The spectacular cloud shapes that were observed on Saturn’s moon Titan by the Cassini mission arise from planetary waves in the moon’s atmosphere, suggests a paper published online this week in Nature Geoscience. Cloud patterns formed by this mechanism can lead to high precipitation rates that may be important in shaping Titan’s surface by erosion.

Jonathan Mitchell and colleagues simulated Titan’s atmospheric dynamics with a three-dimensional general circulation model, and found that two distinct modes of atmospheric waves organize clouds and precipitation. In combination, these modes can lead to downpours with precipitation rates of up to twenty times the local average.

In an accompanying News & Views, Tetsuya Tokano writes: “The study by Mitchell and colleagues is a first step towards assembling a precipitation climatology for Titan.”