Search Publications
Enceladus's measured physical libration requires a global subsurface ocean
Burns, J. A.; Porco, C.; Tajeddine, R. +5 more
Several planetary satellites apparently have subsurface seas that are of great interest for, among other reasons, their possible habitability. The geologically diverse saturnian satellite Enceladus vigorously vents liquid water and vapor from fractures within a south polar depression and thus must have a liquid reservoir or active melting. However…
Enceladus's internal ocean and ice shell constrained from Cassini gravity, shape, and libration data
Bourgeois, Olivier; Massé, Marion; Čadek, Ondřej +8 more
The intense plume activity at the South Pole of Enceladus together with the recent detection of libration hints at an internal water ocean underneath the outer ice shell. However, the interpretation of gravity, shape, and libration data leads to contradicting results regarding the depth of ocean/ice interface and the total volume of the ocean. Her…
Flux and composition of interstellar dust at Saturn from Cassini’s Cosmic Dust Analyzer
Kempf, S.; Postberg, F.; Srama, R. +12 more
Interstellar dust (ISD) is the condensed phase of the interstellar medium. In situ data from the Cosmic Dust Analyzer on board the Cassini spacecraft reveal that the Saturnian system is passed by ISD grains from our immediate interstellar neighborhood, the local interstellar cloud. We determine the mass distribution of 36 interstellar grains, thei…
Titan's surface at 2.18-cm wavelength imaged by the Cassini RADAR radiometer: Results and interpretations through the first ten years of observation
Lorenz, R. D.; Janssen, M. A.; Hayes, A. G. +12 more
A comprehensive calibration and mapping of the thermal microwave emission from Titan's surface is reported based on radiometric data obtained at 2.18-cm wavelength by the passive radiometer included in the Cassini RADAR instrument. Compared to previous work, the present results incorporate the much larger data set obtained in the approximately ten…
Constraints on the location of a possible 9th planet derived from the Cassini data
Laskar, J.; Fienga, A.; Manche, H. +1 more
To explain the unusual distribution of Kuiper belt objects, several authors have advocated the existence of a super-Earth planet in the outer solar system. It has recently been proposed that a 10 M⊕ object with an orbit of 700 AU semi major axis and 0.6 eccentricity can explain the observed distribution of Kuiper belt objects around Sed…
The B-ring's surface mass density from hidden density waves: Less than meets the eye?
Nicholson, P. D.; Hedman, M. M.
Saturn's B ring is the most opaque ring in our Solar System, but many of its fundamental parameters, including its total mass, are not well constrained. Spiral density waves generated by mean-motion resonances with Saturn's moons provide some of the best constraints on the rings' mass density, but detecting and quantifying such waves in the B ring…
Surface Temperatures on Titan during Northern Winter and Spring
Flasar, F. M.; Coustenis, A.; Achterberg, R. K. +9 more
Meridional brightness temperatures were measured on the surface of Titan during the 2004-2014 portion of the Cassini mission by the Composite Infrared Spectrometer. Temperatures mapped from pole to pole during five two-year periods show a marked seasonal dependence. The surface temperature near the south pole over this time decreased by 2 K from 9…
Nature, distribution, and origin of Titan's Undifferentiated Plains
Janssen, M. A.; Cassini RADAR Team; Lopes, Rosaly M. C. +15 more
The Undifferentiated Plains on Titan, first mapped by Lopes et al. (Lopes, R.M.C. et al., 2010. Icarus, 205, 540-588), are vast expanses of terrains that appear radar-dark and fairly uniform in Cassini Synthetic Aperture Radar (SAR) images. As a result, these terrains are often referred to as ;blandlands;. While the interpretation of several other…
Composition, seasonal change, and bathymetry of Ligeia Mare, Titan, derived from its microwave thermal emission
Lorenz, R. D.; Karatekin, O.; Janssen, M. A. +8 more
For the last decade, the passive radiometer incorporated in the Cassini RADAR has recorded the 2.2 cm wavelength thermal emission from Titan's seas. In this paper, we analyze the radiometry observations collected from February 2007 to January 2015 over one of these seas, Ligeia Mare, with the goal of providing constraints on its composition, bathy…
Observational Constraints on Planet Nine: Cassini Range Observations
Holman, Matthew J.; Payne, Matthew J.
We examine the tidal perturbations induced by a possible additional, distant planet in the solar system on the distance between the Earth and the Cassini spacecraft. We find that measured range residuals alone can significantly constrain the sky position, distance, and mass of the perturbing planet to sections of the sky essentially orthogonal to …