%0 Journal Article %1 Prieto-Ballesteros2003 %A Prieto-Ballesteros, O. %A Rodriguez, N. %A Kargel, J. S. %A Kessler, C. G. %A Amils, R. %A Remolar, D. F. %D 2003 %J Astrobiology %K BIOMASS; CHAOS; ENERGY; ICE LIFE; MODEL; OCEAN; ORGANISMS; %N 4 %P 863--877 %T Tirez lake as a terrestrial analog of Europa %V 3 %X Tirez Lake (La Mancha, central Spain) is proposed as a terrestrial analogue of Europa's ocean. The proposal is based on the comparison of the hydrogeochemistry of Tirez Lake with the geochemical features of the alteration mineralogy of meteoritic precursors and with Galileo's Near Infrared Mapping Spectrometer data on Europa's surface. To validate the astrobiological potential of Tirez Lake as an analog of Europa, different hydrogeochemical, mineral, and microbial analyses were performed. Experimental and theoretical modeling helped to understand the crystallization pathways that may occur in Europa's crust. Calculations about the oxidation state of the hypothetical Europan ocean were estimated to support the sulfate-rich neutral liquid model as the origin of Europa's observed hydrated minerals and to facilitate their comparison with Tirez's hydrogeochemistry. Hydrogeochemical and mineralogical analyses showed that Tirez waters corresponded to Mg-Na-SO4-Cl brines with epsomite, hexahydrite, and halite as end members. A preliminary microbial ecology characterization identified two different microbial domains: a photosynthetically sustained community represented by planktonic/benthonic forms and microbial mat communities, and a subsurficial anaerobic realm in which chemolithotrophy predominates. Fluorescence in situ hybridization has been used to characterize the prokaryotic diversity of the system. The subsurficial community seemed to be dominated by sulfate-reducing bacteria and methanogens. Frozen Tirez brines were analyzed by Fourier-transform infrared techniques providing spectra similar to those reported previously using pure components and to the Galileo spectral data. Calorimetric measurements of Tirez brines showed pathways and phase metastability for magnesium sulfate and sodium chloride crystallization that may aid in understanding the processes involved in the formation of Europa's icy crust. The use of fluorescence hybridization techniques for microbial detection and characterization in hypersaline environments makes this methodology strongly advisable for future Europa astrobiological missions.

@article{Prieto-Ballesteros2003, abstract = {Tirez Lake (La Mancha, central Spain) is proposed as a terrestrial analogue of Europa's ocean. The proposal is based on the comparison of the hydrogeochemistry of Tirez Lake with the geochemical features of the alteration mineralogy of meteoritic precursors and with Galileo's Near Infrared Mapping Spectrometer data on Europa's surface. To validate the astrobiological potential of Tirez Lake as an analog of Europa, different hydrogeochemical, mineral, and microbial analyses were performed. Experimental and theoretical modeling helped to understand the crystallization pathways that may occur in Europa's crust. Calculations about the oxidation state of the hypothetical Europan ocean were estimated to support the sulfate-rich neutral liquid model as the origin of Europa's observed hydrated minerals and to facilitate their comparison with Tirez's hydrogeochemistry. Hydrogeochemical and mineralogical analyses showed that Tirez waters corresponded to Mg-Na-SO4-Cl brines with epsomite, hexahydrite, and halite as end members. A preliminary microbial ecology characterization identified two different microbial domains: a photosynthetically sustained community represented by planktonic/benthonic forms and microbial mat communities, and a subsurficial anaerobic realm in which chemolithotrophy predominates. Fluorescence in situ hybridization has been used to characterize the prokaryotic diversity of the system. The subsurficial community seemed to be dominated by sulfate-reducing bacteria and methanogens. Frozen Tirez brines were analyzed by Fourier-transform infrared techniques providing spectra similar to those reported previously using pure components and to the Galileo spectral data. Calorimetric measurements of Tirez brines showed pathways and phase metastability for magnesium sulfate and sodium chloride crystallization that may aid in understanding the processes involved in the formation of Europa's icy crust. The use of fluorescence hybridization techniques for microbial detection and characterization in hypersaline environments makes this methodology strongly advisable for future Europa astrobiological missions.}, added-at = {2009-11-03T20:21:25.000+0100}, author = {Prieto-Ballesteros, O. and Rodriguez, N. and Kargel, J. S. and Kessler, C. G. and Amils, R. and Remolar, D. F.}, biburl = {https://www.bibsonomy.org/bibtex/27f2cbf55953270b5e5c0b77d764ab840/svance}, citedreferences = {AIRIEAU SA, 2001, LUN PLAN SCI C 32 ; AMANN RI, 1995, MICROBIOL REV, V59, P143 ; BALLESTEROS OP, 2003, FORUM CONCEPTS APPRO ; BARR AC, 2002, LUN PLAN SCI C 33 ; CARLSON RW, 2002, Icarus, V157, P456 ; CLAYTON RN, 1999, GEOCHIM COSMOCHIM AC, V63, P2089 ; COLLINS GC, 2000, J GEOPHYS RES-PLANET, V105, P1709 ; CONRAD R, 1995, FEMS MICROBIOL ECOL, V16, P295 ; CRAWFORD GD, 1988, Icarus, V73, P66 ; DELAPENA JA, 1982, ESTUD GEOL, V38, P245 ; EUGSTER HP, 1970, MINERAL SOC AM SPEC, V3, P273 ; FAGENTS SA, 2000, Icarus, V144, P54 ; FANALE FP, 2001, J GEOPHYS RES-PLANET, V106, P14595 ; FRUND C, 1992, APPL ENVIRON MICROB, V58, P70 ; GONZALEZ AP, 1981, THESIS COMPLUTENSE U ; GOUNELLE M, 2001, LUN LAN SCI C 32 ; Greenberg R, 1999, Icarus, V141, P263 ; GUERRERO MC, 1992, LIMNETICA, V8, P197 ; HEAD JW, 1999, J GEOPHYS RES-PLANET, V104, P24223 ; HOGENBOOM DL, 1997, LUN PLAN SCI C 28 ; JOHNSON JW, 1992, COMPUT GEOSCI, V18, P899 ; KARGEL J, 1996, LUNAR PLANET SCI, P643 ; KARGEL JS, 2000, Icarus, V148, P226 ; KEMPE S, 1985, CHEM GEOL, V53, P95 ; KEMPE S, 2002, Astrobiology, V2, P123 ; KHURANA KK, 1998, Nature, V395, P777 ; LAROCK PA, 1979, APPL ENVIRON MICROB, V37, P466 ; MARION GM, 2002, GEOCHIM COSMOCHIM AC, V66, P2499 ; MCCOLLOM TM, 1999, J GEOPHYS RES-PLANET, V104, P30729 ; MCCORD TB, 1998, Science, V280, P1242 ; MCCORD TB, 2002, J GEOPHYS RES, V107 ; MCKINNON WB, 2002, B AM ASTRON SOC, V34 ; OBRIEN DP, 2002, Icarus, V156, P152 ; PAPPALARDO RT, 1999, J GEOPHYS RES-PLANET, V104, P24015 ; RUBIN AE, 1988, METEORITES EARLY SOL, P488 ; SCHULZEMAKUCH D, 2002, Astrobiology, V2, P105 ; SPAUN NA, 1998, GEOPHYS RES LETT, V25, P4277 ; STEFANSSON A, 2002, CHEM GEOL, V190, P251 ; ZOLENSKY M, 1988, METEORITES EARLY SOL, P114 ; ZOLOTOV MY, 2001, LUN PLAN SCI C 32 ; ZOLOTOV MY, 2003, J GEOPHYS RES, V108, P1029}, interhash = {a189cf18a1c25502be9aa05a95a965b6}, intrahash = {7f2cbf55953270b5e5c0b77d764ab840}, journal = {Astrobiology}, keywords = {BIOMASS; CHAOS; ENERGY; ICE LIFE; MODEL; OCEAN; ORGANISMS;}, number = 4, owner = {svance}, pages = {863--877}, timestamp = {2009-11-03T20:22:10.000+0100}, title = {Tirez lake as a terrestrial analog of Europa}, volume = 3, year = 2003 }