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Mass of Saturn's magnetodisc: Cassini observations
Author(s) -
Arridge C. S.,
Russell C. T.,
Khurana K. K.,
Achilleos N.,
André N.,
Rymer A. M.,
Dougherty M. K.,
Coates A. J.
Publication year - 2007
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl028921
Subject(s) - saturn , magnetosphere , physics , magnetosphere of saturn , spacecraft , current sheet , current (fluid) , centrifugal force , rings of saturn , astronomy , astrobiology , astrophysics , planet , magnetohydrodynamics , magnetic field , classical mechanics , rotational speed , magnetopause , quantum mechanics , thermodynamics
Saturn's ring current was observed by Pioneer 11 and the two Voyager spacecraft to extend 8–16 R S in the equatorial plane and appeared to be driven by stress balance with the centrifugal force. We present Cassini observations that show thin current sheets on the dawn flank of Saturn's magnetosphere, symptomatic of the formation of a magnetodisc. We show that the centrifugal force is the dominant mechanical stress in these current sheets, which reinforces a magnetodisc interpretation – the formation of the current sheet is fundamentally rotational in origin. The stress balance calculation is also used to estimate the mass density in the disc, which show good agreement with independent in‐situ measurements of the density. We estimate the total mass in the magnetodisc to be ∼10 6 kg.