“We just hope the citizens don’t cause any obstructions,” said Don Aaron, a public affairs manager at the Metropolitan Nashville Police Department.
In Carbondale, where the moon will obscure the sun for more than two and a half minutes, 15,000 people are expected to gather in a football stadium to experience it.
Among them will be Sarah Kovac, a recent graduate of Southern Illinois University’s physics department, who will operate a telescope to observe the sun’s corona, the wispy shroud of super hot plasma that is usually not visible from the ground on Earth. She is one of many scientists across the country who will be studying the corona to gain more insight into its scorching mysteries.
Total eclipses are visible someplace around the globe about every year and a half, and Hawaiians experienced one in 1991. But the United States has not seen such a sweeping eclipse — the path of totality drapes across the country like the sash on a beauty queen, covering parts of 14 states and St. Louis, Nashville, Charleston, S.C., and other cities — in nearly a century.
Those who cannot make it to the path of totality will not be left out, however. Viewers in all 50 states will experience at least a partial eclipse, with the moon dancing across some of the sun’s surface. In New York City, about three-quarters of the sun will eventually be blocked.
The total eclipse’s cross-country trek begins in the morning on the West Coast, when beachgoers in Oregon will be the first to experience the changes that occur as the moon begins to align between Earth and the sun. Over 75 minutes the sky will gradually darken as more and more of the sun is obscured until totality at about 10:15 local time, when it will seem that twilight has quickly descended.
Some birds may become confused and start singing their end-of-the-day songs. The temperature will quickly drop, the air will grow still and, if the sky is cloudless, Venus, Jupiter and some of the firmament’s brightest stars will appear.
But the moon will still be moving. On the Oregan coast, near the centerline of the eclipse track, totality will end less than two minutes after it began and the sky will begin to brighten.
That gradual fading out and in of the light — from partial to total eclipse and back — will last for about two and a half hours in each location. Totality will continue its parade across the country until 90 minutes later, when viewers here in coastal South Carolina will be the last to experience it.
On Sunday, everyone was keeping an eye on the weather. Even one cloud, poorly timed, can spoil the party, although viewers will still experience the darkening sky.
The National Weather Service’s Weather Prediction Center said conditions looked highly favorable in Oregon and the Tennessee Valley, with cloud cover forecast at 10 percent or less. The weather service’s station in Paducah, Ky., closest to Makanda, Ill., where the eclipse has its longest duration, at 2 minutes and 41 seconds, anticipated mostly sunny skies on Monday.
The forecast was more uncertain elsewhere. Cloudy skies were anticipated in Nebraska, and the prospect of thunderstorms and variably cloudy skies were forecast around St. Louis. The weather service station here in Charleston warned that a storm system near Florida “could interfere with our view of the eclipse.”
Haze from wildfires in Oregon and elsewhere in the West was threatening to affect viewing in some locations.
There were some human-caused problems too, notably a recall by Amazon of thousands of viewing glasses which the company said offered insufficient protection for eclipse watchers.
Here in South Carolina, the College of Charleston planned to distribute 15,000 pairs of glasses for a campuswide viewing party. College officials said they consulted with professors in the astronomy department before ordering the glasses from an approved vendor.
Proper glasses, which filter out almost all light, or filter-covered binoculars, are the only ways to safely look directly at the sun during the partial portions of the eclipse. They can be removed only during totality.
Veteran eclipse watchers said a perfectly fine, and inherently safe option to watch the eclipse was a simple pinhole in a thin piece of cardboard or paper plate, through which the eclipsed sun can be projected on any flat surface.
Also going fast in some locations were groceries suitable for eclipse picnics, including “items that make you think moon and sun, like Moon Pies,” said Melissa Eads, a marketing and public relations manager for Kroger grocery’s Nashville Division in Tennessee.