Solar System

3. a scientist who studies the universe beyond Earth
5. objects that revolve around the sun that are too small and too numerous to be considered planets
6. a description of the solar system in which all of the planets revolve around the sun
9. the path of an object as it revolves around another object in space
11. a meteoroid that has hit Earths surface
12. a system of millions or billions of stars held together by gravitational attraction
14. the region of the solar system between the orbits of Mars and Jupiter where many asteroids are found
15. a description of the solar system in which all of the planets revolve around earth
17. the attractive force between two objects; its magnitude depends on their masses
18. a chunk of rock or dust in space

1. the study of the moon, stars, and other objects in space
2. the name given to the four inner planets; Mercury, Venus, Earth, and Mars
4. a ball of ice and dust whose orbit is usually a long, narrow ellipse
7. the spinning motion of a planet from east to west, opposites to the direction of rotation of most planets and moons
8. the combining of two atomic nuclei on to a single larger nucleolus, as when two hydrogen atom joined together to form helium releasing energy
10. a streak of light in the sky produced by the burning of a meteoroid in Earths atmosphere
13. the name given to the first four other planets: Jupiter, Saturn, Uranus, and Neptune
16. any object that revolves around another object in space