What Is a Solar Eclipse?

In the hours leading up to 3 p.m. on Monday, April 8, students, faculty and curious visitors from the Orlando community will head over to UCF’s iconic Reflecting Pond to marvel at the solar eclipse.

“Scientifically, it’s a rare event,” says Professor of Physics Yan Fernandez. “Philosophically, it’s a bonding opportunity.”

This is why there will be telescopes, protective glasses, TV displays and tables set up at UCF’s most visible outdoor gathering spot. Fernandez will be watching and bonding, too, but a thousand miles from campus. He and about a dozen others from UCF’s robust space research community are traveling to remote areas of Texas, Indiana and Mexico. Fernandez and his wife, Professor of Technical Communication Sonia Stephens, will tuck themselves into the southeast corner of Oklahoma, where he can do the type of experiential research that’s rarely attainable.

“We learned a few lessons from the eclipse in 2017,” Fernandez says.

We’ve come to him with questions about eclipses, but let’s start there, with a lesson learned.

What did you learn seven years ago?
An eclipse like that hadn’t happened in this part of North America in decades. That’s what makes the April 8 event unique — you’d normally wait almost a lifetime for an eclipse of such magnitude. In 2017 my wife and I traveled to Nebraska to watch from the path of totality, but thousands of people had done the same thing. When the sky started to cloud up, we were lucky enough to avoid the worst traffic and drive to a better spot to actually see totality. But afterward we were caught in traffic jams. This time we’ll be in a rural area where we can move around easier. That’s a tip for anyone — watch the forecast and move if necessary.

In your words, what exactly is a solar eclipse versus a lunar eclipse?
A solar eclipse is a really precise alignment of the sun, moon and Earth. It’s so perfect that the moon passes directly between the sun and Earth, casting a dramatic shadow on us. With a lunar eclipse, Earth passes directly between the sun and moon, with Earth casting a shadow on the moon.

You’re traveling to the “path of totality.” Explain that.
It’s the geographical line on Earth where the sun is completely blotted out behind the moon. If you’re on that line — on an arc from northwest Mexico to northern Indiana and into New England — you experience the weird darkness of a total solar eclipse. Orlando is off the path, so the sun will only be partially blocked by the moon. That’s a partial solar eclipse.

How will this eclipse compare to the 2017 eclipse in Orlando?
The moon blocked about 80% of the sun in 2017. This time the sun will be about 60% blocked. One of the advantages of being in Orlando for a partial eclipse is that you can see it for more than an hour. In the path of totality, you only see the sun totally eclipsed for about four minutes — although totality for even a short time is far more amazing than 99% partiality.

As an astronomer, you’ve seen a lot of phenomena. Why is a solar eclipse special?
To me, it’s the most awe-inspiring sight you can see. When I was a kid, our family would sail on Chesapeake Bay at night and look at the stars against the dark sky. I remember looking for Halley’s Comet through a telescope in 1986 — a once-in-a-lifetime event. And then as a researcher, I spent time studying asteroids from the top of Mauna Kea on Hawaii’s Big Island. All of those are fun and interesting, but nothing compares to a total solar eclipse.

If someone says, “Maybe I’ll watch, maybe I won’t,” what do you say?
Why wouldn’t you? It’s the easiest way to see an astronomical spectacle. All you have to do is go outside with protective glasses and look up. Unless it’s cloudy, as long as you have the right protection there’s no way not to see it. You don’t need optical aids, like a telescope. Ultimately, I think all of us should look up at the sky more often — whether there’s an eclipse or not.

Why do you want people to look at the sky more often?
The eclipse is special, but there are a lot of interesting things to see on a regular basis. Bright planets. Peculiar clouds. The International Space Station flies over us all the time. People travel to Central Florida from around the world to watch rocket launches that we can watch without going anywhere. Curiosity about the world and the worlds around us is always a good thing.

Have you wondered what solar eclipses must have been like without scientists forecasting them in advance?
It would have been horrifying to see the sun disappear. There were probably a lot of people with eye damage. It doesn’t take long to look at sun and burn the retina.

You’ve mentioned protective eyewear. What do you recommend?
Sunglasses aren’t enough protection. It’s the infrared, not just the visible light, that can damage the eyes. Use special eclipse glasses. Be careful of counterfeiters. A pair for 50 cents might not do the job, but you don’t need to spend $30 either.

For those of us staying in Florida, what’s one more piece of advice?
Do not go toward Miami — that’s the wrong direction. If you travel at all, go northwest. Most importantly, don’t drive into a rain cell. That’s the only way to see nothing at all.

How long will we need to wait for the next solar eclipse?
From Orlando, the next partial solar eclipse will be visible in January 2028, but it won’t be as deep as the one on April 8. For this much sun blockage, we’ll have to wait until January 2038 — that one will be in progress close to sunrise. The big one in Orlando, where we’re in the path of totality, will be in August 2045.

Like you said, get outside and look up on April 8.
And watch it with other people. Watch with friends. Watch with your spouse. Watch with kids. It’s why we invite everyone to watch from the Reflecting Pond. Moments like this are more memorable when you experience them with others.