Experts at the SETI Institute contend that humanity has been overlooking potential radio transmissions from extraterrestrial civilizations for decades, owing to an inappropriate strategy in their detection efforts.
As detailed in a study appearing in The Astrophysical Journal, the “space weather” surrounding a source star—turbulent plasma, stellar winds, and coronal mass ejections—can distort even a perfectly focused signal, effectively “smearing” it across the frequency spectrum. Consequently, this signal diminishes in peak power, rendering it undetectable by conventional algorithms calibrated to spot sudden, narrow-band spikes.
This issue is particularly pronounced concerning red dwarfs, which constitute roughly 75% of the stars within our Galaxy: their inherent high activity severely corrupts radio emissions. This implies that signals originating from the majority of potentially habitable star systems in the Milky Way are the most challenging to pick up using current detection technology.
Researchers have devised a procedure for quantifying such distortions and are urging that detection arrays be modified to account for these actual propagation conditions.
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