Harlan is a lunarimpact crater near the southeastern limb of the Moon. It is located just to the northeast of the crater Marinus. To the northeast is the flooded walled plain Abel, and to the southeast is Mare Australe.
This crater has a worn outer rim, with a crater attached to the northeastern rim and an irregular southern edge. The inner wall has slumped to form a shelf along the northwestern side. The interior floor has been resurfaced by basalticlava, producing a level, nearly featureless surface with a lower albedo than its surroundings.
Harlan was previously designated Marinus D before being assigned its current name by the IAU.
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.