An Investigation of Carbon Isotope Abundances in ALH84001

这个火星岩石特别研究机会活动的奖项支持加州大学圣克鲁斯分校海洋科学研究所的格雷格·h·劳博士对火星陨石中碳-14丰度的研究。该项目由极地项目办公室、化学部门和MPS多学科活动办公室资助。碳同位素测量（C-13/C-12比率和C-14浓度）将使用离散无机和有机碳提取技术对从ALH84001陨石收集的碳进行测量。该项目的目标是更好地了解陨石中碳的来源和可能的火星生物源性。这项工作将作为NASA-Ames研究中心合作研究项目的一部分进行，该项目将对AHL84001样品和地面类似物进行单独的酸、紫外激光烧蚀和阶梯加热提取。将对这些萃取馏分中释放的二氧化碳进行同位素分析。测定有机组分和无机组分的质量丰度和同位素丰度，测定各组分的陆地污染程度，测定陨石有机碳和无机碳的同位素碳比。这些结果将在火星地质和气候的背景下进行解释。陆地碳污染很可能影响了陨石的有机碳浓度，为了准确推断火星有机/无机碳同位素丰度、分异和有机碳形成过程，将考虑这一点。行星样品中的碳可能以无机形式存在，也可能被生物活动修饰过。由于物理或生物力量的作用，样品中碳的同位素组成可能已经改变，以提供一个独特的“特征”。“这项研究汇集了来自美国宇航局艾姆斯、加州大学和劳伦斯利弗莫尔国家实验室的碳同位素专家的独特组合，以调查陆地和陨石样本。”这些结果将有助于确定来自火星陨石ALH84001的证据是否与生物活动相一致。

This award in the Mars-Rock Special Research Opportunity activity supports study of carbon-14 abundances in martian meteorites by Dr. Greg H. Rau of the Institute of Marine Sciences, University of California, Santa Cruz. The project is funded by the Office of Polar Programs, the Chemistry Division, and the MPS Office of Multidisciplinary Activities. Carbon isotopic measurements (C-13/C-12 ratio and C-14 concentration) will be conducted on carbon collected from the ALH84001 meteorite using discrete inorganic and organic carbon extraction techniques. The goal of the project is to gain a better understanding of the sources and possible martian biogenicity of carbon contained in the meteorite. The work will be conducted as part of a collaborative research project based at NASA-Ames Research Center where individual acid, UV-laser ablation, and stepped heating extractions will be performed on AHL84001 samples and terrestrial analogs. Isotopic analysis will be performed on the carbon dioxide released from these extraction fractions. The mass and isotopic abundances within the organic and inorganic fractions will be determined, as well as the degree of terrestrial contamination of each fraction, and the isotopic carbon ratio of both the meteorite organic and inorganic carbon. The results will be interpreted in the context of Martian geology and climate. It is likely that terrestrial carbon contamination may have influenced the meteorite's organic carbon concentration, and this will be considered in order to accurately infer Martian organic/inorganic carbon isotope abundances, fractionations, and organic carbon formation process. Carbon in planetary samples may be present in inorganic forms or may have been modified by biological activity. As a result of either physical or biological forces, the isotopic composition of carbon in the sample may have been altered to provide a distinctive `signature.` This research brings together a unique combination of carbon isotope extertise from NASA-Ames, the University of California, and the Lawrence Livermore National Laboratory to investigate both terrestrial and meteorite samples. The results will aid in determining whether or not the evidence from martian meteorite ALH84001 is consistent with biological activity.