Search Publications
Fluvial erosion and post-erosional processes on Titan
Sotin, Christophe; Barnes, Jason W.; Rodriguez, Sebastien +16 more
The surface of Titan has been revealed by Cassini observations in the infrared and radar wavelength ranges as well as locally by the Huygens lander instruments. Sand seas, recently discovered lakes, distinct landscapes and dendritic erosion patterns indicate dynamic surface processes. This study focus on erosional and depositional features that ca…
Dust devil speeds, directions of motion and general characteristics observed by the Mars Express High Resolution Stereo Camera
HRSC Co-Investigator Team; Greeley, Ronald; Whelley, Patrick L. +4 more
A total of 205 dust devils were detected in 23 High Resolution Stereo Camera (HRSC) images taken between January 2004 and July 2006 with the ESA Mars Express orbiter, in which average dust devil heights were ∼660 m and average diameters were ∼230 m. For the first time, dust devil velocities were directly measured from orbit, and range from 1 to 59…
Formation and evolution of the chaotic terrains by subsidence and magmatism: Hydraotes Chaos, Mars
Mangold, Nicolas; Neukum, Gerhard; Costard, François +3 more
The origin of the martian chaotic terrains is still uncertain; and a variety of geologic scenarios have been proposed. We provide topographic profiles of different chaos landscapes, notably Aureum and Hydraotes Chaos, showing that an initial shallow ground subsidence occurred at the first step of the chaos formation. We infer that the subsidence w…
Titan's surface: Search for spectral diversity and composition using the Cassini VIMS investigation
Sotin, Christophe; Barnes, Jason W.; Le Mouélic, Stéphane +11 more
The surface composition of Titan is of great importance for understanding both the internal evolution of Titan and its atmosphere. The Visual and Infrared Mapping Spectrometer (VIMS) investigation on Cassini is observing Titan from 0.35 to 5.11 µm with spatial resolution down to a few kilometers during each flyby of the spacecraft as it orbi…
Resurfacing of Titan by ammonia-water cryomagma
Showman, Adam P.; Lopes, Rosaly M. C.; Lunine, Jonathan I. +1 more
The Cassini Titan Radar Mapper observed on Titan several large features interpreted as cryovolcanic during the October 26, 2004 pass at high northern latitudes [Lopes, R.M.C., and 43 colleagues, 2007. Icarus 186, 395-412]. To date, models of ammonia-water resurfacing have not been tied to specific events or evolutionary stages of Titan. We propose…
Distribution of icy particles across Enceladus' surface as derived from Cassini-VIMS measurements
Sotin, C.; Brown, R. H.; Baines, K. H. +16 more
The surface of Enceladus consists almost completely of water ice. As the band depths of water ice absorptions are sensitive to the size of particles, absorptions can be used to map variations of icy particles across the surface. The Visual and Infrared Mapping Spectrometer (VIMS) observed Enceladus with a high spatial resolution during three Cassi…
Global and temporal variations in hydrocarbons and nitriles in Titan's stratosphere for northern winter observed by Cassini/CIRS
Fletcher, L.; Irwin, P. G. J.; Teanby, N. A. +8 more
Mid-infrared spectra measured by Cassini's Composite InfraRed Spectrometer (CIRS) between July 2004 and January 2007 ( L=293°-328°) have been used to determine stratospheric temperature and abundances of C 2H 2, C 3H 4, C 4H 2, HCN, and HC 3N. Over 65,000 nadir spectra wi…
Titan's hydrodynamically escaping atmosphere
Strobel, Darrell F.
The upper atmosphere of Titan is currently losing mass at a rate ∼(4-5)×10 amus, by hydrodynamic escape as a high density, slow outward expansion driven principally by solar UV heating by CH 4 absorption. The hydrodynamic mass loss is essentially CH 4 and H 2 escape. Their combined escape rates are restricted by po…
The depth of the convective boundary layer on Mars
Pätzold, M.; Hinson, D. P.; Häusler, B. +2 more
We are using observations obtained with Mars Express to explore the structure and dynamics of the martian lower atmosphere. We consider a series of radio occultation experiments conducted in May-August 2004, when the season on Mars was midspring of the northern hemisphere. The measurements are widely distributed in latitude and longitude, but the …
Thermal convection in ice-I shells of Titan and Enceladus
Showman, Adam P.; Mitri, Giuseppe
Cassini-Huygens observations have shown that Titan and Enceladus are geologically active icy satellites. Mitri and Showman [Mitri, G., Showman, A.P., 2005. Icarus 177, 447-460] and McKinnon [McKinnon, W.B., 2006. Icarus 183, 435-450] investigated the dynamics of an ice shell overlying a pure liquid-water ocean and showed that transitions from a co…