Earth

[S Austion]

How does the earth's position to the sun determine the lenght of daylight?

[mibn2cweus]

Because the Earth�s axis of rotation is tipped at an angle relative to its orbital path around the Sun, we experience the annual cycle of the seasons. Between autumn and spring, the North Pole of the Earth gradually falls into (and then out of) the shadow of the Earth. During this period of the year the further north of the Equator you are, the shorter the duration of time each day the Sun appears above the horizon. At Winter Solstice the Sun never rises north of the Arctic Circle. This scenario plays out in reverse during the other half of the year. At Summer Solstice north of the Arctic Circle the Sun spends the whole day (24 hours) above the horizon.

During the Spring and Autumn Equinox, along the Equator, the Sun rises and sets perpendicular to the horizon and crosses directly over head in the sky; this takes place over a period lastly 12 hours. This same thing takes place the day of Summer Solstice along the Tropic of Cancer.

The above applies to the Northern Hemisphere. The inverse what was described above is true for the Southern Hemisphere during the opposite half of the year.

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[Loosehead]

As above the Earth's proximity to the sun does not have an effect on the length of daylight. It's the 23.5 degree tilt.

[mibn2cweus]

D�oh! On the day of Summer Solstice the Sun crosses directly over head in the sky for those at the latitude of the Tropic of Cancer but rises and sets about 26 degrees towards the north. Also the Sun stays above the horizon 13 � hours . The Sun rises due east and sets due west at the spring and autumn equinoxes.