Astronomy Puzzle

5. A loose collection of ice, dust, and small rocky particles, typically with a long, narrow orbit
11. The name often given to the four inner planets: Mercury, Venus Earth, ans Mars
12. A thin disk of small ice and rock particles surrounding a planet
13. The trapping of heat by a planet's atmosphere
15. The region of the solar system between the orbits of Mars and Jupiter, where many asteroids are found
17. A chunk of rock or dust in space

1. A model of the solar system in which Earth and the other planets revolve around the sun
2. A doughnut-shaped region that stretches from around Pluto's orbit to about 100 times Earth's distance from the sun
3. The fuzzy outer layer of a comet
4. A meteoroid that passes through the atmosphere and hits Earth's surface
6. Life that exists other than that on Earth
7. A model of the universe in which Earth is at the center of the revolving planets and stars
8. The name often given to the first four outer planets: Jupiter, Saturn, Uranus, and Neptune
9. The solid inner core of a comet
10. An oval shape, which may be elongated or nearly circular; the shape of the planets orbits
14. A spherical region of comets that surrounds the solar system
16. A streak of light in the sky produced by the burning of a meteoroid in Earth's atmosphere