What you see in an eclipse is entirely different from what you know

One night last February, I was already in bed and about to fall asleep when I looked at the clock. It was just after 10:30. At 10:40, I suddenly remembered, the totality of a total eclipse of the moon was due.

I have to go, I thought. I got out of bed and pulled on a shirt. In cosmic time, there’s no particular hurry. Eclipses take hours.

On the porch it was black and cold. The sky over the fir tops was starry, and high up southeasterly, near Regulus, was a reddish, waferlike moon. I stood in the cold for a few minutes looking up. The moon seemed surprisingly small this time. A slightly sick feeling came into my mind. I wasn’t expecting it, but I recognized it anyway because it was the same feeling I’ve had during other lunar eclipses I’ve seen.

Some years ago I patiently watched most of a lunar eclipse in upstate New York. It takes more than four hours. First you see the moon start dimming in the Earth’s shadow. Slowly it turns a kind of burnt-red color. Then gradually it returns to its full white brightness. During that eclipse in 1992, the moon seemed huge. It hung like a dark weight over the trees and buildings. A friend and I talked astronomy and joked about all the meaningless nothingness graduate students joke about, but still that darkening to red made me sick at heart.

I had it during the first lunar eclipse I watched from start to finish 25 years or so ago, looking through an attic window with a folding chair, a blanket and a pair of binoculars. That was when I discovered how slowly things happen in the sky, and how inexorably.

I understood the mechanism: The Earth was passing between the moon and the sun and throwing a shadow over the moon. The shadow is described as having two parts – the penumbra, which is the shadow’s edge, and the umbra, which is the dark center.

I did not expect the moon to turn red, though. I thought it would turn black, like in a solar eclipse, when the moon passes between the sun and Earth and throws a shadow over us. And I thought it would happen more quickly. Maybe that was when the sick feeling overshadowed me. As if you’d fallen asleep and were having a bad dream, whose details and events you can’t remember when you wake up, only the heartsick, fearful feeling. I don’t know. I can’t explain it.

It’s not the same feeling you get in a solar eclipse. When you’re in the shadow, which covers a relatively small swath of the Earth, the sun gets obliterated. By a weird coincidence, if coincidence it is, the sun and moon are just the right diameters that at certain distances from us they appear to be almost exactly the same size. When the moon in its new-moon phase passes directly between us and the sun, if you’re in the right place at the right time you can see the moon, which is just a blackness, eat the sun into blackness too. All that’s left is a fine ring of light which is the sun’s corona, or outer edge. A total eclipse was visible in eastern Siberia early last month.

Not all eclipses are total. The Earth, moon and sun have to line up in just the right plane for shadows to be cast, and this only happens a few times each year. Sometimes they line up so the shadow just seems to graze the other, and this is called a partial eclipse.

A kind of partial eclipse of the sun is an annular eclipse. This occurs when the moon is distant enough from the Earth that it appears smaller than the sun, like putting a dime on a nickel. It doesn’t cover the sun completely and leaves a significant ring of light like a Life Saver.

In a total solar eclipse, though, darkness falls on Earth, or a swath of it anyway. That obliteration of the sun can be scary, even to us modern humans. Understanding the mechanics of what is happening is not the same thing as experiencing it. I mean, I understand the basic motions of eclipses. So did the amateur naturalist Annie Dillard when she set out to watch one 30 years or so ago, but the facts did not stop her from screaming when the darkness fell.

Emotions vary, no doubt. The natural world joins with people’s feelings in different ways. And a total eclipse of the moon bears the same relation to a total eclipse of the sun as an afternoon cloudburst does to a hurricane. But nature and you are joined, and at different and odd times it suddenly wakes you up.

The red moon roused a queasiness in my mind that night last winter, and I can tell you it was as real as the math that predicted the eclipse and got me out of bed. It was too cold to get the telescope out and get a better look at the umbra over the moon. After a few minutes I went back in. I take my sleeping slow, and lay there with the image of that burnt-red moon on my mind’s eye for quite a while.

Dana Wilde may be reached at dwilde@bangordailynews.net. More Amateur Naturalist is available by going to www.bangordailynews.com and www.dwildepress.net/naturalist.