Rare Contrail Shadow Photos

UPDATE: My Awesome Buddy Scott @ SSEC [JessePedia] offers up this satellite image, where you can see the contrails in the upper-left panel of this image. (I am near "KUNV").

I was treated to a rare "clear-air" contrail shadow [Atmospheric Optics] this morning as I drove to work here in State College, PA. A long contrail (sometimes called "jet trail") [WikiPedia] stretched from the sun, which was rising, to the other side of the horizon. It veered away from its original course to the West, so the sun projected a shadow of it to its left. The photos were taken about 10 minutes apart.

I think this is the first time I have ever seen a contrail shadow in thin air -- I have photographed them before on other clouds and I have captured anvil shadows from thunderstorms before. I was just reading a webpage about clear-air contrail shadows a few months ago, but for the life of me I can't find it now. If you run across similar photos as the two below, let me know.

The setup, from the opposite side of the sky, is shown below.

I also got some nice wave cloud and rainbow cloud shots yesterday: