| The Big Bang occurred a little less than ____ billion years ago. |
2 |
| The Moon is about ____ miles from the Earth. |
8 |
| There are ____ planets in the Solar System. |
14 |
| The Sun is about ____ times larger than the Earth. |
30 |
| About ____ planets have been discovered in the Milky Way. |
80 |
| Mercury and Venus have no moons. Mars has ____ moons. |
100 |
| Saturn and Jupiter have about ____ moons each. |
5,100 |
| Neptune is about ____ astronomical units (AU) from the Sun. |
239,000 |
