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International cometary explorer encounter with giacobini-zinner: magnetic field observations
Science (New York, N.Y.)
|April 18, 1986
Summary
The International Cometary Explorer detected a comet Giacobini-Zinner magnetic tail, revealing oppositely directed fields and a thin current sheet. This interaction with the solar wind created turbulence and a distant bow wave.
Area of Science:
- Space Physics
- Cometary Science
- Magnetohydrodynamics
Background:
- Comets interact dynamically with the solar wind, creating complex plasma environments.
- Understanding these interactions is key to deciphering cometary evolution and space weather.
Purpose of the Study:
- To investigate the magnetic field structures generated by the interaction of comet Giacobini-Zinner with the solar wind.
- To analyze the characteristics of the comet's magnetotail and surrounding plasma environment.
Main Methods:
- In-situ magnetic field measurements using the vector helium magnetometer on the International Cometary Explorer.
- Analysis of plasma and field data to identify structural features like the magnetic tail, plasma sheet, and ionosheath.
Main Results:
- A magnetic tail, approximately 10^4 km wide, was observed 7800 km downstream from the comet.
- The tail comprised two lobes with oppositely directed fields (up to 60 nT) separated by a ~10^3 km thick plasma sheet containing a thin current sheet.
- An extended ionosheath with intense hydromagnetic turbulence and draped interplanetary fields surrounded the magnetotail. A distant bow wave was noted, with weak turbulence observed upstream.
Conclusions:
- The study provides detailed in-situ evidence of a comet's induced magnetotail structure and its interaction with the solar wind.
- The findings highlight the complex plasma dynamics, including turbulence and field draping, occurring in the cometary environment.
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