1. Day & Night

2. The Earth spins on its axis
The spinning is called ROTATION
The direction of rotation is counterclockwise if you are looking at it as if you were floating over the North Pole

3. As the Earth spins, part of the Earth is facing toward the Sun, and part is facing away from the Sun.

4. The part of the Earth facing the Sun has daytime

5. Because the Earth is tilted, different parts of the planet get different amounts of sunlight at different times of the year.

7. In the Spring and Fall EQUINOX
A day lasts 12 hours and a night lasts 12 hours at all latitudes. Sunlight strikes the earth most directly at the equator.
uinox.gif

8. In the Summer and Winter
SOLSTICE
During the winter the Northern Hemisphere day lasts fewer than 12 hours and the Southern Hemisphere day lasts more than 12 hours.
During the winter solstice, the North Pole has a 24-hour night and the South Pole has a 24-hour day.
Sunlight strikes the earth most directly at the Tropic of Capricorn.
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9. In the Summer and Winter
SOLSTICE
 During the summer solstice the Northern Hemisphere day lasts more than 12 hours and the Southern Hemisphere day lasts fewer than 12 hours.
During the summer, the North Pole has a 24-hour day and the South Pole has a 24-hour night.
Sunlight strikes the earth most directly at the Tropic of Cancer.
ence/solstice.gif

10. What about San Antonio?

11. Notice our latitude

12. Notice the latitude of the Tropic of Cancer.
Bexar County
Notice the latitude of the Tropic of Cancer.