Cysatus (Moon)

Named after Cysat, Jean-Baptiste Cysatus - Swiss mathematician, astronomer (1588-1657).

Cysatus is a lunar impact crater that is located in the southern part 's near side. It is joined to the northeastern rim of the larger crater Gruemberger, and intrudes slightly into the interior of that formation. Due south is the larger Moretus, and to the east is Curtius. These craters appear foreshortened when observed from Earth because of their far south location. (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.