Center for Astronomy and Astrophysics (ZAA), Astrobiology Research Group, Technische Universität Berlin, Berlin, Germany.
German Research Centre for Geosciences (GFZ), Section Geomicrobiology, Potsdam, Germany.
Astrobiology. 2020 Apr;20(4):552-561. doi: 10.1089/ast.2019.2139. Epub 2020 Feb 24.
The question whether organic compounds occur on Mars remained unanswered for decades. However, the recent discovery of various classes of organic matter in martian sediments by the Curiosity rover seems to strongly suggest that indigenous organic compounds exist on Mars. One intriguing group of detected organic compounds were thiophenes, which typically occur on Earth in kerogen, coal, and crude oil as well as in stromatolites and microfossils. Here we provide a brief synopsis of conceivable pathways for the generation and degradation of thiophenes on Mars. We show that the origin of thiophene derivatives can either be biotic or abiotic, for example, through sulfur incorporation in organic matter during early diagenesis. The potential of thiophenes to represent martian biomarkers is discussed as well as a correlation between abundances of thiophenes and sulfate-bearing minerals. Finally, this study provides suggestions for future investigations on Mars and in Earth-based laboratories to answer the question whether the martian thiophenes are of biological origin.
火星上是否存在有机化合物这一问题数十年来一直没有得到解答。然而，好奇号探测器最近在火星沉积物中发现了各种有机物质类别，这似乎强烈表明火星上存在本土有机化合物。在已检测到的有机化合物中，引人注目的一类是噻吩，它通常存在于地球的干酪根、煤、原油以及叠层石和微生物化石中。在这里，我们简要概述了噻吩在火星上生成和降解的可能途径。我们表明，噻吩衍生物的起源可以是生物的或非生物的，例如，通过早期成岩作用中有机物质中的硫掺入。还讨论了噻吩作为火星生物标志物的潜力，以及噻吩丰度与含硫酸盐矿物之间的相关性。最后，本研究为未来在火星和地球实验室进行的研究提供了建议，以回答火星噻吩是否具有生物起源的问题。
