If you live near the equator, then you're used to virtually no
seasons (except summer, of course). If you live at the North or
South Pole, then you get two very long seasons: the sun stays up
all summer, then stays down all winter. At the North Pole, the sun
stays down for 182 straight days during winter.
If you live in between, you get four seasons.
The Earth, which orbits around the sun once each year, is tilted
23.5 degrees. When the top of the Earth is inclined toward the sun,
it's summer in the Northern Hemisphere, where the sun rises highest
in the sky and the days are longest. A quarter of the way around in
the orbit, fall sets in. When the top of the Earth points away form
the sun it's winter in the Northern Hemisphere. Another quarter of
the orbit brings spring.
Seasons have nothing to do with Earth's distance from the sun,
which varies slightly because our planet's orbit is not a perfect
circle. And season's are not caused by Earth's rotation on its own
axis, a 24-hour cycle that brings night and day (based on which
side of the Earth is facing the sun). By now, if you didn't already
know, perhaps you can guess that the sun never really "rises."
Instead, the spot on Earth where you are rotates into the
morning.
