Autumn equinox, that's why this year it is September 23rd

Since ancient times, the equinoxes have represented a 'mystical' moment, as well as a purely scientific one, a 'passage' celebrated around the world and linked to numerous traditions

ROME – Although temperatures say otherwise, summer officially ends this Saturday, at least astronomically speaking.The September 23, in fact, it is autumnal equinox.In September each year, the Sun crosses the celestial equator and i Solar rays hit the Earth's rotation axis perpendicularly.This event is named in astronomy of autumnal equinox.

READ ALSO: Winter solstice, that's why it's the shortest day of the year

THIS IS WHY SEPTEMBER 23 IS THE AUTUMN EQUINOX

In astronomy, the equinox (from the Latin æquinoctium, or "equal night") represents the moment when the Sun shines directly on the equator. This happens in March (vernal equinox) and September (autumnal equinox).Although it is common knowledge that the first day of autumn is always the same, in reality the date can change every year.

This depends on the our calendar. Earth employs just over 365 days to complete one revolution around the Sun.However, the Gregorian calendar rounds up to 365 days and does not take into account theextra 0.256 days. We do not see the difference in hours on the calendar but, in astronomy, they cause the dates of equinoxes and solstices to be postponed or brought forward.

This year the autumnal equinox is September 23rd.In 2024 it will be September 22nd.

WHAT IS AN EQUINOX?

The Earth's axis is always tilted by an angle of approximately 23.5 degrees with respect to the ecliptic, i.e. the imaginary plane created by the Earth's path around the Sun.However, although the angle remains the same, the orientation of the tilt changes throughout the year.In astronomy, the equinox is that moment in which the Sun's rays hit the Earth's rotation axis perpendicularly.

It happens in two moments:We in the Northern Hemisphere experience the autumn equinox in September, and the spring equinox in March.Vice versa occurs in the southern hemisphere.

The word 'equinox' comes from the Latin 'aequinoctium', 'same night'. Even if during the equinox the day and the night they are not exactly the same, dark and light can be both very close to 12 hours.

EQUINOX BETWEEN CULTURE AND TRADITION

The equinox coincides with many cultural events, religious observances and traditions.

Ancient Greece

In Greek mythology, autumn is associated with the return of the goddess Persephone to the underworld to be with her husband Hades.It was considered a good time to carry out rituals for protection and safety, as well as reflect on the successes or failures of the previous months.

Japan

In Japan 'Higan' it is a week of celebration observed by Buddhist schools during the equinoxes of September and March.Higan means 'the other shore' and refers to the spirits of the dead who reach Nirvana. It is a time to remember the dead visiting, cleaning and decorating their graves.Both equinoxes have been national holidays since the Meiji period (1868-1912).

Mabon

On the day of the autumnal equinox the neopagans celebrate the Mabon.It is part of the eight Sabbats and is a festival to honor the harvest and fruits of the earth, sharing them with others.

Stonehenge is the hub of the mysteries related to the solstice and equinox. The stones that compose it are, in fact, aligned in correspondence with the points where the Sun rises on those days.For this reason, it has been hypothesized that the site was an ancient astronomical observatory.