The Hubble Space Telescope's Advanced Camera for Surveys snapped this close-up view of the Aristarchus crater on Aug. 21, 2005. The crater is 26 miles (42 kilometers) in diameter and approximately 2 miles (3.2 kilometers) in depth, and sits at the southeastern edge of the Aristarchus Plateau. Aristarchus is one of the youngest and largest craters on the Moon. The crater formed between 100 and 900 million years ago.