Basic Astronomy Terms
Enter the number from the column to the left into the text box next to the appropriate word in the right-hand column.
1. the tendency of a body at rest to stay at rest, and of a body in motion to stay in motion, unless acted upon by another force light year
2. a natural object surrounded by the vacuum of space celestial body
3. the force of attraction between all objects inertia
4. the relatively empty area between and around stars, planets, and other celestial bodies solar system
5. the path a satellite travels around a larger object universe
6. the area containing all matter, energy, and space satellite
7. the distance light travels in one year (about 5.88 trillion miles; or 9.45 trillion kilometers) The Big Bang
8. unit of distance equal to 3.26 light years gravity
9. an object (natural or manmade) that is held by gravity and inertia in a circular or elliptical path around a larger object orbit
10. an explosion that scientists believe occurred at the beginning of our universe; it is thought that after this explosion the first celestial bodies formed parsec
11. the average distance from the earth to the sun (about 93 million miles; or 149.6 million kilometers) astronomical unit
12. a star and all of its satellites space



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