Tags: Crater.
Theon Junior is a lunar impact crater that is located just to the west-southwest of the crater Delambre. It forms a matching pair with Theon Senior only a couple of crater diameters to the north-northwest. The crater is circular and bowl-shaped with a small floor at the bottom of the high sloping interior walls. It is named for Theon of Alexandria a 4th-century Greek astronomer and mathematician. The crater is from the Eratosthenian period which lasted from 3.2 to 1.1 billion years ago.
