Across
- 4. The solid part of the head of a comet
- 6. A regular oval shape
- 7. Having or representing the earth as the center, as in former astronomical systems
- 9. An object _____ when it spins around a central axis
- 10. Having or representing the sun as the center, as in the accepted astronomical model of the solar system
- 12. the earth's atmosphere, becoming incandescent as a result of friction and appearing as a streak of light
- 14. Sun, Heliocentric
- 15. Sphere,Photosphere
- 16. A celestial body that orbits the sun, has sufficient mass to assume nearly a round shape, clears out dust and debris from the neighborhood around its orbit, and is not a satellite of another planet.
- 17. Often called the inner planets
- 19. A celestial object consisting of a nucleus of ice and dust and, when near the sun, a “tail” of gas and dust particles pointing away from the sun
- 20. Color, Chromosphere
- 21. A celestial body resembling a small planet but lacking certain technical criteria that are required for it to be classed as such.
- 22. A small body moving in the solar system that would become a meteor if it entered the earth's atmosphere
- 23. Stretches more than 1,000 times the distance between the sun and neptune
- 24. The collection of planets and their moons in orbit around a sun, together with smaller bodies such as asteroids, meteoroids, and comets.
- 28. One of many small solid celestial bodies thought to have existed at an early stage in the development of the solar system
- 29. Force that attracts all objects together
- 30. A thin disk of small particles of ice and rock
Down
- 1. A region of the solar system beyond the orbit of Neptune, believed to contain many comets, asteroids, and other small bodies made largely of ice
- 2. A meteor that survives its passage through the earth's atmosphere such that part of it strikes the ground.
- 3. The trapping of the sun's warmth in a planet's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface
- 5. A large, bowl-shaped cavity in the ground or on the surface of a planet or the moon caused by an explosion, the impact of a meteorite, etc.
- 8. The area between the orbits of Mars and Jupiter where a whole bunch of asteroids orbit.
- 11. A diffuse cloud of gas and dust surrounding the nucleus of a comet
- 13. motion of one object round another
- 18. A unit of measurement equal to 149.6 million kilometers, the mean distance from the center of the earth to the center of the sun.
- 25. Hardened rock formed from lava flows on the moon
- 26. A large planet of relatively low density consisting predominantly of hydrogen and helium, such as Jupiter, Saturn, Uranus, or Neptune
- 27. A small rocky body orbiting the sun