What is it? How does it happen? How long can it last?
Totality occurs during a total solar eclipse, that is, the sun is entirely and perfectly blocked by the moon which in turn casts a shadow on Earth. It’s as if the sun, moon, and Earth were billiard balls perfectly aligned, one behind the other. While the sun is covered by the moon, you will see the sun’s atmosphere, or corona, appearing as a bright glow around the moon. The corona is never visible to us except during the few moments of a total solar eclipse. In real-time, you’ll be watching the solar system in motion as it moves through space, the moon around Earth, and Earth around the sun. On Earth, areas in the immediate path of totality will experience a darkened sky that will last approximately two minutes, depending on where you are viewing the eclipse.
In the graphic below, the shaded area shows the Path of Totality; locations within the shaded areas will experience the total solar eclipse:
