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SETI Dossier

The WOW! Signal

On August 15th, 1977, at the Big Ear radio Telescope of Ohio State University, professional astronomer Dr. Jerry Ehman, while donating time for SETI, noticed an anomaly on a printout that lasted for 72 seconds that was potentially non-terrestrial in origin. He circled the data and wrote in “WOW!” an evocative name that quickly overruled its technical designation: 6EQUJ5. The WOW! Signal soon became the unofficial title of SETI’s first credible alien intercept.

The scientific name of the WOW! Signal, 6EQUJ5, is a combination of letters and numbers that represent the strength of the transmission from the moment of its reception to its completion. It went from a low end (6) to a high (U) back to a low (5), which meant that it was modulated. It came in at less than 10kHz, an extremely narrowband frequency within the 1420 Mhz range, exactly where, in 1959, Cornell physicists Giuseppe Cocconi and Philip Morrison had predicted in a historic paper published in the scientific journal, Nature, an alien signal might be found.

While it was true that the WOW! Signal matched the 1959 Cocconi/Morrison prediction in several technical areas, from the moment it was received it was clear to SETI scientists that there were serious problems. Science writer Michael Brooks, in 13 Things that don’t Make Sense, writes:

“Three minutes later, when the Earth had turned and brought the telescope’s second receiver around to stare at the same point in the heavens, the signal had gone.”

This was not in the Cocconi/Morrison model. An extraterrestrial signal would not be just a single blip on a computer printout. It would be repeated and continuous, at least long enough for scientists to confirm that it was a non-random event. Brooks goes on:

“The signal came from the constellation of Sagittarius, also known as the Teapot. Just to the northwest of the globular cluster M55 (to the east of the Teapot’s handle) to be exact. There was nothing there.”

Cocconi and Morrison made a theoretical prediction that contained or implied specific characteristics that were not in the WOW! Signal. For that reason, SETI scientists never announced that the WOW! Signal was extraterrestrial, only that it bore some interesting similarities to the Cocconi/Morrison model.

What was missing in the WOW! Signal was not insignificant. It wasn’t repeated and nothing exists at the source. So why all the fuss? It may have been because, after almost twenty years of silence, the press and the public were starving for some positive news, and this was it. Emphasize the positive and downplay the negative.

I think any fair-minded person would agree that the Sagan Signal fares very well when compared to the WOW! Signal that has been formally tested over fifty times. I would be thrilled if SETI officials rated the Sagan Signal high enough on the Rio Scale to merit but a single test to determine if the sequences are a code. The fact that it is solidly anchored in the Sagan Model of ancient alienism should, by itself, insure a reasonably high rating.

With the recovery of the Stanford Paper we know that Carl Sagan’s goal was to create a safe place for rational people of honor and intelligence to talk freely and openly about ancient aliens without being cast as crazies. Unfortunately, his paper was so effectively buried by NASA that few people, including skeptics, were aware of its existence until I made it the centerpiece of my book, The Sagan Conspiracy. Carl’s dream of creating a model of ancient alienism acceptable to mainstream science, had it materialized, would have effectively exposed the pseudoscientific nature of popular ancient alienism from its outset. Unfortunately, that didn’t happen. What a tribute it would be to Carl Sagan and his legacy if the Sagan Signal is tested and results confirm that it is the Smoking Gun that proves that we are not alone in the universe.

The RIO Scale

To better evaluate alien signal candidates, SETI developed the Rio Scale, ranging from 10 to a confirmed candidate, down to zero for a hoax. Now interactive on the internet as the Rio Scale Calculator, it allows anyone with an interest in the Sagan Signal to select from a series of variable metrics those that they believe best describe the data.

Including the CFI investigation, the lowest I can get on the calculator is a 4, or moderate, and the highest is a 6, or noteworthy. Either number would justify an investigation by the SETI Institute.

What the Rio Scale Calculator doesn’t include as one of its descriptives is a signal candidate intrinsically connected to an established search protocol based on a peer reviewed and published paper written by Carl Sagan - one of the founders of the modern SETI movement. This is not pseudoscience, it’s the courageous and individualistic position of one of the leading scientists in SETI research. I believe that fact alone should elevate the Rio Scale rating by at least one number. A rating of 7 is designated “high,” and a rating of 5 is considered “intermediate. 

Where on the Rio Scale the SETI Institute rates the Sagan Signal remains to be seen, but unless someone at SETI can punch a hole in it, which is unlikely, I am hopeful that it will be graded high enough to trigger a formal investigation.

For easy access, the official link to the Rio Scale Calculator is:  Rio 1.1 Calculator (

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