News Archives Astrobiology Science News 25 September 2007 By Keith Cowing September 25, 2007 Extraterrestrial Impact Likely Source of Sudden Ice Age Extinctions, Brown University NASA, NSBRI Select 17 Proposals in Space Radiation Research, National Space Biomedical Research Institute (NSBRI) Spaceflight shown to alter ability of bacteria to cause disease, Arizona State University Keith Cowing SpaceRef co-founder, Explorers Club Fellow, ex-NASA, Away Teams, Journalist, Space & Astrobiology, Lapsed climber. Follow on Twitter