NASA’s Cassini spacecraft has just a little over six months left in its mission orbiting Saturn. During its nearly 13 year stay studying the planet, Cassini has captured some truly stunning images of the ringed planet and its surrounding satellites — including the ravioli shaped moon, Pan. Each new release contains images more stunning than those that came before — and the latest batch doesn’t disappoint.
Photos of Saturn’s north pole seem to show that the region is changing colors. There is a massive, 32,000 kilometer (20,000 mile) wide, six-sided jet stream — known as “the hexagon” — at the pole. Images taken last year show the area with a golden hue, and the more recent photos show a large area of gorgeous cerulean in the center of a 2,011 km (1,250 mile) polar vortex.
The photo was brought to the attention of the masses by a tweet from space-enthusiast Jason Major.
— Jason Major (@JPMajor) March 31, 2017
Why So Blue?
While the images have not been officially validated by NASA, scientists are weighing in on possible explanations. “The color change is thought to be an effect of Saturn’s seasons. In particular, the change from a bluish color to a more golden hue may be due to the increased production of photochemical hazes in the atmosphere as the north pole approaches summer solstice in May 2017,” NASA said in a statement released in 2016.
There was another striking shift in color between images taken in 2012 and 2016: increased exposure to the sun allows compounds in the atmosphere to react and create a haze, changing the colors shown in photos. Since Saturn is much further from the sun, its seasons are much longer. Summer in the north pole began in 2009, so the reactions have been amassing with the longer sun exposure.
Cassini will continue to capture images through September as it continues on its final route.