Astronomy

4. The systematic study of space to discover new facts or confirm what we already suspect.
7. The physical world and everything in it that isn't man-made, including the fundamental laws that govern how planets and stars move.
8. Something that is fixed, stationary, or unchanging. In astronomy, we now know the universe is expanding, so very few things are static.
9. Massive collections of gas, dust, and billions of stars all held together by gravity.
11. The big questions we haven't answered yet, such as the true nature of "Dark Matter" or what happens inside a black hole.

1. The "stuff" the universe is made of. It includes everything from the smallest atom to the largest star.
2. When a planet is on the opposite side of the Earth from the Sun. This is usually the best time to view a planet because it appears bright and large.
3. The act of discovering or identifying the presence of celestial phenomena using instruments.
5. The entire universe regarded as a complex and orderly system; it’s the "everything" out there.
6. The "fuel" of the universe. It comes in many forms, like the light and heat radiating from the sun.
10. A "smart guess" based on evidence. Since we can't visit most of space, we use what we can see to conclude what is happening where we can't see.