Well… hello, fall.
We can thank the autumnal equinox for this shift from sultry summer to cozy fall. And while most of us are aware of when the first day of autumn lands on the calendar, there’s more to the equinox than meets the eye.
1. There are two equinoxes annually, vernal and autumnal, marking the beginning of spring and fall. They are opposite for the northern and southern hemispheres.
2. The autumnal equinox happens the moment the sun crosses the celestial equator, which is an imaginary line in the sky that corresponds to Earth’s equator. Every year this occurs on September 22, 23, or 24.
3. From hereon, the days get shorter until the winter solstice in December, when the light will begin its slow climb back to long summer days. Winter solstice is technically the shortest day of the year, while the summer solstice in June boasts the most sunlight. Hence, the four season, as illustrated below.
4. This year, the autumnal equinox arrives precisely at 4:21 a.m. (EDT) on Wednesday, September 23. Unlike an event like New Year’s midnight that follows the clock around the time zones, equinoxes happen at the same moment everywhere.
5. This year, the sun will rise at 6:56 a.m. EDT on the equinox and will set at 7:04 p.m., giving us 8 minutes of day over night. Although the sun is perfectly over the equator, we mark sunrises and sunsets at the first and last-minute the tip of the disk appears. Also, because of atmosphere refraction, light is bent which makes it seem like the sun is rising or setting earlier.
6. Exactly equal day and night won’t happen until September 26 with sunrise as 6:59 a.m. EDT and sunset at 6:59 p.m.
7. For the astrology-minded, the morning of the autumnal equinox is when the sun enters Libra … the sign of balanced scales. Equal day and night, balanced scales, seeing a connection here?
