This artist’s concept illustrates how charged water particles flow into the Saturnian atmosphere from the planet’s rings, causing a reduction in atmospheric brightness. Image credit: NASA/JPL-Caltech/Space Science Institute/University of Leicester
A new study tracks the “rain” of charged water particles into the atmosphere of Saturn and finds there is more of it and it falls across larger areas of the planet than previously thought. The study, whose observations were funded by NASA and whose analysis was led by the University of Leicester, England, reveals that the rain influences the composition and temperature structure of parts of Saturn’s upper atmosphere. The paper appears in this week’s issue of the journal Nature.
“Saturn is the first planet to show significant interaction between its atmosphere and ring system,” said James O’Donoghue, the paper’s lead author and a postgraduate researcher at Leicester. “The main effect of ring rain is that it acts to ‘quench’ the ionosphere of Saturn. In other words, this rain severely reduces the electron densities in regions in which it falls.”
O’Donoghue explains that the ring’s effect on electron densities is important because it explains why, for many decades, observations have shown those densities to be unusually low at certain latitudes on Saturn. The study also helps scientists better understand the origin and evolution of Saturn’s ring system and changes in the planet’s atmosphere.
