On Aug. 21, North America will witness its first total solar eclipse since 1979. The total eclipse will be visible in a 70-mile-wide band running from Oregon to South Carolina.
In northern Wisconsin, we will see a partial solar eclipse. States in the path of totality or “totality zone” include Nebraska, Missouri and Illinois. According to the U.S. Naval Observatory Solar Eclipse Calculator, the eclipse in the Wausau area will begin at 11:50 a.m. and end at 2:34 p.m. The maximum eclipse will occur around 1:13 p.m., when about 80 percent of the sun will be blocked by the moon.
Wherever you plan to view the eclipse, you should take the necessary precautions to protect your eyes from permanent damage. There are several options for safe viewing.
One method is to use a pinhole projector. Using a thumbtack or hole punch, you can make a pinhole projector by punching a small, circular hole in a piece of paper or cardstock. Put your back toward the sun and hold the projector a few feet above the ground, then look at the shadow. Instead of a circular bright spot within the shadow, you will see a crescent shape. (Do not look toward the sun through the pinhole, as this may damage your eyes.) NASA’s eclipse website (see below) has other suggestions for fun activities with projectors.
Another option is to use eclipse glasses, made with a special material that filters out ultraviolet and visible light. While wearing such glasses, you can view the eclipse directly. Eclipse glasses are not the same as ordinary sunglasses, which should not be used to view the eclipse. Visit https://eclipse.aas.org/resources/solar-filters for more information on finding eclipse glasses that meet international safety standards.
If you are fortunate enough to be somewhere inside the totality zone on Aug. 21, you can safely view the eclipse with the naked eye during the brief window of totality. NASA’s eclipse website has a guide showing when you can safely remove your eclipse glasses.
Viewing a total solar eclipse is a much richer experience than viewing a partial one, so if you can make it to the path of totality, I recommend doing so. With the sun fully blocked by the moon, the daytime sky becomes nearly as dark as night, and stars and planets become visible. You can also see the sun’s corona — the wispy outermost part of its atmosphere.
For more information about the eclipse, check NASA’s official website, eclipse2017.nasa.gov.
The next chance to see a total solar eclipse in the U.S. will be in 2024.
Happy (and safe) viewing!
Bradley Peterson is an assistant professor of physics and astronomy with the University of Wisconsin Colleges. He is based in Rice Lake.
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