Astronomy Puzzle

2. Dry ice and dry lakes are on the surface here.
4. The only planet whose day is longer than its year.
8. This planet has 146 confirmed moons! Many are waiting classification.
10. The distance between the Earth and the Sun (on average)
12. The planet that has the most extreme tilt.
13. The cause of the twinkle we see from stars.
15. The temp here ranges from -290F (-180C) to 800F (430C).
18. What is theorized to make up about two thirds of the mass of the universe?
19. The actual planet that causes my issues (take that astrology).
20. What is theorized to make up about a quarter of the mass of the universe?

1. Seen directly overhead at the northpole no matter the time of year.
3. The first stage of death for our sun.
5. The only planet that was close (relatively speaking) to also be a star in our solar system.
6. Needs justice.
7. Math determined this planet existed before it was observed!
8. The largest star in our visible sky.
9. The alleged scent of the moon.
11. Real big explosion in big mass stars.
14. The type of galaxy we live in.
16. Our galaxy.
17. The celestial object in our solar system that is the coldest (-391F or -295C).
21. The amount of planets besides Earth that can fit between the Earth and the Moon.