Autolycus 30.7°N, 1.5°E

Aristillus 33.9°N, 1.2°E

A very conspicuous and prominent pair of craters in the Apennine region of Mare Imbrium. Under high solar illumination both craters exhibit ray systems. Autolycus, with a diameter of 39 km, has a very rough crater floor with a heavily eroded central peak. Aristillus has a diameter of 55 km. The inner walls of the crater are terraced and the central peak appears prominent above a level, smooth crater floor. The individual summits of the central mountain reach a height of up to 900 m above the floor. Particularly conspicuous is the broad annular zone of melted ejecta that is piled up outside the crater's wall. Directly north of Aristillus, this ejecta covers a submerged ghost crater, about 40 km in diameter, which may be seen only under grazing illumination.

Sinus Lunicus

32.0°N, 1.0°W

The Sinus Lunicus, ‘Bay of the Moon’, is a lava plain enclosed by two low ridges and lies between the craters Autolycus and Aristillus in the northeast and Archimedes in the southwest. In 1959, the Russian lunar probe Luna 2 made a hard landing on the lunar surface west of Autolycus. The region was officially named Sinus Lunicus by the IAU in 1970. Luna 2 was the first lunar probe to reach the Moon's surface. Its predecessor, Luna 1 missed the Moon by about 6000 km on 4 January 1959.