P31E-2100
Evolution of the Plasma Environment of Comet 67P
Wednesday, 16 December 2015
Poster Hall (Moscone South)
Anders I Eriksson1, Elias Odelstad1, Niklas J. T. Edberg1, Erik Vigren1, Ilka Annabel Dorothée Engelhardt1, Henri Pierre2, Jean-Pierre Lebreton3, Chris Carr4, Christoph Koenders5, Hans Nilsson6, Thomas W Broiles7, Tomas Karlsson8, Riku Jarvinen9, Wojciech Miloch10 and Martin Rubin11, (1)IRF Swedish Institute of Space Physics Uppsala, Uppsala, Sweden, (2)Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E) - CNRS - Université d'Orléans, Orléans, France, (3)University of Orleans, Orleans, France, (4)Imperial College, London, United Kingdom, London, United Kingdom, (5)Technical University of Braunschweig, Braunschweig, Germany, (6)IRF Swedish Institute of Space Physics Kiruna, Kiruna, Sweden, (7)Southwest Research Institute, San Antonio, TX, United States, (8)KTH Royal Institute of Technology, Stockholm, Sweden, (9)Finnish Meteorological Institute, Helsinki, Finland, (10)University of Oslo, Department of Physics, Oslo, Norway, (11)University of Bern, Bern, Switzerland
Abstract:
Since the arrival of Rosetta at comet 67P in August 2014, the plasma environment around the nucleus has been dominated by plasma of cometary origin, as witnessed by a strong modulation by the rotation of the nucleus on the plasma density from the Langmuir probe (RPC-LAP) and Mutual impedance probe (RPC-MIP) instruments. As 67P is not a particularly active comet, coma densities have mainly been too low to efficiently cool the electrons emitted by ionization of neutrals, keeping the electron temperature well into the eV range and driving the spacecraft to a potential often below -10 V. The plasma density has evolved from tens of cm-3 at the early stage to hundreds and thousands of cm-3 during the approach to perihelion. In addition to the large scale structures and slow evolution, the data also show a multitude of transient features of which we will also provide some examples.
