Physics Institute, Space Research & Planetary Sciences, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland.
Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA.
Nat Commun. 2022 Jun 25;13(1):3639. doi: 10.1038/s41467-022-31346-9.
In-situ study of comet 1P/Halley during its 1986 apparition revealed a surprising abundance of organic coma species. It remained unclear, whether or not these species originated from polymeric matter. Now, high-resolution mass-spectrometric data collected at comet 67P/Churyumov-Gerasimenko by ESA's Rosetta mission unveil the chemical structure of complex cometary organics. Here, we identify an ensemble of individual molecules with masses up to 140 Da while demonstrating inconsistency of the data with relevant amounts of polymeric matter. The ensemble has an average composition of CHONS, identical to meteoritic soluble organic matter, and includes a plethora of chain-based, cyclic, and aromatic hydrocarbons at an approximate ratio of 6:3:1. Its compositional and structural properties, except for the H/C ratio, resemble those of other Solar System reservoirs of organics-from organic material in the Saturnian ring rain to meteoritic soluble and insoluble organic matter -, which is compatible with a shared prestellar history.
在哈雷彗星 1986 年出现期间的原位研究揭示了彗发中丰富的有机彗发物质。这些物质是否源自聚合物质仍不清楚。现在，欧空局罗塞塔任务在彗星 67P/楚留莫夫-格拉希门克收集的高分辨率质谱数据揭示了复杂彗星有机物的化学结构。在这里，我们鉴定出了一整套质量高达 140Da 的单个分子，同时证明这些数据与相关聚合物质的数量不一致。该集合具有 CHONS 的平均组成，与陨石可溶有机物相同，并且包含大量链状、环状和芳烃，其比例约为 6:3:1。其组成和结构特性（除了 H/C 比）与其他太阳系有机物储层相似——从土星环雨中的有机物到陨石可溶和不可溶有机物——这与一个共同的前恒星历史是一致的。
