Search Publications
How to link the relative abundances of gas species in coma of comets to their initial chemical composition?
Marboeuf, Ulysse; Schmitt, Bernard
Comets are expected to be the most primitive objects in the Solar System. The chemical composition of these objects is frequently assumed to be directly provided by the observations of the abundances of volatile molecules in the coma. The present work aims to determine the relationship between the chemical composition of the coma, the outgassing p…
New constraints on Mars rotation determined from radiometric tracking of the Opportunity Mars Exploration Rover
Park, Ryan S.; Dehant, Veronique; Kuchynka, Petr +4 more
The Opportunity Mars Exploration Rover remained stationary between January and May 2012 in order to conserve solar energy for running its survival heaters during martian winter. While stationary, extra Doppler tracking was performed in order to allow an improved estimate of the martian precession rate. In this study, we determine Mars rotation by …
Glory on Venus cloud tops and the unknown UV absorber
Roatsch, T.; Markiewicz, W. J.; Titov, D. V. +6 more
We report on the implications of the observations of the glory phenomenon made recently by Venus Express orbiter. Glory is an optical phenomenon that poses stringent constraints on the cloud properties. These observations thus enable us to constrain two properties of the particles at the cloud tops (about 70 km altitude) which are responsible for …
Physical and dynamical properties of the main belt triple Asteroid (87) Sylvia
Berthier, J.; Carry, B.; Marchis, F. +2 more
We present the analysis of high angular resolution observations of the triple Asteroid (87) Sylvia collected with three 8-10 m class telescopes (Keck, VLT, Gemini North) and the Hubble Space Telescope. The moons’ mutual orbits were derived individually using a purely Keplerian model. We computed the position of Romulus, the outer moon of the syste…
Valles Marineris dune sediment provenance and pathways
Wray, James J.; Chojnacki, Matthew; Moersch, Jeffrey E. +1 more
Although low-albedo sand is a prevalent component of the martian surface, sources and pathways of the sands are uncertain. As one of the principal present-day martian sediment sinks, the Valles Marineris (VM) rift system hosts a diversity of dune field populations associated with a variety of landforms that serve as potential sediment sources, inc…
Timescales of fluvial activity and intermittency in Milna Crater, Mars
Head, James W.; Fassett, Caleb I.; Buhler, Peter B. +1 more
Milna Crater, Mars (23.4S, 12.3W) exhibits signs of fluvial modification early in Mars history, including a large multi-lobed fan deposit cut by several sinuous valleys. We describe the past hydrologic conditions in Milna and the surrounding area, including a potential lake with a volume of 50 km3. We also introduce new methods (i) to c…
A radar map of Titan Seas: Tidal dissipation and ocean mixing through the throat of Kraken
Soderblom, Jason M.; Kirk, Randolph L.; Lorenz, Ralph D. +9 more
We present a radar map of the Titan’s seas, with bathymetry estimated as proportional to distance from the nearest shore. This naïve analytic bathymetry, scaled to a recent radar sounding of Ligeia Mare, suggests a total liquid volume of ∼32,000 km3, at the low end of estimates made in 2008 when mapping coverage was incomplete. We note …
Modeling the microphysics of CO2 ice clouds within wave-induced cold pockets in the martian mesosphere
Montmessin, F.; Spiga, A.; Lefèvre, F. +2 more
Mesospheric CO2 ice clouds on Mars are simulated with a 1D microphysical model, which includes a crystal growth rate adapted to high supersaturations encountered in the martian mesosphere. Observational constraints (crystal radius and opacity) exist for these clouds observed during the day around the equator at ∼60-80 km altitude. Night…
The methane mole fraction in Titan’s stratosphere from DISR measurements during the Huygens probe’s descent
Bézard, Bruno
We present a determination of the methane mole fraction in Titan's stratosphere using spectral measurements by the Upward Looking Infrared Spectrometer (ULIS) of the Descent Imager/Spectral Radiometer (DISR) aboard the Huygens probe. We analyzed the 1.4-µm band of methane for which a complete linelist, down to very low intensities, was recen…
Cassini-VIMS observations of Saturn's main rings: I. Spectral properties and temperature radial profiles variability with phase angle and elevation
Brown, R. H.; Clark, R. N.; Nicholson, P. D. +10 more
The spectral properties and thermal behavior of Saturn's rings are determined from a dataset of ten radial mosaics acquired by Cassini-VIMS (Visual and Infrared Mapping Spectrometer) between October 29th 2004 and January 27th 2010 with phase angle ranging between 5.7° and 132.4° and elevation angles between -23.5° and 2.6°. These observations, aft…