Organic matter preserved in 3-billion-year-old mudstones at Gale crater, Mars
Organic matter preserved in 3-billion-year-old mudstones at Gale crater, Mars
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DOI：
10.1126/science.aas9185
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发表时间：
2018-06-08
期刊：
影响因子：
56.9
通讯作者：
Coll, Patrice
中科院分区：
文献类型：
--
作者：
Eigenbrode, Jennifer L.;Summons, Roger E.;Coll, Patrice
尽管关于火星上存在有机物的报道有限，但在火星物质中确定有机物的存在和状态，包括其可能的生物特征，一直是一个难以捉摸的任务。我们报告了通过好奇号火星探测器上的火星仪器套件的样本分析，在Gale陨石坑Pahrump Hills的35亿年前的穆雷地层底部的湖相泥岩中保存的有机物的原位检测。通过演化气体分析，直接检测高温（500 ~ 820℃）下释放的不同热解产物，包括噻吩类、芳香族和脂肪族化合物。同时用气相色谱-质谱法对噻吩进行了观察。它们的存在表明硫化作用有助于有机物的保存。至少有50纳摩尔的有机碳存在，可能是有机硫分子中含有5%碳的大分子。
Establishing the presence and state of organic matter, including its possible biosignatures, in martian materials has been an elusive quest, despite limited reports of the existence of organic matter on Mars. We report the in situ detection of organic matter preserved in lacustrine mudstones at the base of the similar to 3.5-billion-year-old Murray formation at Pahrump Hills, Gale crater, by the Sample Analysis at Mars instrument suite onboard the Curiosity rover. Diverse pyrolysis products, including thiophenic, aromatic, and aliphatic compounds released at high temperatures (500 to 820 degrees C), were directly detected by evolved gas analysis. Thiophenes were also observed by gas chromatography-mass spectrometry. Their presence suggests that sulfurization aided organic matter preservation. At least 50 nanomoles of organic carbon persists, probably as macromolecules containing 5% carbon as organic sulfur molecules.