Galen is a small lunarimpact crater that lies in the rugged region between the Montes Apenninus range to the west and the Montes Haemus in the east. It is located to the south-southeast of the crater Aratus, a slightly larger formation. Further to the west is the crater Conon, near the flanks of the Montes Apeninnus. Galen was previously designated Aratus A before being given a name by the IAU.
Galen is a circular crater with a bowl-shaped interior and a sharp rim that has not undergone significant erosion. The small interior floor has a lower albedo than the surrounding walls.
Menzel, D. H.; Minnaert, M.; Levin, B.; Dollfus, A.; Bell, B. (1971). "Report on Lunar Nomenclature by the Working Group of Commission 17 of the IAU". Space Science Reviews. 12 (2): 136–186. Bibcode:1971SSRv...12..136M. doi:10.1007/BF00171763. S2CID122125855.