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Sulfates in Martian Layered Terrains: The OMEGA/Mars Express View
Le Mouélic, Stéphane; Gendrin, Aline; Mangold, Nicolas +8 more
The OMEGA/Mars Express hyperspectral imager identified hydrated sulfates on light-toned layered terrains on Mars. Outcrops in Valles Marineris, Margaritifer Sinus, and Terra Meridiani show evidence for kieserite, gypsum, and polyhydrated sulfates. This identification has its basis in vibrational absorptions between 1.3 and 2.5 micrometers. These m…
Mars Surface Diversity as Revealed by the OMEGA/Mars Express Observations
Sotin, Christophe; Fouchet, Thierry; Drossart, P. +39 more
The Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) investigation, on board the European Space Agency Mars Express mission, is mapping the surface composition of Mars at a 0.3- to 5-kilometer resolution by means of visible-near-infrared hyperspectral reflectance imagery. The data acquired during the first 9 months of the…
Phyllosilicates on Mars and implications for early martian climate
Mangold, N.; Bibring, J. -P.; Arvidson, R. E. +6 more
The recent identification of large deposits of sulphates by remote sensing and in situ observations has been considered evidence of the past presence of liquid water on Mars. Here we report the unambiguous detection of diverse phyllosilicates, a family of aqueous alteration products, on the basis of observations by the OMEGA imaging spectrometer o…
Sulfates in the North Polar Region of Mars Detected by OMEGA/Mars Express
Bibring, Jean-Pierre; Langevin, Yves; Gondet, Brigitte +1 more
The Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) imaging spectrometer observed the northern circumpolar regions of Mars at a resolution of a few kilometers. An extended region at 240°E, 85°N, with an area of 60 kilometers by 200 kilometers, exhibits absorptions at wavelengths of 1.45, 1.75, 1.94, 2.22, 2.26, and 2.48 …
Olivine and Pyroxene Diversity in the Crust of Mars
Mangold, N.; Bibring, J. -P.; Gendrin, A. +6 more
Data from the Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) on the Mars Express spacecraft identify the distinct mafic, rock-forming minerals olivine, low-calcium pyroxene (LCP), and high-calcium pyroxene (HCP) on the surface of Mars. Olivine- and HCP-rich regions are found in deposits that span the age range of geolog…
Tropical to mid-latitude snow and ice accumulation, flow and glaciation on Mars
Jaumann, R.; Head, J. W.; Neukum, G. +11 more
Images from the Mars Express HRSC (High-Resolution Stereo Camera) of debris aprons at the base of massifs in eastern Hellas reveal numerous concentrically ridged lobate and pitted features and related evidence of extremely ice-rich glacier-like viscous flow and sublimation. Together with new evidence for recent ice-rich rock glaciers at the base o…
Radar Soundings of the Subsurface of Mars
Gurnett, Donald A.; Johnson, William T. K.; Stofan, Ellen R. +31 more
The martian subsurface has been probed to kilometer depths by the Mars Advanced Radar for Subsurface and Ionospheric Sounding instrument aboard the Mars Express orbiter. Signals penetrate the polar layered deposits, probably imaging the base of the deposits. Data from the northern lowlands of Chryse Planitia have revealed a shallowly buried quasi-…
Radar Soundings of the Ionosphere of Mars
Gurnett, D. A.; Persoon, A. M.; Averkamp, T. F. +8 more
We report the first radar soundings of the ionosphere of Mars with the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) instrument on board the orbiting Mars Express spacecraft. Several types of ionospheric echoes are observed, ranging from vertical echoes caused by specular reflection from the horizontally stratified ionosphere…
Fluvial sedimentary deposits on Mars: Ancient deltas in a crater lake in the Nili Fossae region
Head, James W.; Fassett, Caleb I.
New spacecraft observations in the Nili Fossae region of Mars reveal two valley networks (~80 and ~200 km long) that each formed distributary fans as they entered an ancient 40-km diameter impact crater. An outlet channel on the eastern crater rim, lying at an elevation above the fans, suggests these fans formed as subaqueous deltas in a crater la…
Discovery of an aurora on Mars
Bertaux, Jean-Loup; Leblanc, François; Korablev, Oleg +5 more
In the high-latitude regions of Earth, aurorae are the often-spectacular visual manifestation of the interaction between electrically charged particles (electrons, protons or ions) with the neutral upper atmosphere, as they precipitate along magnetic field lines. More generally, auroral emissions in planetary atmospheres ``are those that result fr…