| Term | Definition |
| capture theory | moon was fully formed in a different place then was passing the earth slowly that it was captured by the earths gravitational field |
| sisters theory | when the moon and the earth formed at the same time 4.5 billion years ago when dust and gas pulled together |
| the big impact theory | the earth was hit by a large object that broke apart with some of the pieces of earth eventually formed the moon |
| the daughter theory | earth was spinning so fast when it formed that a large piece of earth flew off and formed the moon |