Do you know about the 1977 “Wow! Signal”? A sign from a distant civilization or just an unexplained phenomenon?

A few decades after the first wireless radio was invented, Guglielmo Marconi said Mars was trying to talk to Earth after he had detected radio wavelengths that seemed to long to be explained by natural electromagnetic phenomena. In 1924, taking advantage of the Red Planet’s closest approach to Earth in centuries a massive project was set up to listen for transmissions from what was believed to be a dying Martian civilization.

Unfortunately, no one was home on Mars to make the long-distance call and all was quiet. But that didn’t stop the search for extraterrestrial civilizations. An effort to look even farther afield for intelligent life began in 1960 when astronomer Frank Drake focused a giant radio telescope in West Viriginia on two nearby stars.

While he originally called his endeavor ‘Project Ozma,” after the Queen of Oz, it would eventually become known as the Search for Extraterrestrial Intelligence (SETI). The program has been going strong ever since with radio telescopes from around the world participating as well as everyday people.

Unfortunately, all has been quiet so far, that is except for one remarkably intense radio burst received one night on 15 August 1977 that’s been called the Wow! Signal.

What is the Wow! Signal?

The Wow! Signal was picked up by the Big Ear radio observatory at the Ohio State University. The powerful transmission, which lasted for 72 seconds, had the characteristics of what would be expected from an artificial source sent by extraterrestrial intelligent life; it was an extremely narrowband frequency without the hallmarks of a natural astrophysical phenomenon.

The event, however, was a one-off anomaly, and has never been detected again. But that hasn’t stopped the Wow! Signal captivating the imaginations of people the world over and entering into science fiction like Cixin Liu’s book the ’Three Body Problem‘.

One person who long dismissed the Wow! Signal as a glitch in the instruments, Abel Méndez, director of the Planetary Habitability Laboratory at the University of Puerto Rico, is now convinced that it was the real-deal and thinks he may know what it was.

The Wow! Signal: a sign from a distant civilization or just an unexplained phenomenon

Méndez and his team analyzed archival data from the Arecibo Observatory, Puerto Rico, once the largest and most powerful radio telescopes which was inaugurated in 1963 and decommissioned in 2020. During their investigations, they found signals, that although weaker, were very similar to the Wow! Signal.

They theorize that “the Wow! Signal could be the first recorded event of an astronomical maser-like flare in the hydrogen line.” Given that the event has not repeated itself, the mystery cannot be definitively put to rest. But their findings do provide a plausible natural phenomenon to explain the 1977 anomaly.