11 July 1991 - Shadow images of crescent sun

11 July 1991 - Shadow images of the crescent sun

This was a really peculiar effect. The asymmetrical shape of the sun made shadows appear to have a fuzzy edge, particularly around sharp objects (like your fingers). Normally, a shadow cast by the sun has a dark core (umbra) and a slightly lighter outer part (penumbra), but because it is very uniform, and due to the eye/brain perception, you see it as a very sharp line. This is decidedly not the case here. I had heard about this, but it is far more striking in person.

This is a shadow of my hand making a small hole between my fingers and palm. Note the distinct crescent image in the middle as well as less distinct ones by my finger tips.