SAN ANTONIO – San Antonio and the Hill Country are in the path of two eclipses within six months.
The first will be an annular eclipse. On Oct. 14, the moon will pass in front of the sun, creating a halo or “ring of fire” in the sky.
So, you may be wondering about how you can safely view the eclipse.
Remember those eclipse glasses from The Great American Eclipse in 2017? You’ll need another pair.
The 411 on the viewing glasses
The sun is never completely blocked by the Moon during an annular solar eclipse. Therefore it is never safe to look directly at the sun without specialized eye protection designed for solar viewing. Even when 99% of the Sun’s surface is obscured, the remaining sun is still intense enough to cause retinal burn, experts say.
If you’re going to be watching the eclipse directly, you’ll need eclipse glasses. And make sure you check the safety authenticity, to ensure the glasses meet the basic proper viewing standards that NASA recommends on its website.
Eclipse glasses and hand-held solar viewers should meet all the following criteria:
- Have certification information with a designated ISO 12312-2 international standard
- Have the manufacturer’s name and address printed somewhere on the product
- Not be used if they are more than three years old, or have scratched or wrinkled lenses
- Viewers of the eclipse should not use homemade filters or ordinary sunglasses — not even very dark ones — because they are not safe for looking directly at the sun.
NASA’s partner, the American Astronomical Society, has verified manufacturers that are making eclipse glasses and hand-held solar viewers that meet the ISO 12312-2 international standard. You can check out the full list on their website.
The American Astronomical Society says modern eclipse glasses with the ISO 12312-2 designation do not expire as long as they have no punctures, scratches or tears, and the filters/lenses remain attached to the frames.
Are there any alternatives to the glasses?
You could try a pinhole projection if you want to see the partially eclipsed sun.
Here’s how you do it: Cross the outstretched, slightly open fingers of one hand over the outstretched, slightly open fingers of the other. With your back to the sun, look at your hands’ shadow on the ground. The little spaces between your fingers will project a grid of small images on the ground, showing the sun as a crescent during the partial phases of the eclipse.
Otherwise, the only safe way to look directly at the uneclipsed or partially eclipsed sun is through special-purpose solar filters, such as the eclipse glasses, or hand-held solar viewers. Homemade filters or ordinary sunglasses, even very dark ones, are not safe.
It’s also unsafe to look at the sun through an unfiltered telescope or binoculars because optical instruments intensify the light.
A few ground rules
- Always inspect your solar filter before using it. If you find it’s scratched or damaged, don’t use it. Read and follow any instructions printed on or packaged with the filter. Always supervise children.
- Stand still and cover your eyes with your eclipse glasses or solar viewer before looking up at the sun. After glancing at the sun, turn away and remove your filter. Don’t remove it while looking at the sun.
- Do not look at the sun through an unfiltered camera, telescope, binoculars or other optical device. Similarly, do not look at the sun through a camera, a telescope, binoculars or any other optical device while using your eclipse glasses or hand-held solar viewer. The concentrated solar rays will damage the filter and enter your eyes, causing injury.
The annular solar eclipse will carve a path from Oregon to the Gulf of Mexico. Here in San Antonio, the partial eclipse will begin at 10:23 a.m. and end at 1:33 p.m. The peak of the event — the full annular eclipse will last for a little more than 4 minutes from 11:52 a.m. to 11:56 a.m.
When October’s astronomical event is over, you might want to hang onto your glasses. Parts of San Antonio and the Hill Country are in the path of another solar eclipse in April. That one will be a total solar eclipse on Monday, April 8, 2024!