Signatures of abiotic organic matter and its processing: Implications for the detection of biosignatures

非生物有机物的特征及其加工：对生物特征检测的影响

• 批准号: RGPIN-2019-06456
• 负责人: Slater, Gregory
• 金额: $ 5.46万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=738922
• 关键词: Signatures; abiotic; organic; matter; its

Understanding how life originated on Earth and whether it may have arisen elsewhere in the Universe are the most fundamental questions we can ask, but they are also the most daunting. Nonetheless, progress is being made that is increasing our understanding of how we might answer them. Central to these questions is the ability to identify signatures of life, "biosignatures", and to differentiate them from signatures of abiotic processes, "abiosignatures". Biosignatures of life include recognizable organic molecules, isotopic ratios and mineral compositions, and patterns therein that can be unambiguously attributed to life. These biosignatures must be differentiated from patterns in these same parameters that existed prior to the advent of life, when only abiotic processes were operating. This understanding is all the more necessary as we continue to expand our interest in searching for evidence of life beyond the Earth. We need to interpret new observations including the detection of organic molecules on Mars by the Curiosity rover, the results of the ongoing Hyabusa 2 and OSIRIS Rex missions to asteroids, the planned Mars 2020 and ExoMars missions to Mars that include proposed sample return, and the proposed explorations of the moons of Saturn and Jupiter. This research proposal will continue my research program that seeks to further our understanding of biosignatures and abiosignatures with a much stronger emphasis on abiosignatures. It will further develop newly established collaborations with the Royal Ontario Museum (ROM) that brings an organic geochemistry perspective to their ongoing work characterizing and investigating meteorites. This will include analysis of the ROMs samples of the uniquely pristine and carbon rich Tagish Lake meteorite as well as analysis of meteorites from North West Africa which have yet to be characterized. The samples will be selected to provide insights into the amounts and signatures of organic matter that was delivered to the prebiotic Earth and thus supported the advent of life. Complimentary to the meteorite analyses, this research program will continue my investigation of microbial communities in the Earth's subsurface. It will seek to assess the extent to which we can identify biosignatures of microbial communities in the presence of abiosignatures of organic compounds produced via water-rock interaction. Finally, the stability of both biosignatures and abiosignatures will also be addressed via experimental studies of organic compound stability in the planetary simulators at McMaster and York Universities. These facilities allow the impact of changes in temperature, humidity, UV flux and atmospheric composition on the preservation, or potentially on the production, of organic compounds to be assessed. This research program will increase our ability to recognize abiosignatures and biosignatures and concurrently provide insight into the organic compounds that supported the advent of life.

了解生命是如何在地球上起源的，以及它是否在宇宙的其他地方出现，是我们能问的最基本的问题，但也是最令人生畏的问题。尽管如此，正在取得的进展正在增加我们对如何回答这些问题的理解。这些问题的核心是识别生命特征的能力，即“生物特征”，并将它们与非生物过程的特征区分开来，即“非生物特征”。生命的生物特征包括可识别的有机分子、同位素比例和矿物组成，以及其中可以明确归因于生命的模式。这些生物特征必须与在生命出现之前存在的相同参数中的模式区分开来，当时只有非生物过程在运作。随着我们对寻找地外生命证据的兴趣不断扩大，这种理解就更加必要了。我们需要解释新的观测结果，包括好奇号火星车对火星上有机分子的探测，正在进行的Hyabusa 2和OSIRIS Rex小行星任务的结果，计划中的火星2020和ExoMars火星任务（包括拟议的样本返回），以及拟议的土星和木星卫星探索。这项研究计划将继续我的研究计划，旨在进一步了解我们对生物签名和生物签名的理解，并更加强调生物签名。它将进一步发展与皇家安大略博物馆（ROM）新建立的合作关系，为他们正在进行的表征和调查陨石的工作带来有机地球化学的视角。这将包括对独特的原始和富含碳的塔吉什湖陨石的rom样本的分析，以及对来自北非尚未表征的陨石的分析。这些样本将被选中，以提供对有机物质的数量和特征的见解，这些有机物被运送到生命起源前的地球上，从而支持了生命的出现。作为对陨石分析的补充，这个研究项目将继续我对地球地下微生物群落的调查。它将试图评估在水岩相互作用产生的有机化合物的非生物特征存在的情况下，我们可以识别微生物群落的生物特征的程度。最后，通过麦克马斯特大学和约克大学的行星模拟器对有机化合物稳定性的实验研究，也将解决生物特征和非生物特征的稳定性问题。这些设施可以评估温度、湿度、紫外线通量和大气成分变化对有机化合物保存或潜在生产的影响。这个研究项目将提高我们识别非生物特征和生物特征的能力，同时提供对支持生命出现的有机化合物的深入了解。