Search Publications
The bathymetry of a Titan sea
Paillou, Philippe; Zebker, Howard; Lunine, Jonathan +9 more
We construct the depth profile—the bathymetry—of Titan's large sea Ligeia Mare from Cassini RADAR data collected during the 23 May 2013 (T91) nadir-looking altimetry flyby. We find the greatest depth to be about 160 m and a seabed slope that is gentler toward the northern shore, consistent with previously imaged shoreline morphologies. Low radio s…
Growth mechanisms and dune orientation on Titan
Lorenz, Ralph D.; Tokano, Tetsuya; Rodriguez, Sébastien +8 more
Dune fields on Titan cover more than 17% of the moon's surface, constituting the largest known surface reservoir of organics. Their confinement to the equatorial belt, shape, and eastward direction of propagation offer crucial information regarding both the wind regime and sediment supply. Herein, we present a comprehensive analysis of Titan's dun…
Surface of Ligeia Mare, Titan, from Cassini altimeter and radiometer analysis
Le Gall, Alice; Hayes, Alex; Zebker, Howard +3 more
Cassini radar observations of the surface of Ligeia Mare collected during the 23 May 2013 (T91) Cassini flyby show that it is extremely smooth, likely to be mostly methane in composition, and exhibits no surface wave activity. The radar parameters were tuned for nadir-looking geometry of liquid surfaces, using experience from Cassini's only compar…
The long-term steady motion of Saturn's hexagon and the stability of its enclosed jet stream under seasonal changes
Hueso, R.; Sánchez-Lavega, A.; Rojas, J. F. +14 more
We investigate the long-term motion of Saturn's north pole hexagon and the structure of its associated eastward jet, using Cassini imaging science system and ground-based images from 2008 to 2014. We show that both are persistent features that have survived the long polar night, the jet profile remaining essentially unchanged. During those years, …
The flushing of Ligeia: Composition variations across Titan's seas in a simple hydrological model
Lorenz, Ralph D.
We use a simple box model to explore possible differences in the liquid composition of Titan's seas. Major variations in the abundance of involatile ethane, somewhat analogous to salinity in terrestrial waters, arise from the hydrological cycle, which introduces more "fresh" methane rainfall at the highest latitudes in summer. The observed composi…
Cusp observation at Saturn's high-latitude magnetosphere by the Cassini spacecraft
Coates, A. J.; Krupp, N.; Dougherty, M. K. +11 more
We report on the first analysis of magnetospheric cusp observations at Saturn by multiple in situ instruments onboard the Cassini spacecraft. Using this we infer the process of reconnection was occurring at Saturn's magnetopause. This agrees with remote observations that showed the associated auroral signatures of reconnection. Cassini crossed the…
Can magnetopause reconnection drive Saturn's magnetosphere?
Coates, A. J.; Russell, C. T.; Dougherty, M. K. +3 more
While solar wind-driven compression of Saturn's magnetosphere is an important trigger of magnetospheric dynamics, the importance of magnetopause reconnection has been the subject of debate. Here we use Cassini observations at Saturn's magnetopause to address this open issue. Measured conditions at the boundary suggest a typical reconnection electr…
Nanodust detection near 1 AU from spectral analysis of Cassini/Radio and Plasma Wave Science data
Schippers, P.; André, N.; Kurth, W. S. +3 more
Nanodust grains of a few nanometers in size are produced near the Sun by collisional breakup of larger grains and picked up by the magnetized solar wind. They have so far been detected at 1 AU by only the two STEREO spacecraft. Here we analyze the spectra measured by the radio and plasma wave instrument onboard Cassini during the cruise phase clos…
The ionosphere of Saturn as observed by the Cassini Radio Science System
Anabtawi, Aseel; Barbinis, Elias; Fleischman, Don +5 more
Fifty-nine ionsopheric radio occultation observations of the vertical electron density profile in the Saturn ionosphere have been made since the Cassini spacecraft was inserted in orbit around Saturn in 2004. Significant orbit to orbit variations were observed, but the general trend noted in earlier orbits, namely, increasing electron densities wi…
Discontinuities in the magnetic field near Enceladus
Dougherty, Michele K.; Saur, Joachim; Kriegel, Hendrik +2 more
The plasma interaction of Saturn's icy moon Enceladus generates a hemisphere coupling current system that directly connects the giant planet's northern and southern polar magnetosphere. Based on Cassini magnetometer observations from all 20 targeted Enceladus flybys between 2004 and 2014, we study the magnetic field discontinuities associated with…