47 years have passed since ‘Wow’, the most enigmatic extraterrestrial signal

MADRID (EUROPA PRESS) -The story behind the famous alien signal known by the exclamation ‘Wow!’ has a mysterious quality that has inspired countless encounters with extraterrestrials in science fiction.

However, its authenticity as coming from an ‘extraterrestrial intelligence’ has been questioned ever since that night on 15 August 1977 – 47 years ago now – at 03:16 UTC, when astronomer Jerry Ehman was using Ohio State University’s large radio telescope to scan the skies for signals that might have originated from an extraterrestrial civilisation.

That night, Ehman found something. And ever since that night, astronomers have been trying to figure out what it means. While pointed in the direction of three star systems called Chi Sagittarii, in the constellation Sagittarius, the radio telescope detected a 72-second burst of radio waves, a signal much stronger than the background noise. On the observatory’s computer printout, Ehman glossed the record of the explosion with the notation, “Wow!”

This enthusiasm was not an exaggeration, it was the kind of signal he was looking for, the kind of signal that astronomers believe a technologically capable extraterrestrial civilization would produce.

The printout for “Big Ear,” the nickname for Ohio State University’s radio telescope, contains a bunch of seemingly random numbers and letters, but Ehman outlined with a red pen a cluster of digits “6EQUJ5” with other circles around a “6” and “7” in separate columns. This particular code first uses the numbers 1-9 and then the alphabet A-Z to denote signal strength. As the burst suggests, the signal strength peaked at “6” and then burst through the letters reaching a “U” peak before coming back up the numerical scale at “5.” There was then a slight ripple out of the main signal (circled “6” and “7”).

Yet since that day in 1977, a detection of a signal of that strength has not been repeated. Even after the SETI Institute was founded in 1984, and countless efforts were made to find another similar radio burst, astronomers have been confronted with silence in the cosmos; a problem that has only served to intensify the unease of the Fermi Paradox.

Sceptical that the signal originated from a distant advanced civilization, Ehman himself recently stated that it could be related to a mysterious FRB (Fast Radio Burst). Astronomer Antonio Paris of St. Petersburg College in Florida maintains that the signal’s origin could be an uncatalogued comet.