Tags: Crater.
Theon Senior is a lunar impact crater that is located to the northwest of the crater Delambre and south of D’Arrest. It forms a matching pair with Theon Junior about two crater diameters to the south-southeast. The satellite crater Theon Senior A can be found to the north. Theon Senior is named for Theon of Smyrna a 1st-century Greek mathematician and philosopher.This crater is circular and bowl-shaped with only a small floor at the center of the steeply sloping interior walls.
