Arecibo's Digital Time Capsule: From Billions of Signals to 100 Technosignature Candidates and the Quest for Quiet Skies

To the point

Signals from Arecibo collected between 1999 and 2020 were processed by SETI@home volunteers and a Max Planck Institute supercomputer, shrinking about 12 billion signals of interest down to roughly 100 persistent candidates, none of which has been confirmed as artificial, with the search targeting the 21-centimeter hydrogen line and using 3,000 fake signals to test the method, while acknowledging that radio noise from satellites and devices makes detection difficult and stressing the importance of keeping radio-quiet skies for future surveys.