| 1. |
- Baqué, Mickael, et al.
(författare)
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Biosignature stability in space enables their use for life detection on Mars
- 2022
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Ingår i: Science Advances. - : NLM (Medline). - 2375-2548. ; 8:36
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Tidskriftsartikel (refereegranskat)abstract
- Two rover missions to Mars aim to detect biomolecules as a sign of extinct or extant life with, among other instruments, Raman spectrometers. However, there are many unknowns about the stability of Raman-detectable biomolecules in the martian environment, clouding the interpretation of the results. To quantify Raman-detectable biomolecule stability, we exposed seven biomolecules for 469 days to a simulated martian environment outside the International Space Station. Ultraviolet radiation (UVR) strongly changed the Raman spectra signals, but only minor change was observed when samples were shielded from UVR. These findings provide support for Mars mission operations searching for biosignatures in the subsurface. This experiment demonstrates the detectability of biomolecules by Raman spectroscopy in Mars regolith analogs after space exposure and lays the groundwork for a consolidated space-proven database of spectroscopy biosignatures in targeted environments.
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| 2. |
- de Vera, Jean-Pierre, et al.
(författare)
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Limits of Life and the Habitability of Mars : The ESA Space Experiment BIOMEX on the ISS
- 2019
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Ingår i: Astrobiology. - : Mary Ann Liebert. - 1531-1074 .- 1557-8070. ; 19:2, s. 145-157
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). The design of the multiuser facility supports-among others-the BIOMEX investigations into the stability and level of degradation of space-exposed biosignatures such as pigments, secondary metabolites, and cell surfaces in contact with a terrestrial and Mars analog mineral environment. In parallel, analysis on the viability of the investigated organisms has provided relevant data for evaluation of the habitability of Mars, for the limits of life, and for the likelihood of an interplanetary transfer of life (theory of lithopanspermia). In this project, lichens, archaea, bacteria, cyanobacteria, snow/permafrost algae, meristematic black fungi, and bryophytes from alpine and polar habitats were embedded, grown, and cultured on a mixture of martian and lunar regolith analogs or other terrestrial minerals. The organisms and regolith analogs and terrestrial mineral mixtures were then exposed to space and to simulated Mars-like conditions by way of the EXPOSE-R2 facility. In this special issue, we present the first set of data obtained in reference to our investigation into the habitability of Mars and limits of life. This project was initiated and implemented by the BIOMEX group, an international and interdisciplinary consortium of 30 institutes in 12 countries on 3 continents. Preflight tests for sample selection, results from ground-based simulation experiments, and the space experiments themselves are presented and include a complete overview of the scientific processes required for this space experiment and postflight analysis. The presented BIOMEX concept could be scaled up to future exposure experiments on the Moon and will serve as a pretest in low Earth orbit.
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| 3. |
- Kopacz, Nina, et al.
(författare)
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A Study in Blue : Secondary Copper-Rich Minerals and Their Associated Bacterial Diversity in Icelandic Lava Tubes
- 2022
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Ingår i: Earth and Space Science. - : American Geophysical Union (AGU). - 2333-5084. ; 9:5
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Tidskriftsartikel (refereegranskat)abstract
- Lava tubes on Mars hold exciting potential for the preservation of biosignatures, which may survive on geological timescales in these isolated, stable environments. To support the development of future astrobiological mission concepts, we turn to terrestrial lava tubes, host to a variety of microbial communities and secondary minerals. Following a multidisciplinary sampling protocol, we retrieved biological, molecular, and mineralogical data from several lava tubes in Iceland. We report on blue-colored copper-rich secondary minerals and their associated bacterial communities using a multi-method approach, and an amalgam of 16S rRNA gene sequencing, Raman spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy data sets. We found numerous bacterial genera known for their high metal resistance and ability to survive in low-nutrient environments. Both are characteristics to be expected for any potential life in Martian lava tubes, and should be considered when checking for contaminants in Mars mission preparations. Associated with the microbial mats, we identified several types of copper-rich secondary minerals, indicating localized copper enrichments in the groundwater, possibly stemming from overlying ash deposits and nearby hyaloclastite formations. Molecular analysis revealed carotenoid signals preserved within the copper speleothems. If found in Martian lava tubes, blue copper-rich mineral precipitates would be deserving of astrobiological investigation, as they have potential to preserve biosignatures and harbor life. Plain Language Summary Subterranean lava tubes on Mars are exciting locations to study in the potential discovery of signs of life outside of Earth, as the surface of Mars does not have conditions conducive to the preservation of life as we know it. In order to better study these Martian environments we look first to comparable lava tubes on Earth. Within Icelandic lava tubes we found blue-colored copper minerals, host to microbial life. The microbes that thrive in these caves are able to withstand extreme conditions, and leave behind detectable molecular traces indicative of life, a type of biosignature. Using a variety of tools and techniques, we describe the nature of the blue minerals and their provenance, the role of the microbial populations within them, and the value of the molecular traces as biosignatures. We discuss the potential for such minerals and microbes in Martian lava tubes, and how we might successfully sample them in future missions to Mars.
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