Menomonie On Monday, Aug. 21, central portions of the United States will experience a total solar eclipse when the moon blocks out the sun. Other areas, such as west-central Wisconsin, will have a partial solar eclipse.

Professor Alan Scott, who teaches astronomy and physics at University of Wisconsin-Stout, answered questions about the eclipse, which the National Aeronautics and Space Administration, NASA, calls one of natures most awe-inspiring sights.

Q: What is the solar eclipse?

A: Its the perfect alignment of the sun, moon and Earth. The moons shadow is projected onto the Earth, and the sun is totally blotted out in the region of totality.

Q: Where is the region of totality?

A: It will sweep across the U.S. beginning in Oregon and cut a swath thats about 71 miles wide of total darkness (diagonally through the middle of the country) and exit the U.S. in South Carolina.

Q: How much of the eclipse will be visible in west-central Wisconsin?

A: In west-central Wisconsin, the sun will begin getting a portion of its light blocked at 11:45 a.m. local time. It peaks in blocking about 80 percent of the sun at 1:16 p.m. The partial eclipse will end at 2:31 p.m.

Q: How long will it last?

A: In the region of totality, complete darkness will last about two minutes, and this region travels about 1,500 miles per hour across the surface of the U.S.

Q: How can people safely watch the eclipse?

A: You should not look directly at a partial solar eclipse because a good portion of the suns light is getting through, and it will burn your retina if you look at it for any extended period of time. One should never look directly at the sun. So you need special viewing glasses that are marked eclipse viewing that will protect your eyes. You can look toward the sun in the region of totality during the time of totality because only the outer atmosphere of the sun is observable. This outer atmosphere is not hazardous to directly view with your eyes.

Q: Where do you plan to watch it?

A: I hope to go to St. Joseph, Mo., which will experience the longest period of total darkness. It basically will become just like night. There will be no sun, although you can begin to see the suns outer atmosphere, the corona. The stars will come out. Insects might start chirping. We should see something like twilight 360 degrees around us.

Q: What else makes a total solar eclipse a special event?

A: In the region of totality, one can see star constellations that would never be observable during this time of the year. The planet Mercury will also be observable.

In west-central Wisconsin, unique patterns of crescent-shaped brightness will appear on the ground beneath some trees about the time of peak partial eclipse. This is a result of small openings through the canopy of trees allowing sunlight to pass, acting like a pinhole camera producing such patterns. This is most easily observed on pavement such as a sidewalk.

The last total solar eclipse in the U.S. took place in 1979, and the next one will be in 2024. For more information, go to https://eclipse2017.nasa.gov.

Read more:

Q&A: Astronomy professor prepared for Aug. 21 solar eclipse - Chippewa Herald