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Call for a framework for reporting evidence for life beyond Earth


Our generation could realistically be the one to discover evidence of life beyond Earth. With this privileged potential comes responsibility. The magnitude of the question of whether we are alone in the Universe, and the public interest therein, opens the possibility that results may be taken to imply more than the observations support, or than the observers intend. As life-detection objectives become increasingly prominent in space sciences, it is essential to open a community dialogue about how to convey information in a subject matter that is diverse, complicated and has a high potential to be sensationalized. Establishing best practices for communicating about life detection can serve to set reasonable expectations on the early stages of a hugely challenging endeavour, attach value to incremental steps along the path, and build public trust by making clear that false starts and dead ends are an expected and potentially productive part of the scientific process. Here we endeavour to motivate and seed the discussion with basic considerations and offer an example of how such considerations might be incorporated and applied in a proof-of-concept-level framework. Everything mentioned herein, including the name of the confidence scale, is intended not as a prescription, but simply as the beginning of an important dialogue.

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Fig. 1: The CoLD scale.


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All authors contributed to writing the manuscript after many rigorous discussions.

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Correspondence to James Green.

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The authors declare no competing interests.

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Peer review information Nature thanks Morgan Cable and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Green, J., Hoehler, T., Neveu, M. et al. Call for a framework for reporting evidence for life beyond Earth. Nature 598, 575–579 (2021).

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