The auroral footprint of Enceladus on Saturn
Pryor, W.R. and Rymer, A.M. and Mitchell, D.G. and Hill, T.W. and Young, D.T. and Saur, J. and Jones, Geraint H. and Jacobsen, S. and Cowley, S.W.H. and Mauk, B.H. and Coates, Andrew J. and Gustin, J. and Grodent, D. and Gerard, J.C. and Lamy, L. and Nichols, J.D. and Krimigis, S.M. and Esposito, L.W. and Dougherty, M.K. and Jouchoux, A.J. and Stewart, A.I.F. and McClintock, W.E. and Holsclaw, G.M. and Ajello, J.M. and Colwell, J.E. and Hendrix, A.R. and Crary, F.J. and Clarke, J.T. and Zhou, X.Y. (2011) The auroral footprint of Enceladus on Saturn. Nature 472 (7343), pp. 331-333. ISSN 0028-0836.
Although there are substantial differences between the magnetospheres of Jupiter and Saturn, it has been suggested that cryovolcanic activity at Enceladus(1-9) could lead to electrodynamic coupling between Enceladus and Saturn like that which links Jupiter with Io, Europa and Ganymede. Powerful field-aligned electron beams associated with the Io-Jupiter coupling, for example, create an auroral footprint in Jupiter's ionosphere(10,11). Auroral ultraviolet emission associated with Enceladus-Saturn coupling is anticipated to be just a few tenths of a kilorayleigh (ref. 12), about an order of magnitude dimmer than Io's footprint and below the observable threshold, consistent with its non-detection(13). Here we report the detection of magnetic-field-aligned ion and electron beams (offset several moon radii downstream from Enceladus) with sufficient power to stimulate detectable aurora, and the subsequent discovery of Enceladus-associated aurora in a few per cent of the scans of the moon's footprint. The footprint varies in emission magnitude more than can plausibly be explained by changes in magnetospheric parameters-and as such is probably indicative of variable plume activity.
|School:||Birkbeck Schools and Departments > School of Science > Earth and Planetary Sciences > UCL/Birkbeck Centre for Planetary Sciences|
|Date Deposited:||20 Jun 2011 13:28|
|Last Modified:||17 Apr 2013 12:20|
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