Space Crossword

4. Gas giant, biggest planet
5. Organization that conducts experiments, researches about space
7. Theory that the universe expanded quickly after the Big Bang
8. Point directly above your head
10. A group of stars named by astronomers because of how they look
15. Blue, icy planet
16. Planet bright red in colour
18. Apparent change in the shape of the Moon, Mercury or Venus depending on how much of the sunlit side is facing your direction (Earth)
19. Amount of time it takes for the Earth to spin once on its axis

1. When asteroids hit the Moon and form visible "holes"
2. Composed of 30% forest, 70% ocean
3. Period between new moons
6. A small object orbiting a larger one
9. Compactness of matter
10. Leftover formations of stars or planets, chunks of rock and ice, when close enough to the Sun, has a gaseous trail behind it
11. Has visible rings, pale yellow
12. Small rocks floating in space (remains of planets), not big enough to be called planets
13. Hottest planet
14. Group of stars, gas and dust held together by gravity
17. A sudden violent burst of energy