Müller (Moon)

Named after Karl Müller - Czechoslovakian astronomer (1866-1942).

Müller is a lunar impact crater. To the east lies Halley, while to the northwest is Gyldén. The rim of this crater is irregular and slightly oblong, with the long dimension oriented along a north–south axis. (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.