Wednesday, August 5, 2009

The "Wow!" Signal: More Questions Than Answers

Imagine the scene: it is 15 August 1977, Jerry R. Ehman, an astronomer at Ohio State University's "Big Ear" radio telescope is looking carefully over a long sheet of paper. The paper is full of numbers and letters that represent data gathered from the radio telescope, processed by computer and then printed out. To many of us, these numbers and letters would look completely non-sensical. But Jerry Ehman knows just what to look for. He is scanning a printout from the same day, when the "Big Ear" had been pointed towards a tiny section of the constellation Sagittarius. It can be dull and hard work. Scanning thousands of lines listing a radio signals strength at 12 second intervals in 50 frequencies. Background level signals are represented by blanks; stronger ones by numerals or letters. Even though the work is anything but glamorous-the possible payoff would be incredible. The first known alien communication beamed to humanity. Ehman is suddenly startled to see a strong 72 second signal that appears on the printout as 6EQUJ5. Each character represents the strength of the signal over the course of that 12 second period of time.

For example a '5' would mean the signal is five times the background level. When the signal goes above 10 times the background level, it's represented by a capital letter. In their chart the letter 'A' would stand for 10 times the background level and 'U' thirty times. Whatever this was-it was one powerful signal. In fact, Ehman was astonished. The 15 August signal from Sagittarius was the strongest signal the Search for Extraterrestrial Intelligence (SETI) had recorded so far. In his amazement, Ehman wrote "Wow!" in the margin and circled the numbers and letters to highlight them. Thirty-two years later, Ehman's discovery, now known as the "Wow!" signal (for obvious reasons) is just as big a mystery as it was in 1977. Could it have been the 'Holy Grail' of SETI-extraterrestrial communication? Could an orbiting satellite have generated the signal? Perhaps it was a natural astronomical event? Today Jerry Ehman himself says, "There's just not enough information to pin it down." This isn't from a lack of trying either. The first step Ehman took back then was to look through the printout to see if the signal had repeated. The telescope had been aimed so that it scanned the same patch of sky every 24 hours.

If the signal was repeating-and then maybe artificial, it would appear on the paper day after day. Sadly it didn't. Apparently this was a one-time only event. Even more interesting, the telescope monitored two sections of the sky, one behind the other and about two-thirds of a degree apart. This means that the signal should have appeared twice; as each viewing angle brought it into view. However, it didn't. Could an extraterrestrial civilization have beamed a short, high-intensity burst at us and then lost all interest? Probably unlikely, if the civilization had been there to begin with. Could the Earth have briefly passed in front of a beam an extraterrestrial civilization had directed somewhere else? A possible explanation is that a local source caused the signal-an artificial satellite, or from some object in our own Solar System. A fact about this signal that may provide some hopeful clues-should it even reappear again is that the signal occupied only a narrow bandwidth centered on 1420 Megahertz. Many astronomers and exobiologists think that any possible alien life out there would broadcast on this frequency because it is the radio signal generated by the most common element in the universe-hydrogen.

This frequency was off-limits to both terrestrial and satellite transmission. Even if a satellite was in violation of this rule, no known satellites were located in that position of the sky. One other idea is that it was the reflection of terrestrial radio waves that had bounced off a piece of space junk. This explanation also falls flat, because once again the frequency was not supposed to be in use on Earth. Calculations were also done that showed such a strong reflection could not have happened if the space junk was tumbling this way and that, which is typically the case. Another item of interest: the sign of a steady rise and fall as it crossed the radio telescopes field of view indicated a source much further away in space. If this was not the case orbital motion would have taken it out of view before the standard 72 second scanning window had ended. An exotic explanation is a phenomenon known as gravitational lensing. This happens when an object of large mass (black hole, galaxy, neutron star,etcetera) lies between Earth and the source of the signal. This intensifies the normal radio emissions of stars. This event could produce a strong enough signal, but it should have repeated a few times-at the very least until the motions of the Earth, Sun, and the star where it originated overcame the lensing effect. The fact of the matter is, that no one to this day has offered a conclusive explanation of the "Wow!" signal, and it has never been detected again, despite astronomers looking for it in the same region of the sky many times since then.

Seth Shostak, senior astronomer at the SETI Institute in Mountain View, California says: "Nobody's going to believe a SETI signal you find only once. One possibility is it was ET, and in the meantime he's gone on holiday. The other is that it was some kind of interfererence. We're never going to know." The only event in the history of radio astronomy that comes close to this was the first observation of a pulsar signal in 1967. A pulsar is an extremely small (smaller than a city on earth in diameter) and incredibly dense (a cubic centimeter weighs 1,000 tons!) neutron star which rotates, and like a lighthouse, flashes its beam of energy with an intense narrow beam of radio waves.

A neutron star which becomes a pulsar is created when a star at the end of its life and more massive than the sun is at the 'supergiant' stage of its development. Some of these stars such as Betelgeuse can have diameters of almost one billion kilometers and a brightness of 10,000 of our suns. The outer layers of these stars are not very dense at all and they have a relatively cool atmosphere. Beneath this cool atomosphere the first layer of gas, at about 3 million to 10 million degrees centigrade burns hydrogen and turns it into helium. Below that, helium at over 500 million degrees centigrade is converted into oxygen, carbon and nitrogen. Closer to the core of the star where the temperatures reach over one billion degrees centigrade, sodium, neon, magnesium, sulphur, calcium, silver, nickel and silicon are fused into each other at the progressively higher densities and temperatures. Finally at the dead center of the star atoms of iron are created from the last by-product of nuclear fusion-silicon. Once the supergiant star is at this stage is has just a few days to live. The cause of this is that iron is the dead end of the fusion process. This means that it just builds up in the core and doesn't produce any energy to counteract the force of gravity that tries to compress the star from the time of its birth.

For the last time the core of the star collapses. The state of the material in the core of the star before the final collapse is very hard to imagine. The gas is heated to 10 billion degrees centigrade and the density of this material is more than 1,000 tons per cubic centimeter! Within the atoms, the last of the natural barriers formed by the forces of repulsion fall one by one. Electrons are crushed into the nuclei of atoms, where they combine with protons, which are them immediately converted into neutrons-thus neutron star. The gas with the stars core becomes a fluid of particles, all crushed together with incredible density. There is nowhere in the universe where there is a denser or hotter region than the core of a supergiant star that is imploding. The density of the center reaches 10 to the 15th power or one billion tons per cubic centimeter, and the temperature reaches 150 billion degrees centigrade!

When pulsars were first discovered, many thought that they were extraterrestrial civilizations beaming data out into space. The reason for this was that no natural phenomenon had ever been observed in the heavens which pulsed with such huge amounts of energy in such incredibly short and regular periods. We now know that this is because some pulsars spin up to thousands of times a second. Twenty years after the "Wow!" signal in 1997, astronomers at the Green Bank telescope in West Virginia picked up another signal that seemed to be extraterrestrial in origin. This turned out to be just a run of the mill orbiting satellite. Even though techniques had greatly improved since 1977 it still took sixteen hours to figure out the real source of the signal. Seth Shostak says, "It was a very beneficial false alarm because it showed us what might happen in the case of a real detection. It takes a long time to be sure. And in all that time, the media are very interested. There's no secrecy." Science fiction author Robert Sawyer, whose novel, Rollback, talks about the discovery of a definite alien signal, makes the observation that even though we've been listening for 50 years, that's not a long enough time to answer the question of extraterrestrial communication. Says Sawyer, "I suspect that if we continue for a few more decades, we will either find something that leaves the "Wow!" signal totally forgotten, or we will have to face up to something equally astonishing: that we are alone."

However the question is answered, I cannot imagine the excitement and wonder that Jerry Ehman must have felt for a time in August of 1977! A link to wikipedia's entry on the "Wow!" signal here . The top image is of the original printout that Jerry Ehman was looking over on that night with his writing "Wow!" and highlighting of the actual signal and the second image is of the signal's location in the sky in the contellation of Sagittarius. Peace and be well to anyone stopping by!


Autumnforest said...

That story has always excited me. I know as someone who investigates supposed hauntings, the occurrences can be rare and often not repeatable. Very frustrating. In the case of the Wow signal, I imagine that unless it happened more than once, it could be a glitch in some unforseen way, but then why haven't they had more such glitches? It's intriguing, but I still think that if anyone's out there, the use of radio signals is probably not part of their evolutionary process. In fact, more than likely they are right now bombarding us with psychic signals or some other strange means by which we can't pick up. Exciting to consider. I loved this post. Thanks for the thoughtful research, my intelligent friend!

Michael said...

Wow, wow! Fabu article. Sagittarius (Galactic Center), enigmatic "crop" signal in '77, what's not to like?

I think I'll be looking at August 15 with increased radioscopic intensity.

Cheers, Michael

Justin Russell said...

A fascinating tale. A "Wow!" story indeed.
I still keep thinking that given the immensity of the known universe it may be a long time before any sort of signal, proof of extra-terrestrial intelligent life, is even picked up. There are so many possibilities. That we are a barbaric, war like, destructive species that no off-world intelligent beings would want to come near due to the psychic toxins at the very least; that this world, as Charles Fort would say, is owned, we are property, off limits to other alein races; that alien life would truly be alien and we have no means to communinate in the materialist sense that is being attempted presently, and if we were ale to contact such entities they would be looking for intelligence of a similar nature and pass us over as the level of bacterium; and the one that was mentioned in the piece you posted: that we are alone in the universe.

That last one for me is an even more mind boggling consideration then the notion that intelligent life could to be out there somwhere for the rational materialist skeptics.

Devin said...

Autumnforest-I am so glad to hear that you had known of this story-for the simple reason that it has that same damn "reproducibility" problem that occurrs in so many psychic type phenomena -I reslly appreciate your input here and had never thought of "psychic" signals before-very interesting!-best to you as always and thanks for stopping by!!

Michael -I am so happy you enjoyed this article-didnt know how many would have heard of it in the past or not-the more I got to looking at all of the variables in the case the more interested I became-if only it would happen again!! can't wait to see if you come up with anything on August 15-best to you as always!!

Michael said...

Hi Dev. I hadn't heard of this one before, so it was cool to read. There was an erotic story at Evolution Archives called "Wow", last week, and today I got a comment from the Blob that I had subscribed to way back in Christmas of 2007, which started with Wow! And there have been a few other wows lately, so I'm wondering, what's up with the wows? :-)

All the best, Michael

Devin said...

Justin thanks so much for your fantastic comment!! I couldnt agree more about the last paragraph-if we are "alone" in all this immensity-that would truly be more mind blowing and i think terrifying than if it were proved we were not alone! I enjoyed your thoughts on Charles Fort also and have often wondered myself if we are indeed "property" -I am so glad you enjoyed this article and thanks for stopping by -best to you!!

Michael thanks also for telling me about the plethora of "Wows" out there right now!! That is also very interesting to me because this article was an "out of the blue" one for me in fact because of the abscence of the least smidgen of another signal in all these years I had considered shelving the article -but thought the parts where it was determined what the signal "couldnt" or "shouldnt" be were too interesting -so Wow and best to you as always Michael!!:)

Nina said...

very interesting piece, devin. there's so much we don't know--and the explanation for this one-time signal is likely something about the universe (and/or its inhabitants) that we have yet to discover.

Devin said...

Nina thanks so much for your comment!! I definitely think you are on the right track-even if this wasn't an "ET" signal -what if it was from some fascinating new phenomenon we do not understand yet? it would still be a very worthwhile discovery either way -and I think it was just from what we have learned from it already-it is just too bad it could not have repeated!!best to you as always and have a great weekend!! said...

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Devin said...

factasy-thanks so very much for your kind comment and I will check out your site. I do not think my August pace will be near as much as July was or perhaps even like a slow month would be-not because I dont have anything to say-but I have too much (in a manner of speaking) to say and don't want to mess it up like I am wont to do-and begin things before I am ready. I think a sign for me to slow down was when I typed word for word an extremely long article-but excellent article from 1997 about folklore and urban legends among a sector of American society-well I did this thinking the article was no longer under copyright and free to use (obviously I was going to credit newspaper and reporter who did it) well after 5 "posts" worth of typing the article to begin the series I found out-ooopsie article still under copyright! which has sent me back to the drawing board as I think the whole long article needs to be read and not just glanced at a leisurely pace -thats why I had it "broken down" so I find I am always living and learning so to speak!thanks for dropping by and I will be by to check out your place in a bit-I have been wanting to start up my history blog again in Sept to October so I will add to the list there if we're "compatible":)have a wonderful week and thanks again for stopping by!!

Michael Skaggs said...

WOW indeed! Thanks for sharing this intriguing story! Was that the year "Star Wars" was released? Makes me wonder if movies are "projected" into space via some medium and it scares away potential visitors? LOL

I know, wild idea! Be well bro!

benjibopper said...

very interesting, didn't know of this at all.

could it not be possible that there are other civilizations out there that are NOT sending out signals, that have no interest in communicating with us?

i also wonder if other civilizations have arisen elsewhere and then collapsed, as i expect ours will soon enough, leaving no one with the technological means to reach out to us.

of course, no civilization is not the same as no life or no intelligent life.

Devin said...

Great idea Michael:) that was indeed the year Star Wars was released -that is the only movie in my life I ever watched eight times in a theater! of course some people at the time were over the 100 viewing mark (as you prob remember) now I don't see what all the fuss was about! best to you as always!!

That is the big question-at least when i read about the SETI project benji -is how long does a civilization continue on after it has reached a certain level of technology? Some scientists have said there would be reason to celebrate it we find one that is out there that is considerably more advanced than we are cause it means they "made it" but I have never understood this viewpoint as sometimes I wonder if mankind has some rage issues or issues of irrationality that other civilizations in the cosmos might (hopefully) do not share! best as always benji and thanks for stopping by!!

Alex Robinson said...

Hi Devin
Couldn't resist playing with your numbers - Aug 15 was fascinating from a Shakespearean point of view.
'He who who must not be named' by actors, has Aug 15 as his alpha & omega - that is the date he (Macbeth) killed Duncan & got to be king & that is also the date he died. I'm so sure Shakespeare's play contain much we do not understand & I couldn't help playfully & wildly wondering if there could be an echoing link with your 'stars'! Of course you could just put it down to tiredness :)
Be very well my friend

Ricardo said...

So by error they now know what to look for. BTW I wonder if this inspired Close Encounters of the Third Kind.

Devin said...

O wow -it looks like i missed not one but two comments sorry alex and ricardo!!

i really appreciate both of your comments and your taking the time to post them here! i am very tired this week -back probs again-so i apologize for not seeing them -i hope to get caught up with everyone real soon-all the best to both of you and everyone who comments here-hope all are having a great weekend!!

X. Dell said...

The "Wow" signal is interesting, but expecting a repeat of it any time soon is hard to tell. This comes from a sweep of a huge expanse of space. In short, it was like finding a needle in th haystack. What scientists need to do to verify it is to find the exact location in the haystack where they found it. And that's very difficult to do.

The signal could well be repeating in very short intervals (like a second) but because of the distance, the focus of the SETI antennas, and our uncertainty, that repetition could come in five minutes or five millennia.

Devin said...

i agree xdell! thats what is so sad about this one -I wonder with humanity's luck if we missed the most important broadcast in cosmic history:) by a few milliseconds timing or from the direction the telesescope was focussed by a few arc seconds-all the best to you and thanks so much for stopping by!!

heidilore said...

Nothing is an accident. Synchronicity, my friend! Thank you for stopping by my blog. I like is weird, I was just thinking about the WOW signal today. I lived in Columbus and did some work at OSU, so it was always talked about. Thanks again, it is nice to meet you!

Devin said...

heidilore-very nice to meet you also! thanks so much for stopping by -i was just about to read the newest article at your place and remebered -duhhh! that i had published a comment of yours here:)best to you as always!!