| A | B |
|---|
| asteroid | a large chunk of rock traveling through space |
| comet | a large chunk of ice, dust, frozen gases, and rock freagments that moves through space |
| gaseous giant planets | are huge, low-density planets composed mainly of gases |
| meteor | is formed when a meteoroid enters the atmosphere |
| terrestrial planets | their surfaces are made up of solid rock |
| solar system | the sun, the planets, and manny smaller objects that travel around the sun |
| planet | a body of matter that travels around a fixed path |
| meteorite | a meteor that hits the earth's surface |
| orbit | fixed path that one body of matter follows around another |
| Oort cloud | birhtplace of comets |
| heliopause | a boundary between local space and interstellar space |
| gravity | What holds a comet in orbit around the sun |
| Gaseous | Most of the matter on neptune is in this state of mattter |
| pluto | planet composed of rock and ice unlike terrestrial planets |
| comet | its orbit around the sun is larger than its orbit around the earth |
| The greenhouse effect | scientist think this is the cause of the earth warming |
| ellipse | shape of an orbit of a planet |
| It's atmosphere | is the cause of this planet's high temperatures |
| The shape of pluto's orbit | Is the reason why neptune is sometimes the furthest planet form the sun |
