Seasonal Changes on Saturn

These images were featured in our March 2013 feature "Saturnalia." Read the whole thing here.

Orange-hazed Titan looms in front of Saturn, with the planet’s rings seen nearly edge-on as a thin line. The image, taken in May 2012, contains a surprise: Compared with Cassini’s first views of Saturn in 2004, the planet's southern hemisphere is taking on a bluish tint, and the northern hemisphere is losing its bluish tint. 

Porco realized she was witnessing the subtle change of seasons on Saturn, where each full cycle lasts 29.4 years. Ultraviolet radiation from the sun kicks up haze in the atmosphere. In the winter, when the sun is at a shallow angle, the haze subsides; as a result, the atmosphere clears up and the blue color appears. An observer floating in Saturn’s winter clouds would look up and see, incredibly, an arc of rings hanging over an Earthlike blue sky.

NASA/JPL/Space Science Institute