On August 21, North America will experience a total solar eclipse when the Moon passes directly between the Sun and Earth. The Moon’s shadow, what scientists call the umbra, will pass over Corvallis, Salem and Albany, move on to Madras, Prineville and Redmond and end its Oregon journey over John Day, Baker City and Ontario.

At the May 8 Corvallis Science Pub, Randall Milstein will discuss the science and history of solar eclipses and offer practical tips on how to witness the event safely. “With it crossing so much of North America, it may become the most widely shared natural event in human history,” says Milstein, an astronomy instructor in the Department of Physics and College of Earth, Ocean, and Atmospheric Sciences at Oregon State University.

What scientists call the “path of totality” — a roughly 75-mile wide highway of darkness — will quickly move eastward through twelve states before reaching South Carolina about 90 minutes after arriving in Oregon.

This is the first total solar eclipse to target the continental United States since 1979, the first to run from the North American Pacific Coast to Atlantic Coast since 1918, and the first total solar eclipse since 1776 with its path of totality completely within the continental United States. Although a total solar eclipse happens about once every 18 months somewhere on Earth, it is still a rare event.