What Was The Wow Signal? The Most Interesting Signal SETI Has Ever Seen

What was the signal received in 1977? Was it a cryptic message from an alien civilization?

Follow us on Twitter: @universetoday

Team: Fraser Cain - @fcain
Jason Harmer - @jasoncharmer
Susie Murph - @susiemmurph
Brian Koberlein - @briankoberlein
Kevin Gill - @kevinmgill

Created by: Fraser Cain and Jason Harmer

Edited by: Chad Weber

Music: Left Spine Down - “X-Ray”

In 1977, radio astronomer Jerry Ehman was looking through observation data from the Big Ear Radio Telescope. He was searching for evidence that alien civilizations might be trying to communicate using radio waves as an alternative to metal probes.

Specifically, that aliens would be communicating in a portion of the radio spectrum that mimics hydrogen.

The search generated an immeasurable mountain of remarkably boring data, nothing but the background radio transmissions of the Universe.

But then he saw a data signal so interesting and unique that he circled it and wrote “WOW” in a red pen. A red pen! There was an exclamation point! Only one, though, don’t get too excited.

Ehman circled the characters “6EQUJ5”, distinguishing them from all the other 1s and 2s on the field of data.

What does this code mean? Is it a cryptic message from an alien civilization? Why does it start with a 6 and then end with a 5? What are they trying to tell us?

From the moment Ehman red-penned in WOW, this has been known as the WOW Signal, and it’s been the cause of much speculation by SETI researchers and aliens fans and confusion for World of Warcraft players around the globe.

For starters, it’s important to understand that the Big Ear Radio Observatory didn’t actually receive these characters in a message. The Observatory was listening to radio signals coming from a region of the sky in the Constellation Sagittarius, near the M55 globular cluster.

Each character on this chart corresponds to about 10 seconds of “listening”. If the telescope picked up a signal, it recorded the intensity with a single character. The scale went from 1 to 9, and then through A to Z. The highest ever recorded was U.

So, when you look at this chart, what you’re actually seeing is mostly no radio signal, and then the signal gets brighter and brighter, as the Big Ear’s dish passed whatever was generating the signal, then it gets dim again.

When astronomers tried to follow up, the signal was gone. It happened just this one time, and then not anything else like it, not from this region, or any other region in the the sky.

Hurry up Fraser! Was it aliens? I have to know. I need to put it on the blog l moderate for my favourite death metal conspiracy band “Tinfoil Hate”.

Dr. Ehman, and other astronomers searched that region more than 50 times, trying to detect any signal.

Nothing.

They used the Big Ear again, and then the Oak Ridge Observatory, and even the vastly more powerful Very Large Array.

Ehman himself was doubtful it was intelligent in nature. He wasn’t even sure it came from outside the Solar System at all. He suspected it was either a classified military satellite or a reflection of an Earth-based radio signal bouncing off space debris.

But that doesn’t really explain it very well, does it Scully?

If it was a satellite transmitting in this spectrum, you would expect to see it get picked up in other locations around Earth and at other times.

It’s never been seen again.

It makes sense that aliens would communicate in this spectrum; it’s what we’d do if we wanted to send an unambiguous message out into space.

The signal is a point source, which means it would have come from a specific star or planet in the Milky Way.

The bottom line is that we’ll never know. There just isn’t any more data to help us understand this mystery any more deeply.

I’m a huge fan of searching for signals from extraterrestrial civilizations, and tantalizing mysteries like this means we should keep looking. Whether or not we discover new alien friends, or unusual new natural sources of radio emissions, the search is worth doing.

One last thing.

[sainisahbg]

There are two possibilities... 1. We are not alone in this Universe 2. We are alone in this Universe.
Both are equally terrifying. +Fraser Cain

[dougfreeze]

In the background...
"Dad! Stop talking to that stupid camera and drive me to the mall!"

[ThisOldPanda]

if it happened today it would be the "wtf signal"

[krislol]

There has to be Aliens out there probably saying "There has to be Aliens out there probably saying""There has to be Aliens out there probably saying"""There has to be Aliens out there probably saying...""""

[cizcalodiablopanzon]

The message said "there are ten reasons to invade your planet, and number 4 will shock you"

[georgenelson]

Fraser your videos are perfectly done. I love how you use humor sometimes to teach us about the universe.

[RJ_Co.]

What if one of Humanity's greatest mystery was just a glitch in the computer lmao

[TmatSup]

I wondered if it was from an alien species that just learned how to generate radio frequencies just as there entire planet was destroyed be some comet. very unfortunate.

[unvergebeneid]

We _might_ one day know if a pissed-off alien shows up on our doorstep, knocks angrily and yells: "EY! Didn't you get my message? I sent you like thirty texts! Does this pass as manners in this shitty place you just made me drive 50 light years to?"

BTW, leading experts in interspecies communication and first contacts agree that replying "Oh, I guess it wasn't space junk after all." isn't a good follow-up strategy.

[memedbengul]

By far the best explanation is the second one you mentioned: It was a rogue transmission that happened to be reflected off of space debris that just happened to be in the right place at the right time. This is why it was never heard again and was only picked up by one telescope.
You should have mentioned that the frequency was 1420 mhz, which is that of hydrogen, the most common element in the universe.

[acetylcoa]

"We'll never know" sounds like "Mankind will never be able to fly" :)

[liammaher]

Just stumbled onto these videos. They are brilliant! Thank you Fraser :)

[shiningarmour]

Honestly, why are we sending signals back?

That's like the logic of leaving your doors open/unlocked in the middle of the night, saying "well, not everyone is a crook, only a *minority* is out there trying to rob houses" and then crying when it happens.

Well, maybe not so much of crying, you could be dead.

[joshuahunt]

I've been listening to Astronomy Cast for years now, this guy never ceases to interest me with whatever he has to talk about.

[dartagnanx]

Tinfoil hate - didn't their album sell so well, it went Aluminum?

[gabrielciaffone]

"Tenfold Hate" I had to stop the video to catch my breath hahahaha

[Preliminimal]

The Wow Signal flipped. When earth was located at the edge of Sagittarius, the signal was always reported to have come from Orion. However since reality shifted to Orion in 2016, the history of the Wow Signal changed, now saying that the signal came from Sagittarius

[Riotboy]

The WOW signal sped-up is a police transmission "We lost him at 7pm, we have a 10-61". That's why ONLY Big Ear pick up the local transmission.

[whathappenswhen]

i dont know why but i really like this Fraser Cain guy. He seems like a really cool and funny dude to hang out with

[candyfloss]

it was coming from soo many light years away it can't have been our radiowaves been beamed back to us off our space junk! I believe it was an alien spaceship quickly passing in deep space which would explain why it only lasts about a minute.