Open AccessHubble Space Telescope imaging of Jupiter's UV aurora during the Galileo orbiter mission
Author(s) -
Clarke John T.,
Ballester Gilda,
Trauger John,
Ajello Joe,
Pryor Wayne,
Tobiska Kent,
Connerney J. E. P.,
Gladstone G. Randall,
Waite J. H.,
Ben Jaffel Lotfi,
Gérard JeanClaude
Publication year - 1998
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/98je01130
Subject(s) - jupiter (rocket family) , orbiter , galileo (satellite navigation) , physics , brightness , longitude , astronomy , magnetosphere , geology , latitude , geodesy , magnetic field , space shuttle , quantum mechanics
Hubble Space Telescope (HST) Wide‐Field Planetary Camera 2 (WFPC 2) images of Jupiter's aurora have been obtained close in time with Galileo ultraviolet spectrometer (UVS) spectra and in situ particles, fields, and plasma wave measurements between June 1996 and July 1997, overlapping Galileo orbits G1, G2, G7, G8, and C9. This paper presents HST images of Jupiter's aurora as a first step toward a comparative analysis of the auroral images with the in situ Galileo data. The WFPC 2 images appear similar to earlier auroral images, with the main ovals at similar locations to those observed over the preceding 2 years, and rapidly variable emissions poleward of the main ovals. Further examples have been observed of the equatorward surge of the auroral oval over 140–180° longitude as this region moves from local morning to afternoon. Comparison of the WFPC 2 reference auroral ovals north and south with the VIP4 planetary magnetic field model suggests that the main ovals map along magnetic field lines exceeding 15 R J , and that the Io footprint locations have lead angles of 0–10° from the instantaneous magnetic projection. There was an apparent dawn auroral storm on June 23, 1996, and projections of the three dawn storms imaged with HST to date demonstrate that these appear consistently along the WFPC 2 reference oval. Auroral emissions have been consistently observed from Io's magnetic footprints on Jupiter. Possible systematic variations in brightness are explored, within factor of 6 variations in brightness with time. Images are also presented marked with expected locations of any auroral footprints associated with the satellites Europa and Ganymede, with localized emissions observed at some times but not at other times.