The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument onboard the Rosetta spacecraft has measured molecular oxygen (O2) in the coma of comet 67P/Churyumov-Gerasimenko (67P/C-G) in surprisingly high abundances. These measurements mark the first unequivocal detection of O2 in a cometary environment. The large relative abundance of O2 in 67P/C-G despite its high reactivity and low interstellar abundance poses a puzzle for its origin in comet 67P/C-G, and potentially other comets. Since its detection, there have been a number of hypotheses put forward to explain the production and origin of O2 in the comet. These hypotheses cover a wide range of possibilities from various in situ production mechanisms to protosolar nebula and primordial origins. Here, we review the O2 formation mechanisms from the literature, and provide a comprehensive summary of the current state of knowledge of the sources and origin of cometary O2.

中文翻译：

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彗星中分子氧的起源：当前的知识和观点

罗塞塔航天器上的用于离子和中性分析的罗塞塔轨道器光谱仪 (ROSINA) 仪器测量了彗星 67P/Churyumov-Gerasimenko (67P/CG) 彗发中的分子氧 (O2)，其丰度高得惊人。这些测量标志着在彗星环境中首次明确检测到 O2。尽管 67P/CG 具有高反应性和低星际丰度，但 O2 在 67P/CG 中的相对丰度较大，这对其起源于 67P/CG 彗星和其他可能的彗星提出了一个难题。自发现以来，人们提出了许多假设来解释彗星中O2的产生和起源。这些假设涵盖了从各种原位产生机制到原太阳星云和原始起源的广泛可能性。在这里，我们回顾了文献中的 O2 形成机制，