A total solar eclipse offers a unique opportunity to see the corona, the sun’s outer atmosphere. It’s not usually visible because the surface of the sun is much brighter, but with the moon blocking it during totality, the outer edge shines through.
Compared to the 2017 solar eclipse, the sun’s corona will be more active this year, according to NASA. That means there’s a better chance to see prominence — curls, loops and flares coming off of the sun from behind the moon.
