miércoles, 8 de agosto de 2007

Iridescent auroras

See on top of the cloud

"This is an iridescent pileus cloud. On sunny afternoons, cumulus clouds boil upwards, pushing layers of moist air above them even higher where they cool and condense to form cloud caps or 'pileus' (Latin for cap). Pileus clouds formed very quickly have their water droplets all the same size--the perfect condition for iridescent colors."