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Life Forms Ejected On Asteroid Impact Could Survive To Reseed Earth
New Rochelle NY (SPX) Feb 28, 2008 In the event that an asteroid or comet would impact Earth and send rock fragments containing embedded microorganisms into space, at least some of those organisms might survive and reseed on Earth or another planetary surface able to support life, according to a study published in the Spring 2008 (Volume 8, Number 1) issue of Astrobiology, a peer-reviewed journal published by Mary Ann Liebert. In the report entitled, "Microbial Rock Inhabitants Survive Hypervelocity Impacts on Mars-like Host Planets: First Phase of Lithopanspermia Experimentally Tested", Gerda Horneck and colleagues describe systematic shock recovery experiments designed to simulate a scenario called lithopanspermia, in which microorganisms are transported between planets via meteorites. The first step of lithopanspermia would involve ejection of the microorganism-containing rock from the host planet as a result of an impact event. The researchers sandwiched dry layers of three kinds of biological test systems, including bacterial endospores, endolithic cyanobacteria, and epilithic lichens, between gabbro discs, which are analogous to martian rocks. They then simulated the shock pressures martian meteorites experienced when they were ejected from Mars and determined the ability of the organisms to survive the harsh conditions. The organisms selected represent "potential 'hitchhikers' within impact-ejected rocks," explain the authors, and are hardy examples of microbes that can withstand extreme environmental stress conditions, write the authors. "Given that impacts have occurred on planetary bodies throughout the history of our solar system," says journal Editor, Sherry L. Cady, PhD, Associate Professor in the Department of Geology at Portland State University, "the hypothesis that life in rock could have been transferred between planets at different times during the past 3.5 billion years is plausible. These experiments advance our understanding of the constraints on life's ability to survive the magnitude of impact that would accompany a meteoric trip from Mars to Earth." The results support the potential for rocks ejected on asteroidal impact to carry microorganisms capable of reseeding the Earth, according to Horneck and coworkers, from the Institute of Aerospace Medicine (Kon, Germany), Humboldt University of Berlin, Heinrich-Heine University (Dusseldorf, Germany), Ernst-Mach Institute for Short-Term Dynamics (Freiberg, Germany), Open University (Milton Keynes, U.K.), the German Collection of Microorganism and Cell Cultures (Braunschweig, Germany), the Russian Academy of Science (Moscow), and the Planetary Science Institute (Tucson, AZ). Community Email This Article Comment On This Article Related Links Read the paper Life Beyond Earth Lands Beyond Beyond - extra solar planets - news and science
Amino Acid Ingredients Found In Distant Galaxy
Moffett Field CA (SPX) Feb 19, 2008Using the giant dish at Arecibo, Puerto Rico, radio astronomers have discovered evidence of hydrogen cyanide and methanimine, two carbon compounds that can combine with water to make the amino acid glycine. Because proteins are composed of amino acids, the new results make distant space seem a bit more hospitable to life. |
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