Geological Chronicle
Sinus Lunicus is an area of lunar mare spanning 119.18 kilometers along the southeast edge of Mare Imbrium. The bay is formed by the area enclosed by the prominent craters Archimedes to the southwest, Autolycus to the southeast, and Aristillus to the northeast. Open to the northwest, it faces Montes Spitzbergen, a small chain of mountains. Overlapping ray material from Autolycus and Aristillus brightens the albedo of the surface.
The feature was named the Bay of Lunik by the International Astronomical Union in 1970 to honor the landing site of Luna 2, the first human space probe to make contact with another interplanetary body. The spacecraft landed in the gap between Archimedes and Autolycus on September 14, 1959. The most distinctive features on the bay are the complex outer ramparts of ejecta from Aristillus and Autolycus, along with the small satellite craters Archimedes C and Archimedes D.