NASA’s Cassini mission recently spotted a storm on Saturn created as the result of a massive temperature spike that might be a cyclical weather pattern driven by ethylene in Saturn’s atmosphere.
The storm was first spotted at the end of 2010 by the Cassini probe and monitored through 2011 in visible wavelengths as Saturn entered its “spring” phase of its 30-year orbit around the Sun. More recent observations in the infrared part of the spectrum reveal a lasting turbulent aftermath long after the storm had dissipated, accompanied by a massive rise in the amount of ethylene present – which astronomers are currently baffled at.
During this spring storm, temperatures on Saturn rose by around 83 degrees celsius. Since its average temperature is an extremely cold -170 degrees celsius, this massive temperature rise causes the gaseous atmosphere of Saturn to develop extreme weather patterns that are analogous to the El Nino phenomenon here on Earth. Both events happen around once per year as the planets travel around the Sun, although Saturn’s year is far longer than our own (about 30 Earth years) because of its extreme distance from the Sun.
In 2011 Cassini spotted two unusually hot areas of Saturn’s atmosphere, indicating a localised massive release of energy. Later on, after the storm began to fade in the visual spectrum, infrared data revealed that these two hot areas had merged into one large super hot area larger than Jupiters famous great red spot with a temperature of only -53 degree celsius – about 3 times hotter than normal. For a planet that is normally extremely cold, that is a massive difference in temperature – like going from the Sahara desert in the height of summer to Antarctica in the dead of winter.
At the same time as this massive temperature spike was seen, a spectrometer attached to the McMath-Pierce telescope in Arizona spotted a massive rise in ethylene molecules in the weather system – about 100 times more ethylene than scientists thought possible for Saturn. They’re a bit puzzled as to where this ethylene comes from, but they’ve ruled out a layer of it deeper in Saturns atmosphere. It might be the result of some process driven by increased sunlight that forms large amounts of ethylene from elements already present in the atmosphere.
Scientists think that the storm will fade completely by the end of 2013, but since Saturn wont be at the closest point of its orbit to the Sun until 2017, Cassini stands a good chance of seeing more of these extreme weather patterns as Saturn heats up.
The ESA has a couple of great videos showing the progress of the storm over time available here, and photos at key stages here.
This article summarised from material provided by NASA and the European Space Agency.