Overview
- University of Manchester researcher Louisa Mason led the first SETI survey using ALMA archival data focused on millimetre and submillimetre bands rather than the traditional 'water hole' radio range.
- Her targeted reanalysis scanned two narrow high-frequency windows in ALMA Band 3 for narrow, artificial-looking emission lines but found no confirmed technosignatures.
- Applying the Besançon Galactic Model to 1,327 ALMA pointings raised the estimated number of stars sampled from about 288,000 to more than 6.1 million, greatly increasing the effective search sample.
- Mason used the concept of 'stellar bycatch' to explain that telescope pointings capture many unintended background stars and that sky catalogs like Gaia can miss faint or obscured objects.
- She recommends broadening spectral coverage and systematically mining existing archives because this approach is a low-cost way to expand SETI's reach and reshape future search strategy.