SYNTHESIS OF HALITE UNDER MARTIAN SIMULATED CONDITIONS: A STUDY WITH ASTROBIOLOGICAL IMPLICATIONS.

CANEIRO A.; WILBERGER D. O. ; VARELA M.E.; ABREVAYA XIMENA; GALANTE D.; RODRIGUES F.; HORVATH J. E. ; VEGA-CASTILLO J.

Houston

Conferencia; Lunar and Planetary Science Conference; 2016

The identification of NaCl minerals in the SNC meteorite Nakhla, is usually taken as min-eralogical evidence of the presence of halites on Mars due to its pre-terrestrial origin. One of the hypotheses is that they could have been formed through the evapo-ration of brine pockets on this planetary body [1,2]. Moreover, the existence of evaporitic enviroments on this planet is supported by different measurements perfomed on the surface of this planet [3-9]. Several evaporitic environments on Earth can be considered analogs of hypersaline environments in other planetary bodies. Microorganisms known as halophilic archaea are inhabitants of these environments, requiring the presence of high salt concentrations (2-5 M NaCl), Moreover they have been found entrapped inside hal-ites [11,12] including those found in ancient evaporitic deposits from Permic and Triassic (250 Mya old). This fact raises the possibility to consider these kind of mi-croorganisms as possible inhabitants of Mars [13] and possible candidates for the interplanetary transfer of life by natural processes (e.g. lithopanspermia). Fluid inclusions are commonly found inside halites as it tends to entrap the original brines when they solidify [14]. Halophilic archaea (haloarchaea) were found surviving inside these fluid inclusions and they seem to be fundamental for the survival of the microorgan-isms [15]. Therefore the crystalline structure of the halite could be relevant in order to study the possibility of survival of microorganisms in other planetary con-text. In this study we analyze the structure of halites formed under Terrestrial and Martian conditions in simulated experiments and we discuss the possibility of survival of microorganisms.