BIROn - Birkbeck Institutional Research Online

    Infrared Spectroscopic Detection of biosignatures at Lake Tírez, Spain: implications for Mars

    Preston, L.J. and Barcenilla, Rebeca and Dartnell, L.R. and Kucukkilic-Stephens, E. and Olsson-Francis, K. (2019) Infrared Spectroscopic Detection of biosignatures at Lake Tírez, Spain: implications for Mars. Astrobiology , ISSN 1531-1074. (In Press)

    [img]
    Preview
    Text
    29603.pdf - Published Version of Record
    Available under License Creative Commons Attribution.

    Download (764kB) | Preview

    Abstract

    The detection of potential biosignatures with mineral matrices is part of a multifaceted approach in the search for life on other planetary bodies. The 2020 ExoMars Rosalind Franklin rover includes within its payload three IR spectrometers in the form of ISEM (Infrared Spectrometer for ExoMars), MicrOmega, and Ma-MISS (Mars Multispectral Imager for Subsurface Studies). The use of this technique in the detection and characterization of biosignatures is of great value. Organic materials are often co-deposited in terrestrial evaporites and as such have been proposed as relevant analogs in the search for life on Mars. This study focuses on Ca-sulfates collected from the hypersaline Tírez Lake in Spain. Mid infrared and visible near infrared analysis of soils, salt crusts, and crystals with green and red layering indicative of microbial colonization of the samples was acquired from across the lake and identified the main mineral to be gypsum with inputs of carbonate and silica. Organic functional groups that could be attributed to amides and carboxylic acids were identified as well as chlorophyll; however, due to the strong mineralogical absorptions observed, these were hard to unambiguously discern. Taxonomical assignment demonstrated that the archaeal community within the samples was dominated by the halophilic extremophile Halobacteriaceae while the bacterial community was dominated by the class Nocardiaceae. The results of this research highlight that sulfates on Mars are a mixed blessing, acting as an effective host for organic matter preservation but also a material that masks the presence of organic functional groups when analyzed with spectroscopic tools similar to those due to fly on the 2020 ExoMars rover. A suite of complementary analytical techniques therefore should be used to support the spectral identification of any candidate extraterrestrial biosignatures.

    Metadata

    Item Type: Article
    Keyword(s) / Subject(s): Biosignature, IR spectroscopy, Lake Tírez, Mars, Sulfate
    School: Birkbeck Schools and Departments > School of Science > Earth and Planetary Sciences
    SWORD Depositor: Mr Joe Tenant
    Depositing User: Mr Joe Tenant
    Date Deposited: 02 Dec 2019 12:38
    Last Modified: 03 Dec 2019 14:30
    URI: http://eprints.bbk.ac.uk/id/eprint/29603

    Statistics

    Downloads
    Activity Overview
    25Downloads
    81Hits

    Additional statistics are available via IRStats2.

    Archive Staff Only (login required)

    Edit/View Item Edit/View Item