| A | B |
|---|
| planet | a body of matter that travels around a star |
| orbit | a fixed path in which a planet travels |
| solar system | made up of the sun, planets and many smaller objects |
| terrestrial planets | small planets with dense, rocky surfaces |
| gaseous giant planets | huge, low density planets composed mainly of gases |
| comet | a large chunk of ice, dust, frozen gases and rock |
| asteroid | a large chunk of rock traveling through space |
| meteoroids | small pieces of rock traveling through space |
| meteor | a meteoroid that enters the Earth’s atmosphere |
| meteorite | a meteor that strikes the earth |
| Ceres | the largest asteroid |
| Halley’s Comet | a comet that orbits the sun every 75-79 years |
| Oort Cloud | where comets are formed |
| Charon | Pluto's moon |
| Kuiper Belt | a belt of comets that may exist near Neptune |
| Titan | Saturn’s largest moon |
| Ganymede | the largest satellite in the solar system |
| Olympus Mons | the largest known volcano in the solar system |
| Triton | Neptune’s moon that has geysers on its surface |
