twice a year day and night fall into
balance lasting for nearly equal lengths
known as equinoxes flattened for equal
night they occur in March and September
and along with solstices marked the
changing of seasons as earth travels
around the Sun astronomers like to
describe the equinoxes within the
conceptual celestial sphere here the
heavens are projected around the earth
like an enormous planetarium the model
is bisected by the celestial equator a
projection of Earth's own equator the
equinox occurs at the point at which the
sun's path or ecliptic crosses the
celestial equator in spring it is known
as the vernal equinox and in fall the
autumnal equinox the other two seasonal
points on the sun's path are the two
solstices in the northern hemisphere the
summer solstice marks the longest day of
the year while the winter solstice marks
the shortest the seasonal aligning of
the Sun has been more than just a unique
celestial event for humankind throughout
history ancient sites like Stonehenge in
England and Machu Picchu in Peru have
well-documented solar alignments during
the solstices
similarly the equinoxes have been
associated with some amazing man-made
phenomenon in the ancient Maya city of
Chichen itzá the Great Pyramid known as
El Castillo is oriented along Cardinal
axes
during the equinoxes shadows cast by the
railings create the illusion of a
writhing serpent body descending the
northern steps where it joins the carved
serpents head at the base of the
stairway the cultural significance of
the fall equinox and changing of seasons
continues today especially in the
northern hemisphere where the autumnal
equinox occurs around harvest season in
fact the full moon nearest the autumnal
equinox is commonly referred to as the
Harvest Moon in China and other Asian
countries this time is celebrated with
the mid-autumn kn'l festival the origins
are linked to the birth of the moon
goddess and festival traditions revolve
around families with reunions and feasts
and special moon cakes in Jewish culture
thanks for the harvest is given during
the week-long Feast of the Tabernacles
or Sukkot families eat meals and
temporary shelters outside recalling the
Israelites days in the wilderness after
the exodus from Egypt