The 2017 solar eclipse is loaded with highlights. Among them, for observers in the narrow swath of totality from Oregon to South Carolina, when the sun is obscured by the moon and the sky darkens, the planets and some stars appear. On August 21, four planets will be visible on either side of the eclipsed sun.
Toward the southeast is Jupiter. Below and left of the sun is Mercury, which is usually hard to see because it's always so close to the sun anyhow. Above and right of the sun is Mars. And to the southwest is Venus, the brightest of them all. Meanwhile, a twilight glow (not depicted well in graphic) lingers at the horizon.
So how dark is it during totality near the centerline?