'Ring Rain' Quenches Saturn's Atmosphere

astroengine writes "Saturn's rings rain charged water particles down onto the gas giant's atmosphere, causing measurable changes in the planet's ionosphere. This intriguing conclusion comes from astronomers using the W. M. Keck Observatory atop Mauna Kea in Hawaii that observed dark bands forming in Saturn's ionosphere. 'Saturn is the first planet to show significant interaction between its atmosphere and ring system,' said James O'Donoghue, postgraduate researcher at the University of Leicester and lead author of a paper to appear this week in the journal Nature. 'The main effect of ring rain is that it acts to 'quench' the ionosphere of Saturn, severely reducing the electron densities in regions in which it falls.'"