| A | B |
|---|
| It is important to study smaller bodies such as comets or astroids because they help us | learn the history of our solar system. |
| The surface of the Earth's moon preserves a record of almost all the impacts it has had because it has | no atmosphere. |
| The astroid belt is located between the orbits of | mars and Jupiter. |
| The comets of the kuiper belt are found | outside the orbit of Neptune. |
| Phobos | is an oddly shaped moon and may be a captured astroid. |
| Triton | is a moon that revolves around its planet in retrograde orbit. |
| Ganymede | is a moon that is larger than the planet Mercury. |
| Lunar rocks | brought back by the Apollo mission show the moon to be aobut 4.7 billion years old. |
