Search Publications
Saturn ring seismology: Evidence for stable stratification in the deep interior of Saturn
Fuller, Jim
Seismology allows for direct observational constraints on the interior structures of stars and planets. Recent observations of Saturn's ring system have revealed the presence of density waves within the rings excited by oscillation modes within Saturn, allowing for precise measurements of a limited set of the planet's mode frequencies. We construc…
Chemical composition of Titan’s atmosphere and ionosphere: Observations and the photochemical model
Krasnopolsky, Vladimir A.
Basic observational data on hydrocarbons, nitriles, and ions on Titan are compared with predictions of the photochemical model. Uncertainties of the observed abundances and differences between the data from different instruments and observing teams are comparable with the differences between the observations and the model results. Main reactions o…
Shape, topography, gravity anomalies and tidal deformation of Titan
Lunine, Jonathan I.; Hayes, Alex; Zebker, Howard +5 more
Gravity measurements and elevation data from the Cassini mission have been used to create shape, global topography and gravity anomaly models of Titan that enable an improved understanding of its outer ice I shell structure. We provide constraints on the averaged ice shell thickness and its long-wavelength lateral variations, as well as the densit…
Coupling of oxygen, nitrogen, and hydrocarbon species in the photochemistry of Titan's atmosphere
Dobrijevic, M.; Loison, J. C.; Hickson, K. M. +1 more
Analysis of recent detections of water by Herschel/HIFI-PACS and Cassini/CIRS suggest for a steep gradient of the water profile in the lower stratosphere of Titan's atmosphere (Cottini, V., Nixon, C.A., Jennings, D.E., Anderson, C.M., Gorius, N., Bjoraker, G.L., Coustenis, A., Teanby, N.A., Achterberg, R.K., Béezard, B., de Kok, R., Lellouch, E., …
Titan’s internal structure inferred from its gravity field, shape, and rotation state
Tobie, Gabriel; Lefèvre, Axel; Baland, Rose-Marie +1 more
Several quantities measured by the Cassini-Huygens mission provide insight into the interior of Titan: the second-degree gravity field coefficients, the shape, the tidal Love number, the electric field, and the orientation of its rotation axis. The measured obliquity and tides, as well as the electric field, are evidence for the presence of an int…
Global mapping and characterization of Titan's dune fields with Cassini: Correlation between RADAR and VIMS observations
Le Mouélic, S.; Cornet, T.; Rodriguez, S. +18 more
Vast fields of linear dunes have been observed in the equatorial regions of Titan, Saturn's largest moon. As the Cassini mission, in orbit around Saturn since July 2004 and extended until May 2017, carries on, the high-resolution coverage of Titan's surface increases, revealing new dune fields and allowing refinements in the examination of their p…
Evidence of Titan's climate history from evaporite distribution
Sotin, Christophe; MacKenzie, Shannon M.; Barnes, Jason W. +8 more
Water-ice-poor, 5-µm-bright material on Saturn's moon Titan has previously been geomorphologically identified as evaporitic. Here we present a global distribution of the occurrences of the 5-µm-bright spectral unit, identified with Cassini's Visual Infrared Mapping Spectrometer (VIMS) and examined with RADAR when possible. We explore t…
Cassini observations reveal a regime of zonostrophic macroturbulence on Jupiter
Read, Peter L.; Young, Roland M. B.; Armstrong, David +4 more
In December 2000, the Cassini fly-by near Jupiter delivered high-resolution images of Jupiter’s clouds over the entire planet in a band between 50°N and 50°S. Three daily-averaged two-dimensional velocity snapshots extracted from these images are used to perform spectral analysis of jovian atmospheric macroturbulence. A similar analysis is also pe…
Global climate modeling of Saturn’s atmosphere. Part I: Evaluation of the radiative transfer model
Forget, F.; Millour, E.; Spiga, A. +8 more
We have developed and optimized a seasonal, radiative-convective model of Saturn’s upper troposphere and stratosphere. It is used to investigate Saturn’s radiatively-forced thermal structure between 3 and 10-6 bar, and is intended to be included in a Saturn global climate model (GCM), currently under development. The main elements of th…
The distribution of methane in Titan’s stratosphere from Cassini/CIRS observations
Lellouch, E.; Flasar, F. M.; Bézard, B. +5 more
Cassini/CIRS spectra in the far- and mid-infrared region are used to determine the abundance of methane in Titan's lower stratosphere and investigate its distribution with latitude. The CIRS spectra include emission from both the CH4 ν4 band at 7.7 µm and pure rotational lines longwards of 50 µm, which show differ…