The two rainbows in this picture taken by an instrument on NASA's Aqua satellite are not actually rainbows at all but a phenomenon known as a glory. Glories and rainbows appear rather sumilar, but rainbows are formed by refraction and reflection, whereas glories are the result of backward diffraction. Glories tend to be circular rings of color, commonly seen from airplanes passing over thin clouds with droplets between 10 and 30 microns in diameter. The glory in this picture, taken on June 20th, doesn't have a circular appearance because of the way the Moderate Resolution Imaging Spectroradiometer (MODIS) took the picture, scanning the Earth in strips perpendicular to the satellite's path. Also visible in the image is the Pacific island of Guadalupe and swirling cloud eddies known as von Karman vortices.
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