You’d have to be living on another planet to not know that a special celestial event is happening today: the first total solar eclipse visible in the contiguous United States since 1979.
During this rare and remarkable event, the moon will pass between Earth and the sun at a distance that makes it appear as if the diameter of the moon is larger than that of the sun, thus blocking all direct sunlight. For a few eerie minutes, day will become night, temperatures will drop, and stars and planets normally hidden by daylight will suddenly pop into view in the sky.
Today’s total solar eclipse will be visible from Eugene, Oregon, to Charleston, South Carolina — but not, unfortunately, here in Minnesota. We’ll have to settle for a partial eclipse, with only about 80 percent of the sun’s surface obscured by the moon. Clouds may also impede our view, according to the latest weather reports.
Yet, the event is still likely to be memorable. For us, it will begin at 11:43 a.m., reach its maximum at 1:06 p.m., and end at 2:29 p.m.
Do step outside during the eclipse. But don’t be tempted to look at the sun directly. Doing so can permanently damage your vision — as 71-year-old Louis Tomososki of Portland, Oregon, knows only too well. In 1963, when he was 16 years old, he glanced up at the sun during a partial solar eclipse for about 20 seconds. It burned a hole in the retina of his right eye (he kept his left eye closed), leaving him with a permanent blind spot in his vision.
“I’m glad I didn’t go 40 seconds,” he told a reporter for a Portland TV station. “It would have been even worse.”
One safe option
As the American Astronomical Society (AAS) points out, there’s only one safe option for looking directly at the sun, whether during an eclipse or not: through special-purpose solar filters. Such filters are used in “eclipse glasses” and in hand-held solar viewers.
Legitimate solar filters must meet a very specific worldwide standard for protection known as ISO 12312-2. Unfortunately, unscrupulous makers of counterfeit eclipse glasses and solar viewers have figured this out, and have stamped the ISO number on their products.
If you’ve purchased eclipse glasses or solar viewers for today’s event, make sure they were manufactured by a reputable vendor. The AAS offers a list of those vendors on its website, as well as other detailed information that can help you tell if the devices you’re using are safe.
If you do not have eclipse glasses or a solar viewer, you may still have time this morning to make a simple pinhole camera for viewing the event. Do not be tempted, however, to risk your eyesight by watching the eclipse through your sunglasses.
“Ordinary sunglasses, even very dark ones, or homemade filters are not safe for looking at the sun,” the AAS warns.
Here are other safety tips from the AAS:
Always inspect your solar filter before use; if scratched, punctured, torn, or otherwise damaged, discard it. Read and follow any instructions printed on or packaged with the filter.
Always supervise children using solar filters.
If you normally wear eyeglasses, keep them on. Put your eclipse glasses on over them, or hold your handheld viewer in front of them.
Stand still and cover your eyes with your eclipse glasses or solar viewer before looking up at the bright sun. After looking at the sun, turn away and remove your filter — do not remove it while looking at the sun.
Do not look at the uneclipsed or partially eclipsed sun through an unfiltered camera, telescope, binoculars, or other optical device.
Similarly, do not look at the sun through a camera, telescope, binoculars, or any other optical device while using your eclipse glasses or handheld solar viewer — the concentrated solar rays could damage the filter and enter your eye(s), causing serious injury.
Seek expert advice from an astronomer before using a solar filter with a camera, telescope, binoculars, or any other optical device; note that solar filters must be attached to the front of any telescope, binoculars, camera lens, or other optics.
If you are inside the path of totality, remove your solar filter only when the moon completely covers the sun’s bright face and it suddenly gets quite dark. Experience totality, then, as soon as the bright sun begins to reappear, replace your solar viewer to look at the remaining partial phases.
Outside the path of totality [and that includes all of Minnesota], you must always use a safe solar filter to view the sun directly.
Be careful out there
If you suspect that you or someone you know may have a damaged retina due to careless viewing of the eclipse, see an ophthalmologist as soon as possible. Symptoms may include blurred vision, particularly central vision, sensitivity to light, and changes in how color is perceived. There is no treatment for the condition, known as solar retinopathy, but the ophthalmologist will be able to assess the extent of the damage.
Of course, as long as you’re careful, you won’t have to worry about such damage.
And being careful also means you’ll be able to view the next total solar eclipse scheduled to fall within the continental U.S. — on April 8, 2024.
FMI: For more information about eclipse safety — and about the eclipse itself — go to the AAS website.