H. Todd Smith
Johns Hopkins University Applied Physics Laboratory
The Neutral Particle Environment Inside Saturn's Magnetosphere
Prior to 2004, all knowledge of the Saturnian system was limited to Earth based observations and only three in-situ flybys. The subsequent arrival of the Cassini spacecraft for a 4+ year tour of the Saturnian system is rapidly changing what we know about the system. The Saturnian system is neutral particle dominated and an understanding of these neutral particles sources and processes is essential for understanding the magnetosphere. However, the Cassini neutral particle detector is not sensitive enough (except near atmospheres) to directly detect these neutral particles so we have utilized plasma instruments learn about these particles. During this fascinating period of research we have had to revise our knowledge of Saturn’s magnetosphere and sources. The very dense, relative unprotected atmosphere of the large moon Titan which was once believed to be the dominant source of plasma has taken a back seat to its much smaller cousin, Enceladus. Recent findings underscore the significance of source placement for determining the characteristics of a magnetosphere. We discuss the current understanding of Saturn’s neutral tori and neutral/plasma sources as well as methods used to indirectly study these particles.