A call for a methodical approach to identifying life beyond Earth

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A team of space scientists at NASA has published a Perspective piece in the journal Nature calling for the establishment of a methodical approach to identifying life beyond Earth. In their paper, the group suggests the space science community begin using a "confidence of life detection" (CoLD) scale, similar in some respects to others used in the science community, such as the TRL scale NASA uses to chart the readiness of new technology to be used on missions.

Noting that , technology and space exploration efforts have led humanity to the point that it might be possible to find on Mars or elsewhere—and further noting that in the past, discoveries surrounding the possibility of life in other places, most often on Mars, has led to widespread speculation and often criticism of those reporting the evidence—the authors suggest a new approach may be needed. They suggest the adoption of the CoLD scale and outline its seven levels.

The first level would be assigned if detection of a biosignature suggested life might have been found. That would kick off the second level, which would involve ruling out other factors such as contamination. Once that was done, a third level would begin that involved making predictions about how such a signal could have been generated. If all non-biological sources are ruled out, that would move the effort to level four, where observation of the signal would be verified via other means, pushing the effort to level five. If such means are found, the signal can be moved to level six, indicating the signal is deemed related to a life form living beyond Earth. The final seventh level would involve follow-up study of the life form.

If such a scale were to be used by the , it is notable that some events would already meet the conditions for the first level—the detection of methane by ground-based telescopes, for example. It could be argued that NASA has already taken steps to move the detection of methane to level two by sending spacecraft to Mars to measure surface levels. Sending a flying craft that could measure different levels at different points on the surface and identify the types of methane being admitted might take the effort to level three.

The authors suggest a CoLD scale could head off heated discussions regarding findings on Mars and other objects, allowing energy to be focused instead on learning more about what has been found.


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More information: James Green et al, Call for a framework for reporting evidence for life beyond Earth, Nature (2021). DOI: 10.1038/s41586-021-03804-9
Journal information: Nature

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Citation: A call for a methodical approach to identifying life beyond Earth (2021, October 28) retrieved 28 November 2021 from https://phys.org/news/2021-10-methodical-approach-life-earth.html
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