Friday, September 21, 2007
The Equinox is Here! (On Sunday morning)
In the language of science, an equinox is either of two points on the celestial sphere where the ecliptic and the celestial equator intersect. For the rest of us, it's one of two times a year when the sun crosses the equator, and the day and night are of approximately equal length.
At the autumnal equinox (Sept. 23, 2007, 5:51 A.M. EDT), the sun appears to cross the celestial equator, from north to south; this marks the beginning of autumn in the Northern Hemisphere.
The vernal equinox, also known as “the first point of Aries,” is the point at which the sun appears to cross the celestial equator from south to north. This occurs about March 21, marking the beginning of spring in the Northern Hemisphere.
On the date of either equinox, the sun is above the equator and night and day are of approximately equal length; the word equinox is often used to refer to either of these dates.
The equinoxes are not fixed points on the celestial sphere but move westward along the ecliptic, passing through all the constellations of the zodiac in 26,000 years. This motion is called the precession of the equinoxes. The vernal equinox is a reference point in the equatorial coordinate system. [My two cents: this is evidence to the ridiculousness of horoscopes, as the dates in which the sun is in a particular sign change over time and is not the same as when the astrology was created in the first place.]
More detailed information at wikipedia.
Happy Fall - my favorite season! I love the crisp air, brilliant night skies, first snow, cooler weather, nice smells and colors. And when I was a kid I was always excited about going back to school in the "fall". Further, my family has lots of fall birthdays.