Astrophysics

5. The unit of distance used for stars outside the Solar System. (10 letters)
6. The process by which stars produce energy. (9 letters)
10. This planet has the Great Red Spot. (7 letters)
11. A system of millions or billions of stars held together by gravity. (7 letters)
14. The largest type of galaxies. (8 letters)
15. This planet has the most massive moon, Titan. (6 letters)
18. He proposed the theory of general relativity. (9 letters)
19. The hottest type of stars appear this color on the spectrum. (4 letters)
20. The color of cooler stars. (3 letters)
21. The galaxy that includes our Solar System. (7 letters)

1. A small, rocky object orbiting the Sun, mostly found between Mars and Jupiter. (8 letters)
2. The end stage of a massive star’s life cycle that results in an explosion. (9 letters)
3. The force that keeps planets in orbit around the Sun. (11 letters)
4. The theory that explains the origin of the universe. (3 words, 3, 4, 6 letters)
7. He discovered that galaxies are moving away from us. (6 letters)
8. The law that states: The total energy radiated per unit surface area of a black body is proportional to the fourth power of its temperature. (6 letters)
9. The third planet from the Sun. (5 letters)
12. The outermost planet in our solar system. (6 letters)
13. The name of our star. (3 letters)
16. A cloud of gas and dust in space; a star is born here. (6 letters)
17. The shift in wavelength due to objects moving away from Earth. (6 letters)
21. The term for Earth’s natural satellite. (4 letters)