Nouvel article de l’équipe Exobiologie dans la revue ” Meteoritics and Planteray Science “

16 May 2012 par Super Administrateur
Les analyses du rover martien (MER), Spirit, des basaltes martiens du cratère de Gusev montrent qu’elles sont très différentes chimiquement des basaltes terrestres, se caractérisant notamment par des teneurs élevées en Mg et en Fe. Pour fournir des basaltes analogiques appropriés pour le magasin international de satellites analogiques (ISAR), une collection de roches et minéraux analogues destinés à la préparation de missions spatiales in situ, en particulier la prochaine mission Mars MSL-2011 et la future mission internationale Mars-2018 synthétiser des basaltes martiens.

Bost, N., Westall, F., Gaillard, F., Ramboz, C. and Foucher, F.

Synthesis of a spinifex-textured basalt as an analog to Gusev crater basalts, Mars

Meteoritics & Planetary Science (2012) sous presse – doi:10.1111/j.1945-5100.2012.01355.x

Résumé :

Analyses by the Mars Exploration Rover (MER), Spirit, of Martian basalts from Gusev crater show that they are chemically very different from terrestrial basalts, being characterized in particular by high Mg- and Fe-contents. To provide suitable analog basalts for the International Space Analogue Rockstore (ISAR), a collection of analog rocks and minerals for preparing in situ space missions, especially, the upcoming Mars mission MSL-2011 and the future international Mars-2018 mission, it is necessary to synthesize Martian basalts. The aim of this study was therefore to synthesize Martian basalt analogs to the Gusev crater basalts, based on the geochemical data from the MER rover Spirit. We present the results of two experiments, one producing a quench-cooled basalt (<1 h) and one producing a more slowly cooled basalt (1 day). Pyroxene and olivine textures produced in the more slowly cooled basalt were surprisingly similar to spinifex textures in komatiites, a volcanic rock type very common on the early Earth. These kinds of ultramafic rocks and their associated alteration products may have important astrobiological implications when associated with aqueous environments. Such rocks could provide habitats for chemolithotrophic microorganisms, while the glass and phyllosilicate derivatives can fix organic compounds.