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A glimpse at Eclipse 2017 [excerpt]

The United States mainland has not experienced a total solar eclipse in 38 years, and the upcoming 2017 eclipse promises to be the most-watched total eclipse in history. Why are millions of Americans travelling to witness this event?

In the following excerpt from Eclipse: Journeys to the Dark Side of the Moon, author Frank Close gives us a glimpse into the allure of the total eclipse.

Anyone who has experienced the diamond ring effect that heralds the start of a total solar eclipse will tell you that it is the most beautiful natural phenomenon that they have ever seen.

That this marvel happens is thanks to a cosmic coincidence: the sun is both 400 times broader than the moon and 400 times further away. This makes the sun and moon appear to be the same size. So if the moon is in direct line of sight of the sun, it can completely and precisely block it from view.

Resources provided by NASA.

As the moon moves slowly across the face of the sun, it casts a shadow on the earth’s surface, about 100 miles in diameter. As our planet spins in its daily round, the moon’s silhouette rushes across land and sea at about 2000 miles an hour.

There is a slow build-up to the totality show, as the moon gradually covers the sun, which becomes a thin crescent as twilight falls. As the climax approaches, excitement mounts. The temperature drops, and then, in the west, a wall of darkness like a gathering storm rushes towards you. This apparition is the moon’s shadow.

In an instant you are enveloped by the gloom. The last sliver of sun disappears and, as from nowhere, a diamond ring flashes around a black hole in the sky, vibrant, like a living thing. For those beneath the shadow as it passes, the sounds of animals cease, and life seems in suspended animation as for a few minutes night comes to the dome of the sky directly overhead, and covers the land from one horizon to the other. Look up myopically, and you would see stars as if it were normal night, accompanied by an awesome sight: that inky circle, surrounded by shimmering white light, like a black sunflower with the most delicate of silver petals.

One watcher has described it to me as like “looking into the valley of death with the lights of heaven far away calling for me to enter.” After the thrill of an eclipse you can’t wait to do it again, but wait you must until that exquisite alignment of sun, moon, and earth comes around once more. When it does, you must go to the thin arc where the moon’s shadow momentarily sweeps across a small part of the globe. For a total eclipse is only visible at special places on earth; a mere 0.5% of the earth’s surface is totally obscured by the moon’s shadow for just a few minutes, while the remaining 99.5% sees either a partial eclipse or nothing at all.

Anyone who hasn’t experienced totality might struggle to understand why people are prepared to adventure to the far side of the earth, by plane, ship, even on the hump of a camel, to be there. I didn’t anticipate that I would spend the latter years of my life planning expeditions throughout the globe to watch them.

Featured image credit: “Totalsolareclipse2001cmp” by Fred Espenak. Public Domain via Wikimedia Commons.

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