Astronomers claim the Wow! signal is not from a comet, mystery remains unsolved

A 72 second-long astronomical anomaly recorded in 1977 has been puzzling star gazers attempting to discover its source.

The Wow! signal represented as "6EQUJ5". The original printout with Ehman's handwritten exclamation is preserved by Ohio History Connection

IN 1977, Ohio State University’s Big Ear radio telescope captured a 72 second-long astronomical anomaly that has since been a constant source of speculation among the star gazing community.

While reviewing the recorded data from the radio telescope being used to support the search for extraterrestrial intelligence project, astronomer Jerry Ehman discovered the narrow-bandwidth signal.

Ehman was so intrigued by the peculiar discovery, he circled the reading on the computer printout of the data and wrote ‘Wow!’ on the side of the paper.

The anomaly was then aptly titled the Wow! signal.

As the signal did not repeat and subsequent attempts to find it were unsuccessful, its origin has remained a mystery for 40 years.

However, a new scientific paper published in the Journal of the Washington Academy of Sciences claimed to have solved the four decade enigma.

According to astronomer Antonio Paris, the bizarre 1420 MHz radio signal could be attributed to a comet that was in the vicinity of the recording back in 1977.

The comet, called 266P/Christensen, wasn’t catalogued at the time, although the research suggests its hydrogen clouds were the source of the signal.

When 266P/Christensen returned to the same sector of space earlier this year, Paris’ team was able to match its frequency to the same 1420 MHz bandwidth seen with the Wow! signal.

“This investigation, therefore, has concluded that cometary spectra are observable at 1420 MHz and that the 1977 ‘Wow!’ signal was a natural phenomenon from a Solar System body,” the paper read.

Further testing showed other comets also send radio signals at the same frequency as hydrogen, so even if it wasn’t 266/P Christensen that sent the Wow! Signal, Paris believes it was definitely a comet.

Aerial Photo of Big Ear Radio Telescope.

So that solves that mystery, right?

That answer depends on who you believe, with a number of astronomers rubbishing Paris’ conclusion — even the astronomer who discovered the Wow! signal in 1977 doesn’t believe the paper’s finding.

Ehman explained the Big Ear telescope had two “feed horns” to capture slightly different field of views, yet there was only one recorded signal.  

“We should have seen the source come through twice in about three minutes: one response lasting 72 seconds and a second response for 72 seconds following within about a minute and a half,” he told Live Science.

Ehman said the signal being cut off abruptly was the only reason only one recording was captured, and believe this proves it couldn’t be a comet because it wouldn’t have been possible for it to escape the radio telescope’s field of view that fast.

Comet expert Alan Fitzsimmons also disputes the findings, claiming it would have been impossible to record the apparent 1420 MHz signal from 266P/Christensen because it has little activity even when at perihelion — its closest point to the Sun.

“When he observed the comet it was over four astronomical units from the Sun, which means it would have been effectively inactive,” he told Astronomy Now.

“There would have been no hydrogen coma to detect and therefore he could not have seen the comet.”

Senior Astronomer at the SETI Institute Seth Shostak held similar sentiments.

“I don’t know of any detection of the 21cm line of neutral hydrogen from a comet, and as I used to study galaxies in the neutral hydrogen line, I probably would have heard of that,” he said.

Paris shows little concern over the criticisms, with the astronomer justifying his discovery.

“Astronomers have not detected hydrogen emission from comets because there has not been much research specifically on this subject,” he said.

“While there has been a handful of studies, I suspect we are the first to build a ten-metre telescope to specifically look at this type of Solar System body.”

Who do you believe? Continue the conversation in the comments below or with Matthew Dunn on Facebook and Twitter.