Posted: 14 Feb 2011 12:01 AM PST
Iridescent Heart Cloud above Zabikow, Poland

Photographer: Dariusz Dorosz
Summary Author: Dariusz Dorosz; Jim Foster
The photo above showing a heart-shaped mid-level cloud fringed with
iridescent colors was captured above Zabikow, Poland on July 30, 2010.
Diffraction of sunlight by minute cloud droplets is responsible for the
lovely pastel hues. Because the droplets are so tiny (1/10 to 1/1000 the
size of raindrops), light waves that interact with them aren't refracted
nearly as much as they're deflected — in all directions. Iridescence or
irisation is generally observed in clouds that have formed relatively
recently since then their droplets are more likely to be quite small and of
more uniform size. Iridescent clouds are found within about 20 degrees of
the Sun, so make sure to protect your eyes whenever looking for them.
Zabikow, Poland, Coordinates: 51.8, 22.57
Earth Observatory
Rospuda Valley, Poland
EPOD is a service of NASA's Earth Science Division and the EOS Project Science Office (at Goddard Space Flight Center) and the Universities Space Research Association.