An advanced physical model of cometary activity

A. V. Rodionov, J. F. Crifo, K. Szego, J. Lagerros, M. Fulle

Research output: Contribution to journalReview article

42 Citations (Scopus)


We describe the present state of an advanced physical model aimed at the simulation of the environment of active cometary nuclei. The model can handle the complicated shapes of real cometary nuclei, and is ready to handle alternative assumptions concerning the nucleus composition and structure; its present version is based on the simple, but hitherto highly successful, Whipple (1950) paradigm: at small heliocentric distances, strong sublimation theory is used to compute the surface gas production, taking into account the time-dependent heat flow in the nucleus interior; at large distances, different types of gas molecules may be assumed to dominate the gas production. Any size and shape distribution of dust can be assumed. The nucleus spin motion is modelled with allowance for the outgassing and solar tidal torques. The gas outflow is computed by solving quasistationary flow equations (Euler, or Navier-Stokes), hence the extent of the coma which can be modelled is limited either by the breakdown of the fluid approximation, or by that of the steady-state approximation. The dust outflow is computed by solving quasi-stationary "zero-temperature" multifluid Eulerian equations in the gas-dust interaction region, and from a "Keplerian fountain model" beyond it: the extent of the dust distribution which can be modelled is only limited by computer resources limitations. In addition to the detailed gas and dust coma structure, the resulting net nucleus mass loss, net sublimation recoil force, net sublimation torque, and net thermal emission are computed. We mention the past applications of the model to comets P/Halley and C/Hyakutake, and indicate some of the future steps of development of the model.

Original languageEnglish
Pages (from-to)983-1024
Number of pages42
JournalPlanetary and Space Science
Issue number10-11
Publication statusPublished - Dec 1 2002


  • Comets

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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    Rodionov, A. V., Crifo, J. F., Szego, K., Lagerros, J., & Fulle, M. (2002). An advanced physical model of cometary activity. Planetary and Space Science, 50(10-11), 983-1024.