Online Astronomy eText: Satellites (Moons) The Satellites (Moons) of Jupiter: Callisto (also see The Galilean Satellites of Jupiter, Io, Europa, Ganymede) Callisto from Voyager 2, in 1979 The Valhalla 2 region shown below is near the bottom of this image (Calvin Hamilton) A larger image of Callisto from Voyager 2 The Valhalla 2 region shown below is near the bottom of this image (Calvin Hamilton) Closeup of Valhalla 2 region of Callisto from Voyager 2 (Calvin Hamilton) Galileo spacecraft closeup of intensive cratering in central part of Valhalla structure Shows an area only 7 miles across (Galileo, NASA) Galileo spacecraft color image of Callisto (Galileo, JPL, NASA, apod020120) True color image of Callisto, from Galileo spacecraft (Galileo Project, JPL, NASA, apod980511) Contrast enhanced version of the previous image (Galileo Project, JPL, NASA, apod980512) The icy, heavily cratered surface of Callisto. Jagged mountains on Callisto, photographed by Galileo spacecraft (Galileo, JPL, NASA, Arizona State University, apod010828) A large scarp (cliff) on Callisto's surface, photographed by the Galileo spacecraft (Galileo Project, JPL, NASA, apod970218) Image of a portion of a chain of impact craters, showing an area about 8 miles across. Possibly caused by impact of an object which had split up, a la Comet Shoemaker-Levy 9. (Galileo, NASA) Gipul Catena (crater chain). An even longer chain of impact craters. (Galileo, NASA) Possible internal structure of Callisto Icy crust (white), possible buried ocean (blue), rock (gray) and ice (white) mixture in deep interior (NASA, JPL, apod981106) Comparison of possible internal structures of the Galilean satellites of Jupiter (Calvin Hamilton) Comparison of sizes of smaller planets and larger moons (Calvin Hamilton)