Cassini observes Saturn's pole changing colors

PASADENA, Calif., Oct. 26 (UPI) -- The seasons are changing, and so are the colors on Saturn. A pair of photographs snapped by NASA's Cassini spacecraft reveal Saturn's north pole in flux.

Only a few years ago, a hexagonal region on the gas giant's north pole appeared a grayish blue. Now, the region boasts a golden hue. NASA scientists have been watching the slow transition since 2012. Researchers aren't yet certain what is triggering the color transformation.

Saturn's north pole is also undergoing seasonal change. In May of 2017, the pole will experience the peak of summer. Saturn has been bathed in sun since 2009. Between 1995 and 2009, the pole experienced the cold shadows of winter.

Chemical reactions between sunlight and Saturn's polar atmosphere produce an excess of haze, which can influence the absorption of light and alter the color appearance of the region.

The region is outlined by a six-sided jetstream. Researchers believe shifts in Saturn's season and solar heating influence the polar winds, which affect the behavior the hexagonal region. Changes in the intensity of the jetstream can change how much or little aerosols drift into and become trapped in the region.