| Most dwarf planets (including Pluto) are within the ____ belt. |
Big Bang |
| Phobos and Deimos are the two moons of ____. |
Galileo Galilei |
| ____ is tilted over 90° and thus rolls on its side as it orbits the Sun. |
Halley |
| Jupiter's four largest moons were discovered by ____ in 1610. |
Kuiper |
| The Moon is three times larger than ____. |
Mars |
| Unlike the other planets, ____ has no substantial atmosphere. |
Mercury |
| The ____ occurred about 13.6 billion years ago. |
Pluto |
| The ____ comet can be seen about every 75 years. |
Uranus |
