The Controversy Over the Alien 'Wow!' Signal Is Astronomy's Greatest Beef

A 40-year-old mystery remains unsolved, according to astronomers disputing new research about the Wow! signal.

Ben Sullivan

Ben Sullivan


The origin of the notorious Wow! Signal—a 72 second-long astronomical anomaly some scientists first thought to have been a signal from extraterrestrial life—has been a constant source of speculation for alien hunters ever since it was recorded in 1977 by Ohio State University's Big Ear radio telescope.

Was it a radio signal sent by E.T. or just something more mundanely human?

A new scientific paper, published in the Journal of the Washington Academy of Sciences, claims to have finally nailed it, sparking a flurry of press coverage proclaiming the mystery finally solved. According to the study author, Antonio Paris of St. Petersburg College in Florida, the answer lies in a passing comet called 266P/Christensen (only discovered in 2006) that caused the 1420MHz 'Wow!' radio signal detected some forty years ago.

Paris' research claims to have confirmed that comets emit a 1420MHz signal. Thus, he goes on to argue, this is likely what the telescope picked up on when the comet passed in front of the area of the sky the it was pointed at.

But Paris' conclusion doesn't have fellow astronomers convinced.

"There are some problems with the analysis, which doesn't use many of the standard things one would do in radio astronomy," Chris Lintott, professor of astrophysics at the University of Oxford, told Motherboard.

"The paper appears in a journal that I hadn't heard of before Paris published his Wow/comet ideas in there—it may be peer reviewed, but it's not part of the astronomical mainstream and so I'd be worried about the quality of that review."

"You may as well say it's due to ghosts or due to reality television"

So between interrogative tweets and doubting Reddit threads, Motherboard reached out to Paris to ask what's really going on.

"I have received over 500 emails this week about the Wow paper. About 99.99 percent appear [to be] positive reaction from the public and the scientific community," Paris told Motherboard in an email. "A handful, however, were from those who are still skeptical, mostly from the SETI (Search for Extraterrestrial Life) community. I suspect that SETI, who has used the Wow signal as a source of revenue, is nervous."

SETI, for its part, says such claims are preposterous: "We haven't made any money on the Wow signal whatsoever," Seth Shostak, senior astronomer for the SETI Institute, told Motherboard. "The charge we're making a lot of money off of it is bizarre. It's a bogus claim."

Shostak says he finds Paris's paper hard to believe based on what other astronomers have observed.

"The Ohio State radio telescope has two receivers on it. If it observes something in the sky, it's always reobserved 70 seconds later with a second feed," he said. "With Wow, it found it in one feed but it doesn't find it in the second. It's disappeared. A comet doesn't disappear in a minute. It doesn't move across the sky in a minute. It barely moves at all."

Paris said he had even received a phone call from a technician who helped build the Big Ear telescope who was excited that "the mystery has been solved." But Paris' research is still in the firing line.

"Saying 'The Wow signal might not be a comet if comets do something we haven't seen them doing' seems not very exciting."

"The claimed detection—even if it's real—is much, much weaker than the Wow signal, and lasts for longer. So at best the paper shows that comets are detectable in the radio—not that they're capable of the kind of burst that produced the Wow signal," Lintott told Motherboard. "Saying 'The Wow signal might be a comet if comets do something we haven't seen them doing' seems not very exciting."

A Reddit user, also claiming to be a radio astronomer, posted a lengthy takedown of Paris' paper over the weekend, arguing, "This paper was also just really, really, really short on details that a radio astronomer would want, to the point where it likely wouldn't have passed a referee at a 'regular' journal."

The Wow! signal. Its name inspired by astronomer Jerry R. Ehman, who discovered the anomaly in August 1977.
The Wow! signal. Its name inspired by astronomer Jerry R. Ehman, who discovered the anomaly in August 1977. Image: Big Ear Radio Observatory and North American AstroPhysical Observatory (NAAPO).

But Paris has kicked back against what he calls an "emotional" response. "I am not in the business of responding to emotions," he told Motherboard. "There are too many people 'excited' or 'upset' about this project. Emotions should not have any part in science."

Shostak said that the comet explanation "would be an interesting result if true," but that the data just doesn't back it up: "You may as well say it's due to ghosts or due to reality television or something. If the explanation doesn't fit the data, you have to be a little suspect."

To that end, Lintott has spent the weekend putting together a public list of questions for Paris to answer about his paper, including contributions from other astronomers. The search for extraterrestrial life continues.

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