The Morphology of Saturn's Aurorae Observed During the Cassini Grand Finale
Cassini's mission exploring the Saturn system ended with the Grand Finale, a series of orbits bringing the spacecraft closer to the planet than ever before and providing unique opportunities for observations of the ultraviolet aurorae. This study presents a selection of high‐resolution imagery showing the aurorae's small‐scale structure in unprecedented detail. We find the main arc to vary between a smooth and a rippled structure, likely indicating quiet and disturbed magnetospheric conditions, respectively. It is usually accompanied by a diffuse and dim outer emission on its equatorward side which appears to be driven by wave scattering of hot electrons from the inner ring current into the loss cone. The duskside is characterized by highly dynamic structures which may be signatures of radial plasma injections. This image set will be the only high‐resolution data for the foreseeable future and hence forms an important basis for future auroral research on Saturn.
All Cassini data are publicly available from the NASA Planetary Data System (https://pds.jpl.nasa.gov). Cassini operations are supported by NASA (managed by the Jet Propulsion Laboratory) and European Space Agency (ESA). A. B. was funded by a Lancaster University FST studentship. S. W. H. C. was supported by STFC Grant ST/N000749/1. S. V. B., L. C. R., and J. K. were supported by STFC Grant ST/R000816/1. S. V. B. was also supported by an STFC Ernest Rutherford FellowshipST/M005534/1. B. P. acknowledges financial support from the Belgian Federal Science Policy Office (BELSPO) via the PRODEX Programme of ESA.
CitationBader, A., Cowley, S. W. H., Badman, S. V., Ray, L. C., Kinrade, J., Palmaerts, B., & Pryor, W. R.. ( 2020), The morphology of Saturn's aurorae observed during the Cassini Grand Finale. Geophysical Research Letters, 47, e2019GL085800. https://doi.org/10.1029/2019GL085800
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