This page is under construction. Many of these definitions are placeholders and not the final ones.


  • Highlands - bright, extensively cratered areas of igneous rocks rich in the mineral plagioclase, breccias, and the chemicals calcium and aluminium.

Crater-related landforms

  • Maria - dark areas covered by lavas of the volcanic rock type called [[Basalt|basalt.
  • Impact crater - roughly circular depression formed by the hypervelocity impact of a smaller rock body.
  • Crater ejecta - the debris that is thrown out by the formation of an impact crater. If the material covers the immediate
  • Terraced crater walls - steep walls of an impact crater with stair steps created by slumping due to gravity and landslides.
  • Ray - the light-toned material that is deposited in a radial pattern around a newly formed crater. It is bright because it is finely pulverized rock and the fractured crystals are very reflective.
  • Lava flow
  • Rille
  • Wrinkle ridge
  • Cinder cone
  • Dome