Jupiter's satellite Ganymede

Jupiter

Fig. 2.45 . Large dark blocks are frozen within the icy surface of Ganymede. They are believed to be part of the original crust of the satellite, resembling frozen-over continents floating on a background of translucent ice. The brilliant white material that surrounds some craters is probably clean water ice or bright snow that was splashed out from inside the satellite. The enhanced color of this Galileo image of Ganymede, taken on 29 March 1998, also reveals the two predominant terrain features on the moon, bright grooved terrain and older, dark furrowed areas. The violet hues at the poles may be the result of small particles of frost. (Courtesy of NASA/JPL/DLR.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University