This image of Ceres, taken by NASA's Dawn spacecraft, demonstrates how the relative ages of impact craters can be revealed by their positions relative to each other. In many cases, as with the craters at the center of this view, younger craters are seen to be "superposed" on -- meaning located on top of -- older craters below.
The largest feature in the image scene is the 48-mile-wide (77-kilometer-wide) Geshtin crater, which is superposed by the younger Datan crater, which is 37 miles (60 kilometers) in diameter. On its upper-left rim, Datan is superposed by a smaller, even younger unnamed crater.
The image was taken on Oct. 2, 2015, from an altitude of 915 miles (1,470 kilometers), and has a resolution of 450 feet (140 meters) per pixel. The image is centered at approximately 59 degrees north latitude, 258 degrees east longitude.
http://photojournal.jpl.nasa.gov/catalog/PIA20000