​Impact cratering is just one of many geological processes that shape the surfaces of planets and moons. Three other key processes are:

• Volcanism—the eruption of molten material onto the surface of a planet or moon. In the case of terrestrial planets, the molten material is magma made of melted rock, gases, and solids. Volcanism can also occur on cold, icy bodies, where the erupted material would be composed of ingredients such as water, ammonia, or methane instead of melted rock.
• Tectonics—the deformation of the crust of a planet or moon caused by cooling from a molten stage in its development. The collision, pulling apart, or sliding of sections of the crust against each other causes folding and faulting, which creates mountains, valleys, and other large-scale changes.
• Erosion—the crumbling, loosening, movement, and deposition of rock by wind, water or other flowing liquids, ice, and gravity. Weathering, by chemical reactions or physical changes caused by swings in temperature, moisture, or pressure, causes rock to weaken and fragment. Wind, flowing ice or liquids, or gravity can carry away debris formed by weathering, sculpting dramatic features in the landscape. Sedimentation is the formation of rock from material that has been suspended or dissolved and transported by wind, water, or ice.