论文标题
部分可观测时空混沌系统的无模型预测
Solid grains ejected from terrestrial exoplanets as a probe of the abundance of life in the Milky Way
论文作者
论文摘要
寻找地球外生物签名对于了解地球上的生命及其起源很重要。对系外行星的天文观察可能会发现这种签名，但是很难通过遥感系外行星大气来声称对生命的明确检测。在这里，考虑了另一种方法：收集以银河系的小行星影响弹出的谷物，然后进入太阳系。出于此目的的最佳晶粒尺寸约为1 $ $ m，尽管不确定性很大，但预计每年将在地球上积聚的$ 10^5 $，这可能包含其家乡行星上存在的生命生物签名。这些晶粒可以通过放置在太空中的探测器收集，也可以根据未来的技术发展从南极冰或深海沉积物中提取。
Searching for extrasolar biosignatures is important to understand life on Earth and its origin. Astronomical observations of exoplanets may find such signatures, but it is difficult and may be impossible to claim unambiguous detection of life by remote sensing of exoplanet atmospheres. Here, another approach is considered: collecting grains ejected by asteroid impacts from exoplanets in the Milky Way and then traveling to the Solar System. The optimal grain size for this purpose is around 1 $μ$m, and though uncertainty is large, about $10^5$ such grains are expected to be accreting on Earth every year, which may contain biosignatures of life that existed on their home planets. These grains may be collected by detectors placed in space, or extracted from Antarctic ice or deep-sea sediments, depending on future technological developments.
