The-Day-and-night-cycle-and-the-seasonal-cycle-on-earth

==The Day-Night cycle and the seasonal cycle on earth :) ==

Why does earth have a day and night? Day and night cycles are caused by earths spin on its axis. The earth rotates every 24 hours, The part of the earth facing the sun experiences day, The part not facing the the sun has night.

So why do the days lengths change?

Locations around the earths equator can have up to 12 hours of day light per day. But the north pole can recieve 24 hours of sunlight in a few months. Earth axis is titled 23.5 degrees and it pointed almost directly towards the north star. During our movement around the sun the polar regions spend long time periods pointed towards the sun (july for the northern hemisphere and December for the southern hemisphere). This causes constant days of lightness and darkness in the artic and antartic circle.