Across
- 3. a scientist who studies the universe beyond earth
- 6. A ball of rock and ice who's orbit is usually a long, narrow ellipse
- 8. a region of the solar system between the orbits of Mars and Jupiter, where many asteroids are found
- 10. The attractive force between two objects; its magnitude depends on their masses and the distance between them.
- 11. The combining of two atomic nuclei onto a single larger nucleus, as when two hydrogen atoms join together to for helium, releasing energy.
- 13. A description of the solar system in which all of the planets revolve around Earth.
- 15. Planets The name given to the four inner planets: Mercury, Venus, Earth, and Mars.
Down
- 1. A chunk of rock or dust in space.
- 2. Any object that revolves around another object in space.
- 4. Objects that revolve around the sun that are too small and too numerous to be considered planets
- 5. The path of an object as it revolves around another planet in space.
- 7. A streak of light in the sky produced by the burning of a meteoroid in Earth's atmosphere.
- 8. The study of the moon, stars, and other objects in space
- 9. A meteoroid that has hit Earth's surface.
- 12. a description of the solar system in which all of the planets revolve around the sun.
- 13. A system of millions or billions of stars held together by gravitational attraction
- 14. The name given to the first four outer planets: Jupiter, Saturn, Uranus, and Neptune