This March 9, 2016 file photo shows a total solar eclipse in Belitung, Indonesia. A solar eclipse will be visible from Lawrence on Aug. 21.

A little primer before Aug. 21’s solar eclipse.

What’s the big deal, anyway?

Barbara Anthony-Twarog, a professor of physics and astronomy at the University of Kansas, has been asked that question a lot lately. But she was kind enough to humor the Journal-World by answering our layman’s queries anyway.

“It is true that this is the first time in about a century that a total eclipse has been visible in the United States,” says Anthony-Twarog, before that quipping that she’d “be happy if it’s successfully over in another week or so.”

As ubiquitous as it’s become this summer, media hubbub surrounding the Aug. 21 eclipse is very much warranted, Anthony-Twarog says. A total eclipse (we’ll be getting very, very close to that in Lawrence) occurs when the moon passes between Earth and the sun, blocking out the sun entirely.

“If you’re in the path of totality, it’s not just better or longer — it’s actually really different,” Anthony-Twarog says. “If it’s totally eclipsed, it is a unique experience. There will be people who will go to extraordinary lengths to get somewhere in the path of totality.”

Sticking around Lawrence will be good enough for her, and she’s hoping for beautiful weather. If it’s overcast or rainy, there’s not much we can do, says Anthony-Twarog, aside from catching broadcasts on the Weather Channel and watching NASA’s live stream, among other viewing options — though Anthony-Twarog expects many of the online videos will be “pretty jammed up” the day of.

At the onset of the eclipse, temperatures will begin to drop, stars will begin to appear in the sky, and the natural world (birds suddenly stop chirping, for example) falls out of its normal routine.

“It’s going to be like a long twilight starting at 11:40 or so, and getting a little bit darker and darker,” Anthony-Twarog says, “And half the sun will be covered by 12:30.”

Anthony-Twarog isn’t sure, but thinks we might be able to see planets as the sky gets darker. She’s fairly certain that folks viewing the total eclipse will be able to see Venus and possibly Mars.

Where to watch

While Lawrence doesn’t fall directly on the eclipse’s path of totality, we’re still pretty darn close — at maximum, you’ll see 99.3 percent of the sun’s surface covered, says Anthony-Twarog.

In short, there’s not a bad view in town. But if you want to make it a social event, your best bet might be Shenk Sports Complex, where several KU entities are teaming up with the American Astronomical Society to host “The Eclipse at KU: A Community Event.”

Everyone’s invited to the free viewing party, slated for 11:30 a.m. to 1:30 p.m. Aug. 21 at Shenk, near the intersection of Clinton Parkway and Iowa Street. Before the eclipse, expected to peak around 1:07 p.m., check out science and art activities with the staffers from the Spencer Museum of Art, Lawrence Public Library and the KU Natural History Museum. Astronomers will also be on hand with telescope viewing.

Forget to buy your eclipse glasses? Viewing methods — including safety glasses and specially designed telescopes — will be available for visitors, provided by the AAS, Google and KU.

Ad Astra Food Truck, Kona Ice and Torched Goodness will also be selling refreshments around the complex. Other than cash for food, event organizers suggest bringing a blanket or lawn chair, sunscreen and a hat, water and a sense of wonder.

Related event

Learn more about the eclipse before it happens at “The Great American Eclipse of 2017,” a panel presentation hosted by the Lawrence Public Library. Bruce Twarog, KU professor of physics and astronomy (also Barbara’s husband), will help lead the discussion on the science and significance of this month’s solar eclipse. And if you haven’t gotten your special specs yet, the library will also have about 250 pairs of eclipse glasses on hand for those who drop by.

How to watch it

“Safely” is the short answer. Yes, those funny-looking eclipse glasses are necessary, says Anthony-Twarog, though accidentally catching a glimpse of the sun Aug. 21 won’t hurt your eyes any more than briefly glancing at the sun any other day, she adds.

So, wouldn’t a pair of regular sunglasses work just fine?

“Absolutely not,” says Anthony-Twarog, whose department at KU is providing Lawrence Public Schools students with the special eclipse glasses. Normal sunglasses aren’t designed to block the amount of light generated by the sun, she says, while eclipse glasses “block out probably all but a tiny fraction of the light that passes through them.” The 3-D glasses you buy at the movie theater, similarly, won’t do any good.

Solar glasses have been available at local Dillons stores for several weeks now. The Lawrence Public Library also has a small amount for those who attend its Aug. 20 eclipse event, and KU will have a considerably larger supply for guests at its community viewing party. If you’d rather buy yours online, beware: shady vendors selling counterfeit (hence unsafe) eclipse glasses are all over the internet right now.

Before rocking a pair — and potentially frying your eyes — on the day of the eclipse, make sure your glasses are safe first. Some of these counterfeit shades look pretty convincing, says Anthony-Twarog.

“I’ve been telling people, if you can see anything through those glasses except the sun and the daytime sky, then you shouldn’t be using them,” she says. Lenses on legitimate eclipse glasses are much, much denser and harder to see through.

Only a handful of manufacturers make certified eclipse glasses and handheld solar viewers meeting international standards: Rainbow Symphony, American Paper Optics, Thousand Oaks Optical and TSE 17.

The American Astronomical Society has also published a list of science organizations, retail chains and online vendors selling the glasses. Retailers on the list with locations in Lawrence include Walmart and Best Buy, but you can check out the full list at www.eclipse.aas.org.

No glasses? There are plenty of cheap and easy ways to safely view the sun without special shades. A homemade pinhole camera, Anthony-Twarog says, is “one of the safest ways, especially if you’ve got small children.” For instructions on how to make your own, along with other resources on the upcoming eclipse, visit www.physics.ku.edu/theeclipseatku.