Total solar eclipse coming to United States on April 8: How dark will Daytona Beach get?

It takes the sun's brilliant luminescence eight minutes to travel 93 million miles to light Earth. Except for the two to five times a year when the moon ? in its gravity-obedient revolutions around Earth ? intervenes.

When the sun, moon and Earth are lined up just right, the solar light is blocked, creating a dusk-like experience across a 115-mile-wide swath.

That 4 minutes and 27 seconds is a perfect union of astronomy and physics, so we turned to Terry Oswalt, who teaches both subjects as a professor and associate dean at Embry-Riddle Aeronautical University in Daytona Beach, to talk about the solar eclipse that will be visible across much of North America on April 8.

How will the Daytona Beach area experience the solar eclipse?

"Most people won't notice anything unless somebody tells them because here in Daytona, it will be a near-replay of what we saw in 2017," Oswalt said. "Less than two-thirds of the sun, 63% of the sun, will be covered up."

The partial eclipse begins in our area at around 1:48 p.m. Watch this simulation at https://eclipse2024.org/eclipse-cities/city/9394.html for more exact timing for your area.

The eclipse sky in Daytona Beach will be akin to a partially cloudy day, Oswalt said.

"On the other hand ... the sunlight filtering through little holes, like gaps in leaves and trees and screens and holes in architectural surfaces will cast shadows that are not little pinhole speckles, but little crescents," he said.

Those things will act like small "pinhole cameras, which can form a crude image of the sun."

So what's the fuss about?

Total solar eclipses, however, are the stuff of lore, and they are fairly rare in the United States. The last one was in 2017, and the one before that was in 1979 when only a few Pacific Northwest states experienced totality.

This time, far more Americans should get the full eclipse experience.

"Something like 32 million people in the United States are in the path of totality, which stretches from the Panhandle of Texas all the way up to the New England states, passing through the Midwest, Indiana and Ohio," Oswalt said.

While the next U.S. total eclipse won't be until 2045, it crosses the continent from northern California to Florida, covering much of the peninsula. Daytona Beach is on the northern edge of totality, with Palm Coast falling just outside.

Also inside totality in 2045 will be Tallahassee, Gainesville, Orlando, Tampa, West Palm Beach and just inside the southern edge, Miami.

Where will you be during the eclipse?

Oswalt, who earned a Ph.D. in astronomy from Ohio State University, grew up in the Midwest and said he has only seen one other total eclipse, and since the next one in the United States is 21 years away, he figured he better enjoy this one.

"I plan to go up to Indiana, where I have family in the middle of totality. Indianapolis, for example, is right in the middle of totality," he said.

Why are eclipses so random?

Total eclipses are not only rare, they have a randomness to them. They don’t happen every month. Look at the ones that have crossed the continental United States since 1900. The next one was 1918, then 1923, 1925, 1930, 1932, 1945, 1954, 1959, 1963, 1970, 1979, and then 2017 and 2024.

Oswalt explains it this way:

“The moon goes around the Earth, and the Earth-moon system goes around the sun,” he said. “If you were to put everything on a piece of paper, one single surface, every time the moon was new, between the Earth and the sun, there’d be a solar eclipse. And every time the moon was on the opposite side of its orbit from the sun, there would be a lunar eclipse, when the Earth’s shadow blocks out the Moon.

“But there isn’t. And the reason there isn’t an eclipse of the sun and of the moon every month is because the moon’s orbit is tilted by about 5 degrees from the plane of the Earth’s orbit around the sun," he said. "So the Earth and the moon and the sun all have to be exactly lined up within a half-degree or so for any eclipse to occur. And that only happens when the moon is on the side of its orbit crossing the plane of the Earth’s orbit.”

Think about protection

The human retina is no match for the awesome power of the Sun.

Oswalt would be remiss if he didn't stress the need for caution to view the eclipse.

“You’ll need to have special eye protection in order to view the Sun like that," Oswalt said. "I think it’s important to emphasize that looking at the Sun when it is nearly completely covered is not safe. You could burn the retina of your eye with no pain, permanently damaging your vision in just a second or two. So even glances at the sun with the unprotected eye is not a good idea.”

The American Astronomical Society has a good rundown on eye safety and where you can purchase safety glasses. To check it out, visit https://eclipse.aas.org/eye-safety/viewers-filters.

The physics 'fluke' of Earth's eclipses

Oswalt marvels at the unlikeliness of Earth having solar eclipses as they are.

“It’s kind of a fluke that there are solar eclipses at all, because the sun is about 400 times farther away than the moon, and it’s also about 400 times bigger than the moon, so they look to be the same size in the sky," he said. "And there are probably very few planets out there in the universe that have a moon with that close of a relationship in size that a solar eclipse like this is even possible.”

This article originally appeared on The Daytona Beach News-Journal: How do solar eclipses work? ERAU professor explains 'fluke' of it all