Field Testing the Mars Astrobiology Probe (MAP) Instrument Suite in the Atacama Desert

The Mars Astrobiology Probe (MAP) is an instrument suite consisting of a subcritical water extractor (SCWE) and a sublimation system together with microchip capillary electrophoresis (CE) for extraction and analysis of potential biomarker compounds from soil. The CE instrument provides high resolution analysis of amino acid composition and chirality with ppb to part-per-trillion sensitivity (1). The CE instrument can also be used to analyze amines, diamines, amino sugars and several of the nucleobases, nucleosides and nucleotides (2). Key stages in the selection of in situ instrumentation for Mars exploration include the development of instrument suites advanced enough to operate in relevant field environments and demonstration that they have the analytical capability and sensitivity to detect low levels of biomarkers. We describe here successful field trials of MAP in the Atacama Desert in Chile, an extremely dry, oxidized environment that is an excellent Mars analog site. This work demonstrates the successful and robust operation of the MAP instrument suite in the Atacama Desert. The instruments were subjected to over 30°C temperature variations (0°C to 30°C) during a typical day of operation and the CE system performed 340 separate electrophoretic analyses on only 3 microchips in one week. We have demonstrated that the MAP instrument can detect amino acids and organic amine biomarkers in one of the driest, most Mars-like environments on Earth. In addition, based on our chirality analysis we conclude that these molecules originated from extinct living organisms. Further lab analyses of these samples are being performed to re-determine amino acid concentrations and chirality, and to analyze for culturable bacteria, fatty acids, and total organic carbon and nitrogen. This work demonstrates the successful and robust operation of the MAP instrument suite in the Atacama Desert. The instruments were subjected to over 30°C temperature variations (0°C to 30°C) during a typical day of operation and the CE microchip system performed 340 separate electrophoretic analyses on only 3 microchips over the course of one week. We have demonstrated that the MAP instrument can detect amino acids and organic amine biomarkers in one of the driest, most Mars-like environments on Earth. In addition, based on our chirality analysis we conclude that these molecules originated from extinct living organisms. Further lab analyses of these samples are being performed to re-determine amino acid concentrations and chirality, and to analyze for culturable bacteria, fatty acids, and total organic carbon and nitrogen. 1. Skelley, A. M. et al. (2005) Proc. Natl. Acad, Sci. U.S.A. 102, 1041-1046. 2. Skelley, A. M., Cleaves, J. H., Bada, J. F. & Mathies, R. A. (2005), in preparation. 3. See http://astrobiology.berkeley.edu for additional details