| A | B |
|---|
| comet | mass of dust and roc particles held by frozen water and methan that orbits in space |
| meteoroid | small pieces of comet found in space |
| meteor | small pieces of comet that enter Earth's atmosphere |
| asteroid | piece of rock made of material that was used to form the planets |
| spiral galaxy | galaxy with arms that curve out |
| elliptical galaxy | round or football shaped galaxy |
| irregular galaxy | galaxy with many shapes that are much smaller |
| galaxy | large group of stars, gas, and dust held together by gravity |
| satellite | a celestial body that orbits a planet; another name for a moon |
| moon | an object that revolves around a planet |
| meteorite | small pieces of comet that enter Earth's atmosphere and land on Earth |
| light year | the distance that light travels in one year |
| light second | the distance that light travels in one second |
| ellipse | the shape of a planet's orbit |
| planet | object that orbits the sun, is spherical shape, and has a clear orbit |
