An equinox is when the sun shines directly on the equator and the length of the day and the night is nearly equal. There are two equinox each year. One is in September and the other is in March.
The seasons are opposite on either side of the Equator. Therefore, the equinox in Septembers is also known as the Autumnal, or Fall, equinox, in the northern hemisphere. It is known as the Spring, or vernal, equinox.
This year in the US the Autumnal equinox is Thursday, September 22, 2016 at 10:21 AM EDT. September Equinox in Universal Coordinated Time is on Thursday September 22, 2016 at 14:21 UTC.
The September Equinox occurs the moment the Sun crosses the celestial equator from north to south. The celestial equator is the imaginary line in the sky above the Earth's Equator. This happens either on September 22, 23, or 24 each year.
The Earth's axis is always tilted at an angle of around 23.4 degrees in relation to the imaginary plane created by the Earth's path around the Sun. On all the other days of the year, either the southern hemisphere or the northern hemisphere tilts a little toward the Sun. However, on the two equinoxes, the tilt of the Earth's axis is perpendicular to the Suns' rays so that they hit the equator directly.
The term "equinox" is derived from Latin, meaning "equal night." On the equinox, night and day are nearly exactly the same length of 12 hours all over the world. While this is widely accepted, it isn't entirely true. Thee equinoxes don't have exactly 12 hours of daylight.
In the Northern Hemisphere, the September equinox marks the start of autumn. Many cultures and religions celebrate or observe holidays and festivals around this event. Indigenous tribes traditionally follow the celestial calendar.
I imagine a day when the whole world pauses to celebrate the universality of these events, finding the ways we are all connected, and finding a path to world peace.
Perhaps this year you might take a few minutes to pray or to image for peace - in yourself, in your home, in your neighborhood, in your town/city/country, in the world. Mark your calendar!