Day

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Day Night
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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
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As the Earth spins, part of the Earth is facing
toward the Sun, and part is facing away from the
Sun.
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The part of the Earth facing the Sun has daytime
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Because the Earth is tilted, different parts of
the planet get different amounts of sunlight at
different times of the year.
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http//ithacasciencezone.com/earthzone/lessons/07m
eteor/daylight.jpg
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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.
http//k12.ocs.ou.edu/teachers/reference/equinox.g
if
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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.
http//k12.ocs.ou.edu/teachers/reference/solstice.
gif
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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.
http//k12.ocs.ou.edu/teachers/reference/solstice.
gif
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Lets look at some more computer models

• http//ithacasciencezone.com/earthzone/lessons/07m
  eteor/daynight.htm

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What about San Antonio?
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Notice our latitude
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Bexar County
Notice the latitude of the Tropic of Cancer.
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How does living so close to the Tropics affect
out day length