Annular eclipse 101: Here’s what you need to know when the eclipse passes through San Antonio

A “ring of fire” will cut a path across San Antonio on October 14

It’s an exciting time for San Antonio and surrounding areas, with two big celestial events passing through South Central Texas in less than a year. An annular eclipse occurs on October 14th, while a total solar eclipse will move across the area on April 8th, 2024. First things first, we spoke to an expert who shared what you need to know for the annular eclipse on the 14.

  • An annular eclipse differs from a total eclipse due to the moon’s distance from the earth
  • The Oct. 14 eclipse will produce a “ring of fire” during its peak, known as annularity
  • The partial eclipse begins at around 10:24 a.m., with annularity starting at 11:52 a.m., peaking at 11:54 a.m., and ending at 11:56 a.m.. The duration of annularity is only around 4 minutes in San Antonio. The entire eclipse event will end at 1:33 p.m. For times outside of San Antonio check here.
  • Protective glasses will be needed through the ENTIRE event to protect your eyes, or you can use a pinhole projector to watch the event

While April’s total solar eclipse is grabbing many of the headlines, you won’t want to sleep on the annular eclipse.

“This may be your only chance to see this and it’s an incredible thing to see,” explained Angela Speck, chair of the Department of Physics and Astronomy at UTSA and the Co-Chair of the National Solar Eclipse Task Force. “It looks like there’s a hole in the sun.”

That is the difference between an annular solar eclipse and a total solar eclipse. In a total eclipse, like what we’ll see in April, the moon will completely block out the sun.

“Sometimes [the moon] is just a little bit further away from us,” explained Speck. “Its orbit isn’t perfectly circular and so, when it’s a bit too far [away], you can still see the edge of the sun.”

That’s what we’ll see on October 14. So, then why is called an annular eclipse?

”An annulus is a fancy word for donut, so that’s what we call the eclipse when we can still see the edge of the sun or the ring of fire,” said Speck.

Even at its peak, which will occur around 11:54 a.m., you’ll still need protective glasses. You can buy them at just about any box store. Keep in mind that they need to be certified with the ISO 12312-2 designation, have no punctures, scratches or tears, and the filters/lenses remain attached to the frames.

Homemade pinhole projectors can serve as a nice addition to, or as an alternative to glasses. And, if you plan to use telescopes and binoculars, don’t forget to attach a solar filter. This goes for cameras, too. If all else fails, Speck points out that you can find a tree and look down.

”Look under a tree. Because what happens is that all the little gaps between leaves make little apertures and so you get images of the sun on the ground,” explained Speck. “That happens every day. But, on a normal day, the sun is just a circle. On eclipse day, it’s a crescent. So, you see all these little crescent suns on the ground under the trees.”

It’s also worth noting that the temperature drops during an eclipse. During a total, it can drop close to ten degrees, depending on the current temperature and humidity.

”[During] an annular eclipse, you’ll still feel that change in temperature, it’s enough, it’s more than a cloud going in front of the sun, but it’s not like the total,” said Speck.

And speaking of clouds — they could be a real problem.

”Am I nervous about clouds?” asked Speck. “I’m always nervous about clouds!”

Unfortunately, we won’t know the forecast until we get closer to the event and we’re updating the forecast often. Clouds wouldn’t completely ruin the experience, but they would take away from the once-in-a-lifetime event.

Meantime, you may notice that during the eclipse’s peak wildlife may start to act weird.

”Birds will do the things that they do after sunset,” explained Speck. “So, after the sun sets, but before it gets dark, they do the swooping around thing and they make a lot of noise.”

Lastly, you’ll want to start making plans now, with plenty of out-of-town visitors expected to head our way.

Check out the interactive map created by the Eclipse Company in partnership with The Planetary Society:

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About the Author:

Justin Horne is a meteorologist and reporter for KSAT 12 News. When severe weather rolls through, Justin will hop in the KSAT 12 Storm Chaser to safely bring you the latest weather conditions from across South Texas. On top of delivering an accurate forecast, Justin often reports on one of his favorite topics: Texas history.