Ceres' lack of giant impact basins presents a puzzle to scientists. They expected to observe more large craters on the dwarf planet than have been found by NASA's Dawn mission. Researchers are investigating a variety of processes that might have caused the appearance of the largest basins to be softened or erased over time. For more information about the Dawn mission, visit http://dawn.jpl.nasa.gov/
Credit: NASA/JPL-Caltech
