论文标题
量化未来搜索系外行星生物签名的信息的影响
Quantifying the information impact of future searches for exoplanetary biosignatures
论文作者
论文摘要
在未来几十年中，天文学的主要目标之一是远程搜索生物签名（即生物活性的光谱证据）。在这里，我们采用贝叶斯统计框架来讨论此类未来搜索的含义，无论是在检测到生命的情况下以及找不到明确的证据时。我们表明，即使是对我们恒星系统附近生物签名的单一检测，在对与未来二十年相似的大小相似的调查中，即使是从中性或悲观的立场开始，也会显着影响我们对宇宙生活频率的信念。特别是，在这种发现之后，最初的不可知论观察者将得出结论，银河系中有超过$ 10^5 $居住的行星，概率超过$ 95 $ \％。但是，如在蓬松的场景中，生物材料在星际距离上转移的生存能力将有所削弱。相反，缺乏生物签名的大量证据几乎没有影响，因此对银河系中的丰富生活的评估仍然在很大程度上不确定。
One of the major goals for astronomy in the next decades is the remote search for biosignatures (i.e.\ the spectroscopic evidence of biological activity) in exoplanets. Here, we adopt a Bayesian statistical framework to discuss the implications of such future searches, both in the case when life is detected, and when no definite evidence is found. We show that even a single detection of biosignatures in the vicinity of our stellar system, in a survey of similar size to what will be obtainable in the next two decades, would affect significantly our prior belief on the frequency of life in the universe, even starting from a neutral or pessimistic stance. In particular, after such discovery, an initially agnostic observer would be led to conclude that there are more than $10^5$ inhabited planets in the galaxy with a probability exceeding $95$\%. However, this conclusion would be somewhat weakened by the viability of transfer of biological material over interstellar distances, as in panspermia scenarios. Conversely, the lack of significant evidence of biosignatures would have little effect, leaving the assessment of the abundance of life in the galaxy still largely undetermined.
