Search Publications
Alfvén vortices in Saturn's magnetosheath: Cassini observations
Saur, J.; Alexandrova, O.
First signatures of Alfvén vortices in the Kronian magnetosheath are presented. An Alfvén vortex is a non-linear bi-dimensional magnetic structure associated with sheared magnetic field and velocity perturbations, propagating obliquely to the external magnetic field direction. Such structures have been recently discovered by Cluster in Earth's mag…
On the cause of Saturn's plasma periodicity
André, N.; Coates, A. J.; Dougherty, M. K. +6 more
Periodic plasma enhancements are examined for all Cassini orbits from December 29, 2005 through September 7, 2006. The events, which have UT durations of 3-4 hours, are centered near SLS3 longitude 10° at radial distances near 15 RS and at larger W longitudes at larger distances, reaching 180°W by 49 RS. Magnetic-field data w…
Strong jet and a new thermal wave in Saturn's equatorial stratosphere
Fletcher, Leigh N.; Achterberg, Richard K.; Flasar, F. Michael +7 more
The strong jet, with a speed between 500 and 600 m/s, is inferred in the equatorial region of Saturn by combining the nadir and limb observations of Composite Infrared Spectrometer (CIRS) aboard the Cassini spacecraft. A similar jet was discovered on Jupiter (F. M. Flasar et al., 2004a). These discoveries raise the possibility that intense jets ar…
Magnetic complexity in eruptive solar active regions and associated eruption parameters
Georgoulis, Manolis K.
Using an efficient magnetic complexity index in the active-region solar photosphere, we quantify the preflare strength of the photospheric magnetic polarity inversion lines in 23 eruptive active regions with flare/CME/ICME events tracked all the way from the Sun to the Earth. We find that active regions with more intense polarity inversion lines h…
Cassini encounters with hot flow anomaly-like phenomena at Saturn's bow shock
Coates, A. J.; Dougherty, M. K.; Thomsen, M. F. +7 more
The first observations of the kronian equivalent of hot flow anomalies (HFAs) are presented. Using magnetic field and plasma data we discuss two events that were observed upstream of Saturn's bow shock during the first two orbits of the Cassini spacecraft. We suggest that these events result from the interaction between interplanetary current shee…
Understanding the global evolution of Saturn's ring current
Krimigis, S. M.; Mitchell, D. G.; Carbary, J. F. +3 more
An explanation for the morphology and evolution of the ring current in Saturn's magnetosphere is provided. We use global Energetic Neutral Atom (ENA) images of the 20-140 keV proton distribution obtained by the Ion and Neutral Camera (INCA) on board the Cassini spacecraft. A case where the ring current displays an exceptionally clear spiral shape …
A non-hydrostatic Rhea
Mackenzie, R. A.; Iess, L.; Tortora, P. +1 more
Radiometric data obtained during Cassini's close flyby of Rhea, on 26 November 2005, has been subject to several published analyses aiming to determine the satellite's mass and quadrupole gravity moments. Combining aspects of two of these analyses we present our best, unbiased estimates of the gravity field parameters and point out how the constra…
Spectral variability of the Martian high latitude surfaces
Bibring, J. -P.; Gondet, B.; Langevin, Y. +3 more
We report the surface distributions of some minerals in the high latitude (>50°) regions of Mars using the OMEGA/MEx observations in the near-infrared wavelength domains (1-2.5 µm). Mafic minerals (pyroxene and olivine) are observed in the low albedo terrains. The identification of these minerals is consistent with the presence of volcani…
Retreat and reformation of X-line during quasi-continuous tailward-of-the-cusp reconnection under northward IMF
Khotyaintsev, Y.; Vaivads, A.; Hasegawa, H. +6 more
We present observations on 19-20 November 2006 by the Cluster spacecraft that were skimming the high-latitude dusk-flank magnetopause, which are consistent with more than one reconnection X-line present on the tailward side of the cusp under northward IMF. Evidence of quasi-continuous reconnection over 16 hours exists in the form of Alfvénic accel…
Angular beaming model of Jupiter's decametric radio emissions based on Cassini RPWS data analysis
Imai, Masafumi; Imai, Kazumasa; Higgins, Charles A. +1 more
Observations of the low frequency part of Jupiter decameter wavelength (DAM) emissions were made using the Cassini radio and plasma wave science (RPWS) instrument. We have analyzed non-Io-DAM occurrence dependence from 4 MHz to 16 MHz based on the System III central meridian longitude (CML) of the Cassini spacecraft and calculated the occurrence p…