Formation of Solar System

4. September 21 is the day of what?
5. point where planet is closest to sun
6. when debris enter Earth's atmosphere they are called what?
9. Head of a comet
10. Debris that produces a streak of light once in Earth's atmosphere
13. comets that repeatedly orbit into our inner solar system are called
15. What exists between the stars and leads to the formation of stars and planets
17. Kepler's ______ law states that planets farther from the sun will have a larger orbit and longer orbital period
21. interstellar clouds are made up of ______________
22. The moon affects our hydrosphere by forming ______
23. Debri that collides with the ground is called what?

1. What was the first planet to develop in our solar system
2. We experience ______ when Earth intersects a cometary orbit
3. planet moves in one direction and then reverse in the opposite direction in the sky
4. Leftover debris from the formation of solar system can be found where?
7. comets have a highly _____ orbit
8. Jupiter developed through mergers of _____ planetesimals
9. remnants of the solar system that are made of ice and rock
11. Wobble in Earth's rotational axis
12. point where planet is farthest from sun
13. Objects that have gradually grown to reach 100's of kilometers in diameters
14. debris that have pitted and irregular surfaces
16. direction tails of comets face in relation to the sun
18. Decrease in the portion of the sunlit side of the moon that we see
19. Increase in the portion of the sunlit side of the moon that we can see
20. small solid core inside the head of a comet