Reanalyzing the Wow! Signal

The Wow! Signal, detected in 1977 by the Ohio State University SETI project, remains one of the most intriguing and enduring unexplained radio transients. The last major revision of its properties occurred in the late 1990s, but the availability of archival data limited further progress. In this work, we recovered and analyzed decades of previously unpublished Ohio SETI observations, enabling the most comprehensive reevaluation of the Wow! Signal to date using modern techniques. Our results introduce significant revisions to its measured parameters, which may explain why the signal’s source has been so challenging to identify. The analysis provides additional support for an astrophysical rather than anthropogenic origin. In particular, we confirm that small, cold hydrogen clouds can produce narrowband signals resembling the original detection, suggesting a potentially common mechanism. Our findings yield the most precise constraints yet on the Wow! Signal’s location, intensity, and frequency, offering a new path toward identifying its origin. While a natural explanation remains the most plausible, we also note features consistent with a possible artificial extraterrestrial source.