Aliacensis (crater)

Aliacensis is a lunar impact crater that is located in the rugged southern highlands of the Moon. The crater Werner is located just to its north-northwest, and a narrow, rugged valley lies between the two comparably sized formations. To the southwest is Walther, and Apianus is to the northeast. The crater is named after 14th century French geographer and theologian Pierre d'Ailly. It is from the Nectarian period, which lasted from 3.92 to 3.85 billion years ago.

The rim of Aliacensis is generally circular, with an outward bulge on the eastern wall. The inner wall has some slight terracing particularly in the northeast. There is a small crater located across the southern rim. The interior floor is generally flat, with a low central peak slightly offset to the northwest of the midpoint. South of it lie two somewhat broken rings, Kaiser and Nonius. It is 52 kilometers in diameter and there is a 3.7 kilometer difference in height between its deepest part and its rim.