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 C₁H_1.56O_0.134N_0.046S_0.017, 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.

对 1P/Halley 彗星 1986 年幻影期间的原位研究揭示了令人惊讶的丰富有机昏迷物种。目前尚不清楚这些物种是否来自聚合物。现在，欧空局罗塞塔任务在彗星 67P/Churyumov-Gerasimenko 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，我们确定了质量高达 140 Da 的单个分子的集合，同时证明了数据与相关数量的聚合物质的不一致。该系综的平均成分为 C ₁ H _1.56 O _0.134 N _0.046 S _0.017，与陨石可溶性有机物相同，包括大量链状、环状和芳香烃，比例约为 6:3:1。除了 H/C 比外，它的成分和结构特性与太阳系其他有机物储层相似——从土星环雨中的有机物质到陨石的可溶性和不溶性有机物——这与共同的星前历史相一致。