Delaunay is a lunar crater. The craters La Caille to the southwest and Faye to the northeast border on the outer rim. Further to the northwest is the prominent Arzachel. This is an irregular crater formation that has an interior ridge running from the northeast side that divides the crater nearly in half, and gives it a heart-shaped appearance. (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.
