Comet Halley | Published:

Observations of waves and plasma in the environment of comet Halley

Naturevolume 321pages290291 (1986) | Download Citation



The high-frequency plasma-wave analyser (APV-V) carried by the spacecraft Vega 1 and Vega 2 measured electric fields at frequencies up to 300 kHz and characteristic parameters of the ambient plasma during the encounters with comet Halley. The data collected on Vega 1 and Vega 2 are quite similar. Electric field activity at frequencies of 100 Hz was already significant at a distance of 2.5×l06 km from the nucleus. The field displayed strong fluctuations; its average amplitude and bandwidth increased drastically during the approach, and for distances less than 1.2×105 km a maximum was observed at 200–400 Hz. The plasma density, measured with Langmuir probes, was 104 cm−3 at closest approach.

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  1. Space Science Department, ESA/ESTEC, Keplerlaan, 2200 AG, Noordwijk, The Netherlands

    • R. Grard
    •  & A. Pedersen
  2. Laboratoire de Physique et Chimie de l'Environnement CNRS, 45045, Orléans, France

    • J.-G. Trotignon
    •  & C. Beghin
  3. IZMIRAN, 142092, Troitsk, USSR

    • M. Mogilevsky
    • , Y. Mikhaïlov
    •  & O. Molchanov
  4. Istituto Plasma Spazio, CNR, 00044, Frascati, Italy

    • V. Formisano


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