At the end of totality, the moon starts to uncover the sun’s incredibly brilliant photosphere and creates a visual effect called the “diamond ring”. It lasts only a moment, but leaves an remarkably strong emotional impression that may be responsible for why those that witness it, seek it again, at the next total eclipse of the sun.
During the Great American Eclipse, the moon covered the brilliance of the sun’s photosphere, revealing the activity occurring at its surface. Deep red flares of energized gas erupt and eject for thousands of miles, then follow the lines of magnetic force back to the surface.
Only when the moon covers the sun in a total eclipse can its halo be seen. This is the corona, a mystery to astronomers, who only get a glimpse of it for a few minutes during totality. The dot to the lower left is the star Regulus, in the constellation Leo, suddenly visible while the sun is eclipsed.