I hadn't ever witnessed this before. While driving back through Yellowstone, we noticed the sky opposite the sun looked unusual. I thought it was some kind of alien activity
but turned out to be anti-crepuscular rays -- crepuscular rays from the sun that appear to reconverge at the anti-solar point.
![anticrepuscular_rays.jpg](/proxy.php?image=http%3A%2F%2Fwww.azsj.org%2Fgallery%2Ffiles%2F1%2F3%2F9%2F3%2Fanticrepuscular_rays.jpg&hash=034eed8d58a308522e7527b23c29c0cf)