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 http://vortex.plymouth.edu/sun/sun.html

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.

6. http://ithacasciencezone.com/earthzone/lessons/07meteor/daylight.jpg

7. In the Spring and Fall http://k12.ocs.ou.edu/teachers/reference/e quinox.gifEQUINOX A day lasts 12 hours and a night lasts 12 hours at all latitudes. Sunlight strikes the earth most directly at the equator.

8. In the Summer and Winter http://k12.ocs.ou.edu/teachers/ref erence/solstice.gifSOLSTICE 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.

9. In the Summer and Winter http://k12.ocs.ou.edu/teachers/refe rence/solstice.gifSOLSTICE 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.

10. Let’s look at some more computer models: http://ithacasciencezone.com/eart hzone/lessons/07meteor/daynight. htm

11. What about San Antonio?

12. Notice our latitude

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

14. How does living so close to the Tropics affect out day length