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"Astrobiology of Icy Worlds:  Photochemistry of Planetary Ices," department colloquium Oct 14, 2011

Dr. Paul V. Johnson, Senior Scientist, The Jet Propulsion Laboratory, California Institute of Technology

The icy worlds of the outer Solar System are of significant astrobiological interest due, in large part, to the evidence of liquid water beneath the surfaces of a number of Jovian and Saturnian satellites.  The surfaces of these bodies are irradiated by solar photons as well as energetic solar wind and planetary magnetosphere protons and electrons.  These energy sources can impact/penetrate the surface and can contribute to the chemistry of the surface material.  If compounds of biological origin are present in the surface ice layer, can they be detected as evidence of biological activity, or do they decompose too rapidly in the surface radiation environment? A review of recent amino acid photolysis studies addressing this question will be presented.