The Wow! Signal: An amateur astronomer may have pinpointed 'alien' signal's origin

The global astronomical community is edging nearer to determining whether intelligent alien life really exists, and government agencies and academics may have been given a hand by an amateur astronomer.

That's because astronomy YouTuber and space enthusiast Alberto Caballero believes he might have pinpointed the source of a mysterious signal famously attributed to intelligent alien life, according to Live Science.

According to Caballero, the so-called Wow! Signal, detected by a radio telescope on August 15, 1977, may have originated at a Sun-like star 1,800 lightyears from Earth in the Sagittarius constellation.

A mysterious signal may have come from a Sun-like star

The Wow! Signal was discovered by astronomer Jerry Ehman using the Ohio State University's Big Ear telescope. It was a very brief, but powerful, burst of radio waves lasting one minute and 12 seconds.

"The Wow! Signal is considered the best SETI candidate radio signal that we have picked up with our telescopes," Caballero explained in an interview with Live Science. SETI, which stands for the search for extraterrestrial intelligence, has been looking for signs of aliens for more than 60 years.

At the time the Wow! Signal was detected, the Big Ear telescope, which is no longer operational, was searching for messages in the electromagnetic frequency band of 1420.4056 megahertz, produced by hydrogen. "Since hydrogen is the most abundant element in the universe, there is good logic in guessing that an intelligent civilization within our Milky Way galaxy desirous of attracting attention to itself might broadcast a strong narrowband beacon signal at or near the frequency of the neutral hydrogen line," Ehman wrote in a 30-year anniversary report of the observation.

When Ehman found an anomalous signal — bearing an alphanumeric code — in data from the Big Ear telescope, he wrote the word "Wow!" on the printout, giving the signal its name. Astronomers have since suggested the signal may have been an intelligent alien life form's version of our own Arecibo message, which was sent out to the globular star cluster M13 in 1974 in a bid to transmit information to extraterrestrials. In 2017, a team of scientists suggested the signal could have come from a hydrogen cloud and a comet.

Recently, amateur astronomer Caballero decided to try to pinpoint where this signal may have come from. Knowing the Big Ear telescope was pointed towards the Sagittarius constellation when it detected the Wow! Signal, he searched through a catalog of stars from the European Space Agency's Gaia satellite.

"I found specifically one sun-like star," Caballero said, referring to a star called 2MASS 19281982-2640123 about 1,800 light-years away that has a temperature, diameter, and luminosity that strongly resembles the Sun. Caballero published his findings in the International Journal of Astrobiology this month.

Searching for new alien signals

Caballero believes this star could be a good target for further observation. In particular future observations should aim to detect any exoplanets that might be in the star's habitable zone — meaning life may have evolved there.

For a long time, researchers have looked to Sun-like stars as the most likely candidates for harboring intelligent alien life. However, researchers from the University of Copenhagen recently suggested we should also look at binary star systems, as they may teach us new things about the early formations of planets where life could evolve over millennia. 

With observatories such as the James Webb Space Telescope, the ELT (European Large Telescope), and the SKA (Square Kilometer Array) all expected to start searching for intelligent alien life at different points this decade, we may soon know a great deal more about the potential origin point of the Wow! Signal, and whether it might have really been produced by extraterrestrial life forms.