Titan interaction with the supersonic solar wind: Cassini T96 observations

Friday, 19 December 2014
Cesar Bertucci, University of Buenos Aires, Buenos Aires, Argentina, Douglas C Hamilton, University of Maryland, College Park, MD, United States, William S Kurth, University of Iowa, Iowa City, IA, United States, George B Hospodarsky, Univ Iowa, Iowa City, IA, United States, Donald G Mitchell, JHU/APL, Laurel, MD, United States, Niklas J. T. Edberg, IRF Swedish Institute of Space Physics Uppsala, Uppsala, Sweden, Nick Sergis, National and Kapodistrian University of Athens, Athens, Greece and Michele Karen Dougherty, Imperial College London, Blackett Laboratory, London, United Kingdom
After 9 years in the Saturn system, the Cassini spacecraft finally observed Titan in the supersonic solar wind. These unique observations reveal that Titan’s interaction with the solar wind is in many ways similar to unmagnetized planets Mars and Venus in spite of the differences in the properties of the solar plasma in the outer solar system. In particular, Cassini detected a collisionless, supercritical bow shock under ongoing reformation and a well-defined induced magnetosphere filled with mass-loaded interplanetary magnetic field lines, which drape around Titan’s ionosphere. A study of pressure balance across different plasma regions suggest the presence of fossil fields similar to those detected during T32. Because of the upstream conditions, these observations are relevant for other unmagnetized bodies in the outer solar system such as Pluto, where kinetic processes are expected to dominate.