THE PATH OF REDUCED NITROGEN TOWARD EARLY EARTH: THE COSMIC TRAIL AND ITS SOLAR SHORTCUTS
THE PATH OF REDUCED NITROGEN TOWARD EARLY EARTH: THE COSMIC TRAIL AND ITS SOLAR SHORTCUTS
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通往早期地球的氮减少之路：宇宙轨迹及其太阳捷径
DOI：
10.1088/0004-637x/814/2/107
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
M. Bose
中科院分区：
文献类型：
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作者：
S. Pizzarello;M. Bose
在陨石不溶性有机物质（IOMs）中发现了大的同位素异常，对于氮，15 N-过量高达δ 15？> N = 5000‰这些15 N-富集通常被归因于太阳系前的起源，但这一归因似乎与现有的N-同位素宇宙分布数据相矛盾。我们在这里报告说，15 N热点在几个IOM减少水热处理和它们的损失与15 N值的氨释放处理后。因为释放的氨的15 N富集也与陨石的矿物学有关，即，小行星的过程，并没有目前的模型提供合理的解释的发现，我们占我们的数据与一个新的方案，即15 N富集氨产生的太阳星云是由碳质材料和交付到早期地球的彗星和陨石。该提议还意味着丰富的还原氮（生命起源理论中的必需元素）可能会到达我们新生的行星和其他行星系统，影响其可居住性。
Large isotopic anomalies are found in meteoritic insoluble organic materials (IOMs) and, for nitrogen, show 15N-excesses up to δ 15 ?> N ∼ 5000‰. These 15N-enrichments are commonly ascribed to presolar origins, but the attribution seems contradicted by available data on N-isotopes’ cosmic distribution. We report here that 15N hotspots in several IOMs are reduced by hydrothermal treatment and their loss correlates with 15N values of ammonia released upon treatment. Because released ammonia’s 15N-enrichments also relate with meteorites’ mineralogy, i.e., asteroidal processes, and no current models offer plausible explanations for the finding, we account for our data with a novel scenario whereby 15N-enriched ammonia produced in the solar nebula is incorporated by carbonaceous materials and delivered to early Earth by comets and meteorites. The proposal also implies that abundant reduced nitrogen, a required element in origins of life theories, could reach our nascent planet and other planetary systems affecting their habitability.