Search Publications
Planetary surface dating from crater size-frequency distribution measurements: Spatial randomness and clustering
Platz, T.; Michael, G. G.; Kneissl, T. +1 more
We describe a quantitative procedure to measure the degree of clustering in an observed crater population relative to a series of randomly distributed populations. We split the population by according to crater size to be able to identify clustering at different scales, and find that a clustering analysis based on the mean 2nd-closest neighbour di…
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…
A chronology of early Mars climatic evolution from impact crater degradation
Mangold, N.; Ansan, V.; Adeli, S. +2 more
The degradation of impact craters provides a powerful tool to analyze surface processes in the Martian past. Previous studies concluded that large impact craters (20-200 km in diameter) were strongly degraded by fluvial erosion during early Martian history. Our goal is to study the progression of crater degradation through time with a particular e…
An analysis of open-basin lake deposits on Mars: Evidence for the nature of associated lacustrine deposits and post-lacustrine modification processes
Mustard, John F.; Goudge, Timothy A.; Head, James W. +1 more
A large number of candidate open-basin lakes (low-lying regions with both inlet valleys and an outlet valley) have been identified and mapped on Mars and are fed by valley network systems that were active near the Noachian-Hesperian boundary. The nature of processes that modified the open-basin lake interiors subsequent to lacustrine activity, and…
Dielectric map of the Martian northern hemisphere and the nature of plain filling materials
Pommerol, Antoine; Kofman, Wlodek; Clifford, Stephen M. +2 more
A number of observations suggest that an extended ocean once covered a significant part of the Martian northern hemisphere. By probing the physical properties of the subsurface to unprecedented depth, the MARSIS/Mars Express provides new geophysical evidences for the former existence of a Late Hesperian ocean. The Vastitas Borealis formation, loca…
The origin and timing of fluvial activity at Eberswalde crater, Mars
Mangold, N.; Quantin, C.; Hauber, E. +6 more
The fan deposit in Eberswalde crater has been interpreted as strong evidence for sustained liquid water on early Mars with a paleolake formed during the Noachian period (>3.7 Gy). This location became a key region for understanding the Mars paleo-environment. Eberswalde crater is located 50 km north of the rim of the 150 km diameter crater Hold…
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…
A unique volcanic field in Tharsis, Mars: Pyroclastic cones as evidence for explosive eruptions
Hauber, E.; Brož, P.
Based on theoretical grounds, explosive basaltic volcanism should be common on Mars, yet the available morphological evidence is sparse. We test this hypothesis by investigating a unique unnamed volcanic field north of the shield volcanoes Biblis Patera and Ulysses Patera on Mars, where we observe several small conical edifices and associated lava…
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…
Observations of the nightside ionosphere of Mars by the Mars Express Radio Science Experiment (MaRS)
Hinson, D. P.; Witasse, O.; Withers, Paul +7 more
The vertical structure of the nightside ionosphere of Mars and its dependence on solar zenith angle are currently poorly determined, as is the importance of two key sources of nightside plasma, electron precipitation and transport of dayside plasma. We examined 37 electron density profiles of the ionosphere of Mars at solar zenith angles of 101°-1…