Here’s how to safely observe the solar eclipse

The eclipse is now less than a month away, so this article repeats and expands on the safe-observing article from last fall.

Think about how hard it is to stare at a 100-watt light bulb. Now imagine staring at millions of 100-watt bulbs. That’s only a fraction of how bright the sun is. Imagine the damage that would do to your eyes. So how can you see an eclipse without hurting your eyes?

You want to reduce the brightness of the sun and the effect of infrared and ultraviolet radiation both of which can damage your eyes. So how can you observe safely?

By eye

Don’t use sunglasses. They don’t reduce the brightness or block the infrared and ultraviolet rays enough to be safe.

Welder’s mask: You can use one if it meets the specs described at bit.ly/3PeF4Vz and is in good shape with no scratches, but it’s less trouble to just use eclipse glasses.

Eclipse glasses are simple and inexpensive. They usually have a cardboard frame with filters where the lenses would be. For some examples, search for “NASA approved solar eclipse glasses.”

I just bought a 10-pack for $22.95 plus shipping. Ideally, get glasses that are individually wrapped in plastic and keep them in the plastic until the eclipse. You may also find them locally. The Morrisville library has a limited number of glasses to give away. I’ll be giving a presentation on the eclipse at the Morrisville library on Wednesday, March 20, when I’ll have a limited number of glasses to give away.

Be sure to check your glasses for scratches. Elaine Fortin of Lamoille County Star Gazers says “to test any solar viewers and glasses, hold them up to the sun on a bright day for just a second. If you see any bit of light besides the sun, the glasses are no good. Throw them away and don’t let anyone else use them. They must block out everything except the sun, and even then, no bright spots.”

Binoculars or telescope

Observing through binoculars or a telescope can provide spectacular views of the sun during the eclipse and at other times, when, with the right equipment, you can see sunspots and solar flares. However, observing this way also increases the risk because it concentrates the light that hits your eyes. This concentrated light could also make a telescope or binoculars catch fire. So, a few suggestions:

• Contact the manufacturer of any device you’re using to buy add-on filters that fit over the front of your device and follow the instructions. Make sure that any add-on filters are the proper ones for your device. Third-party filters may not be suitable for your specific device.

• Always keep these devices under your control. The last thing you want is for a child to look through the eyepiece or the finder — the little aiming telescope — and suffer eye damage.

• If you own an old telescope, it may come with a filter marked something like “solar eyepiece” or “sun” that is supposed to screw into the eyepiece. If you do, throw it away. These eyepieces can crack and let in a full blast of sunlight.

Smartphone camera

You can take a photo or selfie of the eclipse with a phone. See NASA’s recommendations at bit.ly/3s7z3RQ.

However, other webpages like space.com’s “Can You Photograph the Solar Eclipse with Your Phone or Tablet?” (bit.ly/48NP6nx) note that safely photographing the eclipse requires adding a solar filter to your phone, remembering when to put it on and take it off, and not inadvertently looking at the sun while aiming the phone. It’s certainly do-able but having to remember all the steps while viewing the eclipse is a risk. In my opinion, better to be safe and look at the sun through the eclipse glasses.

Unusual ideas

You can make a pinhole projector by cutting a small square, say 2-inch by 2-inch, out of a piece of cardboard, taping aluminum foil over the square and poking a small hole in the foil with a pin. You can then hold the projector facing the sun and a piece of cardboard a foot or so behind the pinhole. Do not look through the pinhole! The image of the sun will be very small but visible.

You can face a metal colander, like the one you use to drain spaghetti, at the sun. Each hole acts like a pinhole camera so you’ll see multiple small images of the sun. Sort of a disco ball effect.

Finally, if you’re a do-it-yourselfer and have an old pair of binoculars, an 8-foot, 2-foot by 2-foot board, and a strong tripod, you can build a techie version of the pinhole projector that gives a larger image. It’s good for group viewing if you’re having an eclipse party. If you’d like to try this, pick up the April issue of Sky and Telescope magazine and see page 72 for instructions on how to create “The Eclipsinator.” Note, however, that there’s a risk of the binocular’s innards melting.

A solar eclipse is a dance between two heavenly bodies 250,000 and 93 million miles away, as Peoples Academy teacher Rita Ciambra described in an article last year. Eclipses happen fairly often but having one right overhead is rare. Make it memorable for the experience, not for the eye damage.

For further information, go to bit.ly/4452y3Z.

Neil Perlin is a retired computer consultant, a long-time amateur astronomer, and a member of the Lamoille County Star Gazers.

Lamoille County Star Gazers is a group of amateur astronomers from Morrisville, Hyde Park and Elmore. The group holds public observing sessions at the observatory at Peoples Academy and other special events to look at the sun, moon, planets and more. If you own a telescope and want to use it with a group of like-minded people, come observe with us. You don’t need to be a scientist; you just need to be curious about what’s in the sky. To learn more, email lcvtsg@gmail.com.