论文标题
系外行星生物签名的徒劳
The Futility of Exoplanet Biosignatures
论文作者
论文摘要
天体生物学的最终目标是确定宇宙生活的分布和多样性。但是，正如“生物签名”一词所暗示的那样，被发现的不是生命本身，而是一种观察，暗示了与生活系统相关的特定过程。技术限制和我们对其他世界的有限访问表明，与扭曲的章鱼相比，我们更有可能检测到气体的平衡外套。然而，除了扭曲的章鱼之外，任何东西都会引起天体生物学家对所检测到的事物的怀疑。解决这个怀疑主义需要理论来描述由于生命和仅由于非生物机制而导致的过程。这为生命检测的努力提出了一个生存问题：天体生物学家如何计划通过非生命和生活系统之间共享的特征来检测生命？我们认为，没有潜在的生活理论，您将不可能。我们通过分析“ Earth 2.0”系外行星的假设检测来说明这一点。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积极研究的领域来确定生活的明确特征：了解地球上的生命原理，在实验室中建立生命，检测太阳系中的生活并寻找技术签名。最终，我们问，天体生物学家希望通过寻找生活来学习什么？
The ultimate goal of astrobiology is 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 a particular process associated with living systems. Technical constraints and our limited access to other worlds suggest we are more likely to detect an out-of-equilibrium suite of gasses than a writhing octopus. Yet, anything short of a writhing octopus will raise skepticism among astrobiologists about what has been detected. Resolving that skepticism requires a theory to delineate processes due to life and those due solely to abiotic mechanisms. This poses an existential question for the endeavor of life detection: How do astrobiologists plan to detect life 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. In the absence of a theory of life, we argue the community should focus on identifying unambiguous features of life via four areas of active research: understanding the principles of life on Earth, building life in the lab, detecting life in the solar system and searching for technosignatures. Ultimately, we ask, what exactly do astrobiologists hope to learn by searching for life?
