Does the Measured Abundance Suggest a Biological Origin for the Ancient Alkanes Preserved in a Martian Mudstone? - Alexander A. Pavlov, Caroline Freissinet, Daniel P. Glavin, Christopher H. House, Jennifer C. Stern, Amy C. McAdam, Anais Roussel, Jason P. Dworkin, Luoth Chou, Andrew Steele, Paul R. Mahaffy, Denise Buckner, Felipe Gomez, 2026
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Abstract<br>The measured abundance (30–50 ppb) of long-chain (C10–C12) alkanes and their possible carboxylic acid precursors found in the ancient Cumberland mudstone in Gale crater would have been substantially higher before the onset of exposure to ionizing radiation approximately 80 million years ago. Based on recent radiolysis experiments, we estimate conservatively that the Cumberland mudstone would have contained 120–7700 ppm of long-chain alkanes and/or fatty acids before ionizing radiation exposure. Such a high concentration of large organic molecules in martian sedimentary rocks cannot be readily explained by the accretion of organics from carbon-rich interplanetary dust particles and meteorites, nor by the deposition of hypothetical haze-derived organics from an ancient martian atmosphere. We discuss the feasibility of two additional mechanisms––one abiotic and one biological––that could have been capable of depositing this level of long-straight-chain organic molecules in the ancient martian mudstones: allochthonous transport of hydrothermally synthesized organics and autochthonous accumulation of organics from a hypothetical ancient Mars biosphere. To advance and test these and any additional working hypotheses put forth to explain such high concentrations of primary organics on Mars requires an understanding of the radiolytic degradation products expected for organics preserved in mineralogically comparable mudstones.
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References<br>Aponte JC, Tarozo R, Alexandre MR, et al. Chirality of meteoritic free and IOM-derived monocarboxylic acids and implications for prebiotic organic synthesis. Geochim Cosmochim Acta, 2014; 131:1–12;<br>Crossref<br>Google Scholar
Bechtel A, Schubert CJ. A biogeochemical study of sediments from the eutrophic Lake Lugano and the oligotrophic Lake Brienz, Switzerland. Org Geochem, 2009; 40(10):1100–1114;<br>Crossref<br>Google Scholar
Benner SA, Devine KG, Matveeva LN, et al. The missing organic molecules on Mars. Proc Natl Acad Sci U S A, 2000; 97(6):2425–2430;<br>Crossref<br>PubMed<br>Google Scholar
Bland PA, Smith TB, Jull AJT, et al. The flux of meteorites to the Earth over the last 50,000 years. Mon Not R Astron Soc, 1996; 283(2):551–565;<br>Crossref<br>Google Scholar
Bonnet JY, Szopa C, Coscia D, et al. Operations of the Sample Analysis at Mars instrument suite onboard the Curiosity rover. In: SpaceOps Conferences. SpaceOps; 2018;<br>Crossref<br>Google Scholar
Bristow TF, Bish DL, Vaniman DT, et al. The origin and implications of clay minerals from Yellowknife Bay, Gale Crater, Mars. Am Mineral, 2015; 100(4):824–836;<br>Crossref<br>PubMed<br>Google Scholar
Bristow TF, Grotzinger JP, Rampe EB, et al. Brine driven diagenesis of clay minerals in Gale crater, Mars. Science, 2021; 373(6551):198–204;<br>Crossref<br>PubMed<br>Google Scholar
Bristow TF, Haberle RM, Blake DF, et al. Low Hesperian PCO2 constrained from in situ mineralogical analysis at Gale Crater, Mars. Proc Natl Acad Sci U S A, 2017; 114(9):2166–2170;<br>Crossref<br>PubMed<br>Google Scholar
Chassefière E, Langlais B, Quesnel Y, et al. The fate of early Mars’ lost water: The role of serpentinization. JGR Planets, 2013; 118(5):1123–1134;<br>Crossref<br>Google Scholar
Dartnell LR, Desorgher L, Ward JM, et al. Modelling the surface and subsurface Martian radiation environment: Implications for astrobiology. Geophys Res Lett, 2007; 34(2);<br>Crossref<br>Google Scholar
Eigenbrode JL, Summons RE, Steele A, et al. Organic matter preserved in 3-billion-year-old mudstones at Gale crater, Mars. Science, 2018; 360(6393):1096–1101;<br>Crossref<br>PubMed<br>Google Scholar
Farley KA, Malespin C, Mahaffy P, et al.; MSL Science Team. In situ radiometric and exposure age dating of the Martian surface. Science, 2014; 343(6169):1247166;<br>Crossref<br>PubMed<br>Google Scholar
Flynn GJ. Atmospheric entry heating: A criterion to distinguish between asteroidal and cometary sources of interplanetary dust. Icarus, 1989; 77(2):287–310;<br>Crossref<br>Google Scholar
Flynn GJ. The delivery of organic matter from asteroids and comets to the early surface of Mars. Earth Moon Planets, 1996; 72:469–474;<br>Crossref<br>PubMed<br>Google Scholar
Flynn GJ, McKay DS. An assessment of the meteoritic contribution to the Martian soil. J Geophys Res, 1990;...