News Archives Astrobiology Science News 28 June 2011 By Keith Cowing June 28, 2011 The Structure of a Self-Gravitating Protoplanetary Disk and its Implications to Direct Imaging Observations, astro-ph The statistics of multi-planet systems, astro-ph Carbon and Oxygen in Nearby Stars: Keys to Protoplanetary Disk Chemistry, astro-ph Keith Cowing SpaceRef co-founder, Explorers Club Fellow, ex-NASA, Away Teams, Journalist, Space & Astrobiology, Lapsed climber. Follow on Twitter