Ganymede

This picture of Ganymede was taken on the afternoon of March 5, 1979, from a range of 272,000 kilometers. The center of the picture lies at 13 latitude, 359 longitude. Many bright impact craters are shown that have radial ejecta patterns. These rays lie across and therefore are younger than the bright and dark background material. Many older impact craters are shown that have lost their rays probably by impact erosion. The bright background areas contain grooves and ridges that may be caused by faulting of the surface materials.