This caught my fancy last weekend. As someone who spends most of his time indoors, it's ironic that I'm getting more and more interested in anything outside. Anyway, the photo above is called a fire rainbow. Though it is a very silly and misleading name, the arc is not a rainbow and has nothing to do with fire.
Fire rainbows are the rarest of all naturally occurring atmospheric phenomena. For a fire rainbow to occur, cirrus clouds must be 20,000 feet in the air with the precise amount of ice crystals, and the sun must hit the clouds at 58 degrees.
Ever seen one of these?