论文标题
德雷克任务：在宇宙中找到生活的频率
The DRAKE mission: finding the frequency of life in the Cosmos
论文作者
论文摘要
在寻找宇宙中的生命时，系外行星代表了行星形成，进化和生命的出现中的许多自然实验。这增加了在统计基础上评估宇宙生活的迷人前景。一个关键的统计数据是生命世界的发生率，$ f _ {\ rm l} $，是著名的德雷克方程中的“生命频率”术语。测量$ f _ {\ rm l} $将深入了解生活的共同点，并可能有助于限制生命的理论。我建议$ f _ {\ rm l} $作为Drake任务的目标（专门研究探索外生物学知识的研究）：M-dwarf可居住区陆地行星的过境光谱调查。我调查了$ f _ {\ rm l} $ scale的观察值的不确定性如何具有样本尺寸。我确定采样误差在观察误差上占主导地位，并且不确定性是观察到的$ f _ {\ rm l} $ value的函数。我表明，即使是小样本量也可以在$ f _ {\ rm l} $上提供重大约束，对于过境光谱法而言良好。我使用名义仪器设计和任务计划对Drake任务进行了可行性研究。由于观察效率低，可能需要将Drake纳入更广阔的深空或月球天文台中。如果样本$ f _ {\ rm l} $ = 0，则50个样式的调查可能会将$ f _ {\ rm l} $限制为$ \ leq $ 0.06（以95％的信心），或者如果样本$ f _ {\ rm l} $ = 0，则如果样品$ f _ {\ rm l} $ = 0.1。使用17米的望远镜，可以在10年内（平均）（平均）实现这一目标。 Drake是尝试第一个实验测量$ f _ {\ rm l} $的可行方法。
In the search for life in the Universe, exoplanets represent numerous natural experiments in planet formation, evolution, and the emergence of life. This raises the fascinating prospect of evaluating cosmic life on a statistical basis. One key statistic is the occurrence rate of life-bearing worlds, $f_{\rm L}$, the 'frequency of life' term in the famous Drake Equation. Measuring $f_{\rm L}$ would give profound insight into how common life is and may help to constrain origin-of-life theories. I propose $f_{\rm L}$ as the goal for the DRAKE mission (Dedicated Research for Advancing Knowledge of Exobiology): a transit spectroscopy survey of M-dwarf habitable zone terrestrial planets. I investigate how the uncertainty on the observed value of $f_{\rm L}$ scales with sample size. I determine that sampling error dominates over observational error and that the uncertainty is a function of the observed $f_{\rm L}$ value. I show that even small sample sizes can provide significant constraints on $f_{\rm L}$, boding well for the transit spectroscopy approach. I perform a feasibility study of the DRAKE mission using a nominal instrument design and mission plan. Due to low observing efficiencies, DRAKE may need to be incorporated into a wider-ranging deep-space or lunar observatory. A 50-planet survey could constrain $f_{\rm L}$ to $\leq$ 0.06 (at 95% confidence) if the sample $f_{\rm L}$ = 0, or 0.03-0.2 if the sample $f_{\rm L}$ = 0.1. This can be achieved (on average) in 10 years using a 17-m telescope with an unrestricted field-of-regard. DRAKE is a viable approach to attempting the first experimental measurement of $f_{\rm L}$.
