Search results for " MARS"

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…

Geochemical modeling of evaporation processes on Mars: Insight from the sedimentary record at Meridiani Planum

2005

New data returned from the Mars Exploration Rover (MER) mission have revealed abundant evaporites in the sedimentary record at Meridiani Planum. A working hypothesis for Meridiani evaporite formation involves the evaporation of fluids derived from the weathering of martian basalt and subsequent diagenesis. On Earth, evaporite formation in exclusively basaltic settings is rare. However, models of the evaporation of fluids derived from experimentally weathering synthetic martian basalt provide insight into possible formation mechanisms. The thermodynamic database assembled for this investigation includes both Fe2+ and Fe3+ in Pitzer's ion interaction equations to evaluate Fe redox disequilibr…

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…

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 …

Zvaigžņotā Debess: 2008, Pavasaris

2008

Latvijas Zinātņu akadēmija, Latvijas Universitāte

Territorio, popolazione, economia, polizia: la notitia rerum publicarum in Luigi Ferdinando Marsili

1999

The spread of the Atlantic blue crab Callinectes sapidus Rathbun 1896 in the Mediterranean Sea: analysis of environmental and trophic niche and metal…

2023

Biological invasions are globally acknowledged as one of the major causes of biodiversity loss. Considering the urgency of understanding what are the effects of biological invasions on recipient ecosystems, this research focuses on the Atlantic blue crab Callinectes sapidus, one of the most successful invaders of Mediterranean coastal ecosystems. First, a general assessment of the overlap of the Grinnellian niche of the species in native and invaded ranges was carried out to verify whether the blue crab maintained the characteristics of its climatic niche when establishing in invaded areas (niche conservatism hypothesis) or, alternatively, it adapted to the specific abiotic characteristics …

Surface Analysis in Archaeology Using the Miniaturized Mössbauer Spectrometer MIMOS II

2003

A miniaturized Mossbauer spectrometer (MIMOS II) which was designed and constructed for extraterrestrial applications, such as iron-containing rock and soil analysis on the planet Mars, has been employed to investigate the iron-containing constituents in the paintings of a Lekythos Greek vase. Greek pottery is commonly painted with black figures. The Mossbauer backscattering spectra recorded with MIMOS II at room temperature show that the hand-painted black figures contain hematite.