Extensive analyses and modeling of Cassini imaging and heat-mapping data have confirmed and extended previous ideas that migrating ice, triggered by infalling reddish dust that darkens and warms the surface, may explain the mysterious two-toned "yin-yang" appearance of Saturn's moon Iapetus.

NASA scientists are on the trail of Iapetus' mysterious dark side, which seems to be home to a bizarre "runaway" process that is transporting vaporized water ice from the dark areas to the white areas of the Saturnian moon.

Images returned by NASA's Cassini spacecraft cameras during a New Year's Eve flyby of Saturn's moon Iapetus (eye-APP-eh- tuss) show startling surface features that are fueling heated scientific discussions about their origin.