| A | B |
|---|
| asteroids | apiece of rock that orbits between Mars and Jupiter |
| inner planets | soild rocky planets, closest to the sun |
| planet most like Earth in size and mass | Venus |
| most are large gaseous planets | outer planets |
| the farthest planet from the sun | Pluto |
| a meteoroid that passes into earth's atmosphere and strikes Earth | meteorite |
| a meteoroid that burns up in Earth's atmosphere | meteor |
| small piece of rock moving through space | meteor |
| comet | object composed of dust and rock particles mixed with frozen water, methane, and amonia |
| Oort cloud | cloud located beyond the orbit of Pluto in which comets orbit in |
| coma, nucleus, and tail | 3 main parts of a comet |
| 3rd rock from the sun | Earth |
| Mars | 4th rock from the sun |
| inner planets | Mercury, Venus, Earth, and Mars |
| The Sun | contains 99.86 percent of the mass of the universe |
| Jupiter | the largest planet |
| Earth | the only planet to allow water to exsist in the 3 states of matter |
| Copernicus | the father of modern astronomy |
| Earth centered universe | early theory about the universe |
| Sun centered universe | modern theory about the universe |
| the planets revolve around this | the Sun |
| elliptical | the shape of the planets orbit |
| Mars | the largest volcano in the universe |
| the solar system may have formed from this | rotating cloud of gas, ice, and dust |
