On August 15, 1977, something miraculous happened. Deep inside Ohio State University’s observation laboratories, the “Big Ear” radio telescope picked up and then printed out a seemingly nonsensical string of six letters and numbers: “6EQUJ5.” Though opaque, this was actually what the Big Ear had been waiting for—in fact, what it was built for.
A few days later, volunteer astronomer Jerry R. Ehman came in for his regular shift at the observation lab, picked up his usual printouts, and started scanning the sheets. When he came across the data reading “6EQUJ5,” he nearly jumped out his skin with shock, automatically scrawling, “Wow!” across the sheet.
You see, the Big Ear was no ordinary radio telescope; it had been modified to collect data from outer space. And it had just gotten its first extra-terrestrial message.
The “Wow! Signal,” as it came to be known, is still one of the most compelling arguments for alien life beyond our solar system. Yet its history, origins, and meaning hide almost as many secrets as they reveal. Can you handle the truth?
Somewhere Out There
To understand the Wow! Signal, we have to first understand the Big Ear.
The idea for the Big Ear went all the way back to 1959, during the height of the search for extraterrestrial life. Two physicists, Philip Morrison and Giuseppe Cocconi, argued that any advanced alien civilization would likely try to contact Earth using a frequency of 1420 megahertz.
Why that frequency, you ask? Because this is what hydrogen, the universe’s most common element, naturally emits. In other words, use the hydrogen frequency and you get a kind of alien lingua franca, a frequency even beings from another planet are likely to be familiar with.
Later on, when Ohio State started using its Big Ear radio telescope in conjunction with the search for extraterrestrial intelligence (or SETI), they set it up on that magic 1420 megahertz frequency, pointed it at the sky, and waited hopefully for results.
It was years before Ehman found his Wow! Signal, but it was well worth the wait.
What Does It All Mean?
Many people mistakenly believe that the Wow! Signal is a message from an alien planet. This isn’t strictly true—but the reality is just as fascinating. Technically, the signal is just that, a signal: a flash of radio energy blipped towards Earth from space. Except this is where it gets really interesting.
The strength and shape of the signal are consistent with an extraterrestrial transmission. Each of the characters in the Wow! Signal represent the strength of the frequency, and at its peak in the “U,” the signal was 30 times stronger than expected background noise. This makes it one big flash of energy, and it can’t be explained away by machine malfunction.
Moreover, the signal strength slowly builds and then gradually recedes. This is consistent with the rotation of the Earth—which Big Ear relied upon to scan the sky—as it moved first toward and then away from wherever the signal was coming from, somewhere deep in space.
When all was said and done, Ehman knew he had something extraordinary on his hands. But where did it actually come from?
Based on their calculations, the astronomers at the lab located the origin of the signal in the constellation of Sagittarius, probably closest to the star Tau Sagittarii. For reference, the 20 closest stars to Earth are up to 1,000 light years away. Sagittarius is even further than that, with sections clocking in at about 5,000 lights years away from our green planet.
It was an incredible revelation, but at least one question remains: what could have possibly come from there?
The truth is, we still don’t know what the Wow! Signal meant or what made it, but we do have some vital clues.
After its monumental discovery, scientists tried to recreate the conditions and recapture the signal, often with even more sensitive instruments, but to no avail. They never found the Wow! Signal again, or indeed any other radio sign of extraterrestrial life. It was disheartening, but this failure also led to more hypotheses.
Some scientists argued that the signal could have been a kind of lighthouse emission that turned around and around as it swept the universe. If this was true, further attempts to locate the signal from Earth could have easily missed it. Other scientists posited that the signal came from a hydrogen cloud around two comets, or that it came from Sagittarius and was indeed a radio transmission, but from a source other than aliens. Or perhaps it was just a one-time extraterrestrial burst, traveling through space but lost forever after.
Each of these theories, however, has problems and detractors, and with the absence of any other evidence, none of them can be proven or supported in any substantial way.
Losing The Faith
Unsurprisingly, some scientists, including Ehman himself, turned skeptical. They suggested that after so long without another signal, the original transmission had probably just been a fluke from an Earth-bound device. As Ehman once suggested, “We should have seen it again when we looked for it 50 times. Something suggests it was an Earth-sourced signal that simply got reflected off a piece of space debris.”
There’s just one big problem with that explanation.
An Earth origin is actually extremely unlikely, as Earth technology is expressly forbidden from transmitting at that critical 1420 megahertz frequency. Furthermore, Ehman eventually backed down somewhat from his doubt, though we were still left with a universe of questions and very few answers.
Once More Into the Unknown
After more than 30 years, even as space travel has advanced, we are still waiting for a follow-up response to the Wow! Signal. Yet for all its frustrated promises, scientists haven’t been able to categorically refute the signal’s extraterrestrial origins, and it continues to give many people hope that “the truth is out there,” and that we are not alone.
Somewhere in the Sagittarius constellation, is a second alien transmission streaming toward our Earth at this very moment, rocketing forth from space debris and stardust? Perhaps all we have to do is be patient: after all, 30 years is the blink of an eye to our vast, unknown universe.