asteroid

1. asteroid • a small rocky object in space

2. axis • a line through the center of a sphere or planet

3. comet • an object in space that is made mostly of ice and dust and may appear to have a “tail”

4. eclipse • the hiding of a planet or the moon by the shadow of another; a way in which planets, moons, and stars (such as the Sun) line up so that one creates a shadow hiding the view of another

5. ecliptic • the plane of Earth's orbit around the Sun

6. elliptical • shaped in an oval

7. gibbous • showing more than half, but not the whole, especially of the moon

8. gravity • the pull of the earth on an object; a mutual physical force attracting two bodies, such as planets; the force of attraction between two or more objects, the strength of which is determined by mass and distance

9. orbit • a path that circles around something, especially a body in space such as a planet

10. planet • a large body in space that rotates around a star and does not give off light itself, but reflects light from the star

11. rotation • a spin; a turn around something

12. satellite • an object that goes around a larger body; an object that goes around a planet and is held in orbit by gravity Satellites can be natural, like the moon (left), or man-made like this weather satellite (right).

13. tide • the rising and falling levels of the ocean that happens twice each day

14. wane • to shrink or become smaller

15. wax • to grow and become larger