A Model of Comet P/Giacobini-Zinner

  1. Thomas J. Birmingham and
  2. Alexander J. Dessler
  1. D.C. Boice1,
  2. W.F. Huebner1,
  3. J.J. Keady1,
  4. H.U. Schmidt2 and
  5. R. Wegmann2

Published Online: 19 MAR 2013

DOI: 10.1029/SP027p0206

Comet Encounters

Comet Encounters

How to Cite

Boice, D.C., Huebner, W.F., Keady, J.J., Schmidt, H.U. and Wegmann, R. (1988) A Model of Comet P/Giacobini-Zinner, in Comet Encounters (eds T. J. Birmingham and A. J. Dessler), American Geophysical Union, Washington, D.C.. doi: 10.1029/SP027p0206

Author Information

  1. 1

    T-4, Los Alamos National Laboratory

  2. 2

    Max-Planck-Institut Für Astrophysik

Publication History

  1. Published Online: 19 MAR 2013
  2. Published Print: 1 JAN 1988

ISBN Information

Print ISBN: 9780875902395

Online ISBN: 9781118668757



  • Bulk flow velocity;
  • Comet model;
  • Electron density;
  • Energy balance calculation;
  • Giacobini-Zinner Model;
  • International Cometary Explorer (ICE);
  • Macroscopic hydrodynamic model;
  • Plasma velocity


A computer model of Comet P/Giacobini-Zinner is presented which contains photo-processes, gas-phase chemical kinetics, energy balance, multifluid hydrodynamics with a transition to free molecular flow, and solar wind interaction. Recently, the physics for electrons in the model has been improved by including electron impact ionization and dissociation and separately accounting for electron energetics. Electron heating and cooling mechanisms include photoprocesses, recombination processes, inelastic and elastic collisions with heavy molecules, and expansion cooling. The model incorporates an internally consistent interaction of the solar wind with the coma gas using the axisymmetric ideal fluid dynamic equations.

The nuclear size and composition have been chosen to make the calculations relevant to the 11 September 1985 International Cometary Explorer (ICE) encounter with Comet P/Giacobini-Zinner. Model profiles of the temperature, velocity, and number density of the electrons are in good agreement with measurements along ICE's trajectory. These results indicate that the probe passed through a region of the coma at the onset of the plasma tail.