Ice Crystal Halos

Dean Ketelsen (photo copyrighted by him) took this great photo of ice crystal halos that are not normally seen because the Earth is in the way. But flying in an airplane and paying attention gave him this reward. The British site "Astronomical Optics" is perhaps the best such website in the world at this moment. Dean also posts many photos at his blog theketelsens.blogspot.com. Right now there are start-of-monsoon photos from Kitt Peak, and many others. There's a infrared- airglow video about halfway down the page. Larger photos of the sub-halos at the astronomical optics site.