Gruithuisen (Moon)

Named after Franz von Gruithuisen - German astronomer (1774-1852).

Gruithuisen is a tiny lunar crater that lies on the section of lunar mare that joins Oceanus Procellarum in the west to Mare Imbrium in the east. Southeast is the small crater Delisle. To the south is Dorsum Bucher, a wrinkle ridge running in a north–south direction for about 90 kilometers. The rim is smooth and circular, projecting only slightly above the surrounding mare. (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.