| A | B |
|---|
| axis | the imaginary line the Earth rotates on |
| solar eclipse | When the moon's shadow blocks the sun. |
| lunar eclipse | When the Earth's shadow blocks the moon. |
| phases | The way we see the sun's light reflected on the moon from Earth. |
| gravity | the force that keeps the planets orbiting the sun. |
| orbit | The path an object follows as it revolves. |
| revolution | The Earth's trip around the sun one time. This takes 365 days. |
| rotation | When the earth spins on its axis. This takes 24 hours. |
| This causes day and night. | rotation |
| This causes seasons | Earth revolving around the sun on its axis. |
| solar system | The sun and all the planets. |
| new moon | The phase of the moon we can not see on Earth. |
| Ptolemy, Aristotle | Believed in an Earth-centered solar system. |
| Galileo, Copernicus | Believed in a sun-centered solar system. |
| sun | The closest star to Earth. |
| satellite | An object that revolves around another object. |
