Solar wind interactions with Comet 19P/Borrelly

D. T. Young*, F. J. Crary, J. E. Nordholt, F. Bagenal, D. Boice, J. L. Burch, A. Eviatar, R. Goldstein, J. J. Hanley, D. J. Lawrence, D. J. McComas, R. Meier, D. Reisenfeld, K. Sauer, R. C. Wiens

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

45 Scopus citations


The Plasma Experiment for Planetary Exploration (PEPE) made detailed observations of the plasma environment of Comet 19P/Borrelly during the Deep Space (DS1) flyby on September 22, 2001. Several distinct regions and boundaries have been identified on both inbound and outbound trajectories, including an upstream region of decelerated solar wind plasma and cometary ion pickup, the cometary bow shock, a sheath of heated and mixed solar wind and cometary ions, and a collisional inner coma dominated by cometary ions. All of these features were significantly offset to the north of the nucleus-Sun line, suggesting that the coma itself produces this offset, possibly because of well-collimated large dayside jets directed 8°-10° northward from the nucleus as observed by the DS1 MICAS camera. The maximum observed ion density was 1640 ion/cm3 at a distance of 2650 km from the nucleus while the flow speed dropped from 360 km/s in the solar wind to 8 km/s at closest approach. Preliminary analysis of PEPE mass spectra suggest that the ratio of CO+/H2O+ is lower than that observed with Giotto at 1P/Halley.

Original languageEnglish
Pages (from-to)80-88
Number of pages9
Issue number1
StatePublished - Jan 2004


FundersFunder number
National Aeronautics and Space Administration
Jet Propulsion Laboratory961207, 960439, 960619
Jet Propulsion Laboratory
University of Michigan
Southwest Research Institute1216657
Southwest Research Institute


    • Comets, composition
    • Comets, dynamics
    • Solar wind


    Dive into the research topics of 'Solar wind interactions with Comet 19P/Borrelly'. Together they form a unique fingerprint.

    Cite this