
The “Wow! Signal” was detected on August 15, 1977 as a strong narrowband radio signal by Ohio State University’s Big Ear radio telescope. Its origin was inferred to be extraterrestrial. The latest natural explanation (accessible here) hypothesized that the “Wow! Signal” was caused by a sudden brightening of the hydrogen line emitted from an interstellar cloud, triggered by a strong transient radio source, such as a flare from a highly magnetized neutron star (magnetar).

