an equinox is the moment in which the plane of Earth’s equator passes through the center of the Sun’s disk which occurs twice each year. today the equinox is due around 8pm – its the official end to summer and the start of autumn. lots of cultures celebrate the equinox, including the mexicans for whom it is a big time of year. i feel so sad for all these hurricanes and earthquakes that have affected parts of the world – we may complain about the rain and the grey days, but at least we are relatively free of these intense forces of nature.
on an equinox, day and night are of approximately equal duration all over the planet. they are not exactly equal, however, due to the angular size of the sun and atmospheric refraction. the word is derived from the Latin aequinoctium, aequus (equal) and nox (genitive noctis) (night).