Except for the gaseous worlds—Jupiter, Saturn, Uranus and Neptune—if Ganymede were a planet, it would rank as the fourth-largest body by size, after Earth, Venus and Mars.
It has a voluminous rocky mantle beneath an icy layer.
The icy grayish-brown crust shows dark and light areas where water ice and carbon dioxide ice are present. The dark areas are predominantly covered with impact craters.
MEADE 14" LX200, SBIG ST4020 CCD CAMERA, 0.2-second exposure in high resolution. Image development in CCDOps, Maxim DL4 and Adobe Photoshop CS4 Extended.