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: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=714859
• 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.

了解生命如何起源于地球以及它是否可能出现在宇宙其他地方是我们可以提出的最基本的问题，但它们也是最令人畏惧的。尽管如此，我们正在取得进展，加深了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（“生物特征”）并将其与非生物过程特征（“非生物特征”）区分开来的能力。生命的生物特征包括可识别的有机分子、同位素比率和矿物成分，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生命出现之前存在的相同参数的模式区分开来，当时只有非生物过程在运行。随着我们不断扩大寻找地球以外生命证据的兴趣，这种理解就变得更加必要。 我们需要解释新的观测结果，包括好奇号火星车在火星上检测到的有机分子、正在进行的 Hyabusa 2 和 OSIRIS Rex 小行星任务的结果、计划的 Mars 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，旨在进一步加深我们对生物特征和非生物特征的理解，并更加强调非生物特征。 它将进一步发展与皇家安大略博物馆 (ROM) 新建立的合作，为他们正在进行的陨石表征和调查工作带来有机地球化学的视角。这将包括对独特的原始且富含碳的塔吉什湖陨石的 ROM 样本进行分析，以及对来自西北非尚未鉴定的陨石进行分析。选择这些样本是为了深入了解被输送到生命起源前的地球并从而支持生命出现的有机物的数量和特征。作为对陨石分析的补充，该研究计划将继续我对地球地下微生物群落的调查。它将寻求评估在存在通过水-岩石相互作用产生的有机化合物的生物特征的情况下我们可以在多大程度上识别微生物群落的生物特征。最后，生物特征和非生物特征的稳定性也将通过麦克马斯特大学和约克大学行星模拟器中有机化合物稳定性的实验研究来解决。这些设施可以评估温度、湿度、紫外线通量和大气成分的变化对有机化合物保存或潜在生产的影响。该研究计划将提高我们识别生物特征和生物特征的能力，同时深入了解支持生命出现的有机化合物。