Seasons & Atmosphere

1. The result of the tilt of Earth's axis and the yearly revolution around the sun.
9. The season between summer and winter.
11. Imaginary line drawn around the earth equally distant from both poles.
15. This occurs in September and marks the beginning of fall in North America.
17. Half of a sphere
18. Layer where meteoroids burn up.
19. Leaning toward or away from another object.
20. The lowest layer of Earth's atmosphere
22. Outermost layer extending into space.
23. Two time of the year when day or night lengths are at their longest or shortest.

2. Protective layer in the atmosphere that shields the Earth from UV radiation.
3. 2nd layer of the atmosphere that contains ozone.
4. Energy emitted from the Sun that can cause skin cancer.
5. The season experienced when the earth's axis is tilted away from the sun.
6. The spinning of an object on a fixed point, causing day & night cycles.
7. This occurs in December and marks the beginning of winter in the Northern Hemisphere.
8. Largest layer that reaches highest temperatures.
10. Two times a year when the day and night lengths are about 12 hours each.
12. This occurs in June and marks the beginning of the summer in the Northern Hemisphere.
13. This occurs in March and marks the beginning of spring in North America.
14. The season experienced when the earth's axis is tilted toward the sun.
16. An imaginary line that passes through Earth's center and North & South poles.
21. The season between winter and summer.
24. One celestial object moving around another