Contrail Iridescence - Andrew Kirk of California took this. The contrail forms as water vapour generated in the engines condenses to supercooled water droplets or ice crystals. At any point along the trail the drops or crystals have seen the same history and all have similar sizes. They scatter, diffract, sunlight to form the iridescent colours.. ©Andrew Kirk, shown with permission.

About - Submit Optics Picture of the Day Galleries Previous Next Today Subscribe to Features on RSS Feed