Comet Halley

Nature 321, 288 - 289 (15 May 1986); doi:10.1038/321288a0

Magnetic field observations in comet Halley's coma

W. Reidler^*, K. Schwingenschuh^*, Ye. G. Yeroshenko^†, V. A. Styashkin^† & C. T. Russell^‡

^*Space Research Institute, Inffeldgasse 12, A-8010 Graz, Austria
^†IZMIRAN, 142092 Troitsk, USSR
^‡Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90024, USA

During the encounter with comet Halley, the magnetometer (MISCHA) aboard the Vega 1 spacecraft observed an increased level of magnetic field turbulence, resulting from an upstream bow wave. Both Vega spacecraft measured a peak field strength of 70−80 nT and observed draping of magnetic field lines around the cometary obstacle. An unexpected rotation of the magnetic field vector was observed, which may reflect either penetration of magnetic field lines into a diffuse layer related to the contact surface separating the solar-wind and cometary plasma, or the persistence of pre-existing interplanetary field structures.

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