UE 12-Planetary plasmas

The cours is about the structures and main physical mechanisms of the plasmas surrounding various objects of the solar system (planets, planetary satellites and comets). Emphasis is placed on the possible interactions between the plasma and the body’s surface, its neutral atmosphere, its intrinsic magnetic field (if present) and its coupling with the solar wind

Required skills: Basic physics

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Content of the cours:

1 – Introduction à la physique des plasmas : L. Hadid (Sorbonne Universités, LPP, Jussieu)

  • What is a plasma and what are the equations governing its dynamics ?
  • Characteristic length and time scales in a plasma
  • In which conditions a plasma state is reached ?
  • Observations of plasmas
  • Single particle dynamics in a magnetic field
  • MHD: application to the expansion of the solar wind 
  • Multi-fluid description of a plasma 
  • Solar wind interactions in the solar system

2 – Obstacles non magnétisés et faiblement magnétisés : J.-Y. Chaufray (LATMOS, Guyancourt/Jussieu)

  • Planetary upper atmospheres : Thermosphere – Ionosphere – Exosphere
  • Cometary atmosphere and ionosphere
  • Solar wind interaction with conductive bodies : Induced magnetospheres
  • Surface-Bounded exospheres 
  • Solar wind interaction with airless bodies : Moon and asteroids

3 – Magnetized planets : from Mercury to the giant planets: F. Pantellini (LESIA, Paris Observatory, Meudon)

  • Overview on planetary magnetospheres in the heliosphere.
  • Origin, structure and description of the intrinsic planetary magnetic field.
  • Structure, dimensions and dynamics of a magnetosphere. Influence of the solar wind.
  • Plasma motion and electric currents in a magnetosphere. Effects due to the planet’s rotation.
  • Dynamics of charged particles in a magnetosphere.
  • Radiation belts and auroral emissions.

Bibliography (to start with):

  • Kivelson, M. G. & C. T. Russell, eds., Introduction to Space Physics, Cambridge University Press, 1995 : Historique, Soleil, Vent Solaire, Ionosphères, Magnétosphères etc.
  • Encrenaz, T. et al., Le système solaire (3ème édition), Savoirs Actuels, EDP-Sciences / CNRS-Éditions, Paris, 2003 : introduction aux ionosphères et magnétosphères (chapitres 5, 8, 10).
  • D. Gurnett & A. Bhattacharjee, Introduction to plasma physics, Cambridge Univ. Press, 2005 : rappels utiles de physique des plasmas.
  • G. Belmont, L. Rezeau, C. Riconda, A. Zaslavsky, Introduction à la physique des plasmas, ISTE, 2018. e-book.

Exam: Oral presentation of an article and questions.

Contact teacher: Filippo Pantellini, Laboratoire d’Etudes Spatiales et Instrumentales en Astrophysique (LESIA), Observatoire de Paris, CNRS, Meudon Tel :+33 (0)1-45-07-76-77 email : filippo.pantellini[@robas]obspm.fr