Saturn's Atmosphere

9 Apr 2020

Robert sent in this link to https://phys.org/news/2020-04-saturn-atmosphere-hot.html .... What makes Saturn's atmosphere hot? The same question can also be aimed at Jupiter, Uranus and Neptune. The atmospheres of the gas giants are at least as warm as that of the earth - yet they are situated much further away from the Sun. New analyses of data from Cassini indicated one explanation that may have traction. Auroras at the poles of those planets = electric currents triggered by interactions between the solar wind and charged particles from Saturn's moons. Do aurora really heat up the upper atmosphere? TGhe study comes after mapping of both temperature and density of the atmosphere - a region little understood. Auroral electric currents heat the upper layer of Saturn's atmosphere which in turn drives winds.The global wind system then distributes the energy, we are told. See https://doi.org/10.1038/s41550-020-1060-0 ... and the same story popped up on the NASA newsletter (7th April 2020) - but see https://solarsystem.nasa.gov/cassini

Meanwhile, at https://phys.org/news/2020-04-clue-solar-coronal-problem.html ... we have another study, this time in Astrophyscical Research Letters, which seeks to explain how the sun's corona might be heated up - Alfven turbulence. See https://doi.org/10.3847/2041-8213/ab79a2