Watch what happens during a total solar eclipse

(AP Images) (AP Images)

(AP/MEREDITH) -- On August 21, North America will experience a solar eclipse.

A thin path across the U.S. will be treated to the 1st coast-to-coast total eclipse in nearly a century. Everyone on the continent will be able to view at least a partial eclipse.

With totality crossing 14 states, it is expected to be the most viewed eclipse ever. Cities across the U.S. are gearing up for the event.

A solar eclipse occurs when the moon passes between the sun and earth and blocks the sun.

During a total eclipse, the sun's crown, or corona, is visible to the naked eye. The crown is the sun's outer atmosphere, stretching millions of miles into space.

During totality, it is safe to view a solar eclipse. However, as the moon reveals the sun, you may be caught off guard exposing your eyes to possible damage from the sun's UV rays.

It's best to use protective glasses or indirect viewing devices during all the phases of an eclipse

This Associated Press series was produced in partnership with the Howard Hughes Medical Institute's Department of Science Education.