How fast will October's annular solar eclipse travel?

Oct 1, 2023
I don't think that speed formula works properly near the two ends of the eclipse path. A reasonable estimate simply divides the path width by the duration of totality, and I just don't see how you could possibly get 500,000 mph here.
The Moon's shadow first touches the Earth tangentially. At that moment, the speed is infinite. It slows down until midpoint then speeds up becoming infinite again when the shadow leaves Earth.