This photomosaic of Callisto is composed of nine frames.

This photomosaic of Callisto is composed of nine frames. The impact crater distribution is very uniform across the disk. Notable are the very bright rayed craters that probably are very young. Near the limb is a giant probable impact structure. Several large structures were discovered by Voyager 1. This one is smaller than the largest one found by Voyager 1 but is more clearly shown. About 15 concentric rings surround the bright central spot. Many hundreds of moderate sized impacts are also seen, a few with bright radial ray patterns. The limb is very smooth confirming that no high topography has been seen on the satellite, and observation consistent with its icy composition.