Stadius (crater)

Stadius

Mosaic of Lunar Orbiter 4 images
Coordinates	10°29′N 13°46′W / 10.48°N 13.77°W / 10.48; -13.77Coordinates: 10°29′N 13°46′W / 10.48°N 13.77°W / 10.48; -13.77
Diameter	69 km
Depth	None
Colongitude	13° at sunrise
Eponym	Johannes Stadius

Stadius is a ghostly remnant of an ancient lunar crater that has been nearly obliterated by basaltic lava flows. It lies to the southwest of the much younger crater Eratosthenes, at the north edge of Mare Insularum where the mare joins Sinus Aestuum. To the west is the prominent ray crater Copernicus, and multiple secondary craters from the Copernican ejecta cover this area. To the northwest is a chain of craters that continue in a roughly linear formation until reaching Mare Imbrium.

Only the northwestern rim of Stadius remains nearly intact, and it joins with a north-running ridge line that reaches the western of Eratosthenes. The remainder of the formation forms a ghostly trace of the original rim, created from a few rises in the surface, and there is no indication of a central peak. The flat crater floor is pock-marked by craterlets, many of which were generated by secondary impacts from the creation of Copernicus.

By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Stadius.