Surfaces of Ganymede and Callisto: H2O-ice particle sizes and composition of non-ice materials

Katrin Stephan1, Harald Hoffmann1, Charles Hibbitts2, Roland J Wagner3 and Ralf Jaumann3, (1)German Aerospace Center DLR Berlin, Berlin, Germany, (2)Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States, (3)DLR - German Aerospace Center, Institute of Planetary Research, Berlin, Germany