The NASA Confidence of Life Detection (CoLD) Scale is a seven-level framework designed to help scientists evaluate and communicate the progress made in life detection research, both among themselves and with the public. The CoLD Scale is based on NASA’s Technology Readiness Level (TRL) scale, which is used to characterize the maturation of instruments from concept to implementation in missions. The CoLD Scale aims to provide a standardized method for assessing claims about extraterrestrial life and to facilitate clear communication of findings to the public.
The seven levels of the CoLD Scale act as benchmarks that must be met before proceeding to the next step. The levels are as follows:
The CoLD Scale is intended to be a starting point for a larger conversation within the scientific community and to help guide future missions and technologies in the search for extraterrestrial life. It is also hoped that the CoLD Scale will prevent scientists from “crying wolf” and making overly cavalier claims about the discovery of extraterrestrial life, as it requires more stringent tests to progress up the scale. The scale can also help redirect heated scientific debates and provide a common language for discussing the search for life in the universe.
