Banner image: Spectators gaze at an annular, or "ring of fire," solar eclipse in October 2023 from the CU Boulder campus. (Credit: Glenn Asakawa/CU Boulder)

On April 8, a once-in-a-lifetime event is coming to parts of the United States. Beginning around 12:30 p.m. mountain time, the face of the moon will completely block out light from the sun, casting a shadow over Texas, then portions of the Midwest and eastern United States.

Colorado will only witness a partial solar eclipse, with about two-thirds of the sun’s surface covered. But it will still be quite a show, said Jimmy Negus, a solar scientist at the Cooperative Institute for Research in Environmental Sciences (CIRES) at CU Boulder. 

Negus works in a National Oceanic and Atmospheric Administration (NOAA) lab in Boulder as part of the Geostationary Operational Environmental Satellites (GOES) missions. These instruments in space keep a close eye on the sun, capturing the tremendous flares that burst out from around the star. This year he’ll observe the eclipse, along with thousands of other people, from the Dallas Arboretum and Botanical Garden.

He gives his take on how people in Colorado and beyond can view the eclipse safely—and why this year’s event is not something you want to miss. 

What’s happening on April 8?

The answer may sound like something from a science fiction film. During a total solar eclipse, our moon, which orbits our planet once every 27 days, completely obscures the surface of the sun. 

You might ask, ‘Well, isn't the moon a lot smaller than the sun?’ And you'd be right. The moon is about 400 times smaller than the sun. However, the moon is also about 400 times closer to Earth than the sun. This allows the moon to completely obscure the solar disk. The shadow from that occurrence is what we see projected onto Earth. 

Where can people see it?

The total solar eclipse is going to travel from west to east. It will start in Mexico and travel through Texas, through Dallas specifically, up toward Oklahoma and Missouri, and then through Illinois, Ohio, Pennsylvania, New York, Vermont and Maine.

What about here in Colorado?

In Colorado, unfortunately, we're not going to see totality. We'll see about 65% of totality. While you might notice some dimming and some shadows, you will never see full darkness like you would with the total solar eclipse. That being said, it's still fascinating to see the interplay between the Earth, moon and the sun.

What is a total solar eclipse like?

I had the wonderful opportunity to see an eclipse in 2017. I traveled to Grand Teton National Park, and I have not seen anything more spectacular since. 

The feeling is indescribable. The sky turns black. Planets and stars are visible. The temperature drops. Animals that are usually active like songbirds go quiet. Nocturnal animals like owls become active.

How can people view an eclipse safely?

It is an absolute must to use solar eclipse glasses anytime the sun is not totally obscured. During full totality, it's safe to remove your glasses and to observe the wonderful sight of the sun’s surface being obscured. But as soon as the moon begins to go off disk, and the sunlight returns, you’ll want to make sure you have your solar eclipse glasses back on.

In Colorado, will we have to wear glasses at all times?

Yes. In Colorado, the sun’s surface will never be fully obscured. That means that the eclipse glasses must be worn at all times to protect your eyes.

How have eclipses been important to people throughout history?

Ancient Chinese civilizations looked up and saw eclipses. They saw dragons consuming the sun. And, in fact, during their eclipses, they banged pots and pans to scare the dragons. For ancient Mesopotamian and Egyptian civilizations, they saw total solar eclipses as bad omens. These events dramatically influenced much of their governmental policies.

What kind of research can scientists do during an eclipse?

During a total solar eclipse, the super bright surface of the sun is obscured. Beyond the photosphere, the sun’s surface, is the chromosphere, which is a less dense atmosphere. There's also the solar corona above that, which is a few million degrees Celsius. A total solar eclipse provides us with a rare opportunity to purely observe the sun's atmosphere.

Do you recommend that people check out this eclipse?

There are very few occurrences here on Earth that can mimic the grandeur of seeing the sun, something we are so used to observing daily, be obscured. I would highly encourage anyone along the path or close to the path to make the effort. Many people who see an eclipse once or twice become lifelong eclipse chasers.