SAN DIEGO — A highly-anticipated solar eclipse will be visible from numerous U.S. states on Saturday, creating a “ring of fire” as the moon passes in front of the sun.
Called an annular eclipse, the spectacle is different than other types of eclipses, as the moon will be at its farthest distance from earth on its ellipse-shaped orbit when it moves to block the light from the sun.
When it is at this distance, known as the apogee, the moon’s positioning blocks less of the sun, causing a bright ring effect around its shape.
“When an object is closer, it occupies a greater angle in the sky than when it’s further away,” explained Douglas Leonard, associate professor of astronomy at San Diego State University. “What you’ll get is the moon blocking the sun, but there will be a ray of the solar disk around the moon that’s still visible. It’s called the ‘Ring of Fire.’”
However, the ring will only be visible in the U.S. across a roughly 150-mile-wide tract, known as the “path of totality,” running diagonally from Oregon to Texas. In California, only residents living in towns at the very tip of the state may catch a glimpse of the eclipse in perfect alignment.
A map of the path where the ring with the annular eclipse will be seen is below.
While Southern California is outside the eclipse’s path, San Diegans will still get to enjoy a partial view of the phenomenon.
“If you’re not quite on that line, like we are in San Diego, that just means the moon will be slightly offset as it passes around the sun,” said Dr. Adam Burgasser, professor of physics at UC San Diego. “We’ll still get a blockage of the sun, but it won’t be as full as that kind of line across the globe there.”
Projections of the eclipse’s movement estimate that there will be a roughly three-hour period from 8 a.m. to 11 a.m. Saturday morning where San Diego residents will see the moon pass in front of the sun, reaching its maximum coverage around 9:26 a.m.
During its peak in the region, the moon will cover about 68 to 75% of the sun, creating a sort of “crescent sun” before it continues on its path. The blockage will also likely make a perceptible difference in the sky, dimming and changing the color of light slightly.
“A solar eclipse is a very exciting event … particularly when you have this much blockage, even in San Diego, it will get noticeably dark,” Burgasser continued. “You will notice the environment change a little bit.”
What’s the best way to see Saturday’s eclipse from San Diego?
For those looking to catch a glimpse of the eclipse, experts suggest finding a spot with clear skies and a direct view of the southeastern sky. As Burgasser explained, viewing locations that have any type of cloud cover are likely to obstruct your view of the eclipse.
Although, there’s no need to head up to the mountains or into rural East County unless that’s your preference, given that the sun will be relatively high in the sky at the time of day when the eclipse reaches its peak.
If you plan on watching the event, it’s important to note that you should not look directly at it — unless you have special solar eclipse glasses that are certified ISO 12312-2, meaning they have a darker tint than average sunglasses. Experts say that looking at it with bare eyes can severely damage your vision.
Solar eclipse glasses can be purchased online, but be sure to double check a listing’s certification to make sure they’re not counterfeit. Several stores throughout the county, like the Fleet Science Center in Balboa Park, also have them available.
For those that are not able to get their hands on a pair of glasses, there are other creative ways to enjoy the eclipse indirectly, such as holding up a piece of thick paper or cardboard with a tiny hole to the sun that will cast a shadow of the sun’s shape. According to Leonard, some trees will also do this naturally with their leaves.
When will the next visible eclipse be for San Diego?
Visible solar events like Saturday’s eclipse are quite rare, occurring every five to 10 years in any given place.
As Leonard explained, the moon passes directly in front of the sun at least twice a year, but its concurrent orbit with the Earth makes it so each event’s path of totality is unique. In other parts of the world, people may be able to see an eclipse while it’s a “normal” day in San Diego.
In a few months, though, San Diego is going to get another partial view of a total eclipse on Apr. 8, 2024 that will pass northeast from Mexico through Texas, up towards New York and Canada. After that, the next solar eclipse visible from San Diego won’t be until 2029.
When in the path of totality, total eclipses are generally more exciting spectacles than the annular eclipse, Leonard says, since it’s a complete coverage of the sun. However, Saturday’s eclipse will be a slightly better viewing for San Diegans than the Apr. 8 event.
Projections for the Apr. 8 eclipse estimate that the moon will block about 54 to 62% of the sun.
“Either way, it’s exciting,” Leonard continued. “These things don’t happen very often where you don’t have to go somewhere else to see it … People should make a little effort to, to go witness it.”