[en] Saturn is a source of intense kilometre-wavelength radio emissions that are believed to be associated with its polar aurorae(1,2), and which provide an important remote diagnostic of its magnetospheric activity. Previous observations implied that the radio emission originated in the polar regions, and indicated a strong correlation with solar wind dynamic pressure(1,3-7). The radio source also appeared to be fixed near local noon and at the latitude of the ultraviolet aurora(1,2). There have, however, been no observations relating the radio emissions to detailed auroral structures. Here we report measurements of the radio emissions, which, along with high-resolution images of Saturn's ultraviolet auroral emissions(8), suggest that although there are differences in the global morphology of the aurorae, Saturn's radio emissions exhibit an Earth-like correspondence between bright auroral features and the radio emissions. This demonstrates the universality of the mechanism that results in emissions near the electron cyclotron frequency narrowly beamed at large angles to the magnetic field(9,10).
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Kurth, William S.; University of Iowa > Department of Physics and Astronomy
Gurnett, Donald A.; University of Iowa > Department of Physics and Astronomy
Clarke, John T.; Boston University
Zarka, Philippe; Observatoire de Paris > Space Research Department
Desch, Michael D.; NASA > Goddard Space Flight Center
Kaiser, Michael L.; NASA > Goddard Space Flight Center
Cecconi, Baptiste; University of Iowa > Department of Physics and Astronomy
Lecacheux, Alain; Observatoire de Paris > Space Research Department
Farrell, William M.; NASA > Goddard Space Flight Center
Grodent, Denis ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Prangé, Renée; Observatoire de Paris > Space Research Department
Dougherty, Michele K.; Imperial College of Science and Technology (London) > Blackett Laboratory
Crary, Frank J.; Southwest Research Institute (Texas)
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