Geological Chronicle
Deslandres is the worn and distorted remnant of an impact crater in the rugged southern highlands, southeast of Mare Nubium. Its northern and eastern floor is relatively level but pockmarked with numerous craters. A small region of mare material, due to basaltic lava, lies along the eastern interior floor. It is the third-largest crater formation on the visible Moon, after Clavius and Bailly.
Satellite crater Hell Q lies at the center of a higher-albedo patch in Deslandres's eastern half. Around the time of a full moon, this feature is one of the brightest spots on the lunar surface. Its light hue indicates a relatively youthful feature in lunar geological terms. The patch is sometimes called Cassini's bright spot; Cassini first mapped it at the Paris Observatory in 1672.
Overlapping impacts have eroded Deslandres so heavily that it was not recognized as a crater formation until the 20th century. Older maps named it after the Austrian engineer Hanns Hörbiger, a name assigned by Philipp Fauth. It is now named for French astrophysicist Henri Alexandre Deslandres. Eugène M. Antoniadi suggested the designation in 1942, and the International Astronomical Union adopted it in 1948.
One source reports that Luna 5 impacted the lunar surface in Deslandres at 31°S, 8°W. The first released Lunar Reconnaissance Orbiter images, in 2009, were of an area in the crater's southern part.