Posted by A new four-tier technosignature detection framework expands the SETI search beyond radio to include atmospheric, gravitational, and informational signals.
For decades, the Search for Extraterrestrial Intelligence has focused almost exclusively on radio signals. But a growing consensus among astrobiologists suggests we may be looking in the wrong place — or more precisely, in too narrow a band.
A new detection framework proposed by researchers at the SETI Institute categorizes technosignatures into four tiers: electromagnetic (radio, laser), atmospheric (industrial pollution, megastructure effects), gravitational (Dyson spheres, stellar engineering), and informational (interstellar probes, artifacts).
The James Webb Space Telescope has already demonstrated sensitivity to atmospheric biosignatures on exoplanets. Adapting this capability to detect industrial-scale pollution — chlorofluorocarbons or nitrogen dioxide in particular — could reveal civilizations at our own level of technological development, not just Kardashev Type II or III.
