Craters caused by impacts of meteors, comets, and asteroids on the surface of a body.
Impact Craters Web Pages
Worlds with Craters
Mercury/Craters - Craters caused by impacts on Mercury. These can be cut through by scarps (possibly compressed in the process) or covered over by volcanic ejecta. Some have long bright rays, while others have long dark rays. The transitional diameter of craters (10-12 km) between simple (bowl-shaped) and complex craters (central peaks and ridges) is twice that of Mars, despite the fact that surface gravity at both planets are roughly the same. The fact that the average impact speed is 2-3 times greater than that of Mars may be a contributing factor.
Mars/Craters - Craters on Mars. Surface acceleration is about the same as on Mercury. Craters on Mars have been weathered in a variety of ways. Some contain shifting sand dunes. Some may contain water ice beneath them, such as those as Sinus Sabaeus.