Wrapped in an atmosphere tinted pale blue by high-altitude methane, Uranus has occasionally been observed to develop large storms in its frigid windy skies. NASA’s Voyager 2 saw a few small storm clouds spotting Uranus during its flyby in Jan. 1986, and more recently some large but short-lived storms were observed by Hubble and the W.M. Keck Observatory as the planet moved toward its equinox in 2007. Now, seven years after its equinox, swirling storms are once again blooming on Uranus — and Keck astronomers have caught them on camera (while preparing for terrestrial hurricanes to make landfall!)
Oh man. It’s stuff like this that got me into space blogging in the first place.
Landing here on Earth last night, this is one of several new raw images from Cassini acquired yesterday (Nov. 27) showing the enormous cyclone of clouds swirling around Saturn’s geographic north pole. The angle of sunlight highlights the multilayered structure of the cyclone and surrounding cloud bands wonderfully… this is a roiling feature approximately 3-4,000 km across and in places appears to carve cloud channels hundreds of kilometers into Saturn’s atmosphere. Simply. Beautiful.
It’s been a while since we’ve gotten such a good look at Saturn’s north pole… over four years ago, I’d say, and in fact one of my very first blog posts here on LITD was of the hexagonal feature ringing Saturn’s northern hemisphere. Thanks to Cassini’s new orbital trajectory, which is taking it high over the ring plane and poles of Saturn, we have the opportunity to view the gas giant’s upper latitudes again.
In fact we even have a brand new look at the hexagon, which is still there, four years later:
Storms on Saturn are huge and powerful, with winds blowing many hundreds of miles per hour and often featuring lightning ten thousand times stronger than any seen on Earth. The storms often occur as eddies within Saturn’s jet streams – the atmospheric bands that carry clouds east or west around the planet. Research has discovered that, rather than being created by the friction of the jet streams, Saturn’s storms actually power the jet streams, since they tend to travel along with them. Scientists speculate that this process is what helps Saturn maintain its atmospheric bands and high winds.
The image above is a crop of the original, and I sharpened it and adjusted the curves to enhance detail. The texture in the clouds is often referred to as “coffee-and-cream”, resembling the delicate swirls seen in a hot cup of cappuccino. Make mine a venti!
Image credit: NASA / JPL / Space Science Institute.
In this raw image from Cassini, giant scallop-edged cloud patterns become visible in Saturn’s atmosphere with camera filters specially designed to detect methane. Light and dark banding of the clouds at various latitudes are also extremely distinctive through this filter.
Although mostly hydrogen and helium, Saturn’s atmosphere does contain elements like methane and ammonia.
Saturn’s atmosphere constantly churns with huge eddying storms and powerful jet streams, moving with winds traveling hundreds of miles per hour. While once it was believed the jet streams powered the eddies, it’s now believed the case is just the opposite…the storms are contributing power into the jet streams, which then help spawn new storms.
Image: NASA/JPL/Space Science Institute
Storms of varying sizes churn in Saturn’s northern hemisphere in this true-color image taken by the Cassini orbiter on November 29, 2008. The reason for the blue color is still not known, but it seems to fade with the winter season coming to an end.
This photo was taken from a distance of 683,000 miles from the planet. The larger storms are hundreds of miles wide.
The wavy line at the upper left is part of a polar phenomenon known as the hexagonal pattern. This huge geometric formation wraps around the north polar atmosphere of Saturn and is not entirely understood.
Image credit NASA/JPL/Space Science Institute.