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SEASONALLY ACTIVE BRINES OBSERVED ON MARS SURFACE AS WELL AS THE PRESENCE OF SALTS IN PLUME JETS ON ENCELADUS SUGGEST THAT BRINY WATERS MAY BE COMMON THROUGHOUT THE SOLAR SYSTEM. MODERN BRINES LIKELY CONTAIN IMPORTANT CLUES TOWARD UNDERSTANDING THE GEOLOGIC HISTORY CURRENT SUBSURFACE CONDITIONS AND POTENTIAL HABITABILITY OF THESE AND OTHER PLANETARY BODIES. HOWEVER TRADITIONAL TECHNIQUES USED TO DETECT AND MEASURE AQUEOUS COMPONENTS IN PLANETARY AND TERRESTRIAL WATERS RELY ON DIRECT SAMPLING AND ANALYSIS WHICH CAN LEAD TO CLOGGING AND CORROSION WHEN APPLIED TO BRINES. RAMAN SPECTROSCOPY WHICH MEASURES THE VIBRATIONAL ENERGY OF COVALENT BONDS BY EXCITING THE SAMPLE WITH LASER LIGHT THEN COLLECTING THE PHOTONS PRODUCED BY THE EXCITATION CAN REMOTELY DETECT AND MEASURE AQUEOUS COMPONENTS IN VERY SMALL SAMPLES WITH LITTLE TO NO SAMPLE PREPARATION. THEREFORE RAMAN SPECTROSCOPY COULD BE USED TO REMOTELY ANALYZE PORE WATER FLUID INCLUSIONS AND/OR GRAIN COATINGS IN ADDITION TO BULK WATER SAMPLES WHILE ENHANCING PLANETARY PROTECTION. FOR EXAMPLE RAMAN HAS BEEN PREVIOUSLY UTILIZED TO DETERMINE PH CONDITIONS IN MICROLITER SAMPLES OF ANCIENT SULFATE-RICH WATERS TRAPPED AS FLUID INCLUSIONS (BENISON ET AL. 1998) AND DETERMINE NUTRIENT CONCENTRATIONS (N AND P) IN SEAWATER USING SURFACE ENHANCED RESONANCE RAMAN SPECTROSCOPY (SERS) AT NANOMOLAR CONCENTRATIONS (SHARMA AND TAYLOR 1991). PRELIMINARY RESEARCH IN OUR LABORATORY DEMONSTRATES THAT RAMAN SPECTROSCOPY CAN BE USED TO EVALUATE AQUEOUS CARBONATE NITRATE PHOSPHATE SULFATE AND PERCHLORATE CONCENTRATIONS IN NEAR-SATURATED NACL CACL2 MGSO4 NA2SO4 AND NACLO4 BRINES. HOWEVER RELIABLE WELL DOCUMENTED REFERENCE RAMAN SPECTRA ARE REQUIRED IN ORDER TO SUPPORT FUTURE MISSIONS WHICH MAY ENCOUNTER AQUEOUS PLANETARY SAMPLES. WE AIM TO CREATE A NEW REFERENCE DATABASE OF AQUEOUS RAMAN SPECTRA BY GENERATING NEW REFERENCE SPECTRA FROM ENDMEMBER NEARSATURATED (CACL2 NA2SO4 MGSO4 NACL NACLO4) TO WHICH KNOWN CONCENTRATIONS OF SODIUM SALTS WITH C N P S AND CL-BEARING ANIONS ARE ADDED. SOLUTIONS WILL BE ANALYZED USING A 532 LASER AND THE SIGNAL FOR EACH KNOWN STANDARD WILL BE MEASURED TO DETERMINE DETECTION LIMITS AND DEVELOP CALIBRATION CURVES. WE WILL BUILD UPON THESE INITIAL SOLUTE MEASUREMENTS IN YEAR 2 TO DETERMINE THE EFFECTS OF VARYING PH AND TEMPERATURE ON AQUEOUS RAMAN SPECTRAL SIGNATURES BY COLLECTING RAMAN SPECTRA THROUGHOUT PH TITRATION AND TEMPERATURE RAMP EXPERIMENTS. IN YEAR 3 WE WILL MEASURE RAMAN SPECTRA FROM MIXTURES OF BRINE + SOLID MATRIX COMPOSED ON BASALTIC SEDIMENTS CLAY MINERALS OR WATER ICE TO DETERMINE AQUEOUS RAMAN DETECTION LIMITS IN HETEROGENEOUS SYSTEMS AND FURTHER DEVELOP A SUITE OF PLANETARY-ANALOG REFERENCE SPECTRA. THESE SPECTRA AND CALIBRATION CURVES WILL BE UTILIZED TO GENERATE NEW REFERENCE SPECTRA AND DEVELOP A DATABASE OF RAMAN SPECTRA FOR PLANETARY EXPLORATION OF AQUEOUS SOLUTIONS WHICH WILL BE ARCHIVED IN THE PUBLICALLY AVAILABLE NASA SUPPORTED PLANETARY DATA SYSTEM. FUTURE RESEARCHERS CAN DOWNLOAD AND USE THESE REFERENCE SPECTRA AND CALIBRATION CURVES TO SUPPORT RAMAN-BASED TECHNIQUES AIMED AT ANALYZING PLANETARY FLUIDS ON MARS AS WELL AS ICY PLANETARY BODIES INCLUDING ENCELADUS AND EUROPA. DATA FROM THIS STUDY CAN BE USED TO INTERPRET RAMAN SPECTRA TO ASSESS HABITABILITY ON DIFFERENT SCALES (ASTROBIOLOGY STRATEGY 5.4 I HAYS ET AL. 2013) DETERMINE ANY PAST OR PRESENT HABITABLE ENVIRONMENTS PREBIOTIC CHEMISTRY AND SIGNS OF LIFE ELSEWHERE IN OUR SOLAR SYSTEM AND DETERMINE THE HISTORY OF ANY ENVIRONMENTS HAVING LIQUID WATER CHEMICAL INGREDIENTS AND ENERGY SOURCES THAT MIGHT HAVE SUSTAINED LIVING SYSTEMS (ASTROBIOLOGY ROADMAP GOAL 2 DESMARAIS ET AL 2008). THEREFORE THIS REFERENCE DATA AND SPECTRAL ARCHIVE WILL EXPAND THE KNOWLEDGE GAINED AND RETURN ON INVESTMENT FROM RAMAN SPECTROMETERS THAT MAY BE DEPLOYED FOR PLANETARY EXPLORATION WITHIN THE NEXT DECADE FULFILLING THE PRIMARY MISSION OF THE PDART PROGRAM.

$380,855FY2020National Aeronautics and Space AdministrationNASA

University Of Oklahoma, Norman OK

Investigators

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