The 21.45MB map is available for free download from the USGS address above.U.S. Geological Survey Scientific Investigations Map 3237
Global Geologic Map of Ganymede
... Images of Ganymede suitable for geologic mapping were collected during the flybys of Voyager 1 and Voyager 2 (1979), as well as during the Galileo Mission in orbit around Jupiter (1995–2003). This map represents a synthesis of our understanding of Ganymede geology after the conclusion of the Galileo Mission.
Read more at: http://pubs.usgs.gov/sim/3237/
Click to play embedded YouTube video.
USGS YouTube Channel: Animation of a rotating globe of Jupiter's moon Ganymede, with a geologic map superimposed over a global color mosaic. The 37-second animation begins as a global color mosaic image of the moon then quickly fades in the geologic map.