Signal Broadening in Stellar Environments Prompts Rethink of Narrowband Technosignature Searches

To the point

Vishal Gajjar, the lead author, says the search for alien technosignatures should look beyond narrowband radio signals because solar winds and stellar activity can broaden signals in other star systems, pushing them below current detection thresholds, as shown by data from probes like Mariner IV, Pioneers 6, 10 and 11, Helios 1 and 2, Viking, Mars Express, Venus Express, and Rosetta, where broadening can exceed 10–100 Hz and escape pipelines tuned for sub-Hz channels.