2007_09_09_bos-iad-lhr076.JPG

A rainbow, or "sundog" in cirrus clouds, which are comprised of ice. Unlike rainbows, which are reflective (from the inside surfaces of falling raindrops) , sundogs appear in the same direction as the sun, within a circle around it. These can be seen from the ground, but always appear far away, because cirrus clouds exist only at stratospheric altitudes. Since we were flying at 25,000 feet at this time, we were beside or inside the very clouds producing the rainbows.