| A | B |
|---|
| highlands | Lighter, older part of the Moon |
| maria | Darker, younger parts of the Moon |
| primary craters | craters made by impacts; big |
| secondary craters | craters made by debris thrown out of primary craters |
| rilles | old lava channels; straight or segmented valleyss |
| ejecta | regolith or debris thrown out of craters on impact |
| rays | bright streaks of broken rock around a crater |
| raised rim | edge, or lip of a crater |
| central upift | mountains in the center or a crater |
| regolith | broken rock on the surface of the moon |
| floor | flat, bottom surface of a crater |
| Giant Impact Theory | explains how the moon was formed |
