Aliacensis (Moon)

Named after D'Ailly, Pierre Aliacensis - French geographer (1350-1420).

Aliacensis is a lunar impact crater that is located in the rugged southern highlands. To the southwest is Walther, and Apianus is to the northeast. It is from the Nectarian period, which lasted from 3.92 to 3.85 billion years ago. (wikipedia entry)

A crater is a circular depression likely created by an impact event. On the Moon they are named after deceased scientists, polar explorers, astronauts or cosmonauts.