Contrail Shadow & Cirrus Clouds
Another find while driving today. An airplane passed overhead, its contrail casting a shadow on the thin cloud layer below.
Like the last one, this was shot from the car while stopped at an intersection. The diagonal line extending down from the sun is, I believe, a sun pillar-like effect in the trails left by the windshield wipers.
Also: Unless I'm mistaken, you can just barely see the edge of a halo in the feathery clouds at bottom center. It's the slight reddening.
Atmospheric Optics has a good diagram on how contrail shadows work: