Search Publications
Thermal analysis of fractures at Cerberus Fossae, Mars: Detection of air convection in the porous debris apron
Lopez, T.; Antoine, R.; Baratoux, D. +2 more
This study investigates the cause of high nighttime temperatures within Cerberus Fossae, a system of fractures affecting the Central Elysium Planitia. The inner parts (walls and floor) of the fractures are up to 40 K warmer than the surrounding plains. However, several temperature profiles exhibit a local temperature minima occurring in the centra…
Aram Chaos and its constraints on the surface heat flux of Mars
Zegers, Tanja E.; Schumacher, Sandra
The surface heat flux of a planet is an important parameter to characterize its internal activity and to determine its thermal evolution. Here we report on a new method to constrain the surface heat flux of Mars during the Hesperian. For this, we explore the consequences for the martian surface heat flux from a recently presented new hypothesis fo…
Appearance of layered structures in numerical simulations of polydisperse bodies accretion: Application to cometary nuclei
Lasue, J.; Kofman, W.; Levasseur-Regourd, A. C. +2 more
A model for the aggregation of size distribution of cometesimals (Gaussian or power law) into cometary nuclei is developed. Upon disruption induced by collisions, sticking and evolution of the tensile strength and density of the cometesimals by sintering processes are taken into account. The resulting cometary nuclei present specific internal stru…
Landform hierarchy and evolution in Gorgonum and Atlantis basins, Mars
Capitan, Radu Dan; Van De Wiel, Marco
This paper describes the evolution of landforms in Atlantis and Gorgonum basins, using a geomorphologic approach which interprets landform distribution and hierarchy. Rather than looking at the distribution of large-area (>10 6 km 2) geologic sequences, this study focuses on interpreting the local-scale (<10 3
Titan impacts and escape
Zahnle, Kevin J.; Korycansky, D. G.
We report on hydrodynamic calculations of impacts of large (multi-kilometer) objects on Saturn's moon Titan. We assess escape from Titan, and evaluate the hypothesis that escaping ejecta blackened the leading hemisphere of Iapetus and peppered the surface of Hyperion. We carried out two- and three-dimensional simulations of impactors ranging in si…
Stability of co-orbital ring material with applications to the Janus-Epimetheus system
Murray, Carl D.; Williams, Gareth A.
An analytical model that describes the evolution of ring particles that are co-orbital with two larger bodies on near-circular and near-planar orbits has been formulated. This can be used to estimate the lifetime of the particles within the ring. All the examples investigated, such as the Janus-Epimetheus (JE) system, indicate that the particles s…
The density of the upper martian atmosphere measured by Lyman-α absorption with Mars Express SPICAM
Forget, F.; Bertaux, J. -L.; Chaufray, J. -Y. +3 more
Absorption of interplanetary Lyman-α emission by Mars' nightside lower thermosphere was observed by Mars Express Spectrometer for Investigation of Characteristics of the Atmosphere of Mars (SPICAM), and is analyzed to derive the CO 2 density at 110 km during a martian year. The observed density seasonal variability is consistent with re…
Mid-infrared lightcurve of Vesta
Sykes, M. V.; Tedesco, E. F.; Chamberlain, M. A.
We present a thermal mid-infrared lightcurve of Asteroid 4 Vesta and use this to infer variations in thermophysical properties over the surface. Vesta was observed over three nights during the May 2007 opposition with the Infrared Telescope Facility on Mauna Kea. Mid-infrared observations are compared to a model based on the Standard Thermal Model…
Assessing spectral evidence of aqueous activity in two putative martian paleolakes
Roush, Ted L.; Gross, Christoph; Marzo, Giuseppe A. +4 more
We evaluate the evidence for the presence of mineral spectral signatures indicative of the past presence of water at two putative paleolakes on Mars using observations by the Mars Reconnaissance Orbiter (MRO) Compact Reconnaissance Image Spectrometer for Mars (CRISM). CRISM spectra of both sites are consistent with laboratory spectra of Mg-rich ph…
Sizes, shapes, and derived properties of the saturnian satellites after the Cassini nominal mission
Thomas, P. C.
The Cassini spacecraft has provided data on over twenty satellites orbiting Saturn. In this study we update the shape measurements derived from imaging data of nearly all the observed regular satellites (those with low eccentricities and inclinations) and briefly discuss some of the implications of their properties. In particular, the improved dat…