Search Publications
An overfilled lacustrine system and progradational delta in Jezero crater, Mars: Implications for Noachian climate
Head, James W.; Fassett, Caleb I.; Schon, Samuel C.
The presence of valley networks and open-basin lakes in the late Noachian is cited as evidence for overland flow of liquid water and thus a climate on early Mars that might have supported precipitation and runoff. Outstanding questions center on the nature of such a climate, its duration and variability, and its cause. Open basin lakes, their inte…
Hydrogen peroxide on Mars: Observations, interpretation and future plans
Encrenaz, T.; Atreya, S. K.; Greathouse, T. K. +1 more
Ever since the Viking mass spectrometer failed to detect organics on the surface of Mars in 1976 (Biemann et al., 1976), hydrogen peroxide (H2O2) has been suggested as a possible oxidizer of the Martian surface (Oyama and Berdahl, 1977). However, the search for H2O2 on Mars was unsuccessful for three dec…
Chronology of deposition and alteration in the Mawrth Vallis region, Mars
Mangold, N.; Bibring, J. -P.; Loizeau, D. +2 more
The Mawrth Vallis area displays some of the largest phyllosilicate-rich outcrops of Mars, on Noachian highlands. The Mawrth Vallis region is located just at the dichotomy boundary between the Noachian highlands and the younger, northern lowlands. A large, thick, layered clay-rich unit is present throughout the inter-crater plateaus. Clay-rich laye…
Late Hesperian aqueous alteration at Majuro crater, Mars
Mangold, N.; Poulet, F.; Ansan, V. +3 more
Impact craters cover a large portion of the surface of Mars and could constitute a significant exobiology research target as their formation provided heat sources for aqueous processes. To date, only rare examples of hydrothermal alteration in craters have been reported on Mars while many studies have focused on modeling their effect. Using data f…
Fluvial landforms on fresh impact ejecta on Mars
Mangold, N.
Fluvial valleys provide critical clues to the distribution and state of water throughout the history of the planet Mars. Early in Mars' history (<3.7 Gy), the climate may have been warmer than at present leading to the development of valley networks. Younger valleys formed on volcanic and glacial landforms under colder conditions than experienc…
Morphological and mechanical characterization of gullies in a periglacial environment: The case of the Russell crater dune (Mars)
Lucas, Antoine; Schmidt, Frédéric; Costard, François +4 more
Gullies on terrestrial sand dunes are rare, and their presence on Mars, as well as their mechanical properties, and the quantity of fluid required for their formations currently remain poorly understood. This study focuses on gully morphologies on the Russell megadune (54.5°S; 12.7°E) using High Resolution Imaging Science Experiment (HiRISE) image…
Impact of solar EUV flux on CO Cameron band and CO2+ UV doublet emissions in the dayglow of Mars
Bhardwaj, Anil; Jain, Sonal Kumar
This study is aimed at making a calculation about the impact of the two most commonly used solar EUV flux models - SOLAR2000 (S2K) of Tobiska (2004) and EUVAC model of Richards et al. (1994) - on photoelectron fluxes, volume emission rates, ion densities and CO Cameron and CO2+ UV doublet band dayglow emissions on Mars in thr…
Dune fields on Mars: Recorders of a climate change?
Quantin, Cathy; Silvestro, Simone; Gardin, Emilie +2 more
Dunes have similar morphologies on the Earth and Mars. The main differences between Martian and terrestrial dunes are their size, which is larger on Mars, and their duration of formation, which is longer on Mars. As the characteristic time of Martian dunes is in the same order as that of the Martian climatic oscillations, Martian dunes could be re…
Optical depth of the Martian atmosphere and surface albedo from high-resolution orbiter images
Thomas, N.; Hoekzema, N. M.; Stenzel, O. J. +2 more
In this paper we describe and evaluate the so-called shadow method. This method can be used to estimate the optical depth of the Martian atmosphere from the differences in brightness between shadowed and sunlit regions observed from an orbiter. We present elaborate and simplified versions of the method and analyze the capabilities and the sources …
On the unmixing of MEx/OMEGA hyperspectral data
Schmidt, Frédéric; Daglis, Ioannis A.; Themelis, Konstantinos E. +3 more
This paper presents a comparative study of three different types of estimators used for supervised linear unmixing of two MEx/OMEGA hyperspectral cubes. The algorithms take into account the constraints of the abundance fractions, in order to get physically interpretable results. Abundance maps show that the Bayesian maximum a posteriori probabilit…