Clavius (Moon)

Named after Christopher Klau Clavius - German mathematician (1537-1612).

Clavius is one of the largest crater formations , and it is the third largest crater on the visible near side. It is located in the rugged southern highlands , to the south of the prominent ray crater Tycho. The crater is named for the Jesuit priest Christopher Clavius, a 16th-century German mathematician and astronomer. (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.