Search Publications
Global maps of anhydrous minerals at the surface of Mars from OMEGA/MEx
Bibring, J. -P.; Gondet, B.; Langevin, Y. +7 more
We here reassess the global distribution of several key mineral species using the entire OMEGA/Mars Express VIS-NIR imaging spectrometer data set, acquired from orbit insertion in January 2004 to August 2010. Thirty-two pixels per degree global maps of ferric oxides, pyroxenes and olivines have been derived. A significant filtering process was app…
Extensive surface pedogenic alteration of the Martian Noachian crust suggested by plateau phyllosilicates around Valles Marineris
Jaumann, R.; Quantin, Cathy; Le Deit, Laetitia +6 more
Thousands of phyllosilicate-rich outcrops, mainly iron or magnesium-rich are exposed on Noachian terrains in the Martian southern highlands. We analyzed 90 CRISM observations and more than a hundred HiRISE images located on the plateaus surrounding Valles Marineris. We mapped an extensive Al- and Fe/Mg-phyllosilicate-rich formation covering at lea…
Most Mars minerals in a nutshell: Various alteration phases formed in a single environment in Noctis Labyrinthus
Murchie, Scott L.; Mustard, John F.; Le Mouélic, Stéphane +7 more
A closed depression in the Noctis Labyrinthus region of Mars (at 10.4°S, 98.6°W), believed to have formed in the Late Hesperian, holds an inner pit partially filled with several hundred meters of stratified material. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) visible-near infrared reflectance data reveal signatures of numerous hy…
Ion densities and composition of Titan's upper atmosphere derived from the Cassini Ion Neutral Mass Spectrometer: Analysis methods and comparison of measured ion densities to photochemical model simulations
Edberg, Niklas J. T.; Liang, Mao-Chang; Mandt, Kathleen E. +16 more
The Cassini Ion Neutral Mass Spectrometer (INMS) has measured both neutral and ion species in Titan's upper atmosphere and ionosphere and the Enceladus plumes. Ion densities derived from INMS measurements are essential data for constraining photochemical models of Titan's ionosphere. The objective of this paper is to present an optimized method fo…
Influence of temperature, composition, and grain size on the tensile failure of water ice: Implications for erosion on Titan
Litwin, Kimberly L.; Zygielbaum, Beth R.; Polito, Peter J. +2 more
Ice resistance to tensile fracture influences surface morphodynamics on outer planetary satellites such as Titan, yet measurements of tensile strength and fracture toughness of polycrystalline water ice at temperatures below terrestrial conditions (<220 K) have not been previously reported. We investigated these parameters from 260 K to 110 K u…
Constraints on the history of open-basin lakes on Mars from the composition and timing of volcanic resurfacing
Mustard, John F.; Goudge, Timothy A.; Head, James W. +1 more
Abundant evidence exists for valley network-related fluvial activity near the Noachian-Hesperian transition on Mars, and areally significant quantities of volcanic ridged plains were emplaced during this period as well. Thus, it is worthwhile to explore the hypothesis that lava-water interaction occurred on the surface of Mars at this time. We ana…
Empirical energy spectra of neutralized solar wind protons from the lunar regolith
Barabash, S.; Holmström, M.; Futaana, Y. +7 more
We present an empirical model of the energy spectra for hydrogen energetic neutral atoms (ENA) backscattered from the lunar surface based on Chandrayaan-1 Energetic Neutral Atom (CENA) observations. The observed energy spectra of the backscattered ENAs are well reproduced by Maxwell-Boltzmann distribution functions. The backscatter fraction is con…
Densities and temperatures in the Venus mesosphere and lower thermosphere retrieved from SOIR on board Venus Express: Carbon dioxide measurements at the Venus terminator
Vandaele, A. C.; Robert, S.; Montmessin, F. +4 more
SOIR is a high-resolution spectrometer flying on board the ESA Venus Express mission. It performs solar occultations of the Venus high atmosphere, and so defines unique vertical profiles of many of the Venus key species. In this paper, we focus on the Venus main constituent, carbon dioxide. We explain how the temperature, the total density, and th…
Aphelion water-ice cloud mapping and property retrieval using the OMEGA imaging spectrometer onboard Mars Express
Bibring, J. -P.; Gondet, B.; Langevin, Y. +8 more
Mapping of the aphelion clouds over the Tharsis plateau and retrieval of their particle size and visible opacity are made possible by the OMEGA imaging spectrometer aboard Mars Express. Observations cover the period from MY26 Ls = 330° to MY29 Ls = 180° and are acquired at various local times, ranging from 8 AM to 6 PM. Cloud…
The roles of charge exchange and dissociation in spreading Saturn's neutral clouds
Delamere, P. A.; Bagenal, F.; Fleshman, B. L. +1 more
Neutrals sourced directly from Enceladus's plumes are initially confined to a dense neutral torus in Enceladus's orbit around Saturn. This neutral torus is redistributed by charge exchange, impact/photodissociation, and neutral-neutral collisions to produce Saturn's neutral clouds. Here we consider the former processes in greater detail than in pr…