Over 200 molecules have been detected in multiple extraterrestrial environments, including glycolaldehyde (C₂(H₂O)₂, GLA), a two-carbon sugar precursor that has been detected in regions of the interstellar medium. Its recent in situ detection on the nucleus of comet 67P/Churyumov–Gerasimenko and through remote observations in the comae of others provides tantalizing evidence that it is common on most (if not all) comets. Impact experiments conducted at the Experimental Impact Laboratory at NASA's Johnson Space Center have shown that samples of GLA and GLA mixed with montmorillonite clays can survive impact delivery in the pressure range of 4.5 to 25 GPa. Extrapolated to amounts of GLA observed on individual comets and assuming a monotonic impact rate in the first billion years of Solar System history, these experimental results show that up to 10²³ kg of cometary GLA could have survived impact delivery, with substantial amounts of threose, erythrose, glycolic acid, and ethylene glycol also produced or delivered. Importantly, independent of the profile of the impact flux in the early Solar System, comet delivery of GLA would have provided (and may continue to provide) a reservoir of starting material for the formose reaction (to form ribose) and the Strecker reaction (to form amino acids). Thus, comets may have been important delivery vehicles for starting molecules necessary for life as we know it.

中文翻译：

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彗星乙醇醛作为前 RNA 分子的来源。

已在多个外星环境中检测到超过 200 种分子，包括乙醇醛（C ₂ (H ₂ O) ₂，GLA），这是一种在星际介质区域中检测到的双碳糖前体。它最近的原位对 67P/Churyumov-Gerasimenko 彗核的探测以及通过对其他彗星彗尾的远程观测提供了诱人的证据，表明它在大多数（如果不是全部）彗星上很常见。在美国宇航局约翰逊航天中心实验撞击实验室进行的撞击实验表明，GLA 和 GLA 与蒙脱石粘土混合的样品可以在 4.5 到 25 GPa 的压力范围内承受撞击传递。外推到在单个彗星上观察到的 GLA 量并假设太阳系历史的前十亿年的单调撞击率，这些实验结果表明，多达 10 ²³100 公斤彗星 GLA 可能在撞击传递中幸存下来，同时还产生或传递了大量的苏糖、赤藓糖、乙醇酸和乙二醇。重要的是，独立于早期太阳系中撞击通量的分布，彗星输送 GLA 将提供（并可能继续提供）用于甲糖反应（形成核糖）和 Strecker 反应（形成核糖）的起始材料库。形成氨基酸）。因此，正如我们所知，彗星可能是启动生命必需分子的重要载体。