| A | B |
|---|
| geocentric model | a representation of the universe in which stars and planets revolve around earth |
| heliocentric model | a representation of the relationship between the sun and planets in which the planets revolve around the sun |
| universe | all the matter and the energy that exist |
| big-bang theory | a theory about the origin of the universe in which colliding "things" produced this universe |
| terrestrial planets | planets that are earthlike |
| moon | natural objects that revolve around the planet |
| gas giant | a large planet that is made up of mostly gases and liquids |
| satellite | objects that revolve around the planet |
