| A | B |
|---|
| rotation | the spinning motion of a planet about its axis |
| revolution | the movement of an object around another object |
| orbit | the path of an object as it revolves around another object in space |
| sun | an average size star; closest star to Earth; center of the solar system |
| day | 24 hours; one rotation of Earth on its axis |
| year | 365 1/4 days; one revolution of Earth around the sun |
| gnomon | the part of a sun clock that casts a shadow |
| axis | an imaginary line that passes through Earth's center about which Earth rotates |
| latitude | a measurement of distance north or south from the equator expressed in degrees |
| equator | zero degree line of latitude; divided the Earth into northern and southern hemispheres |
| waxing | appearing to get larger; moon is lit on the right |
| waning | appearing to get smaller; moon is lit on the left |
