Space Fun

4. Planets whose orbit lies outside the asteroid belt.
9. When near the sun, a “tail” of gas and dust particles appears.
10. All the waters on the earth's surface
13. An artificial body placed in orbit around the earth or moon or another planet in order to collect information or for communication.
14. The branch of science that deals with celestial objects, space, and the physical universe as a whole.
16. A planet that is composed primarily of silicate rocks or metals.
17. A large planet of relatively low density consisting predominantly of hydrogen and helium

1. Cycle of the shape of the illuminated (sunlit) portion of the Moon.
2. Found most predominantly in the _____ Belt.
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. Planets whose orbit lies within the asteroid belt.
6. The process of growth or increase.
7. The collection of eight planets and their moons in orbit around the sun, together with smaller bodies in the form of asteroids, meteoroids, and comets.
8. A cloud of gas and dust in outer space.
11. The star around which the earth orbits.
12. A celestial body moving in an elliptical orbit around a star.
15. The solid portion of the earth (distinguished from atmosphere, hydrosphere ).