| A | B |
|---|
| revolution | the movement of one object around another object |
| rotation | one full spin of an object around its axis |
| ellipse | the shape of a circle that has been flattened a little |
| orbit | the path of an object around another object |
| axis | an imaginary line through a spinning object |
| mass | the amount of material that an object has in it |
| gravity | a force that pulls any two objects together |
| solar eclipse | the blocking of sunlight by the moon as the moon passes between the sun and the earth |
| lunar eclipse | the darkening of the moon as it passes through the earth's shadow |
| system | a set of things or parts that form a whole and work together or affect one another |
