Saturn loses its cool
In Roman mythology Saturn is the God of the harvest who presides over a golden age of abundance and peace.
Well, not any more. Beneath the planet's normally serene façade a massive, angry storm is broiling: A storm so powerful it stretches around the entire northern hemisphere and has produced a 3,000 mile-wide dark vortex similar to Jupiter's Great Red Spot.
Caught on film by infrared cameras on the ESO's Very Large Telescope and NASA's Cassini spacecraft, these fantastic images, published in the journal Science, show a phenomenon recorded only six times since 1876 in unprecedented detail.
As spring comes to Saturn's northern hemisphere - an event that occurs only once every 30 earth years - variations in temperature drive giant convection currents through the planet's normally stable upper atmosphere.
"This disturbance creates a gigantic, violent and complex eruption of bright cloud material" according to the lead author of the study, Oxford University's Dr Leigh Fletcher. "By observing it in infrared for the first time we can reveal hidden regions of the atmosphere and measure the really substantial chasnges in temperatures and winds".
It's the first major storm on Saturn observed by an orbiting spacecraft. Cassini's CIRS infrared spectrometer initially detected the disturbance as it emerged in December 2010, but researchers have been surprised by its strength.
"Our new observations show the storm has had a major effect on the atmosphere" says Brigette Hesman, a scientist working on the CIRS team at NASA's Goddard Space Centre. "If you were flying in an airplane on Saturn the storm would reach so high it would probably be impossible to avoid it."