Search Publications
On the origin of gypsum in the Mars north polar region
Bibring, Jean-Pierre; Langevin, Yves; Poulet, François +2 more
We describe the distribution and concentration of the largest Martian gypsum deposit discovered to date by the Mars Express OMEGA (Observatoire pour le Mineralogie, l'Eau, les Glaces et l'Activité) imaging spectrometer, its relationship to the late Amazonian-aged north polar dunes in which it is found, and its likely origin. Gypsum has not been di…
Lineated valley fill and lobate debris apron stratigraphy in Nilosyrtis Mensae, Mars: Evidence for phases of glacial modification of the dichotomy boundary
Head, James W.; Levy, Joseph S.; Marchant, David R.
The Nilosyrtis Mensae region is important among dichotomy boundary fretted terrain outcrops, as it provides evidence of overprinting of ancient landscapes by a suite of glacial features, providing a composite view of the variety of midlatitude glacial modification processes that can occur during recent Martian ice ages. On the basis of a series of…
Hydration state of the Martian surface as seen by Mars Express OMEGA: 2. H2O content of the surface
Mustard, John F.; Bibring, Jean-Pierre; Langevin, Yves +4 more
Visible-near infrared reflectance spectra acquired by the Mars Express Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité (OMEGA) spectrometer are used to estimate the absolute water content within the uppermost fraction of the Martian regolith. This upper surface layer represents the boundary between the regolith and atmosphere; th…
Near-infrared spectral mapping of Titan's mountains and channels
Sotin, Christophe; Barnes, Jason W.; Rodriguez, Sebastien +17 more
We investigate the spectral reflectance properties of channels and mountain ranges on Titan using data from Cassini's Visual and Infrared Mapping Spectrometer (VIMS) obtained during the T9 encounter (26 December 2005). We identify the location of channels and mountains using synthetic aperture radar maps obtained from Cassini's RADAR instrument du…
Hyperspectral imaging of convective CO2 ice clouds in the equatorial mesosphere of Mars
Bibring, J. -P.; Gondet, B.; Langevin, Y. +4 more
A unique feature of the Martian climate is the possibility for carbon dioxide, the main atmospheric constituent, to condense as ice. CO2 ice is usually detected as frost but is also known to exist as clouds. This paper presents the first unambiguous observation of CO2 ice clouds on Mars. These images were obtained by the visi…
Hydration state of the Martian surface as seen by Mars Express OMEGA: 1. Analysis of the 3 µm hydration feature
Bibring, J. -P.; Gondet, B.; Langevin, Y. +5 more
Global mapping by the visible/near-infrared OMEGA spectrometer gives the first opportunity to study in detail the characteristics of the 3 µm hydration absorption on the surface of Mars. This feature is caused by bending and stretching vibrations of adsorbed or structural H2O and/or OH- bound to minerals. A specific data reduction…
Recent glaciation at high elevations on Arsia Mons, Mars: Implications for the formation and evolution of large tropical mountain glaciers
Head, James W.; Fastook, James L.; Marchant, David R. +1 more
The ~166,000 km2 fan-shaped deposit at Arsia Mons contains three characteristic facies (ridged, knobby, and smooth), which are interpreted as the depositional remains of a cold-based glacier that was present on the west-northwestern flanks in the Late Amazonian period of Mars history. Here, we consider several high-elevation graben on t…
Geomorphic and stratigraphic analysis of Crater Terby and layered deposits north of Hellas basin, Mars
Moore, Jeffrey M.; Wilson, Sharon A.; Howard, Alan D. +1 more
The geologic history of Crater Terby is developed through geomorphic and stratigraphic analyses within the regional context of the Hellas basin. Terby exhibits ~2-km-thick sequences of layers that consist of repetitive, subhorizontal and laterally continuous beds. The layers are predominantly fine-grained as indicated by their ease of aeolian eros…
Young lava flows on the eastern flank of Ascraeus Mons: Rheological properties derived from High Resolution Stereo Camera (HRSC) images and Mars Orbiter Laser Altimeter (MOLA) data
Head, J. W.; Neukum, G.; Hiesinger, H.
We report on estimates of the rheological properties of late-stage lava flows on the eastern flank of Ascraeus Mons, Mars. From previous studies it is known that the dimensions of flows reflect rheological properties such as yield strength, effusion rates, and viscosity. Our estimates are based on new high-resolution images obtained by the High Re…
Combinations of processes responsible for Martian impact crater ``layered ejecta structures'' emplacement
Neukum, Gerhard; Ori, Gian Gabriele; Komatsu, Goro +2 more
We utilized images and stereo-derived topographic data acquired by the High Resolution Stereo Camera (HRSC) and Thermal Emission Imaging System (THEMIS) images together with other data in order to study the geology of ``layered ejecta structures'' associated with relatively pristine Martian impact craters. The geomorphology and morphometric proper…