The New "Wow!" Signal - SETI's Recent Close Encounter With An Unidentified Emission

The Allen Telescope Array operated by the SETI institute.

The "Wow!" Signal picked up by a SETI experiment at Ohio State University in 1977 often gets mentioned, as it was the first time an ambiguous and still unexplained signal was picked up by at SETI experiment.

The signal was not witnessed in real time but rather was picked up over night while the experiment was running. Radio Astronomer Jerry R. Ehman saw the signal on a computer printout the next morning and circled it with the word "Wow!" next to it:



The area which the "Wow!" signal of 1977 came from was not centered on any particular star.

It also never repeated. That area of sky has been searched several times since then and nothing was ever found.

(SIDENOTE: There was even a 72 second reply mimicking the original signal sent to the area of sky "Wow!" originated. This was done in 2012 by the mostly useless "Chasing UFOs program on NatGeo.)


That was then..... Fast forward to present day...

(click to enlarge)

In 2010 SETI picked up a new "Wow!" type signal, unlike the 1977 signal this one was not from that fairly blank area of sky.

This time the signal seemed to be from the vicinity of a star called TYC 1220-91-1 (An yellow G2V star around 100 light years away, almost identical to our Sun but older) on the frequency of the number Pi multiplied by the Hydrogen line frequency (4462.3 *1420 Mhz) = ~4462.3 Mhz

And unlike the 1977 signal this one was detected and tracked in realtime. It only lasted 10 seconds but exhibited the characteristics an interstellar beacon signal might be expected to, with the exception that it did not repeat. (I have my theory on why that is and how it may be recovered which I'll get into later.)




That incident is mentioned on page 12 of the following paper on a new theoretical type of alien beacon:

"A new class of SETI beacons that contain information" - G. R. Harp, R. F. Ackermann, Samantha K. Blair, J. Arbunich, P. R. Backus, J. C. Tarter, - (Aug 22, 2010)

Here is an excerpt:

Figure 4 for example shows a result obtained in a narrowband SETI search near
the PiHI frequency (the number π times the HI observing line of 1420.4 MHz). This (extremely
powerful) ~10 second pulse of narrowband radiation appeared in one 50 second observation
period but was never re-observed. This pulse has interesting features: It is observed at a magic
frequency in the direction of a nearby and potentially habitable star. Yet we cannot be sure this
signal was created intentionally or unintentionally by some transmitter on Earth. Hence after
multiple observations over 2 weeks and no re-detection, we gave up (although this direction is
added to a catalogue of directions to re-observe as time permits).

Figure 4: A pulse with maximum power >300σ above the noise background was observed on a nearby
star (~100 LY, (J2000 RA, Dec) = (32.211809⁰, 22.441734⁰)) in the HabCat Catalog (Turnbull, 2003).
This pulse is interesting since it appears to arrive from the direction of a potentially habitable star and
because it appears very close (within the expected Doppler shift tolerance caused by relative motion)
to the “magic” PiHI frequency of 4462.3 MHz, this signal appeared in only one observation and never
thereafter. Given the proximity of this source, we do not expect substantial fading in the ISM; hence the
signal is really not present, most of the time.

(click to enlarge)...

So what happened essentially is SETI tuned to a "magic frequency" which an intelligent species might presumably place a beacon, and detected a loud 10 second signal which did not repeat, presumably from 100 light years away. The signal exhibited the Doppler shift that would be expected from an interstellar signal rather than terrestrial interference and the signal source was close enough that SETI did not expect substantial fading due to passage through the InterStellar Medium (ISM) which are clouds of gas and dust which can fade a continuous signal in and out. So SETI does not think the signal is continuous or present most of the time.

My theory is that if this signal was in fact from a transmitter 100 light years away, that transmitter was not being used as a beacon for us but rather was being used in a similar way as we use the Arecibo planetary radar, which by the way, can also be detected 100 light years away.

We use Arecibo and other such radars take pictures of near Earth asteroids.

When we do this we are not intending to signal anyone and the transmissions are typically a one time affair as different asteroids have different trajectories so we aren't repeating these transmissions to the same areas of sky.

SETI essentially could have picked up a blip of another planet's asteroid avoidance radar. If that were the case, SETI would likely never see it again.

However it's also possible that such a transmission was some other type of radar which only sweeps that area of sky on an infrequent basis. An example of this would be our radar studies of Venus or Mars.

Powerful facilities in the US (Arecibo, Goldstone Deep Space Communications Complex) and the Ukraine (RT-70 and Pluton) have been used to study Mercury, Venus and Mars, including in some cases mapping their surfaces.

If the signal detected was from a planetary radar being used to study another body in the same vicinity as the transmitter such as a planet with a regular orbit, then there is a long shot possibility that 24 hr a day/365 days a year monitoring of that section of sky on 4462 Mhz and other nearby frequencies could produce a repeated observation at some point.

Arecibo at 100 light years away could be detected by a similar set up as the Allen Telescope Array.

The Square Kilometer Arraythat is being built in the next decade or so will be able to detect the signal from an airport radar tens of light years away and something like planetary radar perhaps hundreds of light years away:



So seeing a repeat is not out of the question if it really was some form of radar.

Unfortunately, it is impractical for professional SETI astronomers to simply sit on that frequency, stay fixated on TYC 1220-91-1 and look for that signal to repeat. After all, there are plenty of other places and frequencies that need to be covered.

However, a sufficiently equipped amateur radio astronomer with a big enough dish could perhaps do nothing but look for a repeat of that signal from the vicinity of that star and if the stars aligned (to use a pun) perhaps make the discovery of the ages.

One thing to note from the above information is that SETI did two things upon detecting such a signal:

1 - They published a paper which included all the relevant information on it.

2 - They never claimed the signal to be definitive evidence of aliens, though it looked from their perspective to be a signal of extraterrestrial origin.

Instead they took a cautious approach, as they should. They didn't scream "aliens".

reply to post by JadeStar


You never fail to impress, this is a terrific thread you have started, Do you by any chance remember the other signal from the 1970's when the noise was regared as nothing but random static but an absent minced intern sat there with his pen Joining the dot's litterally on the binary print out and ended up with an image of a stick man with a triangular head and in and three fingered hands standing in front of what looked like a radio satellite dish, it was one of those which used to be fairly well known but I can find nothing on it on the net.

Anyway The real difficulty is attenuation as you know and even a hundred arecibo sized dishes would be luck to pick anything more than a few light years away up unless the transmitters use an incredibly powerful signal on the order of stella magnitude in amplitude of signal and if we ever do detect someone it will likely be someone no more advanced than us as more advanced civilizations may have developed other form's of communication.

JadeStar

 

My theory is that if this signal was in fact from a transmitter 100 light years away, that transmitter was not being used as a beacon for us but rather was being used in a similar way as we use the Arecibo planetary radar, which by the way, can also be detected 100 light years away.

We use Arecibo and other such radars take pictures of near Earth asteroids.

When we do this we are not intending to signal anyone and the transmissions are typically a one time affair as different asteroids have different trajectories so we aren't repeating these transmissions to the same areas of sky.

A very popular topic, with a new twist (at least for me), and nicely presented on top ... inspiring thread, Jade Star!

I think the idea of 'them' (whoever it might be) sending signals in terms of an 'unintentional beacon' (for their own purposes) which we just happen to receive - more or less by chance - is interesting, to say the least. But as this is clearly not my area of expertise, I really look forward to what others on here have to say ... thanks again for posting this!

reply to post by JadeStar


A fine theory, I like the radar twist. Thanks for posting this here, and you could probably put this theory up on some of the Space and NASA boards elsewhere. Taking it to its limit, if "their" civilization was at the point of using deep-scan radar x number of light years (radar years?) ago, just imagine where they'd be now (if they still exist).

LABTECH767
reply to post by JadeStar

 

You never fail to impress, this is a terrific thread you have started, Do you by any chance remember the other signal from the 1970's when the noise was regared as nothing but random static but an absent minced intern sat there with his pen Joining the dot's litterally on the binary print out and ended up with an image of a stick man with a triangular head and in and three fingered hands standing in front of what looked like a radio satellite dish, it was one of those which used to be fairly well known but I can find nothing on it on the net.

Thanks!

Yes. That "signal" was the interpretation of Scottish science and sci-fi writer Ducan Lunan who in the 1970s looked at the phenomenon of Long Delayed Echoes of terrestrial radio transmissions during the 1930s.




The message was supposedly from a probe in orbit near the Earth which originated from the Epsilon Bootes star system. His analysis was published in Spaceflight, the journal of the British Interplanetary Society and that in turn got the attention of April 9 issue Time Magazine.

You can read all about it on Duncan Lunan's web site.

Original paper: "Spaceprobe from Epsilon Bootes" - Duncan Lunan, in "Spaceflight" (British Interplanetary Society), 1973

Interesting idea and it really cemented the idea of intelligent, perhaps self-replicating interstellar probes into the popular public consciousness at the time, though I am not very convinced by the evidence he offered.

That said, it shows that even 'way out there' ideas from reputable people can get published in scientific journals if decent data is gathered and analysis done.

Anyway The real difficulty is attenuation as you know and even a hundred arecibo sized dishes would be luck to pick anything more than a few light years away.

This is incorrect but almost correct.

What is happening here is something many people often confuse: our leakage from TV and Radio with the more powerful transmissions we put out from things like planetary, military search and air traffic radar.

While it is true out radio leakage from TV and Radio stations would not be detectable by Arecibo even as close as 4 light years away at Alpha Centauri however, Arecibo could be picked up by and alien Arecibo quite far away.

It truly is that powerful a transmitter.

The same holds true for the other planetary radars as well as the powerful military search radars that were in use heavily during the cold war.

And as mentioned on the SKA's webpage our airport radars which are detectable by something like the Square Kilometer Array out to a distance of perhaps 50 light years:

Square Kilometer Array

One must remember that when talking about the inverse square law one must know the transmitter power and the receiver sensitivity.

A big enough array on Earth such as the proposed Project Cyclops, which was studied back in the 1970s.would have been able to pick up the equivalent of our TV transmitter's relatively weak signals more than halfway across the galaxy (70,000 light years away). It would have been made up of one thousand 100 meter dishes:


Project Cyclops

Cyclops was the dream. The SKA will be the reality.

BTW: Anyone who wants to do their own calculation of how far a signal can be detected by whatever receiving set up one has can do it with these handy spreadsheets from the amateur SETI League, who by the way, will teach you how to build your own SETI radio telescope.

Range Analysis

Performs range analysis of an electromagnetic communications system, assuming identical antennas at both ends. The example shows that the range over which a 1 MW hydrogen-line signal can be detected with existing receivers, assuming 100 meter dishes at both ends of the path, is on the order of 9 parsecs (28 LY). This spreadsheet may be used for range comparison of various systems.

Receiver Sensitivity

Determines the sensitivity (in Janskys for continuum measurements, and Watts per square meter for narrow-band signal detection) of any radio telescope, given its pertinent receiver and antenna parameters. Also shows the flux density of any received signal as a function of observed Signal-to-Noise Ratio (SNR). The sample calculations seen in this spreadsheet show the sensitivity of the Ohio State University "Big Ear" radio telescope at the time the "Wow!" signal was detected. See this article for an example of sensitivity analysis.

Link Analysis

Determines the Signal-to-Noise Ratio (SNR) for any communications system, given the operating characteristics of the transmitter, receiver, and the intervening free-space propagation path. The sample spreadsheet calculations show that the typical Project Argus station could easily receive a 1 MW hydrogen-line signal into a 100 meter dish, at a range of 1 parsec (3.26 LY), with just 10 seconds of integration. These normalized values may be used for comparison of various systems. See this article for more examples of link analysis.

Never bring up the Inverse Square Law without understanding this stuff

This just goes to show how lousy our kind of communication devices are, I mean if that had been PROOF of an alien civilization living there, then our response would take 100 years to be heard... By then they could all already be dead...

What we need is some kind of "quantum intercom" that allows information to get from point A(us) to point B(aliens) in zero time.
Until we have such a technology there isn't even a point in looking for ETs... :/

reply to post by JadeStar


JadeStar, does SETI use other elemental frequencies? If so, is there an order, whereas He, Li, Be, B, C, etcetera are used? Your theory about asteroid detection radar is quite intriguing. If SETI were to tune in to any other elemental frequency lines, if they exist, maybe we could expect to pick up more data? Also, might that signify an intelligent source fielding a survey of elemental awareness throughout the galaxy, using elemental frequency lines, received and acknowledged by other intelligences?

My imagination is getting ahead of my knowledge of this subject. If my inquiries are possibly relevant, I would warn of the other side of the coin regarding these transmissions, which is that we would be informing distant intelligences of our environmental makeup, essentially being audited and inventoried.

If I am way off base on this, I apologize.

Great thread.

reply to post by JadeStar


How very well written - thank you!

I would love to hear more about the "thousands of interesting eading" captured each day. Do you know anything about what constitutes "interesting" and what makes them not-mentionable?

reply to post by JadeStar


Thank's for correcting my mistaken assumption as I would have imagined that with a non directional radio emission it would attenuate logarythmically over distance though as you point out these are directional emission's which means there cone shaped field of dissipation from there origin gives them a much lower rate of attenuation as in reality they are not saturating the same area of space but instead the same energy is focused and directed, it is worrying though to realize many of our more powerful signal's are military in nature and what potential picture of our species any alien civilization in the future may draw from this, in the future though imagine the capability's of a deep space radio observatory if we could put it out beyond our own radio noise, the far side of the moon would be the most logical and ideal location for such an array as it would naturally shelter the array from the majority of earth originated noise and if somehow to step on other thread's we had done all this before one would imagine a field of radio recieving structures may in that scenario still be there slowly decaying and forgotten looking like antenna masts and an alien base,.

The black night satellite is a truly intriguing story though I am not convinced the radio emission's which were recieved with the epsilon bootes data are from the same source as the infamous black night sattelite of the sputnik era which may have been photographed by NASA on a close fly by (which if they did was deliberate) and I suspect that object to be a relic of an ancient past while the green glowing object some astronaut's or cosmonauts are supposed to have seen changing course and following there capsule was probably another object (AKA UFO), unfortunately these objects are bundled together as the same thing when they are not and possible deliberately so as to confuse that subject but for what it is worth I beleive they did indeed recieve this long delay information just not from that black swing winged ancient wreck with it's underwing jet rocket hybrid hotol like engines and under swung nose which was folded down and under possible to open it's ancient shuttle payload or weapon deployment system, you know the image which was supposedly published in time magazine as the black night satellite (so was probably some dis information) and has muddied the waters as to it's true identity ever since (though it was probably surveyed and destroyed by NASA or the USAF to prevent any advanced technology falling into soviet hand's whether ancient or alien, ufosightingshotspot.blogspot.co.uk...

The following may include hoax, disinformation or error but are definitely worth a look though we get into new age territory here and I provide links as are and state neither belief nor disbelief in there claim's.

www.youtube.com...

humansarefree.com...

paranoidnews.org...

www.nsa.gov...

galacticconnection.com...

www.cropcircleconnector.com...

reply to post by JadeStar


Excellent thread, Jade...! Have there been any other signals besides the WOW signal and this one? I seem to remember that there were other signals.

I've heard of the incident, but not the details. Somehow this leaked out to the news media, though they don't seem to have made too much of it. Apparently only after this did the SETI Instituter make a brief statement about it
The usual statement about one-off detections like this is that they are inconclusive. A 24/7 observation program would be a good idea, of course, it if could be managed.
How large would a single dish antenna need to be to detect a 300 sigma signal like this, with an appropriate integration time to detect 10 second pulses?
I looked for, but didn't find any radial velocity measurements for this star. If we had this figure we could confirm that the signal really was accurately placed on the Pi*HI frequency, by correcting for the doppler shift. Since the reception frequency was around 1.5 MHz higher than the pi*HI frequency, the star would need to be moving toward us for this to work out.

Sorry, I just realized I mean't to put the number for PI (3.14159265359) in the original post *times 1420.4 Mhz which gave the frequency they were listening to ~4462.3 Mhz.

Chock it up to running out of coffee after being up all night.

lostbook
reply to post by JadeStar

 

Excellent thread, Jade...! Have there been any other signals besides the WOW signal and this one? I seem to remember that there were other signals.

There have been but none as interesting as this or the Wow! Signal.

Usually these signals turn out to be interference from Earth or one of our satellites.


They can not say that in the case of this one and Wow!, however that doesn't mean they to don't have a more mundane explanation. It just means they are a mystery until they repeat one way or another.

I posted a whole file containing some other interesting signals I found on their FTP server, over on the Aliens & UFOs forum a bit ago:

SETI Candidate Signals List - January 2014, AboveTopSecret.com

BTW: I just realized this whole post reminds me of a line mentioned in the rap song Above Top Secret: "S.E.T.I. has already obtained alien frequencies"

DupontDeux
reply to post by JadeStar

 

How very well written - thank you!

I would love to hear more about the "thousands of interesting eading" captured each day. Do you know anything about what constitutes "interesting" and what makes them not-mentionable?

What makes them interesting is they appear as an extraterrestrial signal but then disappear. They have all the characteristics of an expect ET signal, the slow drift in frequency as the motion of the earth and presumably the planet or object it originates on move through space, but they blink in and out over seconds and they never repeat from the same area.

SETI just says, 'interesting signal, didn't repeat, looked extraterrestrial, must check again" in these cases. Which they do but only as time and money allow.

The problem is they are on a fairly shoestring budget for what they do.

Ideally what would be wonderful would be a network of citizen SETI amateur astronomers like the SETI League people doing long term follow-up study of the positions these signals seem to originate from, since they have the time to just stare at one star with the converted satellite dish in their back yard.

They could determine if it is some form of terrestrial interference that seldom happens or if it was from beyond our solar system.

The majority of near earth asteroid and comets, until recently were discovered by amateur astronomers because there are so many of them and they don't have to worry about funding.

Ross 54
I've heard of the incident, but not the details. Somehow this leaked out to the news media, though they don't seem to have made too much of it. Apparently only after this did the SETI Instituter make a brief statement about it

The usual statement about one-off detections like this is that they are inconclusive. A 24/7 observation program would be a good idea, of course, it if could be managed.
How large would a single dish antenna need to be to detect a 300 sigma signal like this, with an appropriate integration time to detect 10 second pulses?

Excellent question. The answer is not very big. An old Ku Band satellite dish size.

Remember this signal was 300 sigma above background noise so it was thumping and if it were from 100 light years away then there would not be any fading effect from the Interstellar Medium, just the normal drop off due to distance.

300 above background noise is similar to the 1977 Wow Signal.

Here's a paper which discusses how an amateur could re-detect the Wow! signal using available technology from the 1990s.

SETI Sensitivity: Calibrating on a Wow! Signal - Dr. H. Paul Shuch (1996), Presented to the AMSAT Annual Meeting and Space Symposium, Tucson AZ, 9 November 1996

Here's an excerpt on that very subject:

Thus, any radiotelescope with an overall sensitivity of -204 dBm would, in theory, be able to detect a "Wow!" type signal, if tuned to the right frequency, and pointed in the right direction, at the right time.

There is another way, and it has been described above. Consider that at the 21 cm neutral hydrogen line, a three- to five-meter diameter parabolic antenna (such as is commonly used for satellite TV reception) will have a power gain perhaps 200 times less than that of a "real" radio telescope such as Big Ear. The reduced capture area would also imply that such an antenna would enjoy 200 times the sky coverage, so a mere 5,000 such antennas could, if properly situated, "see" the whole sky at once. And such a global array of small telescopes could be constructed at a cost far less than that of a single Big Ear.

Unfortunately, this increase in angular coverage afforded by smaller antennas was accomplished by a reduction in their capture area, hence gain. Thus, as compared to our Big Ear example, these smaller antennas will experience a reduction in their effective communications range by that same factor of 200, all else being equal. A signal which could be detected by Big Ear at a range of, say, 20,000 LY, would be detectable to our smaller antennas at a distance of only 100 LY. Since for uniform distribution of candidate stars, the number of targets varies roughly with the cube of distance, this sacrifice in sensitivity significantly reduces (perhaps by a factor of several million) the number of suitable stars which might be within range of our sky survey.

Keep in mind that is talking about the hydrogen line at 1420 Mhz. A dish of the same size's collecting area at around 4460 Mhz would be even more sensitive.

I looked for, but didn't find any radial velocity measurements for this star. If we had this figure we could confirm that the signal really was accurately placed on the Pi*HI frequency, by correcting for the doppler shift. Since the reception frequency was around 1.5 MHz higher than the pi*HI frequency, the star would need to be moving toward us for this to work out.

Exactly. I didn't find it either but I think SETI probably has in their extensive HabCat, habitable star database so when they say that it exhibited the expected Doppler shift for that star then I take their word for it.

I may have missed it in the plethora of this wonderful thread....why has is this the first time we have heard of this second WOW?

I'm surprised it hasn't been media hyped, it does seem as though these days there is some push to desensitise us to all things alien.

Apologies if you have already covered this.

LABTECH767
reply to post by JadeStar

 

www.nsa.gov...

galacticconnection.com...

That NSA link and the subsequent ones talking about it was a training exercise for basic cryptography (code breaking). There was no alien message in that case.

Was also in the ATS Hoax forum:
ATS: Major US Intelligence Agency Reveals ET Contact - November 2011

While lecturing at an IEEE Conference on Military Electronics held in Washington, D.C. on 23 September 1965, Dr. Lambros Callimahos, a famous NSA cryptology expert who had authored a number of innovative studies on deciphering coded messages around the same time, seems to have made references to the very same series of “ET” communications as follows:

“As an illustration of how much information could be conveyed with a minimum of material, and as an example of facile inverse cryptography, let us consider a message I have devised to be typical of what we might expect of an initial communication from outer space.”

Indeed, it seems obvious here that Callimahos not only knew of a series of alleged “ET messages,” but admits to having designed them himself as an exercise! Furthermore, looking back at the roundup of articles released at the NSA’s website, among them one will also find the appropriately titled, “Communication With Extraterrestrial Intelligence” by none other than Lambros D. Callimahos.

While it seems obvious to us, looking at the series of documents in this order, what the intentions and goals of the two men were, we are left with a number of websites that do make the assertion that Campaigne’s lone documents were, in fact, addressing actual signals collected from outer space.

solargeddon
I may have missed it in the plethora of this wonderful thread....why has is this the first time we have heard of this second WOW?

I'm surprised it hasn't been media hyped, it does seem as though these days there is some push to desensitise us to all things alien.

Apologies if you have already covered this.

Because the mainstream media often misses some juicy things which are in "boring" academic papers. Most mainstream media's science reporting is marginal and there are so many papers published so even sites like Space.com miss really intersting stories.

By the way, there's a good site to stay up on the latest in astronomy/astrophysics from a layperson point of view:

www.astrobites.com...

Also check out Centauri Dreams - www.centauri-dreams.org... - excellent blog on this and many subjects related to life in the universe, interstellar travel, sci-fi, etc.


Also, the mainstream media did pick up on another radio astronomy mystery recently:

A Brilliant Flash, Then Nothing: New “Fast Radio Bursts” Mystify Astronomers - (Jul 9, 2013) - Scientific American


AND......

A Fast Radio Burst From Close to Home? - Yvette Cendes (Feb 21, 2014) - Astrobites.com

Which looks at this paper...

A Galactic Origin for the Fast Radio Burst FRB010621 -Keith W. Bannister, Greg. J. Madsen (Feb 3, 2014) - ArXiv


Probably not ET related but SETI@Home plans to look at them anyway.

The first story on FRBs was picked up by mainstream media when it looked like they might be from some sort of distant exotic physics object. However the more interesting paper, which shows one closer to home in our own galaxy did not get mainstream attention.

I looked for, but didn't find any radial velocity measurements for this star. If we had this figure we could confirm that the signal really was accurately placed on the Pi*HI frequency, by correcting for the doppler shift. Since the reception frequency was around 1.5 MHz higher than the pi*HI frequency, the star would need to be moving toward us for this to work out.

Exactly. I didn't find it either but I think SETI probably has in their extensive HabCat, habitable star database so when they say that it exhibited the expected Doppler shift for that star then I take their word for it.


The relevant quote from the paper: "within the expected doppler shift tolerance caused by relative motion" That sounds a little vague. It could mean they have a well measured value for the radial velocity of this star. It could also mean that they don't, and assumed a possible range of reasonable values (less than - 50 kilometers per second) and found that the needed doppler shift fell within that range.
If it could be shown that the doppler corrected frequency of the signal was precisely 4462.3 MHz, there would be a good evidence for extraterrestrial intelligence, right there, it seems. It had already been predicted that Pi* HI was a good place to look for SETI signals. A successful prediction supports a hypothesis, doesn't it?