Formation of jets in Comet 19P/Borrelly by subsurface geysers

Roger V. Yelle, Laurence A. Soderblom, J. Randy Jokipii

Research output: Contribution to journalArticle

44 Scopus citations

Abstract

Observations of the inner coma of Comet 19P/Borrelly with the camera on the Deep Space 1 spacecraft revealed several highly collimated dust jets emanating from the nucleus. The observed jets can be produced by acceleration of evolved gas from a subsurface cavity through a narrow orifice to the surface. As long as the cavity is larger than the orifice, the pressure in the cavity will be greater than the ambient pressure in the coma and the flow from the geyser will be supersonic. The gas flow becomes collimated as the sound speed is approached and dust entrainment in the gas flow creates the observed jets. Outside the cavity, the expanding gas loses its collimated character, but the density drops rapidly decoupling the dust and gas, allowing the dust to continue in a collimated beam. The hypothesis proposed here can explain the jets seen in the inner coma of Comet 1P/Halley as well, and may be a primary mechanism for cometary activity.

Original languageEnglish (US)
Pages (from-to)30-36
Number of pages7
JournalIcarus
Volume167
Issue number1
DOIs
StatePublished - Jan 2004

Keywords

  • Comae
  • Comets
  • Jets

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'Formation of jets in Comet 19P/Borrelly by subsurface geysers'. Together they form a unique fingerprint.

  • Cite this