Public libraries across the United States will distribute more than 2 million pairs of free eclipse glasses to skywatchers for the total solar eclipse that will sweep over the country on Aug. 21, 2017. The glasses will be provided by a major outreach program initiated by the Space Science Institute (SSI).

The so-called the Great American Eclipse will pass over the U.S. along a stretch of land from Oregon to South Carolina. Viewers in the path of totality, which spans about 70 miles (113 kilometers) wide, will see the moon directly pass in front of the sun, briefly turning day into twilight. Skywatchers outside that path will still see a partial eclipse, when part of the sun will still be in view.

Looking up at the sun, even when it is partially covered by the moon, can cause serious eye damage, which is why skywatchers need special solar-viewing glasses. Some 4,800 library organizations throughout the country will be giving away free glasses as part of an outreach project funded by a grant from the Gordon and Betty Moore Foundation to SSI, a nonprofit corporation focused on science research, education and outreach. The project is also supported by Google, the National Science Foundation (NSF) and NASA, according to a statement from the SSI. [How to View a Solar Eclipse Without Damaging Your Eyes]

"The Moore Foundation is pleased to help 2 million eyes enjoy and understand this astronomical spectacle with astronomical spectacles," Dr. Robert Kirshner, chief program officer for science at the Moore Foundation, said in the statement.

In addition to the eclipse-viewing glasses, registered organizations will receive an informational booklet about the solar eclipse that includes, times and locations for viewing events, safe viewing techniques, and suggestions for public-outreach programs about the event. The informational booklet is available to everyone and can be downloaded here.

"This is a once-in-a-lifetime opportunity for libraries and their communities to work together to participate in a celestial event of this scope," Paul Dusenbery, project director for the SSI National Center for Interactive Learning (NCIL), said in the statement. "Many organizations, like NASA, the National Science Foundation and the American Astronomical Society, are working together to help people understand and view the eclipse safely, and we are delighted to be part of this important educational effort."

The eclipse project is an initiative led by the STAR Library Education Network (STAR_Net), which is managed by SSI's National Center for Interactive Learning (NCIL). STAR_Net libraries aim to increase engagement in science, technology, engineering and math (STEM) studies.

The solar eclipse on Aug. 21 — partial or total — will have an impact on millions of skywatchers in the continental U.S., which is why educators and both amateur and professional astronomers are asked to help support local public libraries that will be participating in eclipse outreach events. NASA Solar System Ambassadors (a network of volunteer science-outreach experts), museum educators, park rangers and science teachers will also be partnering with libraries in their communities to help prepare for the big event. An interactive map of libraries participating in the eclipse project across the country can be found online.

Although applications to receive free eclipse-viewing glasses have closed, libraries and educators can still purchase discounted glasses from American Paper Optics.

Follow Samantha Mathewson @Sam_Ashley13. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.