Zanstra (Moon)

Named after Herman Zanstra - Dutch astronomer (1894-1972).

Zanstra is a lunar crater on the far side. This is a low, eroded formation that is difficult to distinguish from its surroundings. The interior floor is level and not significantly impacted. (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.