You're looking at a newly released 8-frame movie of Saturn's enigmatic "hexagon." It is the highest-resolution footage ever acquired of the massive six-sided maelstrom atop the ringed planet's north pole, and boy howdy is it gorgeous.
For the uninitiated, Saturn's uncannily symmetric cloud system measures roughly 20,000-miles across, and is utterly unique in our solar system. Its dimensions and dynamics are just bizarre. At the hexagon's center whirls a tightly wound hurricane roughly fifty-times larger than the average hurricane-eye on Earth. About it spins an assortment of smaller vortices, caught up in the hexagon's jet stream, that rotate clockwise, even as the central hurricane, and the outer hexagon, rotate in the opposite direction. These smaller storms are visible in the image above as reddish ovals. The largest of the smaller vortices, appearing white in the lower right corner of the hexagon, spans about 2,200 miles – roughly twice the size of Earth's largest hurricanes. (The lower-resolution animation on the left comprises 19 images captured in June of this year; while it's sped-up here, the footage covers 2 hours and 45 minutes in real time.)
As for the movie up top, its eight frames are in fact a combination of data from 128 images captured over the course of ten hours on December 10th, 2012, with each frame consisting of 16 map-projected images: four per color filter, four filters per frame. The use of these filters, and the detail of the images, are what really set this footage apart. According to NASA, it is the first hexagon movie of its kind, and the first to show a view of the top of Saturn down to roughly 70 degrees latitude.
How the system formed, and how it manages to persist (at least three decades – and probably a lot longer than that), remain two of our solar system's greatest mysteries. To be clear: polar vertices aren't terribly rare in and of themselves (Earth has one!); what makes Saturn's system unique is its scale, symmetry and perseverance – though scientists do have some promising leads on the origins of its shape, having reproduced the effect in the lab:
"The hexagon is just a current of air, and weather features out there that share similarities to this are notoriously turbulent and unstable," said Andrew Ingersoll, a member of the Cassini imaging team, in a release describing the new footage. "A hurricane on Earth typically lasts a week, but this has been here for decades — and who knows — maybe centuries."
"As we approach Saturn's summer solstice in 2017, lighting conditions over its north pole will improve, and we are excited to track the changes that occur both inside and outside the hexagon boundary," added Scott Edgington, Cassini deputy project scientist.
[Via NASA]