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WILD CARD 002 "SETI, a 'Big Ear', and Practical Jokes"

Posted by Rick Shaffer   06/07/2004 12:00AM

WILD CARD 002 "SETI, a 'Big Ear', and Practical Jokes"
In 1978, I went to work at the Jet Propulsion Laboratory in Pasadena, CA, as an assistant Network Operations Project Engineer for Radio Science in the Deep Space Network, which JPL operates for NASA. So, I was an ANOPE for RS in the DSN for NASA. (I put in all those acronyms for all of you who live in or near Akron, OH….)

Most of the time, the antennas in the DSN were used to track and acquire telemetry data from deep space craft, Viking, Pioneer, Voyager, Galileo, and all the rest. But, part of the time, other users who weren’t attached to a big, flashy flight project got to use the antennas. And our little group of astronomy-oriented folk helped those users get time on the antennas to do Radio Astronomy, Radar Astronomy, develop advanced systems, and a wide variety of other activities. A lot more on that later.

Over the next several years, I got promoted a couple of times. While I was deputy NOPE, we changed the name from “Radio Science” to “Radio Astronomy”, and then to “Radio Astronomy and Special Activities”. I remember suggesting that last modification, and also remember regretting it later, because “special activities” was pretty much whatever the guy in the corner office said it was, as in “Nobody wants to do it? OK. Have Shaffer’s folks do it.” (This, of course, was after I’d become the NOPE.)

One of the “special activities” I got assigned was to be the representative of DSN Operations to the Search for Extra-Terrestrial Intelligence Development Team. This team was made up of folks from both JPL and the NASA-Ames Research Center in Mountain View, CA.

Why would two different NASA Centers be charged with doing SETI? It was because of two different approaches to the problem.

Ames had proposed to do a search that would target all stars of spectral types similar to our Sun’s (spectral types F and G) within about 300 light-years from Earth. The assumption was that intelligent life similar to ours would only have time to evolve around sun-like stars, so searching only in the direction of those stars was a reasonable approach to finding radio signals “leaking” from a planet.

JPL’s approach was different. It made no assumptions as to the nature of the intelligent life we might seek. It proposed to search the entire sky for radio signals over a broad range of frequencies.

Apparently, each approach had its proponents within the office at NASA HQ which funds this sort of thing, and neither group could gain the upper hand. Both groups were told to work together to come up with a program that would use both approaches. Neither group liked that much, but they gritted their teeth and went to work.

Since I was the (very) junior member of the team, I found myself handed a draft operations plan and told to “whip it into shape”. I read it over, and rewrote some sections, and sent it around for comment.

It came back – many times. The reason was that no one could agree on what we should write down in the section about what we’d do if we actually found evidence of extraterrestrial life in the radio region of the spectrum we had signed-up to search. I remember being told by one senior manager (offline, of course) that, if we actually found concrete evidence of ETI, he’d just call the NASA administrator for an appointment at the White House, gather up all the data we had, and take the red-eye to DC. The implication was that only the president should be entrusted with making such a decision.

I didn’t much care who was supposed to make the decision. I just wanted not to have to continue writing the ops plan, which was being pulled every which way by this issue, with no end in sight. I got my wish when Sen. William Proxmire of Wisconsin arranged to have our funding discontinued. By the time it was reinstated a year later, I had moved on to working on the Magellan Project (to orbit a radar mapper spacecraft around Venus). It became someone else’s problem. Finally, in 1993, NASA got completely out of the business of Searching for ETI (“SETIing”?), and it’s been in the hands of various not4profits ever since. (BTW, you’ve likely heard of it, but you can participate. Just google on “SETI@Home”.) I’m really not qualified to assess what kind of a job they’re doing, so I won’t. I do note that I’m running SETI@Home on my computer. I know of no reason why you shouldn’t, unless you’re running a machine that can’t keep up with it..

What I didn’t know then was that an “all-sky” search of a limited range of frequencies had already been done. Furthermore, there had been one “hit”, on 15Aug1977. I learned of this event when I was accosted at the Riverside Telescope Maker’s Conference in the mid-80s by a person whose first words to me were, “Why don’t you SOBs at JPL come clean about the ‘Face on Mars’ and the ‘WOW Source’?”

I first mentioned to “The Great Confronter”, whose identity I’ll not reveal, the following:

0. My sainted Mother isn’t canine.
1. I’m not married.
2. I’ve never been married.
3. Therefore, I’ve never beaten my wife, (or anybody else, for that matter!),
4. So, I don’t have to tell you when I stopped beating my wife.
5. And furthermore, what the are you talking about?

I was shown images taken by the Viking Orbiter of the now-familiar “Face on Mars”. I told “The GC” that I’d never seen the image he’d shown me, but that I was sure that it was just a natural formation seen under lighting conditions that made it look like a face. (I just barely suppressed the urge to point out that it looked remarkably like the face of a certain son of a certain deity on a certain burial cloth….)

The “GC” opined that I “must be part of the coverup”. I replied that I sincerely wished that I was important enough, and mostly, well-enough-paid to be part of the coverup, but that I was at the lowest level of management at JPL. Given that, I suggested that it was extremely-, absurdly-, highly-unlikely that anyone would even think of me as being worthy of participating in such a coverup.

Faced with this barrage of unadulterated logic, “The GC” backed off, only to launch a counterattack: “OK, forget the “Face”. What about the ‘WOW Source’?”

“OK.” I replied. “You got me again. I have no idea what the “WOW Source’ is.”

This time, he showed me a monograph written by a fellow in the Urban Studies Department of the University of Chicago. I made him shut up while I read it. I’ll only give you a brief sysnopsis of it here:

On 15Aug1977, an automatic data recording system at the Ohio State Radio Observatory near Delaware, OH, recorded a series of very narrow band radio signals over a 72-second period. The engineer who who inspected the computer printout of the day’s data, Professor Jerry Ehman, wrote a single word in the margin of the page: “WOW”. From that, the name stuck. Besides the fact that the signals were relatively strong, they seemed to exhibit a pattern. Adding to the fun was that a spectral-type F5 star – a “sunlike star”was passing through the “beam” of the radio telescope at the moment the signal was recorded.

You could assume that the good folks at the OSU Radio Observatory spent a LOT of time looking at that F5 star. In fact, they looked at it more than 50 times. Nothing like the “WOW Source” ever recurred. But the aura of mystery surrounding it has never quite faded away.

I replied to “The Great Confronter” that my first guess was that the source of the signal was a classified military spacecraft, but that it was very unlikely that we’d ever know what it was. I also asked him why he thought that “us guys at JPL” would have anything to say about what the folks at the Ohio State Radio Observatory were doing.

If you were expecting bigtime confrontation, you’ll be disappointed. “The Great Confronter” mumbled something about scientists all sticking together and stalked off, never to be seen again, at least by me.


Over the years, the whole issue of the “WOW Source” has occasionally forced its way from the dim, dark corners of my hind brain into my fore brain. Just recently, I’ve reached some startling conclusions about it. But, in order to make any sense of all this, we really need to know more about the famous “Big Ear”.

Radio telescopes come in two sizes: “not big enough”, and “a little bigger than that”. The reason for this is that the wavelength of the radiation a radio telescope receives is rather large. So, radio telescopes don’t have much gain relative to their wavelengths. That means that they don’t resolve radio objects well. In fact, radio astronomers would kill for a radio telescope that would resolve as well as a bad 6” optical telescope!

The earliest radio telescopes operated at rather long wavelengths, some as long as a truck. In order to have enough gain to be useful, a radio telescope had to be huge. Just one example is the 250-foot Jodrell Bank “Mark I” telescope made in the 50s near Manchester, England. A careful reading of the autobiography of Sir Bernard Lovell, the man who got it built, will show that cost over-runs nearly cost him his career. Only the fact that his telescope was used to help us Yanks find an early Lunar probe kept the British Parliament from throwing him in gaol (jail to us provincials)!

Other huge radio telescopes have been built to be fully steerable, including the 100-m built by the Germans near Bonn, and the 70-m tracking antennas built by the Deep Space Network at Goldstone, CA, near Canberra, ACT, Australia, and near Madrid, Spain. (I once played Frisbee inside the one at Goldstone! Don’t tell anyone, though….) The old Soviet Union built some 64-m antennas, and there are a couple of new huge ones in Japan. And, of course, the National Radio Astronomy Observatory operates a new 100-m antenna at Green Bank, WV, that replaced one of that size that collapsed in the 1990s. Finally, there’s the venerable 64-m antenna at Parkes, NSW, Australia. It is one of the stars of a delightful movie made in Australia called, simply, “The Dish”. Rent it and enjoy it. It’s a hoot, and great history, to boot! (Sorry for the bad poetry, but I couldn’t resist….)

But there once was a wonderful radio telescope that was built in a cornfield near Delaware, OH, beginning in the late 1950s, and completed in the mid-1960s. It was built by a group of students at Ohio State University under the direction of one of the genuine pioneers of Radio Astronomy, Dr. John Kraus. It was called “The Big Ear”, and you can read all about it in Dr. Kraus’s book of the same name. Googling on that name will get you all kinds of sites about it. Here’s an image of the “Big Ear””

For the sake of completeness, which I worship both mindlessly and completely, here’s a quick description: Suppose you had parabolic reflector, say, 720-feet across. It might be a bit hard to mount, so you hit on the idea of burying it in the ground in a convenient corn field, half below ground, and half above. To make it easy to get at the focus of your dish, suppose you buried it so that its optical axis was coincident with the surface of the field, and facing due South. That would allow you to put your radio receivers in a building right at the focus.

Of course, nobody but Arnold the Governator could actually bury a 720-foot paraboloid in the ground. But John Krass did effectively that. He and his cohorts made a huge “curtain” of metal mesh in the shape of a section of a paraboloid on the North side of a cleared corn field so that the optical axis was, indeed, running right along the ground and pointing due South. Their section was to be a curtain about 720-feet wide and about 100-feet tall. However, they never got the money for the outer sections, so they settled for a curtain 360-feet wide. All told, their fixed antenna section was the equivalent of a circular dish of about 175-feet in aperture. And they built it for a few pennies on the dollar if you compare it to a fully steerable antenna of the same size.

They built a building at the focus of their antenna in which their receivers were housed. To allow their antenna to “see” the sky, they built a huge, flat, metal reflector due South of the curtain, and hinged so that it would reflect radio radiation from the sky to the curtain reflector. Huge jacks allowed the angle of the reflector to be changed.

The flat reflector allowed the “Big Ear” to be pointed over a rather broad range of Declinations on the sky. And, as the Earth turned, the entire range of Right Ascension would pass through the beam of this remarkable instrument once a day. It was ideal for making a survey of a large portion of the sky, and that’s just what the astronomers and engineers at OSU did. They’d just record the radio power for one strip of Declination, and then change the tilt of the reflector just a bit, and do it all over again, day after day.

Between 1965 and 1971, the Ohio survey of the sky from –36 to +63-degrees Declination was completed. It was done primarily at a frequency of 1415 MHz, which is well above the UHF-TV band.

Not long after the OH survey was completed, the “Big Ear” was thought to have reached the end of its useful life. The reason was that other, newer, fully-steerable radio telescopes were becoming available. But John Kraus and his associates just went off in a new direction. They converted the “Big Ear” to be an instrument to automatically search for extra-terrestrial intelligence.

They did it by making a receiver that would look at many channels very near a frequency of 1421-MHz. That frequency is one at which the water molecule absorbs microwave energy. So, there’s a “hole” in the background static that radio astronomers encounter when they point a radio telescope at the sky. Many radio astronomers think that interstellar civilizations would communicate at this frequency because they would need less power to transmit a message there than at other frequencies.

They started the search with an 8-channel receiver. In Aug1977, an automated 50-channel receiver was operating at the “Big Ear”. Because the Earth moved one width of the peak of the antenna’s beam in about 12-seconds, the computer operating the receiver was programmed to build up or “integrate” a signal for 12-seconds, “dump” the value of each channel into the computer’s memory, and then begin another integration, “ad setium”.

The data were recorded and printed out using an interesting code. The first 10 values were denoted by the numerals 0-9, but 10 was A, 11 was B, and so on.

This made it extremely easy for whoever was analyzing the printouts, because the values of weak signals were all less than 1, and weren’t printed out at all, and signals that might be evidence of extraterrestrial signals would be letters, which would jump off the page at an experienced analyst.

In the days following 15Aug1977, volunteer Jerry Ehmers was analyzing the data from that days’s recordings. In one 72-second stretch, Ehmers saw letters, lots of letters. He wrote his now famous comment on the printout. Further examination of the data showed that, in each succeeding integration, the letters “danced around” a bit. Some folks claimed that there was a pattern in the data.

Here’s a small section of an image of the printout. Judge for yourself:

Specifically, the claim was made that Channel 2 was “on” for all 6 integrations, and that the power found in that channel followed the sensitivity of the antenna as a source passed through the beam. The claim was also made that in the second integration, Channel 4 came “on”, in the third integration, Channel 7, and in the 4th, Channel 16. Alas, in the 5th integration, and in the 6th and final integration, Channel 32 failed to come “on”. Of course, there was no Channel 64.

To folks who believe that this observation was a microwave signal from another star, the pattern 2,4,7,16 was too close to the geometric series 2,4,8,16 to be anything but a message. Add to that the presence of the F5 star in the beam of the antenna, and you have the stuff of which movies are made. There’s just too much coincidence….

Or is there? It’s been conjectured that the “WOW Source” was some sort of signal from a military spacecraft operating in a band in which it shouldn’t be radiating. And that’s certainly a possibility. If it were an extraterrestrial signal, we have to ask a very serious question: How would they know which frequency we had assigned the number 2, which was 4, which was 7 or 8, which was 16, and so on? The answer, of course, is that they wouldn’t and couldn’t know. So, if we buy the “geometric progression” argument, it’s very unlikely to be an actual extraterrestrial source. (It’s more likely that the small number of high power levels in the channels above 2 are simply spurious signals.)

Well, there are too many coincidences for me, too. Those “galloping coincidences” make me suspect that the source of the signal the “Big Ear” received on 15Aug1977 was of a more mundane nature. I think it was generated by a couple of bored college sophomores who just didn’t have enough to do that Summer. Here’s how they could have done it:

First, building a small, portable, very-low-power transmitter that could put out a signal that the “Big Ear” could receive wouldn’t be much of a challenge to an Electrical Engineering major, even in the “dark ages” of 1977. (One switch for Channel 2, another for Channel 4, and so on.)

The Astronomy major of the pair would simply consult a catalog of stars, find one that would be in the beam of the “Big Ear”, and thus know when he and his cohort would have to sneak out into the corn field and generate their spurious signal. (Remember, the place wasn’t staffed.)

The first integration would have been made with the little transmitter set at Channel 2 only, while its operator was standing well to the East of the flat reflector, pointing his transmitter at the curved reflector. The second would have been with Ch2 and 4 on, and the operator would have moved closer to the flat reflector to simulate a source moving through the beam of the antenna on the sky. The 3d and 4th integrations would see the operator standing just in front of the East end of the flat reflector, so that the transmitter would appear to be right in the main beam. He’d press the appropriate buttons for the appropriate channels. For integrations 5 and 6, the operator would repeat what he did in 1 and 2, but in the reverse order. Because the antenna can’t see what side of the beam something is on, he didn’t have to sprint the 360-feet to the other side of the reflector to “exit” the beam!

This might even have been an “inside job”. A program volunteer might very well have known when that star was going to be in the beam, and thus knew when to transmit the spurious signal.

Do I have any knowledge that what I conjecture is true? Absolutely NOT! (Just to clear this up, I’ve never been to Delaware, OH) And, it would be one of the bigger surprises of my life if any of the senior professionals, including Jerry Ehman, had anything to do with such a hoax. So, please don’t think that the folks at OSU were “cooking the SETI books”. I certainly don’t.

No, if it was as I think it was, it was two science nerds doing the “ultimate hack” of a radio telescope’s data. If you’re out there, guys, you’d be in your mid to late 40s, with kids in college about the age you were when you created that fake signal. It’s time to come clean.

A POST-MORTEM: The “Big Ear” was built on land owned by another university, which sold the land in the 80s to developers. It was razed in 1998 to make way for a golf course and luxury homes. Nothing remains but many stacks of printouts, and the memories of all those folks who worked on this wonderful instrument. And, of course, the memory of the “WOW Source”….

Rick Shaffer is an astronomer, teacher, writer, and designer/builder of telescopes and museum exhibits. From 1986-1997, he wrote the “Through the Eyepiece” column in “Astronomy” magazine. He’s also the author of “Your Guide to the Sky” and “Introduction to Astronomy”. He lives in Sedona, AZ, with his pet 20” Newtonian, Dora.