Monday 18 May 2015: Colloquium: Negative ions and photoelectrons in the Saturn system
Prof Andrew Coates - Mullard Space Science Laboratory, UCL
Harrison 004 15:00-16:00
One of the unexpected discoveries from the Cassini mission was that of heavy, up to 13,800 amu/q negative ions in Titan's ionosphere. Before the Cassini mission, only positive ions had been expected there. We will discuss this discovery and its implications for Titan's atmosphere and surface. Negative ions were also found in the plumes of Enceladus, and at Rhea and Dione where they were used to infer weak atmospheres there. Photoelectrons are also found in the Saturn system where neutral particles dominate: near the main rings, in the inner magnetosphere, in the Enceladus plume and at Titan. We will discuss recent work on these topics.