The magnetosphere of Saturn

Pioneer 11 and Voyager 1 and 2 magnetic field measurements over the entire flyby of Saturn's magnetic field have been analyzed by fitting a magnetospheric dipole field (i.e., a dipole field plus the field due to currents in the magnetopause), higher moments of the internal field aligned with the dipole along the rotation axis, and the field due to an equatorial sheet current to the magnetic measurements. We find that a dipole moment of 21,431 nT Rs³, a quadrupole moment of 2403 nT Rs4, an octopole moment of 2173 nT Rs5, and an equatorial sheet current of half thickness 2.0 Rs from about 5 Rs to the solar edge of the magnetopause fit the measurements over the entire magnetosphere with a root mean square deviation of 3.2 nT. (Rs is the planet radius, 66,330 km). The primary feature of our analysis is the explicit inclusion of the calculated magnetopause current field, which reduces the overall root mean square deviation over the entire flyby from σ values of 4.7 and 5.9 nT using previous models to 3.2 nT using ours.