How to safely watch the August solar eclipse

CHICAGO (WLS) -- About 87 percent of the sun will be blocked in Chicago early in the afternoon on August 21 when the solar eclipse takes place.

The eclipse begins at 11:54 a.m., reaching a maximum at 1:19 p.m. and ends at 2:42 p.m.

You'll need a pair of special solar eclipse glasses or you can use the old fashioned key hole punch to view the event, but you should never look directly at the sun. Even your sunglasses aren't safe.

It will be the most photographed, studied and witnessed total solar eclipse in American history.

On August 21, the moon will block out the sun. A small strip from Oregon to South Carolina will experience total solar eclipse where 100% of the sun is blocked. Southern Illinois and the Carbondale area will experience the longest time in total eclipse, just shy of three minutes.

At the peak in Chicago, about 87 percent of the sun will be covered by the moon.

The Evanston Public Library is one of several libraries that will be hosting watching parties.

"We feel that it's our job to educate the community so they can be safe and still enjoy this amazing event," said Evanston Public Library Children's Librarian Kim Kaufmann.

It will be a day long party of learning and observing.

They have 120 safety glasses to give out the day of the eclipse.

They also will have ways to make a safe viewing device like this one.

"This is a once in a lifetime opportunity. You can sit in the same spot for 400 years before another solar eclipse will come over your head so the fact we have to share this with our kids is really important," said Kaufmann.

Eclipse watchers are encouraged to preregister if they would like to receive a free pair of glasses.

The Adler Planetarium is also planning a huge watch party, if eclipse watchers can't find a participating library in their neighborhood.

An important warning about the glasses that are for sale online -- many are not strong enough.

Those intending to watch the eclipse need to look for something that says it is "ISO certified" and they come from one of five manufactures: Rainbow Symphony, American Paper Optics, Thousand Oaks Optical, TSE 17 and Baader Planetarium (the products with AstroSolar silver/gold film only). The products from these companies must have the manufacturer's name and address printed on the glasses, as well as a mark saying they meet the ISO 12312-2 International Standard.

For full list of libraries holding solar eclipse watch events visit: https://www.starnetlibraries.org/2017eclipse/registered-libraries-map/