Infamous 'Wow! signal' that hinted at aliens may actually be an exceptionally rare cosmic event

One of astronomy's grandest riddles may have just gotten even more interesting, according to new research that suggests the source of a mysterious signal that some dubbed an "alien broadcast" may instead have been the result of a remarkably rare cosmic event.

Now known as the "Wow! signal" after the incredulous expression scribbled by astronomer Jerry Ehman on a printout of telescope data, the Mysterious transmission was picked up by The Ohio State University's Big Ear radio telescope in August 1977 during a routine scan for signs of extraterrestrial intelligence.

For 1 minute, 12 seconds that night, Big Ear recorded radio waves from near the constellation Sagittarius that were 30 times stronger than the background hum of deep space and were transmitted in a remarkably specific frequency of 1,420 megahertz. Hydrogen, the most abundant element in the universe, naturally emits radio waves at this frequency, leading some astronomers to think aliens would naturally opt for that frequency to try communicating with Earth.

However, nothing like the Wow! signal has ever been detected again, and no known natural phenomenon has been able to convincingly explain it — perhaps until now.

According to Abel Méndez, a planetary astrobiologist and the director of the Planetary Habitability Laboratory at the University of Puerto Rico, the bizarre Wow! signal may actually be a fortuitous detection of an extremely intense flare striking an interstellar cloud of hydrogen gas. A dense, magnetic star known as a magnetar would be the only source capable of emitting such a strong flare, which would have caused the cold hydrogen cloud to emit the radiation detected by Big Ear, Méndez and his colleagues state in a preprint paper posted to arXiv and submitted to The Astrophysical Journal.

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"It is a very rare event," Méndez told Live Science. "I am still amazed that [astronomers] were able to detect it."