Hot New Mystery Surrounds Saturn
By Robert Roy Britt
Senior Science Writer space.com
For years astronomers have known that the upper atmospheres of
Saturn and other giant planets are hotter than can be explained by absorbed sunlight. Today the mystery deepened.
The phenomenon has long been blamed on a mechanism similar 
to what creates the aurora, or Northern Lights on Earth. On Earth, magnetic energy in the magnetosphere drives the aurora and heats the upper atmosphere.
The giant planets are known for spectacular auroras at their polar regions.
Scientists figured that heat generated by the auroras was blown
toward the equator by some unknown process. But a new calculation reported in
today’s issue of the journal Nature finds that this mechanism, if at work on Saturn, would actually cool the upper atmosphere at the lower latitudes (closer to the equator). Scientists will have to go back to the drawing board to figure out what’s really heating things up.
“This unexplained ‘energy crisis’ represents a major gap in
our understanding of these planets’ atmospheres,” the scientists write.
“We need to re-examine our basic assumptions about
planetary atmospheres and what causes the observed heating,” said study team
member Alan Aylward of the University College London.
Some as-yet-unknown direct heating mechanism is possibly at
work, the scientists speculate. One possibility: the breaking of “buoyancy
waves” generated in the lower atmosphere.Figuring it all out could help
researchers model the future of Earth’s atmosphere.
“Studying what happens on planets such as Saturn gives us
an insight into what happens closer to home,” Aylward said. “Planets can
lose their atmospheres as we see with Mars.
Do we completely understand how this happens? Are there mechanisms heating thegas and causing it to escape that we do not yet fully understand? By studying
what happens in other atmospheres we may find clues to Earth’s future.”
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