Hey, everybody. It’s been a tough couple of days. I hope you’re all safe and well.
Well, here we are, the last full day of summer, here, north of the ol’ equatorizor. Can you believe it? You snap your fingers, and, pow, the Earth has gone about a quarter of the way around the block since the June. I don’t know about where you are, but the weather’s not really acting like fall around here yet. That’s okay, though. It’ll come. Besides, the equinoxes are really an astronomical thing; not really a weather thing. It’s not like everything but my lawn is green today, and then tomorrow, fall will start, all the leaves will turn color, and by the weekend, it’s nothing but bare branches reaching out toward dark and cold sky. That’d be fun, though. Imagine the sound of all of those leaves falling at once.
The start of fall is like any of the other seasons. It’s gradual, and it usually takes a few days or a couple of weeks, even, for the weather to catch up with the astronomy of it all. The pumpkin-spice hot dogs and hypercinnamonized pine cones are already on the store shelves, and the Halloween decorations are already up. So, we’re sort of expecting things to happen faster. In fact, the seasons themselves are sort of an iffy proposition to begin with. When you talk about them, there’s sort of an assumed idea of what those seasons are going to look and feel like. Not everyone lives where it snows during winter, or where it’s hot during summer. Sadly, even the distinctions that do exist are shrinking, and fast. Everywhere’s hotter than it should be.
So, tomorrow’s the equinox. What does this mean? At June’s solstice, the energy from the Sun hit its northernmost point, at about 23.5 degrees north latitude, which is called the Tropic of Cancer. Since then, it’s slowly been moving southward again.
Tomorrow, September 22, 2016, at 14:21 Coordinated Universal Time (UTC), the Sun’s rays will be at the equator, and both hemispheres will get equal amounts of energy. That’s the moment of the equinox. From then on, it’s fall in the north, so there it’s called the autumnal equinox. In the south, it’s the start of spring, and it’s called the vernal equinox. In the north, the days will continue to get shorter until December’s solstice, when the Sun reaches its most southerly point, 23.5 degrees south (the Tropic of Capricorn). Then, the Sun heads back north again, and the cycle continues.
In the US, 14:21 UTC is:
- 10:21 AM Eastern
- 9:21 AM Central
- 8:21 AM Mountain
- 7:21 AM Pacific
- 6:21 AM Alaska
- 4:21 AM Hawaii-Aleutian
In the skies, this is the time when Deneb, in Cygnus, one of the three bright stars that make up the Summer Triangle, is straight overhead. If you’ve been keeping you’re eye on the triangle for the last couple of months, you’ve noticed that Vega has been at the zenith for a while. Well, this is a transitional time of year. So, the Triangle, which spent the summer evenings in the eastern half of the sky, has gone over the top. Now it’s going to spend a bunch of fall getting ready to set in the west.
Also, Cassiopeia, the queen, Andromeda, the princess, and Pegasus, le cheval volant, are going to be at their best. Before you know it, everyone’s old friends the Pleiades Cluster (Messier 45) will be up in the mid-evening sky. It’s a good time of year to get a fresh look on the sky around you, and we’ll talk about a bunch of this stuff before long.
So, what should you do at the equinox tomorrow? Maybe take a minute to wave good-bye to summer, maybe mention it to the person standing next to you in line at the coffee shop, but… don’t be weird about it, and remember it’s only 271 days until summer starts again. Me, I love fall, so I’m going to enjoy the start of stout season.
Clear skies, everyone!