Monday, August 21, 2017


Mom and Niece Hannah, August 21, 2017

I have a pretty distinct memory of the last solar eclipse we had, way back in May, 1994. So long ago in fact that I weighed around 250 lbs. But that's neither here nor there, though I'm still pleasantly happy to have returned to that weight after nearly a quarter-century. Ahem.

The Earth was much closer to the sun that day, which meant that the apparent size of the sun was larger than the apparent size of the moon, and the result was an annular eclipse.

In such cases, as the moon passes between the observer on Earth and the sun, the moon appears to be too small to completely obscure the sun. At the moment the sun and moon are most closely aligned with respect to the observer on the ground, the outer circumference of the sun is still visible, and still very bright, looking like a brilliant, white-hot doughnut, or annulus.

Why do we sometimes have annular and sometimes total solar eclipses? This is down to the fact that the Earth and moon orbit the sun in an elliptical path, rather than in a circle. When we are closest to the sun, or perihelion, we're about 91 million miles away. At aphelion, or farthest away, the distance is about 94.5 million miles.

The diameter of the moon is 1/400 the diameter of the sun. On average, the sun is about 400 times farther away than the moon, and therefore the two have nearly the same apparent size with respect to an observer on Earth. At and around perihelion the sun is less than 400 times more distant than the moon (though not by much) and therefore it appears to be larger and is not completely obscured when the moon crosses between it an an Earthly observer. At and around aphelion is when the distance is right for the apparent sizes to match up, yielding a total solar eclipse.

Back in 1994 we were out of the path of greatest obscuration. According to the record, we saw about 80 percent of maximum obscuration, which for us meant that about three-quarters of the sun was obscured.

While it got twilightish so far as ambient light levels were concerned, it never came close to full darkness. The light was similar to that at sunset, when part of the sun is gone for the day and part of it remains above the horizon.

All of the proceeding is to set the stage for today's total solar eclipse. Twenty-three years ago I read newspaper accounts (the interwebs existed but were not yet a thing out here in the sticks) of the eclipse which noted that there would be a rare total eclipse in 2017.

That was a long way in the future. I wondered if I'd even be alive in 23 years. I didn't worry about it or even spend much time thinking about August 21, 2017, but I did start a countdown timer in my head.

And now the impossibly distant day has come. As I write this it's about two hours before the moons path begins to cross in front of the sun. Once again we'll not be in the path of complete obscuration, but we'll be at about 98-99 percent. I gave serious thought to travelling 80 miles north to get the fullest effect of totality, but I found I'd rather see and feel the experience at the ranch, so that is what I'll do.

I wonder what it'll be like?


It was interesting and odd and it's going to be quite difficult to describe.

As far as ambient light is concerned, it got very dim. At the closest point of complete obscuration the moon was blocking about 98-99 percent of the sun. But it says a lot about the brightness of the sun that it remained daylight with only 1-2 percent of the sun shining down. It was a dim daylight, but it wasn't anything like darkness or even post-sunset dusk.

The dimness was very different than I expected, though in retrospect I kind of remember having the same eerie feeling in 1994. The light level was just so different than any normal daytime or evening experience that the sense of oddness was profound.

It was a little bit like the dimness caused by a dense cloud moving across the sun, but only a little bit like that. I can't say for sure, and I didn't have a light meter (note to self for the next eclipse...), but my feeling is that it was quite a bit more dim than even the cloudiest day.

At the appointed time (10:24 a.m.) I could begin to see evidence (looking through a welding lens) that the moon was "touching" the upper right quadrant of the sun. Within just a few minutes it was quite apparent that the moon was beginning to cross. It didn't take long -- perhaps 20 minutes, before there was a noticeable change in the ambient light level.

About halfway to maximum obscuration I noticed that some of the flowers in the garden were closing up. It began to grow cool, and a breeze began to kick up.
The temp fell off! Who saw that coming?

As the dimness increased a thin haze began to form in the sky, most likely due to water vapor beginning to cool and condense out as cloud. Crickets began to chirp, but I didn't notice any birds nesting. The dogs seemed more quiet and subdued than usual, but but they didn't do anything strange.

At 11:47 a.m. it was as dark as it was going to get. Looking through the welding lens there was only a sliver of sun at the lower right which wasn't occluded, but a quick unprotected glance revealed a sun too bright to look at and with no apparent change in roundness.

Something about the experience was profoundly upsetting to some part of me. I felt off balance a bit, and there was a gnawing sense of wrongness about what my eyes were revealing.

The dimness began to fade, and within another hour or so the event was history.

Except for the folks trying to get home...

Here's the highway (HWY 71) I was whining about traffic on yesterday. Folks will soon forget the eclipse, but not the traffic! :)
Looking south.

Looking north. Pandemonious!

One definition of Der Tag


  1. Replies
    1. Exactly. But no computer systems toasted themselves. Oh wait...

  2. In Little Rhody it just looked dull like on a very cloudy day. But there weren't that many clouds.

    In my dotage I find the science of the thing more exciting than the thing itself, which you explained quite well.

    Nice post Shaun, very nice.

    1. It's a fascinating and relatively uncommon experience. It was cool. Thanks for stopping by.

  3. We ( my wife and neighbor ) noted many of the same effects as you did. Perhaps not as much wind. Thanks for the post.

    Paul L. Quandt

    1. Quite an experience for a lot of Americans. Thanks for stopping by Paul.