Moon Geology

Lunar surface features, maria, highlands, and crater formation

The Moon's surface is divided into dark, flat maria (ancient lava plains) and bright, cratered highlands (older crust). Impact craters form when meteorites strike the surface at hypervelocity (10-70 km/s). Crater diameter depends on impactor size, velocity, angle, and target properties. Simple craters (<15 km) are bowl-shaped; complex craters have central peaks. The largest impacts created multi-ring basins. The Moon has no atmosphere or plate tectonics, so craters are preserved for billions of years. Lunar rock types include anorthosite (highlands), basalt (maria), and breccia (mixed impact debris).