Review of Exchange Processes on Ganymede in View of Its Planetary Protection Categorization Grasset, O. ; Bunce, E. J. ; Coustenis, A. ; Dougherty, M. K. ; Erd, C. ; Hussmann, H. ; Jaumann, R. ; Prieto-Ballesteros, O. Abstract Publication: Astrobiology Pub Date: October 2013 DOI: 10.1089/ast.2013.1013 Bibcode: 2013AsBio..13..991G