association (EANA) and Japan’s Earth Life Science Institute (ELSI).

    The report from the NExSS Exoplanet ...

    Source: [NExSS]

    Read More

  1. The Interplay of Continental Evolution, Plate Tectonics, and Evolution of Life


    Satellite view of the Red Lakes region in Ontario, Canada with four of the sampling areas from the UW-Madison study of Sr isotope compositions of Archaen carbonates. Image source: Google Maps Image credit: None
    Satellite view of the Red Lakes region in Ontario, Canada with four of the sampling areas from the UW-Madison study of Sr isotope compositions of Archaen carbonates. Image source: Google Maps

    As the complexity and diversity of life on Earth keeps getting pushed further back in time with more and more data from the geologic record, the issue of the role of continents in the evolution of the early biosphere has become increasingly prominent. Are emergent continents required for life’s origin? Are nutrients such as P dependent on exposure of evolved continental crust? Are the ecological niches provided by extensive continental shelves required for a diverse ecosystem?

    Scientists with the NASA Astrobiology Institute team based at the University of Wisconsin conducted a detailed study of Sr isotope compositions of Archean ...

    Source: [University of Wisconsin]

    Read More

< prev next >
1 2 3 4 5 6 7 ... 121
Spotlight
Astrobiology Magazine