Search Publications

Kinetic Alfvén solitary waves in a plasma with two-temperature superthermal electron populations: the case of Saturn's magnetosphere

Singh, Manpreet; Saini, N. S.; Kourakis, I.

Thanks to the evidence provided by the Cassini spacecraft mission, it is now established that Saturn's magnetospheric plasma consists of various types of positive ions, as well as two distinct populations of electrons, at different temperatures. The electron population energy distributions are characterized by long suprathermal tails and have been…

Heavy negative ion growth in Titan's polar winter

Coates, A. J.; Jones, G. H.; Wellbrock, A. +4 more

A significant but unexpected result of the Cassini mission was the discovery of heavy organic negative ions in Titan's ionosphere at altitudes between about 950 and 1400 km by the CAPS Electron Spectrometer (ELS). The heaviest ions were observed during the T16 fly-by with masses over 13 000 u/q. This is significantly higher than the maximum masses…

Depth of the dynamo region and zonal circulation of the molecular layer in Saturn inferred from its equatorially symmetric gravitational field

Schubert, Gerald; Kong, Dali; Zhang, Keke

The high-precision equatorially symmetric gravitational field of Saturn (the even gravitational coefficients J₂, J₄, …, J₁₂) measured by the Cassini Grand Finale reflects its internal structure, its non-spherical shape caused by rotation and its strong zonal circulation whose location is controlled by the depth of …

Axisymmetric density waves in Saturn's rings

Nicholson, P. D.; Hedman, M. M.

Density waves in Saturn's rings are usually tightly wrapped spiral patterns generated by resonances with either Saturn's moons or structures inside the planet. However, between the Barnard and Bessel Gaps in the Cassini Division (i.e. between 120 240 and 120 300 km from Saturn's spin axis), there are density variations that appear to form an axisy…

Cassini CIRS and ISS opposition effects of Saturn's rings - I. C ring narrow or broad surge?

Déau, E.; Colwell, J. E.; El Moutamid, M. +6 more

We focus on the thermal and optical opposition effects of Saturn's C ring seen by Cassini CIRS (Composite InfraRed Spectrometer) at 15.7 {µ}m and ISS (Imaging Science Subsystem) at 0.6 {µ}m. The opposition surge is a brightness peak observed at low phase angle (α → 0°). Saturn rings' opposition surge was recently observed in reflected …

The dynamics of the outer edge of Saturn's A ring perturbed by the satellites Janus and Epimetheus

Cooper, N. J.; Murray, C. D.; El Moutamid, M. +4 more

We present an analytical model to study the dynamics of the outer edge of Saturn's A ring. The latter is influenced by 7:6 mean motion resonances with Janus and Epimetheus. Because of the horseshoe motion of the two co-orbital moons, the ring edge particles are alternately trapped in a corotation eccentricity resonance (CER) or a Lindblad eccentri…