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.

Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK, Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team. For a complete list of acknowledgments, see http://dawn.jpl.nasa.gov/mission.

For more information about the Dawn mission, visit http://dawn.jpl.nasa.gov.