Latin is where we can establish that the etymological origin of the term equinox that concerns us now is found. Specifically, it comes from the word “aequinoctium”, which is the result of the sum of two lexical components:
-The word “aequus”, which means “equal”.
-The noun “nox”, which can be translated as “night”.
The concept of equinox is used in the field of astronomy . The term refers to the moment in which day and night last the same throughout planet Earth since the Sun is located on the equator .
Each year, therefore, the equinoxes take place from March 20 to 21 and then from September 22 to 23 . At those moments, for an individual located at the equator, the Sun reaches its zenith just above his head (that is, on a perpendicular line, at 90º).
At the March equinox , the Sun is at the vernal point or Aries point and crosses it to move from the southern hemisphere to the northern hemisphere. This marks the beginning of autumn in the southern hemisphere and spring in the north. On the other hand, at the September equinox , the Sun passes through the Libra point and goes from the northern hemisphere to the southern hemisphere: spring begins in the southern hemisphere and autumn in the north. As you can see, the changes of season that are fixed by convention do not coincide exactly with the equinoxes.
The March equinox, on the other hand, establishes the beginning of a day that will last six months at the North Pole and a night lasting six months at the South Pole . This particularity develops in reverse on the September equinox, with a long night for the North Pole and a very long day for the South Pole .
Sometimes the terms equinox and solstice are confused by many people. However, they are different things and only have in common that they both occur twice a year. Specifically, we have stated that the equinox consists of the sun being above the equator, making day and night the same duration in both hemispheres. However, at the solstice what happens is that the sun is closer or further away from one of the hemispheres, which causes the length of the day to increase in one and the day to decrease in the other.
Exactly, one solstice occurs on June 21, being the summer solstice in the northern hemisphere and the winter solstice in the southern hemisphere, and the other occurs on December 21, being the winter solstice in the northern hemisphere and the summer solstice in the southern hemisphere. Likewise, it must be established that the summer solstice is the longest day and the winter solstice is the shortest day.
Various novels, in addition, have the term in question in their titles, as would be the case of the work “Equinox”, an intrigue novel written by Jimena Tierra.