Space Crossword

2. Hottest planet
4. Leftover formations of stars or planets, chunks of rock and ice, when close enough to the Sun, has a gaseous trail behind it
7. Organization that conducts experiments, researches about space
8. Small rocks floating in space (remains of planets), not big enough to be called planets
9. Point directly above your head
10. A small object orbiting a larger one
11. Composed of 30% forest, 70% ocean
12. A sudden violent burst of energy
14. Period between new moons
15. Planet bright red in colour
16. Theory that the universe expanded quickly after the Big Bang
17. Has visible rings, pale yellow
19. Group of stars, gas and dust held together by gravity

1. Compactness of matter
3. Gas giant, biggest planet
4. When asteroids hit the Moon and form visible "holes"
5. Amount of time it takes for the Earth to spin once on its axis
6. A group of stars named by astronomers because of how they look
13. Blue, icy planet
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)