Detection of cometary ions at a distance of seven million kilometers upstream of comet halley

Koh Ichiro Oyama, Takumi Abe, Takashi Okuzawa, Ichishiro Konno

Research output: Contribution to journalArticle


Between 10 and 12 March 1986 Japan's interplanetary spacecraft, Sakigake, traversed the front of comet Halley. The closest approach was at 04:17:00 U.T. on 11 March at a distance of 7 × 106 km. A small fluctuation of solar wind velocity due to H2O+ ions was first detected at the closest approach. However, maximum fluctuation was detected between 22:30:00 and 24:00:00 U.T. on 11 March. The spacecraft was closer than the time of closest approach to the trajectory of comet Halley during this time period. This might suggest that H2O still remains along the path of comet Halley.

Original languageEnglish
Pages (from-to)517-524
Number of pages8
JournalPlanetary and Space Science
Issue number5
Publication statusPublished - 1989 May


All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

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