In November 2011, the Lunar Reconnaissance Orbiter passed over the crater, which spans almost 25 miles (40 kilometers) and sinks more than 2 miles (3.5 kilometers) deep. "The Aristarchus plateau is one of the most geologically diverse places on the moon: a mysterious raised flat plateau, a giant rille carved by enormous outpourings of lava, fields of explosive volcanic ash, and all surrounded by massive flood basalts," said Mark Robinson, principal investigator of the Lunar Reconnaissance Orbiter Camera at Arizona State University. NASA released photos of the crater on December 25, 2011.