Evolution of Saturn's storm in the stratosphere - front view
This animation shows the evolution of Saturn's 'Great Springtime Storm' in the planet's stratosphere. It is based on observations performed at mid-infrared wavelengths.
As clouds broke out in Saturn's stormy troposphere, waves of heat travelled hundreds of kilometres upwards, depositing their energy as two vast 'beacons' of hot air in the stratosphere in January 2011. Both hotspots travelled in a westerly direction around the planet, but the larger of the two travelled much faster, lapping the smaller one before they merged to create an enormous vortex that for a brief period, in late June 2011, covered about
The giant vortex was visible only to infrared cameras, and persisted long after the clouds from the storm had faded away in the troposphere. Since July 2011, the giant hot vortex has been shrinking and cooling at a very slow pace. It is still present in Saturn's stratosphere, where it has shrunk to less than half of its greatest extent, and is expected to disappear completely by the end of 2013.
The animation is based on mid-infrared data collected by NASA/ESA/ASI's Cassini spacecraft, ESO's Very Large Telescope and NASA's Infrared Telescope Facility.