Journal article
Dusty plasma in the vicinity of Enceladus
Journal of Geophysical Research, Vol.116(A12), A12221
12/2011
DOI: 10.1029/2011JA017038
Abstract
We present in situ Cassini Radio Plasma Wave Science observations in the vicinity of Enceladus and in the E ring of Saturn that indicate the presence of dusty plasma. The four flybys of Enceladus in 2008 revealed the following cold plasma characteristics: (1) there is a large plasma density (both ions and electrons) within the Enceladus plume region, (2) no plasma wake effect behind Enceladus was detected, (3) electron densities are generally much lower than the ion densities in the E ring (n(e)/n(i) < 0.5) as well as in the plume (n(e)/n(i) < 0.01), and (4) the average bulk ion drift speed is significantly less than the corotation speed and is instead close to the Keplerian speed. These signatures result from half or more of the electrons being attached to dust grains and by the interaction between the surrounding cold plasma and the predominantly negatively charged submicrometer-sized dust grains. The dust and plasma properties estimated from the observations clearly show that the dust-plasma interaction is collective. This strong dust-plasma coupling appears not only in the Enceladus plume but also in the Enceladus torus, typically from about 20 R(E) (similar to 5000 km) north and about 60 R(E) (similar to 15,000 km) south of Enceladus. We also suggest that the dust-plasma interaction in the E ring is the cause of the planetary spin-modulated dynamics of Saturn's magnetosphere at large.
Details
- Title: Subtitle
- Dusty plasma in the vicinity of Enceladus
- Creators
- Michiko W. Morooka - Swedish Institute of Space PhysicsJan-Erik Wahlund - Swedish Institute of Space PhysicsAnders I. Eriksson - Swedish Institute of Space PhysicsW. M. Farrell - Goddard Space Flight CenterD. A. Gurnett - University of IowaW. S. Kurth - University of IowaA. M. Persoon - University of IowaMuhammad Shafiq - Swedish Institute of Space PhysicsMats Andre - Swedish Institute of Space PhysicsMadeleine K. G. Holmberg - Institutet för rymdfysik, Uppsalaavdelningen
- Resource Type
- Journal article
- Publication Details
- Journal of Geophysical Research, Vol.116(A12), A12221
- DOI
- 10.1029/2011JA017038
- ISSN
- 0148-0227
- eISSN
- 2156-2202
- Grant note
- name: Swedish National Space Board, award: 0; DOI: 10.13039/100000104, name: NASA, award: 0
- Language
- English
- Date published
- 12/2011
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984455659402771
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