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Solstices and equinoxes
How spacemen hanging out above (north of) Sol see Earth's
solstices and equinoxes. The tilt of Earth’s spin axis creates the seasons.
It's simple. Sometimes, as Earth orbits Sol, one hemisphere tilts mostly
toward the Sun and gets more sunshine than the other one—that’s summer at the
hemisphere tilting toward the Sun and winter for the other one. Sometimes
neither hemisphere tilts much sunward and that’s spring and fall.
We get almost equal days and night on the equinoxes because then
neither hemisphere tilts toward the Sun. The tilt effect is gone. The summer’s
solstice gives the longest day because then our hemisphere tilts directly toward
the Sun and we see the Sun the longest. At the pole, we see the Sun all day (and
a day lasts the summer). Likewise, the winter’s solstice harbors the longest
night because then our hemisphere tilts directly away.
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