Open AccessCassini Plasma Spectrometer Electron Spectrometer measurements during the Earth swing‐by on August 18, 1999
Author(s) -
Rymer A. M.,
Coates A. J.,
Svenes K.,
Abel G. A.,
Linder D. R.,
Narheim B.,
Thomsen M.,
Young D. T.
Publication year - 2001
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2001ja900087
Subject(s) - magnetosheath , magnetopause , magnetosphere , plasmasphere , physics , solar wind , magnetosphere of saturn , plasma sheet , bow shock (aerodynamics) , magnetosphere of jupiter , geophysics , van allen radiation belt , polar wind , saturn , astrobiology , plasma , astronomy , atmospheric sciences , planet , shock wave , quantum mechanics , thermodynamics
On August 18, 1999, Cassini flew by the Earth on its way to Saturn. The Cassini Earth swing‐by was the fastest traversal of the Earth's magnetosphere to date. The spacecraft was traveling at 9.1 R E hr −1 (16.1 km s −1 ) and made rapid traversals of several regions of the terrestrial magnetosphere. During the Cassini Earth swing‐by the Electron Spectrometer (ELS) collected almost 9 hours of data in the Earth's magnetosphere and almost 10 hours of solar wind data upstream of the Earth. During the pass, Cassini ELS sampled electrons in the solar wind, bow shock, magnetosheath, magnetopause, radiation belts, plasmasphere, plasma sheet, lobes, and crossings of the tail magnetopause. The purpose of this paper is (1) to give a summary of electron observations including the locations of magnetosphere boundary crossings and (2) to assess how the ELS is functioning as it takes measurements in the greatly differing plasma regimes encountered. Results are shown to be mainly consistent with previous observations with a few exceptions. In addition to anticipated results we present evidence of a low‐energy field‐aligned beam in the plasma sheet and evidence of asymmetry on the dayside and nightside plasmapause position. Preliminary calculations of density and temperature for the solar wind, magnetosheath, and plasma sheet are also presented.