Examinando por Autor "Medina, J."

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Detection of Potential Lipid Biomarkers in Oxidative Environments by Raman Spectroscopy and Implications for the ExoMars 2020-Raman Laser Spectrometer Instrument Performance.
(Mary Ann Liebert Publishers, 2020-03-02) Carrizo, D.; Muñoz Iglesias, V.; Fernández Sampedro, M.; Gil Lozano, C.; Sánchez García, L.; Prieto Ballesteros, O.; Medina, J.; Rull, F.; Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Fernández Sampedro, M. [0000-0003-1932-7591]; Lozano, C. G. [0000-0003-3500-2850]; Muñoz Iglesias, V. [0000-0002-1159-9093]; Sánchez García, L. [0000-0002-7444-1242]; Prieto Ballesteros, O. [0000-0002-2278-1210]; Carrizo, D. [0000-0003-1568-4591]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The aim of the European Space Agency's ExoMars rover mission is to search for potential traces of present or past life in the swallow subsurface (2 m depth) of Mars. The ExoMars rover mission relies on a suite of analytical instruments envisioned to identify organic compounds with biological value (biomarkers) associated with a mineralogical matrix in a highly oxidative environment. We investigated the feasibility of detecting basic organics (linear and branched lipid molecules) with Raman laser spectroscopy, an instrument onboard the ExoMars rover, when exposed to oxidant conditions. We compared the detectability of six lipid molecules (alkanes, alkanols, fatty acid, and isoprenoid) before and after an oxidation treatment (15 days with hydrogen peroxide), with and without mineral matrix support (amorphous silica rich vs. iron rich). Raman and infrared spectrometry was combined with gas chromatography-mass spectrometry to determine detection limits and technical constrains. We observed different spectral responses to degradation depending on the lipid molecule and mineral substrate, with the silica-rich material showing better preservation of organic signals. These findings will contribute to the interpretation of Raman laser spectroscopy results on cores from the ExoMars rover landing site, the hydrated silica-enriched delta fan on Cogoon Vallis (Oxia Planum).
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Raman semi-quantification on Mars: ExoMars RLS system as a tool to better comprehend the geological evolution of martian crust
(Elsevier BV, 2021-10-13) Veneranda, M.; Manrique, J. A.; García Prieto, C.; Sanz Arranz, A.; Lalla, E.; Kostantinidis, M.; Moral, A.; Medina, J.; Rull, F.; Nieto, L. M.; López Reyes, G.; Agencia Estatal de Investigación (AEI); European Research Council (ERC); Redes de Excelencia, SIGUE-Mars: Ciencia e Instrumentación para el estudio de procesos (bio)geoquímicos en marte, RED2018-102600-T
This work presents the latest chemometric tools developed by the RLS science team to optimize the scientific outcome of the Raman system onboard the ExoMars 2022 rover. Feldspar, pyroxene and olivine samples were first analyzed through the RLS ExoMars Simulator to determine the spectroscopic indicators to be used for a proper discrimination of mineral phases on Mars. Being the main components of Martian basaltic rocks, lepidocrocite, augite and forsterite were then used as mineral proxies to prepare binary mixtures. By emulating the operational constraints of the RLS, Raman datasets gathered from laboratory mixtures were used to build external calibration curves. Providing excellent coefficients of determination (R2 0.9942÷0.9997), binary curves were finally used to semi-quantify ternary mixtures of feldspar, pyroxene and olivine minerals. As Raman results are in good agreement with real concentration values, this work suggests the RLS could be effectively used to perform semi-quantitative mineralogical studies of the basaltic geological units found at Oxia Planum. As such, crucial information about the geological evolution of Martian Crust could be extrapolated. In light of the outstanding scientific impact this analytical method could have for the ExoMars mission, further methodological improvements to be discussed in a dedicated work are finally proposed.
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Raman spectroscopy and planetary exploration: Testing the ExoMars/RLS system at the Tabernas Desert (Spain)
(Elsevier BV, 2021-06-12) Veneranda, M.; López Reyes, G.; Manrique, J. A.; Sánz Arranz, A.; Medina, J.; Pérez, C.; Quintana, C.; Moral, A.; Rodríguez, J. A.; Zafra, J.; Nieto Calzada, L. M.; Rull, F.; European Research Council (ERC); Agencia Estatal de Investigación (AEI)
ExoFit trials are field campaigns financed by ESA to test the Rosalind Franklin rover and to enhance collaboration practices between ExoMars working groups. During the first trial, a replicate of the ExoMars rover was remotely operated from Oxfordshire (United Kingdom) to perform a complex sequence of scientific operation at the Tabernas Desert (Spain). By following the ExoMars Reference Surface Mission (RSM), the rover investigated the Badlands subsoil and collected drill cores, whose analytical study was entrusted to the RLS (Raman Laser Spectrometer) team. The preliminary characterization of core samples was performed in situ through the RLS Engineering and Qualification Model (EQM-2) and the Raman Demonstrator (RAD1), being this a new, portable emulator of the RLS. In situ results where then complemented by laboratory analysis using the RLS ExoMars simulator and the commercial version of the Curiosity/CheMin XRD system. Raman data, obtained by closely simulating the operational constraints of the mission, successfully disclosed the mineralogical composition of the samples, reaching the detection of minor/trace phases that were not detected by XRD. More importantly, Raman analysis detected many vibrational peaks potentially emitted by organic functional groups, thus suggesting the presence of microorganisms in the arid sub-surface of the Tabernas Desert. In light of the forthcoming ExoMars mission, the results here presented proves that RLS could play a critical role in the characterization of Martian sub-surface environments and in the analytical detection of potential traces of live.