Leahy imaged this strange dark shape in the sky that mimicked
the profile of the mountain below it. Taken from Valdez,
Alaska not long after sunrise on June 5, '08. ©2008
M. Joseph Leahy, shown with permission.
The dark shape is the shadow of the mountain. But how? How can the shadow
be above the mountain when sun rays always point downwards? And what
is the shadow being cast upon?
The mountain shadow is cast on a thin translucent cloud layer
nearer to the camera and lower than the mountain. The shadow
is viewed from the underside of the layer - like watching a movie
through the back of the screen. It appears larger than the mountain and above
it because it is much closer to the camera. We sometimes see similar
cloud shadows above the clouds casting them.
More mountain shadows.