International Cometary Explorer Encounter with Giacobini-Zinner: Magnetic Field Observations

See allHide authors and affiliations

Science  18 Apr 1986:
Vol. 232, Issue 4748, pp. 382-385
DOI: 10.1126/science.232.4748.382


The vector helium magnetometer on the International Cometary Explorer observed the magnetic fields induced by the interaction of comet Giacobini-Zinner with the solar wind. A magnetic tail was penetrated ∼7800 kilometers downstream from the comet and was found to be 104 kilometers wide. It consisted of two lobes, containing oppositely directed fields with strengths up to 60 nanoteslas, separated by a plasma sheet ∼103kilometers thick containing a thin current sheet. The magnetotail was enclosed in an extended ionosheath characterized by intense hydromagnetic turbulene and interplanetary fields draped around the comet. A distant bow wave, which may or may not have been a bow shock, was observed at both edges of the ionosheath. Weak turbulence was observed well upstream of the bow wave.