Concept, Characteristics and What is the solstice

We explain that it is the equinox, some of its characteristics and history, and what are its differences with the solstice.

The equinox occurs twice a year, at the end of the months of March and September.

What is the equinox?

It is called equinox to any of the two moments of a year in which the Sun is located on the equatorial plane of the Earth , reaching according to the point of view of a located observer in the Earth's equator, its maximum point or zenith (at 90 ° with respect to the ground).

This occurs twice a year, at the end of the months of March and September , depending on whether it is the spring or autumn equinox, respectively, and serves to formally mark the beginning of these seasons in each hemisphere: in March it is spring in the North and autumn in the South, and in September vice versa.

The term equinox comes from the Latin aequus nocte ("equal night") , which refers to the fact that that day the night and the day have approximately the same duration in all the world, since the parallel of inclination of the Sun coincides with the equator in the middle of the planet.

The equinoxes are also used as a reference point in astronomy, and in numerous human cultures it has an important significance in the religious or cosmological tradition , since it marked the rebirth of life after winter ( spring), and therefore a time of celebration and fertility rites to start the harvest; but also of the onset of decay, cooling and death (autumn), and therefore a time of withdrawal, intimacy and reflection.

See also: Cardinal Points.

Equinox and solstice

The solstices are the opposite and complementary degree of the equinoxes.

If the equinox is the point where the plane of the Sun coincides with the Earth's equator, making the day and night have the same length and marking the transit from the hot to the cold season or vice versa (depending on the hemisphere), the solstices instead are determined by the positioning of the Sun on the imaginary lines of the terrestrial tropics (Cancer and Capricorn, according to constellations located in them) and thus producing the most extreme points of climate and temperature on the planet: winter and summer.

The solstices are, thus, the opposite and complementary degree of the equinoxes , in which the Sun transits instead the constellations of Aries and Libra.The solstices usually occur at the end of the months of June (summer solstice) and December (winter solstice) in the Northern Hemisphere, and vice versa in the Southern Hemisphere.

Follow in: Solstice.