why call it a silhouette when i can be trendy?
if you look around while the sun is partially eclipsed, you may notice strange things in the shadows: a blurring of the sharp line between light and dark, strange shapes in light. leaves in the trees may create a pinhole camera effect giving projections of the eclipsed sun on the ground.
i couldn't find an example in the immediate area so i made one myself ;)
I know, you're thinking that's just my first web space casting a shadow. Here's a more dramatic example i encountered indoors created by holes in the blinds: