Ion Dynamics and Composition in the coma of Comet 19P/Borrelly as measured by Deep Space One

Details Ion Dynamics and Composition in the coma of Comet 19P/Borrelly as measured by Deep Space One Ion Dynamics and Composition in the coma of Comet 19P/Borrelly as measured by Deep Space One

Dec 2009

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009agufm.p11b1210j&link_type=abstract

American Geophysical Union, Fall Meeting 2009, abstract #P11B-1210

Physics

[2780] Magnetospheric Physics / Solar Wind Interactions With Unmagnetized Bodies, [6008] Planetary Sciences: Comets And Small Bodies / Composition, [6050] Planetary Sciences: Comets And Small Bodies / Plasma And Mhd Instabilities

Scientific paper

We report detailed in situ ion measurements from the coma of Comet 19P/Borrelly, as measured by the Plasma Experiment for Planetary Exploration (PEPE) obtained during the flyby of the Deep Space One (DS1) spacecraft on 22 September 2001. Cometary ions were detected at distances from ~5.5 x 105 km to 2200 km from the nucleus of the comet.Previously, plasma interaction measurements were reported by Young et al. (2004). Here, we extend those results, which treated all ion species collectively, and present plasma properties separately for cometary and solar wind ions. We observe the evolution of cometary ions from near stagnation to velocities nearly twice the solar wind proton velocity, which is expected for ion pickup. In addition, we observe the thermal evolution of the cometary ions from ~104 K at closest approach to over 107 K at a distance of 4x104 km from the comet. This is similar to what was observed at Halley (Formisano et al., 1990). Previously, ion composition measurements by the PEPE instruments were reported at closest approach by Nordholt et al. (2003), where it was shown that the water group ion distribution was quite different from Comet Halley observations and cometary models. Here, we refine and extend that work and report on the cometary ion composition as a function of distance from the comet. The key advance in our analysis capability arises from a thorough calibration of the PEPE flight spare over a range of atomic and molecular species relevant to cometary composition. We have also performed extensive ion optic modeling of the ESA tophat analyzer to improve the accuracy of the instrument geometric factor. Our ion abundance analysis shows good qualitative agreement with the cometary model of Boice and Wegmann (2007) for H+, O+, OH+, and H2O+. However, the observed H3O+ and CO+ contents are much lower than model predictions. The H3O+ discrepancy is of particular note, as this was the most abundant molecular ion observed at closest approach to Halley.

Affiliated with

Also associated with

No associations

Rating

Ion Dynamics and Composition in the coma of Comet 19P/Borrelly as measured by Deep Space One does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Ion Dynamics and Composition in the coma of Comet 19P/Borrelly as measured by Deep Space One, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ion Dynamics and Composition in the coma of Comet 19P/Borrelly as measured by Deep Space One will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1767046