Life detection in a universe of false positives
Life detection in a universe of false positives
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DOI：
10.1002/bies.202300050
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发表时间：
2022-05
期刊：
影响因子：
4
通讯作者：
Harrison B. Smith;Cole Mathis
中科院分区：
文献类型：
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作者：
Harrison B. Smith;Cole Mathis
天体生物学旨在确定宇宙中生命的分布和多样性。但正如“生物特征”一词所暗示的那样，将被检测到的不是生命本身，而是涉及生命系统的观察结果。我们对其他世界的有限访问表明，这种观察更有可能反映出不平衡的气体，而不是扭动的章鱼。然而，除了一只扭动的章鱼之外，任何东西都会引起人们对所探测到的东西的怀疑。解决这种怀疑需要一种理论来描述由于生命和那些由于非生物机制的过程。这为生命探测提出了一个存在主义的问题：天体生物学家计划如何通过非生命系统和生命系统之间共享的特征来探测系外行星上的生命？我们认为，你不能没有一个潜在的生命理论。我们通过分析对“地球2.0”系外行星的假设探测来说明这一点。在没有生命理论的情况下，我们认为社区应该专注于通过四个领域来确定生命的明确特征：研究地球上的生命，在实验室中构建生命，探测太阳系以及寻找技术签名。最终，我们会问，天体生物学家到底希望通过寻找生命来了解什么？
Astrobiology aims to determine the distribution and diversity of life in the universe. But as the word “biosignature” suggests, what will be detected is not life itself, but an observation implicating living systems. Our limited access to other worlds suggests this observation is more likely to reflect out‐of‐equilibrium gasses than a writhing octopus. Yet, anything short of a writhing octopus will raise skepticism about what has been detected. Resolving that skepticism requires a theory to delineate processes due to life and those due to abiotic mechanisms. This poses an existential question for life detection: How do astrobiologists plan to detect life on exoplanets via features shared between non‐living and living systems? We argue that you cannot without an underlying theory of life. We illustrate this by analyzing the hypothetical detection of an “Earth 2.0” exoplanet. Without a theory of life, we argue the community should focus on identifying unambiguous features of life via four areas: examining life on Earth, building life in the lab, probing the solar system, and searching for technosignatures. Ultimately, we ask, what exactly do astrobiologists hope to learn by searching for life?