If you are in its direct path, you’ll never forget it.
WHAT is the most beautiful natural phenomenon you have ever seen? A brilliant rainbow set against a distant storm, the shimmering aurora in an Arctic night, or a blood-red sky just after sunset, perhaps? Here’s what puts all those in the shade: the diamond-ring effect that heralds a total solar eclipse, an explosion of light on the edge of the moon’s inky circle, as it blots out the sun.
When the moon is in direct line of sight of the sun, a “totality” completely and precisely blocks our central star from view, casting a shadow on Earth’s surface about 100 miles in diameter. As our planet spins in its daily round, that shadow rushes across land and sea at about 2,000 miles an hour. If you are in its direct path, you’ll never forget it.
Total solar eclipses occur at regular intervals, but each time a mere 0.5 percent of Earth’s surface is totally obscured by the moon’s shadow. On Aug. 21, for the first time in a century, that 0.5 percent will cross the whole of North America, more or less kitty-corner from northwest Oregon through Idaho and across Wyoming, Nebraska and Missouri, then parts of five more states to South Carolina, potentially creating the largest-ever audience for a totality.
There is a slow buildup to the main event. It takes about an hour for the moon to gradually cover the sun. The bright disc shrinks to a sliver and twilight falls, giving the illusion that the sun is disappearing. This frightened the ancients, who feared that the source of all life was about to be extinguished.
As the last of the sun vanishes, the temperature drops, and from the west, a wall of darkness, the moon’s shadow, approaches. In an instant you are enveloped by gloom and the moon has appeared — in silhouette — as if from nowhere, like a rabbit from the conjurer’s hat. This is a truly weird phenomenon.
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, and you will see stars as if it were normal night, but accompanied by a blackened moon surrounded by the sun’s shimmering white corona, like a black sunflower possessed of…