Capella (crater)

Capella is a lunar impact crater 48 km (30 mi) in diameter located on the near side of the Moon. It lies to the north of the Mare Nectaris, in a rugged highland region with many small impact craters. The crater was named after the Roman astronomer Martianus Capella (c. A.D. 400–unknown), and its designation was officially adopted by the International Astronomical Union in 1935.

Location and Physical Characteristics

Capella is centered at approximately 7.6° S latitude and 34.9° E longitude. It intrudes slightly into the eastern rim of the crater Isidorus, a feature only slightly smaller in diameter. The outer circumferential wall of Capella is low but relatively thick and irregular, with a large promontory intruding on the southeastern side. The crater has a depth of approximately 3.5 km (2.2 mi).

Vallis Capella

The crater is crossed by a deep rift known as Vallis Capella, a spear-shaped feature that passes directly through Capella from the north rim through the southeast side of the wall. This valley extends out on both sides for a combined distance of 110 km (68 mi). Vallis Capella was formed by a chain of craters.

Central Peak

In the middle of the crater is a wide, round peak rising 1.2 km (0.75 mi) above the crater floor, with a small craterlet at the top. The western side of the crater is dotted with impact debris, forming clusters of small hills.

Satellite Craters

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

Notably, satellite craters Capella A, D, E, G, and J are included on the ALPO list of bright ray craters, and Capella A is identified as a thermal anomaly crater, implying a relatively youthful age.