Callisto's Valhalla Impact Structure Target Name:   Callisto Spacecraft:   Galileo Produced by:   NASA/JPL Copyright:  Public Domain Date Taken:   4 November 1996

• Callisto

A portion of the central zone of the large impact structure Valhalla on Callisto was imaged by the Galileo spacecraft on November 4, 1996. The area shown here is centered at 16 degrees north, 55 degrees west and is about seven miles (11 kilometers) across. This is the highest resolution picture ever taken of Callisto and shows features as small as 200 feet (60 meters) across. The formation of Valhalla occurred early in Callisto's history; however, the central zone shown here is probably younger than Valhalla's surrounding structure. This newly acquired picture shows some small craters, although they have been softened or modified by downslope movement of debris, revealing bright ice-rich surfaces. In contrast to other areas on Callisto, most of the very smallest craters appear to have been completely obliterated.