Diophantus (Moon)

Named after Diophantus - Greek mathematician (unkn-c. A.D. 300).

Diophantus is a lunar impact crater that lies in the southwestern part of the Mare Imbrium. Diophantus has a wide inner wall and a low central rise. There is a tiny craterlet near the exterior of the southwest wall. (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.