These two natural color images taken by the Cassini spacecraft show how Saturn’s north polar region has changed between 2012 and 2016. The color change is thought to be an effect of Saturn’s seasons. It’s suggested that the change from a bluish color to a more golden hue is due to the increased production of smog in the atmosphere as the north pole approaches summer solstice in May, 2017.

The hexagon, Saturn’s six-sided jetstream, may act as a barrier preventing haze particles produced outside it from entering. If that’s the case, the polar atmosphere could have become clear of aerosols produced by photochemical reactions, reactions caused by sunlight, during the winter. After Saturn’s equinox in August, 2009, the north pole polar has been in continuous sunshine, and smog aerosols are being produced inside the hexagon, making the polar atmosphere appear hazy.

Image Credit: NASA