Mise au point de microspheres magnetiques et essais de therapeutique anticancereuse

CNRS AR 11793 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Search for Organic Matter at Mars with LIBS and Reflectance Complementary Measurements of the ChemCam Instrument Onboard the Curiosity Rover

International audienceOne of the priorities of the Mars Science Laboratory mission is the search for a past or present prebiotic chemistry. Among the possible indicators of such a chemistry, the organic molecules are key entities linked to the emergence and the development of life, as we know it on Earth. However, only rare evidences of the presence of such molecules (chlo-robenzene and other chlorinated hydrocarbons), in the Mars sedimentary rocks [1] and regolith [2] , were recently found at a very low concentration (150-300 ppbw in the Cumberland mudstone). Thus, one of the most pressing questions is to follow the search and identification of molecules currently present at Mars and their concentration. Onboard the NASA Curiosity currently operating on Mars in Gale crater, the ChemCam instrument (Chemistry and Camera) performs quasi-systematic analyses of the elementary composition of rocks and soils of the Mars surface around the rover. This in- strument is used to identify targets of interest to per- form contact science and drilling from a mineralogical point of view, and also gives chemical information that could be used to look for organics present in the soil

Hydrogen detection with ChemCam at Gale crater

International audienceOne of the main advantages of ChemCam’s LIBS (Laser-Induced Breakdown Spectroscopy) instrumentonboard the Curiosity rover is its potential to detect light elements such as hydrogen at fine scales, whichhas never been achieved on Mars. Hydrogen lines are detected in most of the data obtained within thefirst 320 sols of the mission at Gale crater, Mars. This work is a description of the hydrogen signal andits variability in the ChemCam LIBS spectra; it discusses the challenges of qualitative and quantitativeanalysis. Data acquisition and processing steps are investigated and optimized for the detection of hydrogenon Mars. Subtraction of an appropriate dark spectrum and the deconvolution of the superimposedemission of carbon from the low-pressure CO2-dominated atmosphere are particularly important.Because the intensities of hydrogen are also affected by matrix effects, the hydrogen signal was investigatedwithin groups of targets sharing common chemical features and similar matrices. The differentgroups cover a variety of rock and soil compositions encountered along the traverse (calcium sulfateveins, mafic soils, felsic, Mg-rich and Fe-rich rocks) including data from both drill holes and their tailings.Almost all these targets were found to be hydrated to variable extents. Soils have systematically higherhydrogen signals than rocks and pebbles, probably as a result of their alteration. The results from rockssuggest that various alteration processes leading to their hydration have taken place, which is consistentwith the fluvial lacustrine context, the diagenetic features, and the mineralogy observed by Curiosity inYellowknife Bay

The ChemCam Remote Micro-Imager at Gale crater: Review of the first year of operations on Mars

International audienc