How to safely observe 2024 total solar eclipse, according to UF astronomy professors

North America will experience its second total solar eclipse in seven years on April 8 – a captivating event that won’t happen again for another two decades. This unique spectacle will sweep across a vast path of totality, starting in Mexico, traveling over the United States from Texas to Maine, and ending on the eastern coast of Canada. How can observers in the Gainesville community and beyond safely view this rare celestial phenomenon? Paul Sell, Ph.D., an assistant instructional professor of astronomy at the University of Florida, and Triana Almeyda, Ph.D., the director of the UF Teaching Observatory, have the answers.

First off, what exactly is a solar eclipse?

Solar eclipses occur when the sun is obscured by the moon. The timing is dictated by the Saros series and happens only when the sun, moon, and Earth are perfectly aligned. Considering the vast distances in our solar system and the moon's orbit, this alignment is rare. The moon's smaller size (relative to Earth), as well as the requirement for the moon and Earth to share the same orbital plane, make a total eclipse even more rare. 

How do scientists predict solar eclipses?

Using the principles of physics, geometry, and our understanding of celestial mechanics (such as the movements of Earth and the moon around the sun, and the tilt of their orbits), we can predict eclipses. By drawing out these geometrical configurations and measuring them with precision, scientists can confidently predict and explain the occurrence of solar eclipses. People have been predicting eclipses with remarkable accuracy for centuries, even in times when the understanding of celestial mechanics wasn't as advanced as it is today. In ancient times, those who could predict eclipses were often revered, sometimes even being regarded as godlike figures due to their seemingly mystical abilities.

What makes the upcoming eclipse so unique?

This eclipse is particularly fascinating because the sun is in a very high activity phase, known as solar maximum. Our sun goes through an 11-year activity cycle, so it takes 22 years for it to come back, and it is now likely at the peak of its cycle. For those within the path of totality, they will experience a brief period of darkness — totality — for a few minutes. This is the only time to look directly at the sun without a solar filter. If you observe the sun’s corona during totality, you may see solar prominences or coronal mass ejections, which look like a twisted, spiral-like structure high in the atmosphere of the sun.

How can observers prepare to view this eclipse safely?

It is not safe to view the eclipse with the naked eye, binoculars, or telescopes. There is a brief exception for those within the path of totality; only during the few minutes of a total solar eclipse, when the sun is completely blocked, is it safe to observe without proper viewing protection. Outside of this specific window, using solar glasses is imperative for protecting the eyes from harmful solar radiation. Specialized solar glasses can block out more than 99% of harmful solar light, and specific welding glasses with designated shades can also provide adequate protection. Additionally, solar projection methods allow viewers to safely observe the eclipse without direct eye exposure. One common method is the pinhole camera technique, where you make a hole in a piece of paper (or use a household item with built-in circular holes, like a colander) and project the eclipse’s image onto another surface for viewing.

Why do you think solar eclipses garner so much attention?

Rare events inherently appeal to human psychology, evoking a sense of wonder and inspiration. The infrequency of such occurrences, like the transit of Venus or Mercury or a particularly stunning meteor shower, amplifies their allure, drawing people from all walks of life to witness these remarkable displays of nature.

What can people in North Central Florida expect to experience during this eclipse?

While no observers in Florida will be in the path of totality, we will see about 60% of the sun covered. The eclipse will start here at around 1:45 p.m. EST, peak at around 3 p.m., and end at about 4:20 p.m. The UF Teaching Observatory will open at no charge to the public at 1:30 p.m., and we will have five optical telescopes with solar filters and two H-alpha telescopes. Our special filter for viewing the glowing hydrogen will allow us to see unique features like the prominences and flares along the edge of the sun. We also will hand out solar glasses. Additionally, experts from the astronomy department – including faculty members, and graduate and undergraduate students – will be onsite to answer questions. For location and parking information (campus weekday parking restrictions will apply), please visit the UF Teaching Observatory website.