Blue Marble Space Institute of Science, Seattle, Washington.
NASA Goddard Space Flight Center, Greenbelt, Maryland.
Astrobiology. 2020 May;20(5):572-579. doi: 10.1089/ast.2019.2154.
The search for spectroscopic biosignatures with the next generation of space telescopes could provide observational constraints on the abundance of exoplanets with signs of life. An extension of this spectroscopic characterization of exoplanets is the search for observational evidence of technology, known as technosignatures. Current mission concepts that would observe biosignatures from ultraviolet to near-infrared wavelengths could place upper limits on the fraction of planets in the Galaxy that host life, although such missions tend to have relatively limited capabilities of constraining the prevalence of technosignatures at mid-infrared wavelengths. Yet searching for technosignatures alongside biosignatures would provide important knowledge about the future of our civilization. If planets with technosignatures are abundant, then we can increase our confidence that the hardest step in planetary evolution-the Great Filter-is probably in our past. But if we find that life is commonplace while technosignatures are absent, then this would increase the likelihood that the Great Filter awaits to challenge us in the future.
利用下一代空间望远镜寻找光谱生物特征，可能为具有生命迹象的系外行星的丰度提供观测限制。这种对系外行星的光谱特征的扩展是对技术观测证据的探索，称为技术特征。目前的任务概念将在紫外线到近红外波长范围内观测生物特征，这可能会对银河系中存在生命的行星比例设置上限，尽管此类任务往往对限制中红外波长技术特征的流行度的能力相对有限。然而，在寻找生物特征的同时寻找技术特征，将为我们的文明的未来提供重要的知识。如果具有技术特征的行星很丰富，那么我们可以增加信心，认为行星演化中最艰难的一步——大过滤器——可能已经过去了。但是，如果我们发现生命很常见，而技术特征却不存在，那么这将增加未来大过滤器可能会对我们构成挑战的可能性。
