Wiki Word: Equinox

Definition:An equinox is a day where there is an equal amount of day and night.  

First to understand equinoxes you have to break down their name. Equi means equal, and nox means night, therefore equinox means equal night. Equinoxes happen twice a year, most oftenly on March 20 and September 22-3. The semi-accurate pattern for predicting these for the vernal equinox is: the year before leap year is usually the 21st of March and the other three years it's usually on the 20th, though the range is from the 19th to the 21st of March. For the autumal equinox the pattern is most commonly the 22nd on Leap year and the year after and the 23rd the other two years, as you can see below.

Past, Current, and Future Equinoxes 

Vernal Equinox                                         

                      Autumnal Equinox

 SO WHAT???: This term has a big part in what we are currently studying considering that it's the start of two of the seasonsSpring and Fall), so therefore it's cased by the same factors. This term helps you to understand seasons, Earth's revolution, and the effects of that revoultion(Earth's orbit). This term isn't used very often becuase usually people say ' It's the start of Spring/Fall' not 'It's the Vernal/Autumnal Equinox', people just aren't that scientific, but when studying space it comes up very often, so we have to understand what it means. When we're studing you find out that the equinoxes are two special days that happen only twice a year on these days there's equal day and night, but usually there's a few minutes more of light than dark because after the sun sets the light is bent in the Earth's atmosphere. Equinoxes are found inbetween the Winter and Summer Solstices.   

To find out more about equinoxes look at these sources and websites: 

"Equinox." Wikipedia. 2008. 9 May 2008 < http://en.wikipedia.org/wiki/Equinox >.

 A simple way to find out more about equinoxes.

"Equinoxes and Solstices." National Maritime Musem. 2008. National Maritime Museum. 11 May 2008 < http://www.nmm.ac.uk/server/show/conWebDoc.3843 >.

A more in detail way to find out about equinoxes and solstices.

Smith, Ivan. "Vernal Equinox." Vernal Equinox: Dates and Times of Day each year for 1096 years. 17 Mar 2008. 11 May 2008 < http://www.ns1763.ca/equinox/vern1452-1811.html >.  

This page allows you to see past, present, and future Vernal Equinox dates.

Related Wiki Pages:

noct

axis

“equi”

solstice

Classroom Books:

*Bonstetter, Ron Ph.D et al. Sciencesaurus: A Student Handbook. United States: Houghton Mifflin Company, 2006. (Pg. 234)

* Pasachoff, Jay M, Ph.D. Prentice Hall Science Explorer: Astrology. Boston, Massachusetts: Pearson Education,Inc. , 2005