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The Orbits of the Main Saturnian Satellites, the Saturnian System Gravity Field, and the Orientation of Saturn's Pole
Jacobson, Robert. A.
Four spacecraft have been sent to investigate the Saturnian system: Pioneer 11, Voyager 1, Voyager 2, and Cassini. By analyzing data acquired with these spacecraft together with Earth-based and Hubble Space Telescope satellite astrometry and Saturnian ring and satellite occultations, we constructed a model for the orientation and precession of Sat…
The Structure of the Global Heliosphere as Seen by In-Situ Ions from the Voyagers and Remotely Sensed ENAs from Cassini
Krimigis, Stamatios M.; Mitchell, Donald G.; Hilchenbach, Martin +5 more
The exploration of interplanetary space and our solar bubble, the heliosphere, has made a big leap over the past two decades, due to the path-breaking observations of the two Voyager spacecraft, launched more than 44 years ago. Their in-situ particle and fields measurements were complemented by remote observations of 5.2 to 55 keV Energetic Neutra…
The case for an ocean-bearing Mimas from tidal heating analysis
Rhoden, Alyssa Rose; Walker, Matthew E.
Cassini measurements of Mimas' physical libration can be explained by either a non-hydrostatic core or a global, liquid water ocean beneath a 24-31 km thick ice shell. An ocean within Mimas would be surprising, given the lack of comparable geologic activity to that observed on other ocean-bearing moons like Europa and Enceladus, and thus has impor…
Compositional Measurements of Saturn's Upper Atmosphere and Rings From Cassini INMS: An Extended Analysis of Measurements From Cassini's Grand Finale Orbits
Yelle, R. V.; Hörst, S. M.; Koskinen, T. T. +5 more
The Cassini spacecraft's final orbits sampled Saturn's atmosphere and returned surprisingly complex mass spectra from the Ion and Neutral Mass Spectrometer. Signal returned from the instrument included native Saturn species, as expected, as well as a significant amount of signal attributed to vaporized ices and higher mass organics believed to be …
Polar and mid-latitude vortices and zonal flows on Jupiter and Saturn
Yadav, Rakesh K.; Featherstone, Nicholas A.; Aurnou, Jonathan M. +1 more
Zonal flow on Jupiter and Saturn consists of equatorial super-rotation and alternating East-West jet streams at higher latitudes. Interacting with these zonal flows, numerous vortices occur with various sizes and lifetimes. The Juno mission and Cassini's grand finale have shown that the zonal jets of Jupiter and Saturn extend deeply into their mol…
Implications from secondary emission from neutral impact on Cassini plasma and dust measurements
Edberg, N. J. T.; Vigren, E.; Eriksson, A. I. +4 more
We investigate the role of secondary electron and ion emission from impact of gas molecules on the Cassini Langmuir probe (RPWS-LP or LP) measurements in the ionosphere of Saturn. We add a model of the emission currents, based on laboratory measurements and data from comet 1P/Halley, to the equations used to derive plasma parameters from LP bias v…
Influence of Titan's Variable Electromagnetic Environment on the Global Distribution of Energetic Neutral Atoms
Simon, Sven; Tippens, Tyler; Liuzzo, Lucas
We combine the electromagnetic fields from a hybrid plasma model with a particle tracing tool to study the spatial distribution of energetic neutral atoms (ENAs) emitted from Titan's atmosphere when the moon is exposed to different magnetospheric upstream regimes. These ENAs are generated when energetic magnetospheric ions undergo charge exchange …
Tracking the Evolution of an Ocean Within Mimas Using the Herschel Impact Basin
Rhoden, A. R.; Denton, C. A.
Mimas' small size, lack of geologic activity, and high eccentricity suggest a frozen, inactive history. However, Cassini libration measurements are best explained by a present-day liquid ocean under an ice shell 24-31 km thick, a configuration that tidal heating can support. These unexpected findings have motivated further study of Mimas' surface …
Winter Weakening of Titan's Stratospheric Polar Vortices
Toigo, A. D.; Teanby, N. A.; Newman, C. E. +3 more
Polar vortices are a prominent feature in Titan's stratosphere. The Cassini mission has provided a detailed view of the breakdown of the northern polar vortex and formation of the southern vortex, but the mission did not observe the full annual cycle of the evolution of the vortices. Here we use a TitanWRF general circulation model simulation of a…
Impacts of zonal winds on planetary oscillations and Saturn ring seismology
Fuller, Jim; Dewberry, Janosz W.; Mankovich, Christopher R.
The excitation of density and bending waves in Saturn's C ring by planetary oscillation modes presents a unique opportunity to learn about gas giant interiors and rotation. However, theoretical complications related to Saturn's rapid and differential rotation pose a barrier to the full utilization of ring wave detections. We calculate oscillation …