is the longest day of the year for us living in the Northern
Hemisphere. With the summer solstice
comes the longest day of the year and the official start of the
why do we have seasons, anyway?
all about Earth's tilt. If the Earth were spinning on its axis with
no tilt at all, everyone would be treated to days of identical length
every day of the year, with latitudes nearer the equator having
longer days than those nearer the poles. However, with the tilt, the
angle of the Earth relative to the Sun changes as or planet moves
about its orbit. On the Winter Solstice (shortest day of the year)
the Northern Hemisphere is tilted up and away from the Sun. On the
Summer Solstice (today), the Northern Hemisphere will be tilted down
toward the Sun. On the equinoxes, the tilt is half way between the
solstices. To see this effect, go out and observe the path the Sun
takes through the sky for the course of day of winter).