Detection and Preservation of Biosignatures in Mars Analogs Hot Spring Deposits from the Taupo Volcanic Zone, New Zealand

Characterizing the preservation potential of biosignatures in martian analogs is essential in the quest for biosignatures with martian rovers. Hot spring silica deposits are part of the minerals with a high preservation potential. As part of an ongoing study, we are characterizing the nature and distribution of organic molecules including lipid biomarkers in a range of analog hot spring deposits, evaluating their preservation potential, and determining the potential signals from flight-like experiments. We are focusing on various geothermal fields in the New Zealand Taupo Volcanic Zone with physical and chemical variabilities. Samples are being extracted for lipid biomarker characterization as well as analysis using flight-like experiments from the current and future pyrolyzer-gas chromatographmass spectrometer instruments SAM and MOMA on the Curiosity and Exomars2020 rovers. The aim of work is to improve our knowledge of the detection and preservation of biosignatures in different hot spring lithologies while simultaneously evaluating the potential limits and biases of flight experiments.Fil: Millan, Maëva. University Of Georgetown; Estados Unidos. National Aeronautics and Space Administration; Estados UnidosFil: Campbell, Kathleen A.. Universidad Nacional y Kapodistriaca de Atenas; GreciaFil: Van Kranendonk, Martin J.. University of New South Wales; AustraliaFil: Sriaporn, Chanenath. Universidad Nacional y Kapodistriaca de Atenas; GreciaFil: Handley, Kim M.. Universidad Nacional y Kapodistriaca de Atenas; GreciaFil: Dobson, Michaela. Universidad Nacional y Kapodistriaca de Atenas; GreciaFil: Camp, Sîan. Universidad Nacional y Kapodistriaca de Atenas; GreciaFil: Teece, Bonnie. University of New South Wales; AustraliaFil: Guido, Diego Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; ArgentinaFil: Djokic, Tara. University of New South Wales; AustraliaFil: Farmer, Jack D.. Arizona State University; Estados UnidosFil: Stewart Johnson, Sarah. University Of Georgetown; Estados UnidosEPSC-DPS Joint Meeting 2019GenevaSuizaEuropean Process Safety Centr

Organic biosignatures through the geological record: challenges and progress

This thesis investigates the reliability of organic biosignatures in geological materials that span most of Earth’s geological record. The aim is to determine the syngeneity and reliability of organic matter (OM) and the best techniques to use on geological materials with different compositions and thermal histories. Active to recently fossilised (<14 ka) hot spring sinter samples from El Tatio, Chile, Taupo Volcanic Zone (TVZ), New Zealand, and Yellowstone National Park (YNP) were examined as these are key astrobiological targets due to their excellent preservation potential. El Tatio and TVZ samples were analysed using gas chromatography-mass spectrometry (GC-MS). TVZ samples returned aromatic hydrocarbon ratios, low isoprenoid/n­-alkane ratios, and smooth n-alkane distributions, that indicate OM had reached the oil window despite lack of burial. Surface samples from three localities in YNP record a similar complex history. Raman spectrometry and GC-MS results (hopane ratios and low isoprenoid/n-alkane ratios) are again indicative of the oil window. Thus, some of the preserved OM in hot springs was transported into the samples from hot subsurface reservoirs. GC-MS analyses of Jurassic (~178 – 151 Ma) sinter from Argentina show that the proximal sinter apron contains a low abundance of compounds with mixed thermal maturities, whereas the cooler distal apron contains thermally immature OM and a wide variety of hydrocarbons. These results indicate that the distal apron of fossil sinters is an attractive target for organic biosignature research. The reliability of OM in ancient rocks was tested on samples of three distinct fossil types from an overmature c. 2.4 Ga microbialite reef in the Turee Creek Group, Western Australia using in situ micro-Fourier transform infrared spectrometry (micro-FTIR) and flash pyrolysis GC-MS. Micro-FTIR revealed differences in branching and chain length of the hydrocarbon moiety, but anthropogenic contaminants were also detected. This thesis highlights the need for a whole system approach when considering the origin of OM in geological materials. The veracity of results depends on a thorough understanding of both the environmental context and geological history, and on bespoke analytical approaches to increase confidence in biosignature detection

Community Report from the Biosignatures Standards of Evidence Workshop

The search for life beyond the Earth is the overarching goal of the NASA Astrobiology Program, and it underpins the science of missions that explore the environments of Solar System planets and exoplanets. However, the detection of extraterrestrial life, in our Solar System and beyond, is sufficiently challenging that it is likely that multiple measurements and approaches, spanning disciplines and missions, will be needed to make a convincing claim. Life detection will therefore not be an instantaneous process, and it is unlikely to be unambiguous-yet it is a high-stakes scientific achievement that will garner an enormous amount of public interest. Current and upcoming research efforts and missions aimed at detecting past and extant life could be supported by a consensus framework to plan for, assess and discuss life detection claims (c.f. Green et al., 2021). Such a framework could help increase the robustness of biosignature detection and interpretation, and improve communication with the scientific community and the public. In response to this need, and the call to the community to develop a confidence scale for standards of evidence for biosignature detection (Green et al., 2021), a community-organized workshop was held on July 19-22, 2021. The meeting was designed in a fully virtual (flipped) format. Preparatory materials including readings, instructional videos and activities were made available prior to the workshop, allowing the workshop schedule to be fully dedicated to active community discussion and prompted writing sessions. To maximize global interaction, the discussion components of the workshop were held during business hours in three different time zones, Asia/Pacific, European and US, with daily information hand-off between group organizers