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Columbus crater and other possible groundwater-fed paleolakes of Terra Sirenum, Mars
Clark, R. N.; Wray, J. J.; Milliken, R. E. +11 more
Columbus crater in the Terra Sirenum region of the Martian southern highlands contains light-toned layered deposits with interbedded sulfate and phyllosilicate minerals, a rare occurrence on Mars. Here we investigate in detail the morphology, thermophysical properties, mineralogy, and stratigraphy of these deposits; explore their regional context;…
Orbital observations of contemporary dune activity in Endeavor crater, Meridiani Planum, Mars
Chojnacki, Matthew; Moersch, Jeffrey E.; Michaels, Timothy I. +1 more
Although aeolian landforms are pervasive on Mars, evidence for contemporary activity has been limited. The next major campaign for the Mars Exploration Rover “Opportunity” is the investigation of the ∼20 km diameter Endeavor crater, ∼6 km to southeast of the rover's position as of December 2010. We present evidence from orbital imagery that eight …
Dayside ionosphere of Mars: Empirical model based on data from the MARSIS instrument
Gurnett, D. A.; Němec, F.; Morgan, D. D. +2 more
We present results of a systematic study of electron densities in the dayside Martian ionosphere measured by the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument on board the Mars Express spacecraft. There are two distinct regions controlled by different physical mechanisms. The first region is located at altitudes up…
Winter and spring evolution of northern seasonal deposits on Mars from OMEGA on Mars Express
Bibring, J. -P.; Gondet, B.; Langevin, Y. +6 more
The OMEGA visible/near-infrared imaging spectrometer on Mars Express has observed the retreat of the northern seasonal deposits during Martian year 27-28 from the period of maximum extension, close to the northern winter solstice, to the end of the retreat at Ls 95°. We present the temporal and spatial distributions of both CO2
Dark aeolian sediments in Martian craters: Composition and sources
Poulet, F.; Jaumann, R.; Tirsch, D. +1 more
Our research focuses on the mineralogical characteristics of dark sediment deposits in Martian craters (dunes, dune fields, and sand sheets) and their local sediment sources, carried out on the basis of 70 selected localities. Morphological analyses reveal dark layers exposed in a number of crater walls, showing indications of material transport f…
New near-IR observations of mesospheric CO2 and H2O clouds on Mars
Bibring, Jean-Pierre; Gondet, Brigitte; Vincendon, Mathieu +2 more
Carbon dioxide clouds, which are speculated by models on solar and extra-solar planets, have been recently observed near the equator of Mars. The most comprehensive identification of Martian CO2 ice clouds has been obtained by the near-IR imaging spectrometer OMEGA. CRISM, a similar instrument with a higher spatial resolution, cannot de…
Areas of enhanced ionization in the deep nightside ionosphere of Mars
Gurnett, D. A.; Němec, F.; Morgan, D. D. +1 more
We present observations of areas of enhanced ionization located in the deep nightside ionosphere of Mars as observed by Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) on board the Mars Express spacecraft. Oblique ionospheric echoes coming from the same region observed during several consecutive MARSIS measurements enable us t…
Influence of the scar geometry on landslide dynamics and deposits: Application to Martian landslides
Lucas, Antoine; Mège, Daniel; Mangeney, Anne +1 more
Landslides dynamics prediction remains difficult in spite of a considerable number of studies. The runout distance is widely used in analysis of landslide dynamics and in the calibration of the rheological parameters involved in numerical modeling. However, the unknown impact of the significant uncertainty in the shape of the initial released mass…
Observations of thermal tides in the middle atmosphere of Mars by the SPICAM instrument
Montmessin, F.; Bertaux, J. -L.; Withers, Paul +1 more
We use vertical profiles of Martian atmospheric density, pressure, and temperature from the Mars Express SPICAM UV spectrometer to study thermal tides in the poorly studied middle atmosphere region at 70-120 km. Here we show that nonmigrating tides cause zonal pressure variations of tens of percent and zonal temperature variations on the order of …
Interior layered deposits within a perched basin, southern Coprates Chasma, Mars: Evidence for their formation, alteration, and erosion
Hauber, E.; Le Deit, L.; Gwinner, K. +3 more
A basin-like area containing three interior layer deposits (ILDs) on the southern margin of Coprates Chasma was studied. We interpret the area as an ancestral basin and demonstrate that ILD deposition postdates the formation of the current wall rock slopes. The geometry of the ILD and the wall rock spurs form a catchment area between each ILD and …