Reanalysis of Wow! signal points to a natural galactic origin

Astronomers reexamining the famous Wow! signal say the 72-second burst detected in 1977 likely did not originate from Earth but may have arisen from a natural, astrophysical event within our galaxy. A new analysis combines decades of archival data with modern data-processing techniques, refining the signal’s sky position, frequency, and strength. While the finding strengthens natural explanations—for example, a brief, intense interaction involving a hydrogen cloud—the researchers caution that the case is not closed and that the possibility of an extraterrestrial origin remains distant but not entirely ruled out.

The Wow! signal was first recorded on August 15, 1977, by listeners at the Big Ear radio telescope in Ohio. Its unusually strong, narrowband profile, centered near the hydrogen line, led astronomers to dub it “Wow!” after the observer circled the data and added the memorable exclamation. Despite subsequent analyses and multiple hypotheses, the transmission has never been observed again, leaving questions about whether it was a natural phenomenon, a terrestrial artifact, or something else entirely.

The latest study, conducted by the AWOW project based at the Arecibo...