by Samantha Reif, associate professor, Lincoln Land Community College
On Monday, Aug. 21, the U.S. will be host to a spectacular phenomenon, and Illinois is the star of this astronomical show.
A total solar eclipse will be visible in a swath that stretches from the Pacific Northwest all the way to the East Coast. Though eclipses happen regularly, the last that was visible anywhere in the continental U.S. was in 1979; here in Illinois, 1918.
As astronomy professor at Lincoln Land Community College, I see this amazing event as a once-in-a-lifetime teaching opportunity. Although it coincides with our first day of classes, we have come up with ways that our students and the community can share in this cosmic dance.
First, a bit of science! The word eclipse refers to any celestial body passing in front of another and blocking its light. On Aug. 21, the moon will pass in front of the sun, blocking its light from reaching Earth. Because of the shape of its orbit, the moon generally does this pass without making an eclipse, but at least once a year, everything aligns just right and the moon gets in the way.
Now, if this alignment is happening, why won’t we see it in Springfield? The reason is that the moon is very small. For it to cover up the whole surface of the sun, you have to be directly below the alignment. Anywhere else, and some portion of the sun’s surface will peek out.
Does this mean that we are left out in central Illinois? No! Here in Springfield, the eclipse will still be visible and its effects will be noticeable. Starting at 11:50 a.m., using eclipse glasses or a pinhole viewer, you will start to see the black disk of the moon takeover the surface of the sun. When the eclipse is at its maximum at 1:18 p.m. here in Springfield, 96 percent of the sun’s surface will be covered. Since all that light is being blocked, the bright midday sunlight will look more like twilight. Even if the day is cloudy, the lack of light will be very noticeable – you might even need headlights!
If you are lucky enough to head south, at totality, the world will be plunged into darkness for about two and a half minutes. At this point, stars will be visible and the sun will appear to have a fiery ring around it (this is actually the glowing atmosphere of the sun that is usually blocked from view by the bright surface). It’s a once-in-a-lifetime experience!
Can’t make it to southern Illinois but still want to experience what a total eclipse is like? You can join me! I’ll be live streaming the eclipse and answering any questions you might have throughout the three-hour event. From approximately 11:30 a.m. – 2:30 p.m., I’ll be going live on Facebook every half hour to show you what the sun looks like, as well as the light around me, and let you experience all the interesting phenomenon associated with an eclipse. You can find these broadcasts through the Lincoln Land Community College Facebook page at www.facebook.com/LincolnLandCommunityCollege. If Facebook isn’t for you, you can come join the festivities on the main campus in Springfield where we plan to show the videos in A. Lincoln Commons, as well as making pinhole viewers so you can monitor the eclipse.
Whichever way you choose, I hope you will take advantage of this amazing experience. I look forward to your questions and comments.
Remember these eclipse safety tips!
It is never safe to look directly at the sun, even during an eclipse (unless you are in the zone of totality).
Sunglasses provide no protection – you will have serious eye damage if you observe the eclipse with sunglasses.
Eclipse glasses can be purchased, or welding glass #14 or higher can be used to directly see the eclipse. (Hint – to check that you have safe equipment, you should not be able to see anything through it unless you are looking at the sun.)
Indirect viewing is safe and easy, and will show you all the details. A pinhole viewer can be made by poking a pin through a piece of cardboard, stiff paper or even a paper plate. Turn your back to the sun, hold your viewer above your head and the shadow will have a perfect image of the sun and the eclipsing moon.