Saturn’s Magnetospheric Configuration

This Chapter summarizes our current understanding of Saturn’s magnetospheric configuration. Observations from the Cassini Prime and Equinox Missions have answered some questions and opened new ones. One of the fundamental questions of magnetospheric physics is what are the sources of the plasma that populate the magnetosphere. At Saturn, there is a rich set of possible plasma sources: the solar wind, Saturn’s ionosphere, Titan, the rings, and the T.I. Gombosi Center for Space Environment Modeling, Department of Atmospheric, Oceanic and Space Sciences, The University of Michigan, Ann Arbor, MI, USA e-mail: [email protected] T.P. Armstrong Fundamental Technologies, LLC, Lawrence, KS, USA e-mail: [email protected] C.S. Arridge Mullard Space Science Laboratory, University College London, London, UK and Centre for Planetary Sciences, University College London, London, UK e-mail: [email protected] K.K. Khurana Institute of Geophysics and Planetary Physics, University of California at Los Angeles, Los Angeles, CA, USA e-mail: [email protected] S.M. Krimigis Applied Physics Laboratory, Johns Hopkins University, Laurel, MD, USA and Center of Space Research and Technology, Academy of Athens, Athens, Greece e-mail: [email protected] N. Krupp Max-Planck Institute for Solar System Research, Katlenburg-Lindau, Germany e-mail: [email protected] A.M. Persoon University of Iowa, Iowa City, IA, USA e-mail: [email protected] M.F. Thomsen Los Alamos National Laboratory, Los Alamos, NM, USA e-mail: [email protected] icy satellites. One of the most significant discoveries of the Cassini mission was Enceladus’ role as a source. Saturn’s magnetospheric convection pattern falls somewhere between that of Earth and Jupiter. Earth is a slow rotator with a relatively small internal mass source and its magnetosphere is primarily dominated by the solar wind. At Jupiter the solar wind only plays a minor role since Jupiter is a fast rotator with a strong surface magnetic field and a significant plasma source (Io) deep inside the magnetosphere. As a consequence, internal processes dominate the magnetosphere and solar wind interaction is only marginally important. Saturn falls somewhere between Earth and Jupiter thus Saturn’s magnetosphere exhibits both solar wind and internal controls at the same time. This fact makes the Kronian magnetosphere even more fascinating and complex than the magnetospheres of Earth and Jupiter.