Broadening and Occultation of Radio Sources by Comet Giacobini-Zinner as Observed from Ice

  1. Thomas J. Birmingham and
  2. Alexander J. Dessler
  1. J.L. Steinberg1,
  2. J. Fainberg2,
  3. N. Meyer-Vernet1 and
  4. S. Hoang1

Published Online: 19 MAR 2013

DOI: 10.1029/SP027p0133

Comet Encounters

Comet Encounters

How to Cite

Steinberg, J.L., Fainberg, J., Meyer-Vernet, N. and Hoang, S. (1988) Broadening and Occultation of Radio Sources by Comet Giacobini-Zinner as Observed from Ice, in Comet Encounters (eds T. J. Birmingham and A. J. Dessler), American Geophysical Union, Washington, D.C.. doi: 10.1029/SP027p0133

Author Information

  1. 1

    Observatoire De Paris, Département De Recherche Spatiale, Unité Associée Au CNRS No264

  2. 2

    Laboratory for Extraterrestrial Physics, Nasa Goddard Space Flight Center

Publication History

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

ISBN Information

Print ISBN: 9780875902395

Online ISBN: 9781118668757



  • Coma;
  • Comet Giacobini-Zinner;
  • Earth radio;
  • Electron density;
  • International Cometary Explorer (ICE)


During the encounter of the International Cometary Explorer (ICE) with comet P/Giacobini-Zinner, the radio astronomy experiment observed occultation and propagation effects on several distant radio sources. The observations of the partial occultation of the galactic radio source between 360 and 1000 kHz show that the 3-dimensional large scale structure of the coma is consistent with the structure determined from in-situ measurements made along the encounter trajectory. In addition, these observations remove a previously existing ambiguity in the position of the galactic source. Between 110 and 360 kHz the Earth source is broadened by scattering by the comet random density inhomogeneities. The amount of broadening indicates that the electron density fluctuations measured in situ by ICE along its trajectory (100% fluctuations with a scale length of 1 to 2 103 km over a path length of 105 km) exist with the same properties in the perpendicular direction.