Search results for "MARS EXPLORATION"
showing 10 items of 65 documents
New insights into the mineralogy and weathering of the Meridiani Planum meteorite, Mars
2011
– Meridiani Planum is the first officially recognized meteorite find on the surface of Mars. It was discovered at and named after the landing site of the Mars Exploration Rover Opportunity. Based on its composition, it was classified as a IAB complex iron meteorite. Mossbauer spectra obtained by Opportunity are dominated by kamacite (α-Fe-Ni) and exhibit a small contribution of ferric oxide. Several small features in the spectra have been neglected to date. To shed more light on these features, five iron meteorite specimens were investigated as analogs to Meridiani Planum with a laboratory Mossbauer setup. Measurements were performed on (1) their metallic bulk, (2) troilite (FeS) inclusions…
The Opportunity Rover's Athena Science Investigation at Meridiani Planum, Mars
2004
The Mars Exploration Rover Opportunity has investigated the landing site in Eagle crater and the nearby plains within Meridiani Planum. The soils consist of fine-grained basaltic sand and a surface lag of hematite-rich spherules, spherule fragments, and other granules. Wind ripples are common. Underlying the thin soil layer, and exposed within small impact craters and troughs, are flat-lying sedimentary rocks. These rocks are finely laminated, are rich in sulfur, and contain abundant sulfate salts. Small-scale cross-lamination in some locations provides evidence for deposition in flowing liquid water. We interpret the rocks to be a mixture of chemical and siliciclastic sediments formed by e…
Identification of Morphological Biosignatures in Martian Analogue Field Specimens Using In Situ Planetary Instrumentation
2008
International audience; We have investigated how morphological biosignatures (i.e., features related to life) might be identified with an array of viable instruments within the framework of robotic planetary surface operations at Mars. This is the first time such an integrated lab-based study has been conducted that incorporates space-qualified instrumentation designed for combined in situ imaging, analysis, and geotechnics ( sampling). Specimens were selected on the basis of feature morphology, scale, and analogy to Mars rocks. Two types of morphological criteria were considered: potential signatures of extinct life ( fossilized microbial filaments) and of extant life (crypto-chasmoendolit…
An integrated view of the chemistry and mineralogy of martian soils
2005
The mineralogical and elemental compositions of the martian soil are indicators of chemical and physical weathering processes. Using data from the Mars Exploration Rovers, we show that bright dust deposits on opposite sides of the planet are part of a global unit and not dominated by the composition of local rocks. Dark soil deposits at both sites have similar basaltic mineralogies, and could reflect either a global component or the general similarity in the compositions of the rocks from which they were derived. Increased levels of bromine are consistent with mobilization of soluble salts by thin films of liquid water, but the presence of olivine in analysed soil samples indicates that the…
Exploration of Victoria Crater by the Mars Rover Opportunity
2009
“Lake” Victoria? After having explored the Eagle and Endurance craters, which are separated by only 800 meters, the Mars Exploration Rover Opportunity spent 2 years at Victoria, a much larger impact crater located 6 kilometers south across Meridiani Planum. Sedimentary rocks previously analyzed at Eagle and Endurance point to local environmental conditions that included abundant liquid water in the ancient past. Now, an analysis of rocks in the walls of Victoria by Squyres et al. (p. 1058 ) reveals that the aqueous alteration processes that operated at Eagle and Endurance also acted at Victoria. In addition, sedimentary layering in the crater walls preserves evidence of ancient windblown du…
An astrobiological perspective on Meridiani Planum
2005
Sedimentary rocks exposed in the Meridiani Planum region of Mars record aqueous and eolian deposition in ancient dune and interdune playa-like environments that were arid, acidic, and oxidizing. On Earth, microbial populations have repeatedly adapted to low pH and both episodic and chronic water limitation, suggesting that, to a first approximation, the Meridiani plain may have been habitable during at least part of the interval when deposition and early diagenesis took place. On the other hand, the environmental conditions inferred for Meridiani deposition would have posed a challenge for prebiotic chemical reactions thought to have played a role in the origin of life on Earth. Orbital obs…
Missions to Mars: Characterization of Mars analogue rocks for the International Space Analogue Rockstore (ISAR)
2013
International audience; Instruments for surface missions to extraterrestrial bodies should be cross-calibrated using a common suite of relevant materials. Such work is necessary to improve instrument performance and aids in the interpretation of in-situ measurements. At the CNRS campus in Orléans, the Observatoire des Sciences de l'Univers en région Centre (OSUC) has created a collection of well-characterised rocks and minerals for testing and calibrating instruments to be flown in space missions. The characteristics of the analogue materials are documented in an accompanying online database. In view of the recent and upcoming rover missions to Mars (NASA's 2011 Mars Science Laboratory (MSL…
Indication of drier periods on Mars from the chemistry and mineralogy of atmospheric dust
2005
The cover shows part of the Larry's Lookout panorama, seen from the Mars Exploration Rover (MER) Spirit during its drive up Husband Hill: the summit is about 200 metres from the rover. Six papers this week report in detail on the MER mission. An Analysis compares predictions used to select a landing site with the conditions actually encountered. This ‘ground truth’ will be invaluable for interpreting future remote-sensing data. Surface chemistry suggests that the upper layer of soil may contain 1% meteoritic material. MER provides a unique glimpse of solar transits of the moons Phobos and Deimos. Rover Opportunity examined wind-related processes, and spectroscopy indicates a dry origin for …
Mapping Susceptibility to Debris Flows Triggered by Tropical Storms: A Case Study of the San Vicente Volcano Area (El Salvador, CA)
2021
In this study, an inventory of storm-triggered debris flows performed in the area of the San Vicente volcano (El Salvador, CA) was used to calibrate predictive models and prepare a landslide susceptibility map. The storm event struck the area in November 2009 as the result of the simultaneous action of low-pressure system 96E and Hurricane Ida. Multivariate Adaptive Regression Splines (MARS) was employed to model the relationships between a set of environmental variables and the locations of the debris flows. Validation of the models was performed by splitting 100 random samples of event and non-event 10 m pixels into training and test subsets. The validation results revealed an excellent (…
Prediction of debris-avalanches and -flows triggered by a tropical storm by using a stochastic approach: An application to the events occurred in Moc…
2019
Abstract Landslides are among the most dangerous natural processes. Debris avalanches and debris flows in particular have often caused casualties and severe damage to infrastructures in a wide range of environments. The assessment of susceptibility to these phenomena may help policy makers in mitigating the associated risk and thus it has attracted special attention in the last decades. In this experiment, we assessed susceptibility to debris-avalanche and -flow landslides by using a stochastic approach. Two different modeling techniques were employed: i) Multivariate Adaptive Regression Splines (MARS) and ii) Logistic Regression (LR). Both MARS and LR allow for calculating the probability …