Van Maanen (Moon)

Named after Adriaan Maanen - Dutch-American astronomer (1884-1946).

Van Maanen is an eroded lunar crater on the far side. It lies to the east of the crater Kidinnu, and southeast of Tesla and H. G. Wells. Since this crater was formed, it has been heavily battered by subsequent impacts to the point where it is little more than a depression in the surface surrounded by an irregular rim. The rim edge is heavily worn and poorly defined, with smaller craters lying along the sides. (wikipedia entry)

A crater is a circular depression likely created by an impact event. On the Moon they are named after deceased scientists, polar explorers, astronauts or cosmonauts.