Autumnal equinox: 5 things you need to know
Ready or not, it’s the first day of fall, also known as the September, fall, or autumnal equinox. It’s a time marked as much by the emergence of wayfaring leaf peepers as it is by celestial coincidences. Sure, it happens every year, but this time you’ll be able to impress your friends with your budding seasonal knowledge. Take a look at the things you ought to know.
1. The basics
In the language of science, the autumnal equinox is the exact moment when the sun crosses the Earth's equator from the north and moves to the southern hemisphere.
For the rest of us, it’s when most of the world enjoys nearly equal amounts of light and darkness, and, of course, when those in the southern hemisphere experience the first day of spring, known as the vernal equinox.
The exact moment for this fall’s equinox will occur on Friday at 9:04 a.m. Coordinated Universal Time (UTC), which is 12:04 a.m. Eastern time.