lunar crater

A lunar crater is a circular depression on the Moon's surface. These formations are primarily the result of impacts from meteorites or, less commonly on the Moon, volcanic explosions.1

Lunar craters vary in size, from microscopic to hundreds of kilometers in diameter. Younger craters have sharp profiles and are surrounded by ejecta blankets and rays of expelled material. Older craters appear more rounded and subdued due to continuous bombardment. The impact process that forms these craters can melt or vaporize the impacting body and target material, creating a melt sheet and shock waves that alter the subsurface rocks. While volcanic activity on the Moon is minimal compared to Earth, some features like sinuous rilles and eruption craters suggest past volcanic events.2