Sun show

UWL retired Physics Professor Bob Allen expects the upcoming solar eclipse — with 87 percent partial totality in La Crosse — will cause street lights to come on mid-day.

Aug. 21 eclipse will be historic

La Crosse area residents will join those from around the country Monday, Aug. 21, heading outside for the first total solar eclipse in the continental U.S. from coast to coast in about 100 years.

In La Crosse, there will be about an 87 percent partial solar eclipse, while those in a narrow band from South Carolina to Oregon will see totality.

“If it’s clear out, the street lights will come on in La Crosse,” predicts UWL retired Physics Professor Bob Allen. “If it’s cloudy, there will still be some strange lighting.”

The eclipse will start around 11:45 a.m., with the maximum coverage at mid-eclipse around 1:10 p.m. The astronomical show ends around 2:30.

The La Crosse Area Astronomical Society plans to hold a viewing area in La Crosse’s Riverside Park during the eclipse. Allen won’t be there — he and many other astronomy enthusiasts are going out-of-town to try to see totality.

Allen reminds those heading out to see the eclipse that it is not safe to look directly at the sun without proper filters for protection, even around mid-eclipse here. “It is not safe to use sunglasses or exposed film negatives,” he notes.

Rather, a good way to view the partial phases is to use pinhole projection with two pieces of cardboard. “Put a small hole in the front one and hold the back one at various distances from the front one to see an image of the sun,” he explains. “Binoculars can also be used to project an image onto a piece of cardboard.”

Allen says telescope owners use Mylar or glass solar filters in front of their scope. Society members plan to have some eclipse glasses available during the Riverside Park observation. Also, No. 14 welder’s glasses can be used to safely view.

Allen says it’s probably too late now to order filters and glasses with the recent rush to buy them.

To prepare for the event, the UWL Planetarium has been holding a special public program, “A Total Solar Eclipse Experience,” at 1 p.m. Saturdays through Aug. 12.

Allen says the most recent eclipse that went from coast to coast was 99 years ago. In 1979, there was a significant partial eclipse in the continental U.S., and in 1991 in Hawaii. He traveled to witness both. The next glimpse of totality across the U.S. will be in 2024.

Here are a few websites to help you prepare for viewing an eclipse:

Projection: Pinhole & Optical
How to Safely See a Partial Solar Eclipse – Sky & Telescope
Solar Filters (“White Light”) – Thousand Oaks Optical