Radio and Plasma Waves in the Magnetosphere of Saturn: Similarities to Earth and Jupiter

With a few notable exceptions, most of the radio and plasma waves observed in the magnetosphere of Saturn are remarkably similar to those observed in the magnetospheres of Earth and Jupiter. For example, Saturn kilometric radiation, terrestrial kilometric radiation, and Jovian decametric radiation have many characteristics in common and are all generated by the same basic plasma mechanism, namely the cyclotron maser instability. Similar statements can be made about a broad range of other radio and plasma wave phenomena, for example, electrostatic emissions at the upper hybrid frequency, electrostatic waves near odd half-integral harmonics of the electron cyclotron frequency, and various whistler-mode electromagnetic emissions. What is different at these various planets are the plasma parameters and the types of interactions that lead to the plasma instabilities. Thus, the frequencies of the cyclotron maser radiation at Saturn, Earth and Jupiter are all different because the magnetic field strengths are different. And, there is no terrestrial analog of the Io-controlled Jovian decametric radiation, since there is no moon orbiting in the inner region of the terrestrial magnetosphere. In this talk, we will review the radio and plasma wave observations obtained by the Cassini Radio and Plasma Wave Science (RPWS) instrument in the vicinity of Saturn, and compare these to similar observations at Earth and Jupiter with the objective of contrasting and understanding the physical processes involved.