Search Publications
Identification of hydrated silicate minerals on Mars using MRO-CRISM: Geologic context near Nili Fossae and implications for aqueous alteration
Murchie, Scott L.; Ehlmann, Bethany L.; Mustard, John F. +9 more
The Noachian terrain west of the Isidis basin hosts a diverse collection of alteration minerals in rocks comprising varied geomorphic units within a 100,000 km2 region in and near the Nili Fossae. Prior investigations in this region by the Observatoire pour l'Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) instrument on Mars Expre…
Amazonian northern mid-latitude glaciation on Mars: A proposed climate scenario
Forget, F.; Montmessin, F.; Head, James W. +3 more
Recent geological observations in the northern mid-latitudes of Mars show evidence for past glacial activity during the late Amazonian, similar to the integrated glacial landsystems in the Dry Valleys of Antarctica. The large accumulation of ice (many hundreds of meters) required to create the observed glacial deposits points to significant atmosp…
The global martian volcanic evolutionary history
Werner, Stephanie C.
Viking mission image data revealed the total spatial extent of preserved volcanic surface on Mars. One of the dominating surface expressions is Olympus Mons and the surrounding volcanic province Tharsis. Earlier studies of the global volcanic sequence of events based on stratigraphic relationships and crater count statistics were limited to the im…
Radar evidence for ice in lobate debris aprons in the mid-northern latitudes of Mars
Head, James W.; Frigeri, Alessandro; Seu, Roberto +5 more
Subsurface radar sounding data indicate that lobate debris aprons found in Deuteronilus Mensae in the mid-northern latitudes of Mars are composed predominantly of water ice. The position in time delay and the relatively low amount of signal loss of the apparent basal reflectors below the debris aprons indicate that aprons contain only a minor comp…
A review of observed variability in the dayside ionosphere of Mars
Withers, Paul
Recent measurements by Mars Global Surveyor and Mars Express have greatly increased the number of observations of the martian dayside ionosphere available for study. Together with earlier measurements from the Viking era, these datasets have been used to investigate variations in well-known properties of the martian dayside ionosphere and to disco…
Observed variations of methane on Mars unexplained by known atmospheric chemistry and physics
Lefèvre, Franck; Forget, François
The detection of methane on Mars has revived the possibility of past or extant life on this planet, despite the fact that an abiogenic origin is thought to be equally plausible. An intriguing aspect of the recent observations of methane on Mars is that methane concentrations appear to be locally enhanced and change with the seasons. However, metha…
Density and temperatures of the upper Martian atmosphere measured by stellar occultations with Mars Express SPICAM
Montmessin, Franck; Bertaux, Jean-Loup; González-Galindo, Francisco +6 more
We present one Martian year of observations of the density and temperature in the upper atmosphere of Mars (between 60 and 130 km) obtained by the Mars Express ultraviolet spectrometer Spectroscopy for Investigation of Characteristics of the Atmosphere of Mars (SPICAM). Six hundred sixteen profiles were retrieved using stellar occultations techniq…
An improvement to the volcano-scan algorithm for atmospheric correction of CRISM and OMEGA spectral data
Seelos, Frank P.; Murchie, Scott L.; Mustard, John F. +12 more
The observations of Mars by the CRISM and OMEGA hyperspectral imaging spectrometers require correction for photometric, atmospheric and thermal effects prior to the interpretation of possible mineralogical features in the spectra. Here, we report on a simple, yet non-trivial, adaptation to the commonly-used volcano-scan correction technique for at…
Discovery of jarosite within the Mawrth Vallis region of Mars: Implications for the geologic history of the region
Glotch, Timothy D.; Farrand, William H.; Swayze, Gregg A. +2 more
Analysis of visible to near infrared reflectance data from the MRO CRISM hyperspectral imager has revealed the presence of an ovoid-shaped landform, approximately 3 by 5 km in size, within the layered terrains surrounding the Mawrth Vallis outflow channel. This feature has spectral absorption features consistent with the presence of the ferric sul…
Composition, Morphology, and Stratigraphy of Noachian Crust around the Isidis basin
Mangold, N.; Bibring, J. -P.; Mustard, J. F. +5 more
Definitive exposures of pristine, ancient crust on Mars are rare, and the finding that much of the ancient Noachian terrain on Mars exhibits evidence of phyllosilicate alteration adds further complexity. We have analyzed high-resolution data from the Mars Reconnaissance Orbiter in the well-exposed Noachian crust surrounding the Isidis basin. We fo…