On August 21 people across North America will have a unique opportunity to see a total solar eclipse. It is a very rare event, and especially rare to have so much of the United States involved. The experience itself is worth a considerable drive if you don’t live in a zone of totality.
The Moon is just the right size to cover the the Sun. That means that the shadow of the Moon will fall on a small area of the Earth. Normally the bright photosphere of the Sun overpowers everything else. In a total eclipse of the Sun, the photosphere is covered, and you can see the outer atmosphere of the Sun called the corona. When light from the photosphere shines through a valley on the Moon just before and after totality, a blast of bright light appears to viewers on Earth. It looks like a huge diamond ring.
The sky is not the only place where strange things happen. We enjoyed a partial eclipse when I taught astronomy at Riley High School in South Bend, Indiana. We made a point of telling our 1600-member student body what was going to happen. We set up our telescopes and pin-hole cameras to project the event onto poster board. The principal allowed the whole student body to gather in front of the school.
When the eclipse started, there was the usual teenage horsing around as the Moon began to cover the Sun. All of a sudden the kids got very quiet as it became noticeably darker and you could feel the air become cooler. Dogs started howling as the eclipse progressed. Leaves in the maple tree in front of the school projected small pin-hole images on the sidewalk of the Sun with a chunk missing. We even had a few kids who became disturbed by what was happening. This was not a total solar eclipse, but just a partial eclipse which didn’t cover the entire Sun. Those who live near the path of totality will have the rare experience of seeing complete coverage of the Sun and darkness in the middle of the day.
It is amazing that our solar system is designed in such an incredible way that even high school students with a knowledge of math and astronomy can predict when the eclipse will start, reach totality, and end. The fact that the Moon is just the right size to cover the Sun is remarkable. In the past, humans believed that eclipses were the prognosticators of a coming disaster. For us, the total solar eclipse is simply a wonderful display of the precision and design built into our solar system and the fact that we can understand what God has done by studying the events that we see in the sky.
A word of warning–don’t look at the eclipse with your naked eye. Special eclipse glasses are available. Don’t risk losing your eyesight.
–John N. Clayton © 2017