Composition and Dynamics of Plasma in Saturn's Magnetosphere

Science. 2005 Feb 25;307(5713):1262-6. doi: 10.1126/science.1106151.

Abstract

During Cassini's initial orbit, we observed a dynamic magnetosphere composed primarily of a complex mixture of water-derived atomic and molecular ions. We have identified four distinct regions characterized by differences in both bulk plasma properties and ion composition. Protons are the dominant species outside about 9 RS (where RS is the radial distance from the center of Saturn), whereas inside, the plasma consists primarily of a corotating comet-like mix of water-derived ions with approximately 3% N+. Over the A and B rings, we found an ionosphere in which O2+ and O+ are dominant, which suggests the possible existence of a layer of O2 gas similar to the atmospheres of Europa and Ganymede.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Atmosphere
  • Extraterrestrial Environment
  • Hydrogen
  • Ice
  • Ions
  • Magnetics*
  • Oxygen*
  • Protons
  • Saturn*
  • Spacecraft
  • Spectrum Analysis

Substances

  • Ice
  • Ions
  • Protons
  • Hydrogen
  • Oxygen