| A | B |
|---|
| asteroid | piece of rock smaller than a planet that orbits the sun |
| astronomical unit | average distance from the Earth to the sun |
| comet | mass of frozen gases, dust, and rock particles; develops bright tail when near sun |
| Earth | third planet from the sun |
| Great Red Spot | giant, swirling, high-pressure gas storm in Jupiter's atmosphere |
| inner planet | the four solid, rocky planets closest to the sun |
| Jupiter | fifth planet from the sun; it's the largest |
| Mars | fourth planet from the sun; the red planet |
| Mercury | planet closest to the sun |
| meteor | meteoroid that burns up in Earth's atmosphere; shooting star |
| meteorite | meteor that strikes the Earth's surface |
| Neptune | usually the eighth planet from the sun |
| Oort Cloud | mass of comets beyond Pluto's orbit |
| outer planet | the five planets furthest from the sun |
| Pluto | usually the farthest planet from the sun; the smallest planet |
| Saturn | sixth planet from the sun; has rings |
| solar system | all the objects that circle our sun |
| Uranus | seventh planet from the sun |
| Venus | second planet from the sun |
