Across
- 3. must be round, orbit the sun, and have cleared out the region of the solar system along its orbit.
- 6. an object that orbits the sun and has enough gravity to be spherical, but has not cleared the area of its orbit.
- 10. trapping of heat by the atmosphere
- 11. large round pits on the moon
- 12. sun
- 13. oval shape
- 14. distance between the earth and sun, about 150,000,000 kilometers.
- 16. is the force that attracts all objects toward each other
- 17. the four large outer planets
- 18. clouds of gas and dust form this fuzzy outer layer of a comet
- 19. are hardened rock formed from huge lava flows that occured 3-4 billion years ago
- 20. stretches out more than 1000 times the distance between the sun and Neptune
- 21. solid inner core of a comet
- 22. in this system, earth and other planets revolve around the sun
- 24. consists of the sun, the planets, their moons, and a variety of different objects.
- 26. are loose collections of ice, dust, and small rocky particles whose orbits can be very long, narrow ellipses.
- 29. motion of one object around another
Down
- 1. Beyond Neptune's orbit which extends to about 100 times Earth's distance from the sun.
- 2. region of the solar system between Mars and Jupiter
- 4. when an object spins around a central axis
- 5. earth-centered model
- 7. sphere
- 8. inner planets, comes from latin word "terra" which means Earth.
- 9. small bodies formed by rock and ice
- 15. chunks of rock and dust from space
- 23. color
- 25. meteoroids that pass through the atmosphere and found on Earth's surface
- 27. streak of light caused when a meteoroid enters Earth's atmosphere
- 28. thin disk of small particles of ice and rock