Extra-terrestrial Signals – Did we really receive a message?

Over the years we have all seen headlines such as the one above. Talking about extra-terrestrial signals that repeat and are seemingly extremely regular. It always implies aliens.

You click the article excitedly and….disappointment. It’s a fast radio burst. Usually originating from a neutron star spinning rapidly. Or it’s some other completely plausible natural phenomena. And I hate those headlines. It’s said that if a headline asks a question, the answer is pretty much always no.

So have I set myself up with the above headline? Maybe. Because the answer really is, on this occasion, we don’t know. You see, there is a candidate that stands out above all others. One that has not been explained by natural sources even after 43 years has elapsed.

The WOW! Signal

Most natural radio phenomena happens on the wideband spectrum. In a 1959 paper, two Cornell University physicists speculated that any intelligent alien civilisation would use the narrowband frequency of 1420 megahertz, which is naturally emitted by hydrogen. Hydrogen is the most abundant element in the universe, and would be well known by all civilisations.

In 1973, Big Ear, a radio telescope at Ohio State University turned its attention from wideband sources to looking for narrowband sources. The project was named SETI (Search for Extra-Terrestrial Intelligence).

Not much happened at SETI for the first four years. Scouring the known universe for signals is a thankless task. The likely hood of finding one is miniscule. You would have to be pointing in the right direction at exactly the right time and looking on the right frequency. It’s like looking for a needle in a haystack, except the haystack is the size of the sun!

Which makes the below picture even more remarkable.

August 15, 1977

It doesn’t look like much, does it? Without the context of this story, it’s just a piece of paper with a load of numbers on it. But to someone scouring the night sky in 1977, this was so exciting, WOW! is hastily scribbled next to it.

It was written by Jerry R. Ehman. Jerry is an Astronomer and on that day in 1977, he was going over reams of data a few days after the telescope had picked up the signal.

To us, it looks like nonsense, but this is what Ehman saw. A signal that starts off low, picks up in strength and then weakens again. Strongly showing it is in one area of the sky only. This narrowband signal also only appeared on one channel. Let’s allow Ehman to explain:

It was a narrowband signal, just what we were looking for. It didn’t take long for me to recognize that this was extremely interesting. And the word ‘Wow!’ came to my mind very quickly, so I wrote it down.

Jerry R Ehman

They went back and looked for it again. It appeared to originate from the constellation of Sagittarius. Some 25,000 light years away.

Going through all the past data printouts, they hoped to find the signal appear again, but to no avail.

A month later they tried again. Nothing.

Same thing a year later. The SETI project lasted for 24 years. In all that time there was never another signal anything like the WOW! signal.

The project was scrapped after Congress in America deemed it too costly to fund. All it needed was around $150,000 a year to function. A rounding error in the American budget. The amount was literally less than 0.00001% of the budget that year.

By 1998 the Big Ear telescope had been demolished to make way for a golf course.

Attempts to explain the signal

Over the years there have been several attempts to attribute the signal to natural phenomena. The most pervasive paper was published by Antonio Paris just a few years ago. He and his team asserted that the signal came from comets. Hydrogen on comets gives out a signal of 1420MHz, which is where Big Ear caught the signal. And according to Paris, there were two comets near to where Big Ear saw the signal that night. So case closed right?

No.

Here’s why.

Radio astronomers have never been able to measure strong hydrogen signals from a comet, so this would have been beyond anything seen before. But hang on, maybe two comets could double the signal?

Big Ear was fitted with two receivers. During its sweep of the sky, only one of them picked up the signal. Due to the slow speed comets move at, this would make no sense. It’s not like the comets could have moved out of range in the 90 seconds it took to sweep that patch of sky. The only explanation to this has to be that the signal finished before the second sweep.

And lastly, Robert Dixon, the director of the Ohio State Radio Observatory has pointed out that the comets were in fact no where near the telescopes sightlines when the signal was found. And he should know, seeing as he was in charge of the telescope.

So what was the signal? As I said at the beginning, we just don’t know. Maybe there was/is a sentient civilisation living in the heart of the Sagittarius constellation and we managed to catch a glimpse of their communications. Communications that would have had to have started on their journey over 25,000 years ago to reach us now.

Or maybe it’s something else. A natural phenomena we don’t understand yet. But one thing is certain. It wasn’t a comet that was heard that night.

The search for extra-terrestrial intelligence lives on with SETI. Although the original project was defunded, it continues with donations. If this article has inspired you in any way, go give them a few dollars if you can. Who knows, the next news piece you read about them could be a confirmed extra-terrestrial signal, and you could have contributed to it in a small way.

SETI Donations Page (click here)

Sources:

The Big Ear Wow! Signal (bigear.org)

The Wow! Signal: An alien missed connection? (astronomy.com)

Was it ET on the line? (seti.org)

Wow! Signal (wikipedia.org)

Hydrogen Line Observations of Cometary Spectra (planetary-science.org)

Image Header (pixabay.com)