A Guide to the Total Solar Eclipse

On April 8th, the moon will partly and then entirely block out the sun. The total eclipse will be visible to those in a hundred-and-fifteen-mile-wide sash, called the path of totality, slung from the hip of Sinaloa to the shoulder of Newfoundland. At the path’s midline, the untimely starry sky will last nearly four and a half minutes, and at the edges it will last for a blink. On the ground, the lunacy around total eclipses often has a Lollapalooza feel. Little-known places in the path of totality—Radar Base, Texas; Perryville, Missouri—have been preparing, many of them for years, to accommodate the lawn chairs, soul bands, food trucks, sellers of commemorative pins, and porta-potties. Eclipse viewers seeking solitude may also cause problems: the local government of Mars Hill, Maine, is reminding people that trails on Mt. Katahdin are closed, because it is mud season and therefore dangerous. I have a friend whose feelings and opinions often mirror my own; when I told her a year ago that I had booked an Airbnb in Austin in order to see this eclipse, she looked at me as if I’d announced I was bringing my daughter to a pox party.

Altering plans because of this periodic celestial event has a long tradition, however. On May 28, 585 B.C., according to Herodotus, an eclipse led the Medes and Lydians, after more than five years of war, to become “alike anxious” to come to peace. More than a hundred years before that, the Assyrian royalty of Mesopotamia protected themselves from the ill omen of solar eclipses—and from other celestial signs perceived as threatening—by installing substitute kings and queens for the day. Afterward, the substitutes were usually killed, though in one instance, when the real king died, the stand-in, who had been a gardener, held the throne for decades. More recently, an eclipse on May 29, 1919, enabled measurements that recorded the sun bending the path of light in accordance with, and thus verifying, Einstein’s theory of general relativity.

Any given spot on the Earth witnesses a total solar eclipse about once every three hundred and seventy-five years, on average, but somewhere on the planet witnesses a total solar eclipse about once every eighteen months. In Annie Dillard’s essay “Total Eclipse,” she says of a partial solar eclipse that it has the relation to a total one that kissing a man has to marrying him, or that flying in a plane has to falling out of a plane. “Although the one experience precedes the other, it in no way prepares you for it,” she writes. During a partial eclipse, you put on the goofy paper eyeglasses and see the outline of the moon reducing its rival, the sun, to a solar cassava, or slimmer. It’s a cool thing to see, and it maybe hints at human vulnerability, the weirdness of light, the scale and reality of the world beyond our planet. But, even when the moon blocks ninety-nine per cent of the sun, it’s still daylight out. When the moon occludes the whole of the sun, everyday expectations collapse: the temperature quickly drops, the colors of shadows become tinny, day flips to darkness, stars precipitously appear, birds stop chirping, bees head back to their hives, hippos come out for their nightly grazing, and humans shout or hide or study or pray or take measurements until, seconds or minutes later, sunlight, and the familiar world, abruptly returns.

It is complete earthly luck that total eclipses follow such a dramatic procession. Our moon, which is about four hundred times less wide than our sun, is also about four hundred times closer to us. For this reason, when the Earth, moon, and sun align with one another, our moon conceals our sun precisely, like a cap over a lens. (I stress “our moon” because other moons around other planets, including planets that orbit other stars, have eclipses that almost certainly don’t line up so nicely.) If our moon were smaller or farther away, or our sun larger or nearer, our sun would never be totally eclipsed. Conversely, if our moon were larger or closer (or our sun smaller or farther away) then our sun would be wholly eclipsed—but we would miss an ecliptic revelation. During totality, a thin circle of brightness rings the moon. Johannes Kepler thought that the circle was the illumination of the atmosphere of the moon, but we now know that the moon has next to no atmosphere and that the bright circle (the corona) is the outermost part of the atmosphere of the sun. A million times less bright than the sun itself, the corona is visible (without a special telescope) only during an eclipse. If we’re judging by images and reports, the corona looks like a fiery halo. I have never seen the sun’s corona. The first total solar eclipse I’ll witness will be this one.

The physicist Frank Close saw a partial eclipse on a bright day in Peterborough, England, in June, 1954, at the age of eight. Close’s science teacher, using cricket and soccer balls to represent the moon and the sun, explained the shadows cast by the moon; Close attributes his life in science to this experience. The teacher also told the class that, forty-five years into the future, there would be a total eclipse visible from England, and Close resolved to see it. That day turned out to be overcast, so the moon-eclipsed sun wasn’t visible—but Close described seeing what felt to him like a vision of the Apocalypse, with a “tsunami of darkness rushing towards me . . . as if a black cloak had been cast over everything” and then the clouds over the sun dispersing briefly when totality was nearly over. Close has since seen six more eclipses and written two books about them, the first a memoir of “chasing” eclipses (“Eclipse: Journeys to the Dark Side of the Moon”) and the second a general explainer (“Eclipses: What Everyone Needs to Know”).

“I’ve tried to describe each of the eclipses I’ve seen, and I do describe them, but it’s not really describable. There’s no natural phenomenon to compare it to,” he told me recently. Describing an eclipse to someone who hasn’t seen one is like trying to describe the Beatles’ “Good Day Sunshine” to someone who has never heard music, he said. “You can describe notes, frequencies of vibration, but we all know that’s missing the whole thing.” Total eclipses are also close to impossible to film in any meaningful way. The light level plummets, which your eye can process in a way that, say, your mobile phone can’t.

In the half hour or so before totality, as the moon makes its progress across the circle of the sun, colors shift to hues of red and brown. (Dillard, a magus of describing the indescribable, writes that people looked to her as though they were in “a faded color print of a movie filmed in the Middle Ages”—the faces seemed to be those of people now dead, which made her miss her own century, and the people she knew, and the real light of day.) As more of the sun is covered, its light reaches us less directly. “Much of the light that you will be getting is light that has been scattered by the atmosphere from ten to twenty miles away,” Close said. Thus the color shift.

He showed me the equipment that he has used to watch six eclipses: a piece of cardboard about the size of an LP sleeve, with a square cut out of the middle, covered by dark glass. “I used gaffer tape to affix a piece of welder’s glass,” he said. There are small holes at the edge of the board, so he can see how shadows change as the moon eclipses more, and then less, of the sun. When sunlight comes from a crescent rather than from a circle, shadows become elongated along one axis and narrowed along another. “If you spread out your fingers, and look at the shadow of your hand, your fingers will look crablike, as if they have claws on them,” Close said.

Each eclipse Close has seen has been distinct. On a boat in the South Seas, the moon appeared more greenish black than black, “because of reflected light from the water,” he said. In the Sahara, the millions of square miles of sand acted as a mirror, so it was less dark, and Close could see earthshine making the formations on the moon’s surface visible. At another eclipse, he found himself focussed on the appearance of the light of the sun as it really is: white. “We think of it as yellow, but of course that’s just atmospheric scattering, the same mechanism that makes the sky appear blue,” he said. When he travelled to Jackson Hole, Wyoming, with his family, in 2017, his seven-year-old grandson said, half a minute before totality, that the asphalt road was “moving.” “It was these subtle bands of darker and lighter, moving along at walking pace. The effect it gave to your eye was that you thought the pavement was rippling,” Close said. He had never seen that before.

The moon doesn’t emit light; it only reflects it, like a mirror. In Oscar Wilde’s play “Salomé,” each character sees in the moon something of what he fears, or desires. The etymology of “eclipse” connects to the Greek word for failure, and for leaving, for abandonment. In Chinese, the word for eclipse comes from the term that also means “to eat,” likely a reference to the millennia-old description of solar eclipses happening when a dragon consumes the sun. If the moon is a mirror, then the moon during a solar eclipse is a dark and magic mirror.

A Hindu myth explains eclipses through the story of Svabhanu, who steals a sip of the nectar of the gods. The Sun and the Moon tell Vishnu, one of the most powerful of the gods. Vishnu decapitates Svabhanu, but not before he can swallow the sip of nectar. The nectar has made his head, now called Rahu, immortal. As revenge, Rahu periodically eats the Sun—creating eclipses. But, his throat being cut, he can’t swallow the Sun, so it reëmerges again and again. Rahu is in the wrong, obviously, but in ancient representations of him he is often grinning. To me, he looks mischievous rather than frightening.

The first story I can remember reading that featured an eclipse is Mark Twain’s “A Connecticut Yankee in King Arthur’s Court.” The wizard Merlin imprisons an engineer named Hank Morgan, who has accidentally travelled from nineteenth-century America to sixth-century Camelot. Morgan, a man who dresses and acts strangely for the sixth century, finds himself, as one would, sentenced to be burned at the stake. But he gets out of it—by convincing others that he is the cause of an eclipse that he knew would occur. As seems only natural for a beloved American story, it’s the (man from the) future that wins this particular standoff, over the ancient ways of Merlin.

To Close, the beginning of an eclipse feels like “a curtains-up statement from the heavens: Science works. Come back in an hour.” He finds it particularly moving that someone, using only measurements and reason, and the laws of celestial motion, could have predicted the April 8th eclipse down to the minute, maybe to the second. The eclipse that surprised the warring Medes and Lydians into peace may not have been a surprise to all; it is said to have been predicted by Thales of Miletus.

I asked Close if he’d ever met someone on his eclipse journeys who wasn’t much impressed. He said no. Still, it’s possible that I and my mirror friend both have the right intuition about this experience we’ve never had. In the last chapter of Roberto Bolaño’s novella “French Comedy of Horrors,” the young narrator witnesses an eclipse while at a soda fountain with his friends; he also witnesses the people around him witnessing the eclipse, including a couple doing a dance “that was somehow anachronistic but at the same time terrifying.” On his way home, he answers a ringing pay phone and finds himself in a lengthy conversation with a stranger who claims to be a member of the Clandestine Surrealist Group, writers living in Paris’s sewer system. The stranger invites the narrator (who wants desperately to be a poet) to join them, at an appointed time and place, months into the future—but says that they can’t pay for his ticket.

His whole eclipse day is banal (soda fountain, pay phone, the price of things) but also tempting, literally surreal, and like a dream. When our hero finally makes it home, at dawn, he sees Achille, the local drunk. Achille tells him that “the eclipse thing wasn’t such a big deal and that people were always getting excited about nothing. In his opinion, true and incredible things happened in the sky every day.” Nature’s everyday wonders might be the more clandestine ones. ♦

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