Part of the southern hemisphere on dwarf planet Ceres is seen in this image taken by NASA's Dawn spacecraft. Two prominent, similarly sized craters (at left) demonstrate how impact features become degraded over time.
The leftmost of the pair is younger; its rim is crisp and its walls are generally smooth, peppered with only a few small craters. Its older twin, to its right, has been battered by more impacts, and the material around its rim has slumped and softened. In fact, the blanket of material ejected from the younger crater, during its formation, would have partly covered its older neighbor. Planetary scientists call this slow, progressive changing of the surface of planetary bodies by cratering "impact gardening."
Dawn took this image on Oct. 15, 2015, from an altitude of 915 miles (1,470 kilometers). It has a resolution of 450 feet (140 meters) per pixel.
The Dawn mission to Vesta and Ceres is managed by NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, for NASA’s Science Mission Directorate, Washington D.C. UCLA is responsible for overall Dawn mission science.
The Dawn framing cameras have been developed and built under the leadership of the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, with significant contributions by DLR German Aerospace Center, Institute of Planetary Research, Berlin, and in coordination with the Institute of Computer and Communication Network Engineering, Braunschweig. The framing camera project is funded by the Max Planck Society, DLR, and NASA/JPL.
More information about Dawn is online at http://dawn.jpl.nasa.gov.
Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA