On Monday, Aug. 21, a total solar eclipse will pass over the continental U.S. for the first time since 1979—and a 70-mile swath of Southern Illinois (including Carbondale, Carterville, Makanda and Waterloo) will be among the nation’s best places to see it. In fact, the Makanda area will have the longest period of darkness (about two minutes and 40 seconds) than any other place in the country.
What is a solar eclipse?
A total solar eclipse occurs when the moon appears to cover the sun—with the resulting moon shadow creating night in the middle of the day. The sun is actually about 400 times bigger than the moon, but in the vastness of space the moon is just “close” enough to the Earth (at about 239,000 miles away) to appear to be the same size. (For a fun explanation, watch this video with Bill Nye, the science guy.)
So what’s the big deal?
Usually when a total eclipse occurs, the moon’s shadow (dramatically called the “path of totality”) is cast in a remote area, like the middle of the ocean. But this Monday will be the first time since 1979 that a total eclipse hits the continental U.S., and the first time since 1918 that the path of totality stretches from coast-to-coast, beginning in Oregon and ending in South Carolina.
What will Illinoisans see?
The phases of the eclipse will start around 11:50 a.m. and end around 2:50 p.m. But if you’re in Illinois’ 70-mile path of totality you will see a total solar eclipse sometime between 1:15 p.m. and 1:21 p.m. Depending on where you are in the path, the night-like conditions will last from a minute to two minutes and 40 seconds (longer than anywhere else in the country). Other parts of Illinois will see a partial solar eclipse. For example, Chicagoans will see the moon blocking about 80-90 percent of the sun.
How do I view an eclipse?
Warning: Do NOT look at the eclipse without protecting your eyes!
You have to get special glasses to protect your eyes. (That really expensive pair of fancy sunglasses that you wear at the beach won’t do!)
Libraries throughout Illinois are giving away glasses for eclipse viewing. (See a map of those libraries at Spacescience.org.)
If you buy glasses (simple cardboard frames cost a few dollars online or at drugstores), look for a pair bearing the “ISO 12312-2” designation, along with the manufacturer’s name and address. Avoid glasses that are more than three years old and those with scratched or wrinkled lenses. NASA has urged people to go with reputable manufacturers, listed here by the American Astronomical Society.
What happens if I don’t use proper eyewear?
It’s not pretty. You can lose your vision temporarily (a few months to a year), even permanently.
Vision science expert Ralph Chou told National Public Radio that when any part of the sun is uncovered—even just a tiny crescent—the light can burn the back of the eye. Even making quick glances, off and on, at a partial eclipse can add up and cause damage. Here’s the icky part: With these types of injuries, he says it’s typical for people to go to bed thinking everything is fine—and then wake up the next morning not being able to see.
“Everything is really, really badly blurred right in the center of their vision,” he told NPR. “So they can’t read. They can’t see faces. They can’t see road signs.”
The bottom line: Don’t take any chances. So get the right glasses—and have fun!
If I can’t get down to Southern Illinois, what can I do where I live?
Eclipse celebrations are happening everywhere. Chicago’s Adler Planetarium, for example, is holding an eclipse block party to view the partial eclipse. Check out these articles on eclipse-related events in Northern Illinois and Southern Illinois. (Also, read this nice list of the best places to view the eclipse.)
Bonus Question: How will the eclipse affect solar power?
While relatively little solar capacity lies in the “path of totality,” the obscured sun, and sudden drop in solar capacity, will cause some issues at the 1,900 utility-scale solar power plants in the U.S. But those should all be manageable, and the North American Electric Reliability Corporation (NERC) says it doesn’t expect the event to create reliability issues for the overall power system.