Title:[0453] Ganymede from 6 million km Caption:A Voyager 2 image of Ganymede taken on 2 July 1979 from a distance of 9 million km (4 million miles). It shows the light bluish regions near the north and south poles, which may be a covering of ice or frost. Copyright: Credit:A NASA/JPL PHOTO

Title:[0745] Ganymede from 1.2 million kilometers Caption:This Voyager image shows most of the hemisphere of Ganymede that faces permanently away from Jupiter. The dark area is the oldest part of the surface and the white spots are impact craters in the icy surface. Copyright: Credit:National Optical Astronomy Observatories

Title:[0746] Ganymede from 151,800 miles Caption:A Voyager close-up of Ganymede showing the wide icy bands that criss-cross the surface, and bright impact craters. Copyright: Credit:National Optical Astronomy Observatories

Title:[0324] Close-up of impact features on Ganymede Caption:Ganymede, showing a variety of impact features including razed and unrazed craters, groove-like structures and bright ray craters. The image was taken by Voyager 1 on 5 March 1979 from 250,000 km. Copyright: Credit:NASA

Title:[0293] Northern hemisphere of Ganymede Caption:This color reconstruction of part of the northern hemisphere of Ganymede was made from pictures taken at a range of 313,000 kilometers (194,000 miles). The scene is approximately 1,300 kilometers (806 miles) across. It shows part of a dark, densely cratered block which is bound on the south by lighter and less cratered, grooved terrain. The dark blocks are believed to be the oldest parts of Ganymede's surface. Numerous craters are visible, many with central peaks. The large bright circular features have little relief and are probably the remnants of old, large craters that have been annealed by flow of the icy near-surface material. The closely spaced arcuate, linear features are probably analogous to similar features on Ganymede that surround a large impact basin. The linear features here may indicate the former presence of a large impact basin to the southwest. Copyright: Credit:NASA

Title:[4016] Galileo Resolutions: Ganymede and the San Francisco Bay Area Caption:These frames demonstrate the dramatic improvement in the resolution of pictures that NASA's Galileo spacecraft is returning compared to previous images of the Jupiter system. The top left frame shows the best resolution (1.3 kilometers per pixel) data of the Uruk Sulcus region on Ganymede which was available after the 1979 flyby of the Voyager 2 spacecraft. The top right frame shows the same area as captured by Galileo during its closer flyby of Ganymede on June 27, 1996. For comparison, the bottom frames show images of the San Francisco Bay area trimmed to the size of the Ganymede images and adjusted to similar resolutions. Copyright: Credit:NASA-JPL

Title:[4018] Detail of Ganymede's Uruk Sulcus Region Caption:View of a portion of the Uruk Sulcus region on Ganymede showing how the fine details of the grooved terrain that are the principal features in the brighter regions of this satellite relate to the global view of the moon. Copyright: Credit:NASA-JPL

Title:[4019] Ganymede Uruk Sulcus High Resolution Mosaic Shown in Context Caption:A mosaic of four Galileo high-resolution images of the Uruk Sulcus region of Jupiter's moon Ganymede (Latitude 11 N, Longitude: 170 W) is shown within the context of an image of the region taken by Voyager 2 in 1979, which in turn is shown within the context of a full-disk image of Ganymede. Copyright: Credit:NASA-JPL

Title:[4017] Stereo View of Ganymede's Galileo Regio Caption:New topographic detail is seen in a stereoscopic view of this part of Ganymede. The newly processed picture is a computer reconstruction from two images taken by Galileo spacecraft. The topographic nature of the deep furrows and impact craters that cover this portion of Ganymede is apparent. The blue-sky horizon is artificial. Copyright: Credit:NASA-JPL