News Picks : Saturn’s rings yield clues to planet’s geology
New Scientist: Until now, scientists thought Saturn was composed of a solid central core surrounded by a turbulent mix of helium and hydrogen in gas and liquid forms. But vibrations detected in Saturn’s rings indicate that the planet may have a stable stratified layer of liquid and rock between its core and its roiling exterior. In his paper published in the journal Icarus, Jim Fuller of the Kavli Institute for Theoretical Physics in Santa Barbara, California, says that density waves within the rings reflect oscillation modes within the planet. Using interior structure modeling, Fuller was able to determine that the planet’s combination of gravity modes indicates the presence of a deep layer of stratification. It is the first time such a seismological investigation has been conducted on another planet.