Measuring martian organics and methane The Curiosity rover has been sampling on Mars for the past 5 years (see the Perspective by ten Kate). Eigenbrode et al. used two instruments in the SAM (Sample Analysis at Mars) suite to catch traces of complex organics preserved in 3-billion-year-old sediments. Heating the sediments released an array of organics and volatiles reminiscent of organic-rich sedimentary rock found on Earth. Most methane on Earth is produced by biological sources, but numerous abiotic processes have been proposed to explain martian methane. Webster et al. report atmospheric measurements of methane covering 3 martian years and found that the background level varies with the local seasons. The seasonal variation provides an important clue for determining the origin of martian methane. Science, this issue p. 1096, p. 1093; see also p. 1068 Complex organic compounds may have been detected by the Curiosity rover in ancient martian sedimentary rocks. 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 ~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°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.

中文翻译：

---

火星盖尔陨石坑 30 亿年前泥岩中保存的有机物

测量火星有机物和甲烷 好奇号火星车过去 5 年一直在火星上采样（参见 10 位凯特的观点）。艾根布罗德等人。使用 SAM（火星样品分析）套件中的两台仪器捕捉保存在 30 亿年前沉积物中的复杂有机物的痕迹。加热沉积物会释放出一系列有机物和挥发物，让人想起地球上发现的富含有机物的沉积岩。地球上的大多数甲烷是由生物来源产生的，但已经提出了许多非生物过程来解释火星甲烷。韦伯斯特等人。报告对火星 3 年的甲烷进行大气测量，发现背景水平随当地季节变化。季节性变化为确定火星甲烷的来源提供了重要线索。科学，这个问题 p。1096 页。1093; 另见第。1068 好奇号火星车可能在古代火星沉积岩中检测到复杂的有机化合物。尽管关于火星上存在有机物质的报道有限，但在火星材料中确定有机物质的存在和状态，包括其可能的生物特征一直是一项难以捉摸的探索。我们报告了通过好奇号火星车上的火星仪器套件的样品分析，在盖尔陨石坑 Pahrump Hills 约 35 亿年前的 Murray 地层底部的湖相泥岩中原位检测到有机质。多种热解产物，包括在高温（500° 至 820°C）下释放的噻吩、芳香族和脂肪族化合物，可通过逸出气体分析直接检测到。通过气相色谱-质谱法也观察到噻吩。它们的存在表明硫化有助于有机物质的保存。至少有 50 纳摩尔的有机碳存在，可能是含有 5% 碳的大分子有机硫分子。