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 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…
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…
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…
The dispersal of pyroclasts from ancient explosive volcanoes on Mars: Implications for the friable layered deposits
Head, James W.; Forget, François; Madeleine, Jean-Baptiste +2 more
A number of voluminous, fine-grained, friable deposits have been mapped on Mars. The modes of origin for these deposits are debated. The feasibility for an origin by volcanic airfall for the friable deposits is tested using a global circulation model to simulate the dispersal of pyroclasts from candidate source volcanoes near each deposit. It is c…
Orbital identification of clays and carbonates in Gusev crater
Poulet, Francois; Carter, John
Gusev crater was selected as the landing site of one of the two NASA Mars Exploration Rovers because water once could have ponded within the crater and partly filled it with sediments as suggested by the presence of a feeder channel and the fluvial-lacustrine morphology of the in-filling. However, the paucity of mineralogical evidence for fluvial-…
Major episodes of geologic history of Isidis Planitia on Mars
Hiesinger, H.; Ivanov, M. A.; Erkeling, G. +2 more
We have mapped the area of Isidis Planitia (1-27°N, 75-103°E) in order to assess the geologic history of this region using modern data sets such as MOLA topography and the high-resolution images provided by the HRSC, CTX, and HiRISE cameras. Results of our mapping show that the geologic history of Isidis Planitia consists of three principal episod…
Climate-driven deposition of water ice and the formation of mounds in craters in Mars’ north polar region
Le Mouélic, Stéphane; Conway, Susan J.; Orosei, Roberto +4 more
This paper explores the origins and evolution of ice-rich interior mounds found within craters of the north polar region of Mars. We present a systematic study of impact craters above 65°N, and identify 18 craters that have interior mounds. At least 11 of these mounds are composed of water ice and geometric similarities suggest that dune-covered m…
Patterns of accumulation and flow of ice in the mid-latitudes of Mars during the Amazonian
Head, James W.; Fassett, Caleb I.; Dickson, James L.
Evidence has accumulated that non-polar portions of Mars have undergone significant periods of glaciation during the Amazonian Period. This evidence includes tropical mountain glacial deposits, lobate debris aprons, lineated valley fill, concentric crater fill, pedestal craters, and related landforms, some of which suggest that ice thicknesses exc…
Mars exospheric thermal and non-thermal components: Seasonal and local variations
Leblanc, F.; Modolo, R.; Hess, S. +3 more
A model of the martian exosphere is built for average solar conditions. A Chamberlain’s approach (Chamberlain, J.W. [1963]. Planet. Space Sci. 11, 901) is used to describe the O, CO, CO2, and O2 thermal exospheric components. The average thermal oxygen density at 300 km in altitude varies by about one order of magnitude with …