There is more interaction than one would think between interplanetary bodies. In this case 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.