For Science! How does a Solar Eclipse work?


Only a few days left until one of the greatest astronomical events in nearly 100 years -- a total eclipse of the sun!

On Monday, millions of people will witness an eclipse that happens only a few times a lifetime. A total solar eclipse will occur coast-to-coast, moving from Oregon to South Carolina.

While Michiana won't experience a total solar eclipse, just under 90-percent of the Sun's light will be blocked Monday afternoon.

"It is pretty rare to get a total eclipse of the Sun in the United States,” said Dr. Peter Garnavich, Chair of the Physics Department at Notre Dame.

He describes the upcoming solar eclipse as a perfect dance between the Sun, Moon and Earth. An eclipse occurs when the Moon passes directly between Earth and Sun, causing the Moon's shadow to be cast onto the Earth.

The path of totality is a narrow band, only about 70-miles wide, where 100-percent of the Sun’s light is fully blocked for two minutes. Even though we are not in the path of totality, don't underestimate the significance of what you’ll see.

“90-percent of the Sun will be blocked by the Moon,” says Dr. Garnavich. “It will get dark, it might even get cool, and then there will be a crescent sun you'll see for about a half an hour.”

Dr. Garnavich and his students have been preparing for this event for months. They’ll utilize the 1890-era telescope on top of Nieuwland Science Hall.

Keith Davis teaches education programs at the planetarium at Notre Dame. He’s traveling to the path of totality, but says it’s not just about looking up at the Sun but taking in the entire environmental event.

"One of the things that is really interesting, is that every little hole between leaves is a pin hole camera and will project an image of the eclipse on the ground,” says Davis. “So look at the shadows, because they will be dramatic and interesting."

While the eclipse will be something you and your kids remember for years to come, it’s extremely important to remember that it can cause permanent damage to your eyes if you don’t plan ahead.

"The only reason the eclipse is dangerous is because you want to look at it,” says Keith. “You normally can't look at the Sun safely because it is so bright and keeps you from looking. When you take that brightness down to 10-percent, it is bright enough to damage your eyes but it doesn't feel as painful so you're more likely to look."

There are several ways to view the eclipse. If you have special eclipse glasses, you are set!

How to make your own viewing device: