Saturn Makes Waves in its Own Rings

NASA’s Cassini mission revealed spiral waves rippling through Saturn’s inner rings. Some of these spiral patterns act like seismometers, picking up subtle changes in Saturn’s gravitational field. A new analysis of these waves has helped reveal the hidden structure of Saturn’s sloshing interior. It now appears that the planet core is large and “fuzzy,“ lacking defined layers. Hydrogen and helium gradually mix with larger quantities of ice and rock at greater depths in the core. These results are based on a study titled “A diffuse core in Saturn revealed by ring seismology,” published in Nature Astronomy, August 2021. More information: