Following images of the rings of Saturn and its dumplings satellite, NASA's Cassini spacecraft is surprising with new views of the gaseous world. This strange blue blob surrounded by gold is an atmospheric vortex at the center of the planet's north polar hexagon.
Jason Major compiled an image from the raw data released Thursday in the Cassini Imaging Archive. "If I see something interesting and it turns out to be captured in the visible light color channels, I put together the color version in Photoshop."
Here is the same polar vortex last October, which is a 1,250 mile wide hurricane that sits at the center of a much larger jet stream called Saturn's hexagon. There is a hint of an azure formation in the center, but if the new image, not yet calibrated by NASA, is to be believed, events in the north have become more dramatic in recent months.
NASA
The image above is from a NASA press release showing a striking color change across the entire North Polar Hexagon from 2012 to 2016. The chameleon effect was suggested by the agency as “increased production of photochemical haze in the atmosphere as the North Pole approached the summer solstice in May. 2017.
In other words, as Saturn's north pole tilts toward the Sun, the interaction between sunlight and atmospheric compounds that produce haze begins to intensify, altering the overall hue of the hexagon. As Kunio Sayanagi of the Cassini Imaging team pointed out in 2013, the hexagon acts like the Earth's ozone hole, creating a barrier to atmospheric particles. Therefore, any chemical changes within it remain within it.
In a speech at the American Geophysical Union's annual conference in San Francisco last December, planetary scientist John Blalock confirmed that while Saturn's north polar vortex is indeed blue, the rest of the hexagon is now clearly yellow. "The increase in the brightness of this area is consistent with the growth of products of photochemical haze in the upper atmosphere," - said the scientist.
Meanwhile, Cassini still has six and a half months of daring maneuvers that promise some of the most stunning planetary portraits in space history.
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