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XIsle Guest
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Posted: Tue Mar 20, 2012 4:05 am Post subject: Equinox----Today |
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UT date and time of equinox: March 20, 2012, 5:14
An equinox occurs twice a year, when the tilt of the Earth's axis is inclined neither away from nor towards the Sun, the center of the Sun being in the same plane as the Earth's equator. The term equinox can also be used in a broader sense, meaning the date when such a passage happens. The name "equinox" is derived from the Latin aequus (equal) and nox (night), because around the equinox, the night and day have approximately equal length.
At an equinox, the Sun is at one of two opposite points on the celestial sphere where the celestial equator (i.e. declination 0) and ecliptic intersect. These points of intersection are called equinoctial points: classically, the vernal point and the autumnal point. By extension, the term equinox may denote an equinoctial point.
An equinox happens each year at two specific moments in time (rather than two whole days), when there is a location (the subsolar point) on the Earth's equator, where the center of the Sun can be observed to be vertically overhead, occurring around March 20 and September 22 each year.
Although the word equinox is often understood to mean "equal [day and] night", this is not strictly true. For most locations on earth, there are two distinct identifiable days per year when the length of day and night are closest to being equal; those days are referred to as the "equiluxes" to distinguish them from the equinoxes. Equinoxes are points in time, but equiluxes are days. By convention, equiluxes are the days where sunrise and sunset are closest to being exactly 12 hours apart.[2]
From: http://en.wikipedia.org/wiki/Equinox |
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dongato Guest
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Posted: Tue Mar 20, 2012 6:25 am Post subject: |
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Wow! How cool!
Disclaimer: This post is not intended to insult, intimidate or otherwise molest any new members, any old members or anyone else at all. "Thank you and say goodnight Gracie. Goodnight Gracie." Source of quote, George Burns and Gracie Allen. |
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Captain John Super Windy Senior

Joined: 06 Feb 2007 Posts: 1678 Location: Captain John's Rio Dulce Marina
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Posted: Tue Mar 20, 2012 6:29 am Post subject: |
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OK navigators, if today here in Rio Dulce you were to take out your trusty sextant and do a noon sight, what would be the angle of the sun to the horizon?  _________________ I have been asked...what do you old folks do now that you're retired? Well..I'm fortunate to have a chemical engineering background, and one of the things I enjoy most is turning beer, wine, Scotch , and margaritas into urine. |
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dongato Guest
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Posted: Tue Mar 20, 2012 6:39 am Post subject: |
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| I don't own a sextant and am not smart enough to use one if I had one, but I'll take a wild guess.....90 Degrees. |
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Avian Feathered Troublemaker

Joined: 23 Sep 2010 Posts: 707 Location: Flying Overhead... Taking Aim
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Posted: Tue Mar 20, 2012 6:49 am Post subject: |
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72 degrees (give or take a little). _________________ #1 Birdbrain on the Rio!
*** Don't take life so seriously - we're only stardust *** |
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XIsle Guest
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Posted: Tue Mar 20, 2012 7:01 am Post subject: |
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| ...or a more general answer is: angle of sun at noon is 90 degrees minus latitude of sight taken, wherever one is on the earth (N or S) at equinox. |
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