Search Publications
Measurement and implications of Saturn's gravity field and ring mass
Iess, L.; Tortora, P.; Zannoni, M. +10 more
The interior structure of Saturn, the depth of its winds, and the mass and age of its rings constrain its formation and evolution. In the final phase of the Cassini mission, the spacecraft dived between the planet and its innermost ring, at altitudes of 2600 to 3900 kilometers above the cloud tops. During six of these crossings, a radio link with …
Titan's gravity field and interior structure after Cassini
Iess, L.; Durante, Daniele; Hemingway, D. J. +2 more
Since its arrival at Saturn in 2004, Cassini performed nine flybys devoted to the determination of Titan's gravity field and its tidal variations. Here we present an updated gravity solution based on the final data set collected during the gravity-dedicated passes, before Cassini's plunge into Saturn's atmosphere. The data set includes an addition…
Cassini Ring Seismology as a Probe of Saturn’s Interior. I. Rigid Rotation
Fortney, Jonathan J.; Marley, Mark S.; Mankovich, Christopher +1 more
Seismology of the gas giants holds the potential to resolve long-standing questions about their internal structure and rotation state. We construct a family of Saturn interior models constrained by the gravity field and compute their adiabatic mode eigenfrequencies and corresponding Lindblad and vertical resonances in Saturn’s C ring, where more t…
Saturn's Deep Atmospheric Flows Revealed by the Cassini Grand Finale Gravity Measurements
Iess, L.; Guillot, T.; Miguel, Y. +4 more
How deep do Saturn's zonal winds penetrate below the cloud level has been a decades-long question, with important implications not only for the atmospheric dynamics but also for the interior density structure, composition, magnetic field, and core mass. The Cassini Grand Finale gravity experiment enables answering this question for the first time,…
Titan as Revealed by the Cassini Radar
Rodriguez, S.; Barnes, J. W.; Soderblom, J. M. +45 more
Titan was a mostly unknown world prior to the Cassini spacecraft's arrival in July 2004. We review the major scientific advances made by Cassini's Titan Radar Mapper (RADAR) during 13 years of Cassini's exploration of Saturn and its moons. RADAR measurements revealed Titan's surface geology, observed lakes and seas of mostly liquid methane in the …
Isotopic ratios of Saturn's rings and satellites: Implications for the origin of water and Phoebe
Clark, Roger N.; Brown, Robert H.; Cruikshank, Dale P. +1 more
Isotopic ratios have long been used to learn about physical processes acting over a wide range of geological environments, and in constraining the origin and/or evolution of planetary bodies. We report the spectroscopic detection of deuterium in Saturn's rings and satellites, and use these measurements to determine the (D/H) ratios in their near-s…
Plasma Pressures in the Heliosheath From Cassini ENA and Voyager 2 Measurements: Validation by the Voyager 2 Heliopause Crossing
Krimigis, Stamatios M.; Mitchell, Donald G.; Dialynas, Konstantinos +1 more
We report "ground truth," 28- to 3,500-keV in situ ion and 5.2- to 55-keV remotely sensed ENA measurements from Voyager 2/Low Energy Charged Particle detector and Cassini/Ion and Neutral Camera, respectively, that assess the components of the ion pressure in the heliosheath. In this process, we predict an interstellar neutral hydrogen density of ∼…
Observations of the chemical and thermal response of 'ring rain' on Saturn's ionosphere
Baines, Kevin H.; O'Donoghue, James; Moore, Luke +4 more
In this study we performed a new analysis of ground-based observations that were taken on 17 April 2011 using the 10-metre Keck telescope on Mauna Kea, Hawaii. Emissions from H3+, a major ion in Saturn's ionosphere, were previously analyzed from these observations, indicating that peaks in emission at specific latitudes were …
Kronoseismology III: Waves in Saturn's inner C ring
Nicholson, Philip D.; French, Richard G.; McGhee-French, Colleen A. +1 more
We investigate waves driven in Saturn's rings by planetary normal modes, concentrating on the previously unexplored inner C ring. In this region, the known waves all have exceptionally short wavelengths, which has proven problematic for previous studies that depended on the accurate estimate of wave phases for wave identification. However, detaile…
Cassini-VIMS observations of Saturn's main rings: II. A spectrophotometric study by means of Monte Carlo ray-tracing and Hapke's theory
Clark, R. N.; Nicholson, P. D.; D'Aversa, E. +9 more
This work is the second in a series of manuscripts devoted to the investigation of the spectrophotometric properties of Saturn's rings from Cassini-VIMS (Visible and Infrared Mapping Spectrometer) observations. The dataset used for this analysis is represented by ten radial spectrograms of the rings which have been derived in Filacchione et al. (2…