The Mars Organic Molecule Analyzer (MOMA) is a key scientific instrument on the ExoMars Rover mission. MOMA is designed to detect and characterize organic compounds, over a wide range of volatility and molecular weight, in samples obtained from up to 2 m below the martian surface. Thorough analog sample studies are required to best prepare to interpret MOMA data collected on Mars. We present here the MOMA characterization of Mars analog samples, microbial streamer communities composed primarily of oxygenic and anoxygenic phototrophs, collected from an alkaline silica-depositing hot spring in Yellowstone National Park, Wyoming, USA. Samples of partly mineralized microbial streamers and their total lipid extract (TLE) were measured on a MOMA Engineering Test Unit (ETU) instrument by using its laser desorption/ionization mass spectrometry (LDI-MS) mode. MOMA LDI-MS detected a variety of lipids and pigments such as chlorophyll a, monogalactosyldiacylglycerol, digalactosyldiacylglycerol, diacylglycerols, and β-carotene in the TLE sample. Only chlorophyll a was detected in the untreated streamer samples when using mass isolation, which was likely due to the higher background signal of this sample and the relative high ionization potential of the chlorophyll a compared with other compounds in unextracted samples. The results add to the LDI-MS sample characterization database and demonstrate the benefit of using mass isolation on the MOMA instrument to reveal the presence of complex organics and potential biomarkers preserved in a natural sample. This will also provide guidance to in situ analysis of surface samples during Mars operations.

中文翻译：

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ExoMars Mars 有机分子分析仪 (MOMA) 激光解吸/电离质谱 (LDI-MS) 分析美国黄石国家公园二氧化硅沉积温泉的光养群落

火星有机分子分析仪 (MOMA) 是 ExoMars 漫游者任务的关键科学仪器。MOMA 旨在检测和表征从火星表面以下 2 m 处获得的样品中具有广泛挥发性和分子量的有机化合物。需要进行彻底的模拟样本研究，以最好地准备解释在火星上收集的 MOMA 数据。我们在这里展示了火星模拟样品的 MOMA 特征，这些微生物流光群落主要由含氧和无氧光养生物组成，采集自美国怀俄明州黄石国家公园的碱性二氧化硅沉积温泉。在 MOMA 工程测试单元 (ETU) 仪器上使用其激光解吸/电离质谱 (LDI-MS) 模式测量部分矿化的微生物流光及其总脂质提取物 (TLE) 样品。MOMA LDI-MS 检测到叶绿素等多种脂质和色素a， TLE 样品中的单半乳糖基二酰基甘油、二半乳糖基二酰基甘油、二酰基甘油和 β-胡萝卜素。使用质量分离时，未处理的流光样品中仅检测到叶绿素a，这可能是由于该样品的背景信号较高，并且与未提取样品中的其他化合物相比，叶绿素a 的电离电位相对较高。结果添加到 LDI-MS 样品表征数据库中，并证明了在 MOMA 仪器上使用质量分离来揭示天然样品中保存的复杂有机物和潜在生物标志物的存在的好处。这也将为火星作业期间表面样品的原位分析提供指导。