Space Systems

3. The largest planet in our solar system.
4. Our home galaxy.
8. Buildings with telescopes where astronomers can study the universe from Earth.
9. The movement of the Earth around the Sun, takes a little more than 365 days.
10. Imaginary line that runs through the middle of the Earth.
12. Collections of stars, gas clouds, and dust particles.
14. Glowing balls of hot gas.
20. A small mobile robot that is used to study the surface of planets and moons.
21. All the objects that orbit around the sun.
23. The spinning motion of the Earth, takes about 24 hours.
25. Our home planet.
27. The colors of stars are dependent on its _____.
28. Where astronauts spend weeks or months during space explorations.
29. The largest and most massive stars.
30. Tool that takes pictures of galaxies and other space objects.

1. The Earth is _____ on its axis.
2. Caused by the way the Earth moves around the Sun.
4. The Earth's natural satellite.
5. The size of a star plays a role in its _____.
6. The hot, glowing ball at the center of our solar system.
7. The ocean's _____ are influences by gravity.
11. People throughout history would use these to tell time because they are predictable.
13. How far light can travel in one year.
15. The study of stars, planets, and space.
16. The empty area where everything exists, including planets, stars, and galaxies.
17. Represent the average distance between the Sun and the Earth.
18. Tool that sends information by sending signals from space to receivers on Earth.
19. A group of stars that form a recognizable pattern in the sky.
22. The moon goes through different _____.
24. The path an object takes as it moves around another object.
26. Force of nature that affects all objects with mass.