Overview
- Louisa Mason presented a proof-of-concept SETI search at NAM2026 using four archived ALMA Band 3 observations and found no candidate narrowband signals above the survey thresholds.
- The analysis targeted narrowband radio features because such signals are less likely to arise from natural astrophysical processes and so are stronger technosignature candidates.
- Mason used the Besançon Galactic Model to count ‘stellar bycatch’ and found that a past survey’s apparent 288,000 Gaia stars could represent more than 6.1 million stars when modeled, greatly increasing estimated survey coverage.
- The study demonstrates that existing millimeter and submillimeter telescope archives can be repurposed for SETI without new observing time, but the small dataset means the null result does not rule out extraterrestrial technology.
- Researchers recommend expanding systematic searches into higher-frequency bands and mining archival interferometric data to broaden the range of frequencies and the number of stars examined in future SETI efforts.