Search Publications
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,…
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 ∼…
The Ion Composition of Saturn's Equatorial Ionosphere as Observed by Cassini
Kurth, W. S.; Wahlund, J. -E.; Waite, J. H. +5 more
The Cassini Orbiter made the first in situ measurements of the upper atmosphere and ionosphere of Saturn in 2017. The Ion and Neutral Mass Spectrometer (INMS) found molecular hydrogen and helium as well as minor species including water, methane, ammonia, and organics. INMS ion mode measurements of light ion species (H+, H2
Understanding Cassini RPWS Antenna Signals Triggered by Dust Impacts
Hospodarsky, G. B.; Kurth, W. S.; Zaslavsky, A. +11 more
Electric field antennas are capable of detecting dust impacts in different space environment. We analyze the dust impact signals detected by the Cassini Radio and Plasma Wave Science instrument at different locations around Saturn and compare them with dust impact signals simulated in laboratory conditions and numerically. The spacecraft potential…
Saturn's Ionosphere: Electron Density Altitude Profiles and D-Ring Interaction From The Cassini Grand Finale
Persoon, A. M.; Kurth, W. S.; Wahlund, J. -E. +8 more
We present the electron density (ne) altitude profiles of Saturn's ionosphere at near-equatorial latitudes from all 23 orbits of Cassini's Grand Finale. The data are collected by the Langmuir probe part of the Radio and Plasma Wave Science investigation. A high degree of variability in the electron density profiles is observed. However,…
Raised Rims Around Titan's Sharp-Edged Depressions
Lunine, J. I.; Hayes, A. G.; Lopes, R. M. C. +6 more
We perform a systematic survey of Titan's sharp-edged depressions (SEDs) using a combination of Cassini synthetic aperture radar images and delay-Doppler processed altimetry. We identify a characteristic bright-dark pattern around 172 SEDs that correlates with elevated features only resolved with the highest resolution topographic data. We find th…
Observational Evidence for Summer Rainfall at Titan's North Pole
Sotin, Christophe; Barnes, Jason W.; Soderblom, Jason M. +13 more
Methane rain on Saturn's moon Titan makes it the only place, other than Earth, where rain interacts with the surface. When and where that rain wets the surface changes seasonally in ways that remain poorly understood. Here we report the discovery of a bright ephemeral feature covering an area of 120,000 km2 near Titan's north pole in ob…
Energetic Oxygen and Sulfur Charge States in the Outer Jovian Magnetosphere: Insights From the Cassini Jupiter Flyby
Wilson, R. J.; Krimigis, S. M.; Mitchell, D. G. +10 more
On 10 January 2001, Cassini briefly entered into the magnetosphere of Jupiter, en route to Saturn. During this excursion into the Jovian magnetosphere, the Cassini Magnetosphere Imaging Instrument/Charge-Energy-Mass Spectrometer detected oxygen and sulfur ions. While Charge-Energy-Mass Spectrometer can distinguish between oxygen and sulfur charge …
Spectral Signatures of Adiabatic Electron Acceleration at Saturn Through Corotation Drift Cancelation
Krupp, N.; Roussos, E.; Zong, Q. G. +3 more
The energetic electron spectra of Saturn's radiation belts are studied using Cassini's 13 years of measurements by the Magnetosphere Imaging Instrument/Low Energy Magnetospheric Measurement System detector. We find that between L shells (L) of 10 and 4.5 the differential flux spectrum of 0.3- to 1.6-MeV electrons evolves from a single power law to…
The Dynamics of Saturn's Main Aurorae
Badman, S. V.; Ray, L. C.; Cowley, S. W. H. +9 more
Saturn's main aurorae are thought to be generated by plasma flow shears associated with a gradient in angular plasma velocity in the outer magnetosphere. Dungey cycle convection across the polar cap, in combination with rotational flow, may maximize (minimize) this flow shear at dawn (dusk) under strong solar wind driving. Using imagery from Cassi…