Arzachel (Moon)

Named after Al-Zarqālī Arzachel - Spanish-Arabic astronomer (died 1100).

Arzachel is a young lunar impact crater located in the highlands in the south-central part of the visible Moon, close to the zero meridian It lies to the south of the crater Alphonsus, and together with Ptolemaeus further north the three form a prominent line of craters to the east of Mare Nubium. The smaller Alpetragius lies to the northwest, and Thebit is to the southwest along the edge of the mare. (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.