Benjamin's Crossword Puzzle

2. What holds the planets in orbit around the sun and what keeps the moon in orbit around Earth.
4. A small planetary-mass object that is in direct orbit of the Sun.
7. The Sun together with eight planets and the other group of celestial bodies.
11. Collections of stars and planets that are held together by gravity.
12. A celestial body that has its own heat and light.
13. The star around which Earth and other planets orbit
15. Used to measure distances within our Solar System.
17. A natural object moving around a larger object in space.
19. Eclipses occur when the Sun, the Moon, and Earth line up, either fully or partially.

1. All of space including everything that exists.
3. The Planet with Life.
5. A characterization of the wave in space, that is functionally related to its frequency, as constrained by the physics of the system.
6. When a star dies and create dramatic formations of radiating cosmic gas. Some great examples of planetary nebulae in the night sky.
8. The distance light travels in one year.
9. A celestial object consisting of a nucleus of ice and dust.
10. A regular, repeating path that one object in space takes around another one.
14. An invisible (yet incredibly fast) ripple in space.
15. An imaginary straight line around which an object spins.
16. The earth's natural satellite that shines by reflecting light from the sun and revolves about the earth.
18. A large, irregularly shaped object in space that orbits our Sun.