Search Publications
Evidence for Hesperian impact-induced hydrothermalism on Mars
Tornabene, Livio L.; Roush, Ted L.; Bishop, Janice L. +7 more
Several hydrated silicate deposits on Mars are observed within craters and are interpreted as excavated Noachian material. Toro crater (71.8°E, 17.0°N), located on the northern edge of the Syrtis Major Volcanic Plains, shows spectral and morphologic evidence of impact-induced hydrothermal activity. Spectroscopic observations were used to identify …
A cold and wet Mars
Fairén, Alberto G.
Water on Mars has been explained by invoking controversial and mutually exclusive solutions based on warming the atmosphere with greenhouse gases (the "warm and wet" Mars) or on local thermal energy sources acting in a global freezing climate (the "cold and dry" Mars). Both have critical limitations and none has been definitively accepted as a com…
A comparison of global models for the solar wind interaction with Mars
Kallio, E.; Barabash, S.; Lammer, H. +24 more
We present initial results from the first community-wide effort to compare global plasma interaction model results for Mars. Seven modeling groups participated in this activity, using MHD, multi-fluid, and hybrid assumptions in their simulations. Moderate solar wind and solar EUV conditions were chosen, and the conditions were implemented in the m…
Stratigraphy in the Mawrth Vallis region through OMEGA, HRSC color imagery and DTM
Mangold, N.; Bibring, J. -P.; Gondet, B. +7 more
The Mawrth Vallis region contains an extensive (at least 300 km × 400 km) and thick (⩾300 m), finely layered (at meter scale), clay-rich unit detected by OMEGA. We use OMEGA, HRSC DTMs derived from stereoscopic imagery, HRSC color imagery and high resolution imagery such as MOC, CTX and HiRISE to characterize the geometry and the composition of th…
Concentric crater fill in the northern mid-latitudes of Mars: Formation processes and relationships to similar landforms of glacial origin
Head, James W.; Marchant, David R.; Levy, Joseph
Hypotheses accounting for the formation of concentric crater fill (CCF) on Mars range from ice-free processes (e.g., aeolian fill), to ice-assisted talus creep, to debris-covered glaciers. Based on analysis of new CTX and HiRISE data, we find that concentric crater fill (CCF) is a significant component of Amazonian-aged glacial landsystems on Mars…
Color imaging of Mars by the High Resolution Imaging Science Experiment (HiRISE)
Tornabene, Livio L.; Bridges, Nathan T.; Thomas, Nicolas +13 more
HiRISE has been producing a large number of scientifically useful color products of Mars and other planetary objects. The three broad spectral bands, coupled with the highly sensitive 14 bit detectors and time delay integration, enable detection of subtle color differences. The very high spatial resolution of HiRISE can augment the mineralogic int…
The age of the Medusae Fossae Formation: Evidence of Hesperian emplacement from crater morphology, stratigraphy, and ancient lava contacts
Head, James W.; Kerber, Laura
The Medusae Fossae Formation (MFF), covering about 2.1 × 10 6 km 2 (with an estimated volume of 1.4 × 10 6 km 3) and straddling the equatorial region of Mars east of Tharsis, has historically been mapped and dated as Amazonian in age. Analysis of the MFF using a range of new observations from recent miss…
Supraglacial and proglacial valleys on Amazonian Mars
Head, James W.; Fassett, Caleb I.; Levy, Joseph S. +2 more
Abundant evidence exists for glaciation being an important geomorphic process in the mid-latitude regions of both hemispheres of Mars, as well as in specific environments at near-equatorial latitudes, such as along the western flanks of the major Tharsis volcanoes. Detailed analyses of glacial landforms (lobate-debris aprons, lineated valley fill,…
Flow patterns of lobate debris aprons and lineated valley fill north of Ismeniae Fossae, Mars: Evidence for extensive mid-latitude glaciation in the Late Amazonian
Head, James W.; Baker, David M. H.; Marchant, David R.
A variety of Late Amazonian landforms on Mars have been attributed to the dynamics of ice-related processes. Evidence for large-scale, mid-latitude glacial episodes existing within the last 100 million to 1 billion years on Mars has been presented from analyses of lobate debris aprons (LDA) and lineated valley fill (LVF) in the northern and southe…
Mapping the mesospheric CO 2 clouds on Mars: MEx/OMEGA and MEx/HRSC observations and challenges for atmospheric models
Bibring, J. -P.; Gondet, B.; Forget, F. +9 more
This study presents the latest results on the mesospheric CO 2 clouds in the martian atmosphere based on observations by OMEGA and HRSC onboard Mars Express. We have mapped the mesospheric CO 2 clouds during nearly three martian years of OMEGA data yielding a cloud dataset of ∼60 occurrences. The global mapping shows that the…