Equinoxes 2019

While waiting for a traffic signal to switch to green yesterday, I glanced at the SUV immediately ahead of my car. The word “Equinox” was on the endgate. I thought to myself, “Now there’s a little truck that’s relevant twice a year.”

How strange that the people in charge of assigning names at Chevrolet have chosen some names associated with astronomy for a few of their vehicles.  There was the “Nova” which was a fairly good car. Then, Chevrolet named their first sub-compact car the “Vega”. Experts said that it was a lemon worse than Ford’s Edsel.  Now there is the “Equinox”, which some people like and some don’t.  If anyone at General Motors is reading this and knows why the name was chosen, please tell me.

Today is one of the Earth’s two annual equinoxes. What does that have to do with Chevys? Only the name of one of their trucks and nothing else.

More to the point is that today signals the beginning of Autumn in the Southern Hemisphere, and the beginning of Spring, here in the Northern Hemisphere. As the late Robin Williams said, “Spring is nature’s way of saying ‘Let’s party!'”

Equinox is defined as the instant in time when the plane of a planet’s equator appears aligned with the center of the Sun. If you were standing on the Equator, the Sun would appear directly overhead. On Earth, this event happens twice per year–right around now and again around September 23rd.

There are Equinoxes on other planets. The most interesting and complicated Equinoxes are the ones on Uranus. This is so, because that planet’s axis of rotation is so radically tilted in relation to its orbital plane. Another interesting fact to remember about Uranus’ year, is that it is much longer than an Earth year because its orbit is much further away from the Sun. The most recent Uranian equinox happened in 2007 and the next one will occur in 2049. For many decades, our view of Uranus was of the planet’s southern hemisphere.

Another nifty aspect about Uranus has to do with its ring system. Astronomers noticed “ring plane crossings”. There were two of them in 2007 and one in 2008. Ring plane crossings are how the Planet Uranus and its rings appear to observers here on Earth. As Uranus approached its equinox, our planet, in our own solar orbit, crossed the plane of Uranus’ tilted rings. So, looking at Uranus through a good telescope, the rings would be seen edge-on.

Looking at Uranus today, shows us that it will be springtime in the northern hemisphere and autumn in the southern hemisphere of that planet for the next several years. (Regardless of Uranus’ ring plane alignment with our point of view.)

Anyway, I’ve digressed twice from the subject of today’s Vernal Equinox in the Earth’s Northern Hemisphere. However, I don’t need to explain today’s equinox because we’re already familiar with it. It’s just nice to know that we’re not the only planet in the Solar System that has equinoxes and somebody decided to name a truck after them.

Ciao
The Blue Jay of Happiness likes this passage by D.H. Lawrence:  “Oh, what a catastrophe for man when he cut himself off from the rhythm of the year, from his unison with the Sun and the Earth. Oh, what a catastrophe, what a maiming of love when it was a personal, merely personal feeling, taken away from the rising and the setting of the Sun, and cut off from the magic connection of the solstice and the equinox!”

About swabby429

An eclectic guy who likes to observe the world around him and comment about those observations.
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