Science 2

5. One of four times of the year with different weather patterns, caused by Earth’s tilt and orbit.
8. A stage or step in a process; the Moon has these as its shape seems to change.
9. The study of stars, planets, and all things in space.
11. The force that pulls objects toward each other, holding us to the Earth.
13. A tool that helps us see distant objects in space more clearly.
15. An imaginary line through the center of Earth that it spins around.
17. Times of the year when day and night are about the same length.
18. Times of the year when we have the longest day or the longest night.

1. A characteristic of matter, like color, shape, or hardness.
2. A huge group of stars, dust, and gas held together by gravity.
3. A group of two or more atoms joined together.
4. To mix completely with a liquid so that you can’t see the separate particles anymore.
6. The smallest unit of matter.
7. A very small piece of matter.
10. To watch and study something carefully.
12. Something that can change in an experiment.
14. The path one object takes as it goes around another object, like Earth around the Sun.
16. A type of mixture where one substance dissolves completely into another.