Jupiter's moon Ganymede viewed by NASA's Galileo spacecraft
This natural colour view of Ganymede was taken from NASA's Galileo spacecraft during its first encounter with the Jovian moon. North is to the top of the picture and the Sun illuminates the surface from the right. The dark areas are the older, more heavily cratered regions and the light areas are younger, tectonically deformed regions. The brownish-gray colour is due to mixtures of rocky materials and ice. Bright spots are geologically recent impact craters and their ejecta. The finest details that can be discerned in this picture are about 13.4 km across. The images which combine for this colour image were taken 26 June 1996 beginning at Universal Time 8:46:04.
Originally published by NASA here.
Image credit: NASA/JPL