
An artist’s rendering of the sweep of cosmic events important to astrobiology. They include the formation of molecular clouds of gas and dust where stars are born, the subsequent evolving of a protoplanetary disk surrounding the new star, and then the organizing of a cleaned-up solar systems with planets and moons. (National Radio Astronomy Observatory and Dina Clark/University of California, Santa Cruz)
The global scientific search for signs of life beyond Earth has produced cutting-edge and paradigm-shifting science for several decades now, and it has clearly found eager audiences around the world. This search is a high-priority goal of NASA and other space agencies, as well as institutions, universities and companies.
While the successes in this broadly defined field of astrobiology are legion, the field has also struggled with a problem that flows precisely from its high-impact subject.
That problem is how to best keep its scientific claims evidence based and how to take into account all the myriad factors that can undermine the strength of a “finding.” And then comes the question of how to best communicate with the public the nature of the findings and all the caveats involved.
There appears to be a widely-held view that some scientific claims and media reports about potential life beyond Earth have become not only a distraction in the field, but have served to undermine some public confidence in the endeavor.

NASA Chief Scientist Jim Green is the lead author of a Nature paper calling for heightened standards for all extraterrestrial life detection science. With discoveries coming in so fast, he said, some formal new standards are needed to increase scientific and public confidence. (NASA /Carla Cioffi)
And some of the leading figures in the field have written a paper, released today by the journal Nature, that calls for the creation of some as yet undefined guardrails or confidence scales to make exciting scientific findings and news about astrobiology more consistently dependable.
The goal is to find ways to make sure that papers meet the widely-embraced Carl Sagan standard that “extraordinary claims require extraordinary evidence”.
This is how the authors introduce the paper:
“Ours could realistically be the generation to discover evidence of life beyond Earth. With this privileged potential comes responsibility.”
“The magnitude of the question, “are we alone?”, 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.… Read more