In 1977, the Ohio State University’s Big Ear radio telescope received an unusually strong narrowband radio signal, leading to widespread excitement about the possibility of having encountered evidence of life beyond Earth.
At the time, astronomer Jerry Ehman spotted the highly unusual outburst in printed out records, annotating the major radio band fluctuation with the word “Wow!” in red pen, thereby giving it a memorable nickname: the “Wow! Signal.”
The incident has remained a mystery for decades, never spotted again in over 48 years, leaving plenty of questions in its wake. Where did it come from, and why did it only last for 72 seconds?
Now, Harvard astronomer and alien hunter Avi Loeb has a wild new theory about the signal. In a new blog post, he suggested that interstellar object 3I/ATLAS, which is currently cruising through our solar system, could’ve sent off the signal back in 1977 — when it was still 600 times the distance between the Earth and Sun away from us.
Examining the sky coordinates of the object and the Wow! Signal, Loeb concluded that the “chance of two random directions in the sky being aligned to that level is about 0.6 percent.”
“If the ‘Wow! Signal’ originated from 3I/ATLAS, how powerful was the transmitter?” he wrote, once again raising the possibility that the object could be an artifact from an advanced extraterrestrial civilization.
Ever since it was first observed in July, 3I/ATLAS — only the third interstellar object ever spotted — has fascinated scientists. Loeb has previously pointed to the object’s unusual chemical makeup, its peculiar path taking it close to the orbits of Mars and Jupiter, and its enormous suspected size to suggest that it could be a piece of technology sent to us by an alien race.
For his latest theory about the Wow! Signal, Loeb suggested that 3I/ATLAS would’ve had to have a power source of 0.5 to 2 gigawatts to send off the Wow! Signal from 600 astronomical units away, equivalent to the “output of a typical nuclear reactor on Earth.”
It’s a far-fetched theory that would require plenty of additional data to confirm.
“So far, no radio telescope reported data on 3I/ATLAS,” Loeb wrote. “Here’s hoping that the coincidence in the arrival direction of 3I/ATLAS and the ‘Wow! Signal’ would motivate radio observers to check whether 3I/ATLAS shows any radio transmission around the hyperfine line of hydrogen.”
“To measure these properties, we should attempt to use all telescopes on Earth and in space,” he argued.
This is far from the first unusual theory about the Wow! Signal to have surfaced over the decades. Most recently, researchers from the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo, which was home to the world’s largest single-aperture telescope, are re-analyzing unexplained radio signals.
As part of the “Arecibo Wow!” project, a team of scientists honed in on the 1977 signal, as Space.com reported last month, creating the most precise characterization of it to date.
So far, the group’s latest findings support a natural astrophysical origin — not proof of an intelligent extraterrestrial civilization. However, their research “doesn’t close the case,” but “reopens it, but now with a much sharper map in hand,” Méndez explained.
“We aim to archive and share all data from the Big Ear telescope by 2027, marking the 50th anniversary of the Wow! Signal,” he told Space.com.
While the scientific community has yet to chime in on his theory, Loeb is already thinking far ahead, arguing that we need a “contingency plan” in case aliens were to make first contact.
“We must consider the possibility of a black swan event from interstellar objects resembling a comet at large distances, but potentially carrying devastating consequences to our future like a Trojan Horse,” he wrote.
To engage with an extraterrestrial civilization, we could either message them “electromagnetically through a radio or laser communication signal, or involve interceptors which cross the path of the interstellar object.”
“Whereas our knowledge is restricted to experiences on Earth, our dating partner might exhibit alien designs which go well beyond our current perception of reality,” he wrote in his latest blog post. “In that case, communication might be as difficult as it is for ants looking from the vantage point of a crack in a pavement at a biker passing by.”
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