Can Cassini magnetic field measurements be used to find the rotation period of Saturn's interior?

摘要

We investigate the determination of the rotation period of Saturn's interior using magnetic field measurements from Cassini. First, we vary the rotation period and search for the period that yields the smallest rms misfit of a magnetic field model to the data. Second, we search for the period that yields the most power in the non-axisymmetric components of a magnetic field model. Neither method enables us to determine the rotation period. However, we are able to place a bound on the magnitude of the non-axisymmetric component of Saturn's magnetic field finding it to be no greater than 4-5% of the axisymmetric component.