Contentious new research suggests that the Wow! signal, one of astronomy’s greatest mysteries that has perplexed scientists since its discovery in 1977, originated from a star system that may be habitable.

Here are the subsequent developments: A radio signal of unknown origin was picked up by the Big Ear radio telescope on August 15, 1977, at 11:16 p.m., for precisely 72 seconds.

It came from the eastern side of the constellation Sagittarius and had an intensity 30 times higher than background noise. This signal was not captured, but rather the observer’s computer recorded it in accordance with the protocol on a continuous piece of paper made specifically for this application.

A few days later, young Ohio State University professor Jerry R. Ehman, volunteering with the SETI project by reviewing computer records, discovered the strongest anomalous signal ever detected by a radio telescope.

The signal was known as Wow! thanks to Ehman’s annotation on the continuous paper, denoting his surprise and excitement. The signal sequence mentioned was: 6EQUJ5.

Image edited by the author

Decades later, researchers are still clueless about the origin of Wow! The signal, or what caused it, has spawned several theories over time, from a pair of passing comets — which has since been debunked — to the ultimate proof that we’re not alone in the universe.

Now, astronomer Alberto Caballero has searched through data collected by the European Space Agency’s Gaia space observatory to zero in on a candidate star system where the signal might come from, as detailed in a new article published in the International Journal of Astronomy of Astrobiology. The goal was to determine if habitable star systems exist in the region where Wow!

Caballero narrowed his search to a single Sun-like star called 2MASS 19281982–2640123, located 1,800 light-years away in the constellation Sagittarius.

Constellation Sagittarius. Image edited by the author

“There is a solar analog in the region where the alien signal is coming from,” Caballero said. “Although this star is too far away to send a radio or light response, it could be a great target for observations looking for exoplanets around it.”

He said in a 2020 YouTube video that “this star has an estimated temperature barely five degrees higher than that of the Sun and an approximately equal radius and brightness.

”While it’s undeniably a stretch — Caballero bases his argument on some very wide assumptions — other astronomers claim it’s not as absurd as it seems. We want to aim our instruments in the direction of things that we find intriguing, therefore I think it’s worth a go” said Rebecca Charbonneau, a historian at the Harvard-Smithsonian Center for Astrophysics and a SETI expert who was not involved in Caballero’s study.

There are billions of stars in the galaxy, and we have to find a way to narrow down and choose where we look.”

However, in the case we were investigating, having the coordinates: 2MASS 19281982–2640123 with our telescopes, we might be able to detect a habitable planet as the Origin of Wow! Signal, but it would take hundreds of years for our answer to arrive.

Meanwhile, Caballero suggests looking for exoplanets and technosignatures — technological signs of extraterrestrial intelligence — in that solar system, and on other planets.