Between 1956 and 1961, The Ohio State University built a large radio observatory at nearby Delaware OH. Known as Big Ear, it had a reflecting surface roughly the size of a football field, with antennae at the end zones. Big Ear was used in the Search for Extraterrestrial Intelligence (SETI) from 1973-1995, longer than any other facility in the world. It was “tuned” to 1420 megahertz, because hydrogen (the most abundant element in the universe) emits that frequency; thus an advanced civilization would likely be aware of it. Signals at 1420 MHz would presumably have an extraterrestrial origin, since that frequency was reserved for SETI, and earth-based facilities were prohibited from transmitting it. On this date in 1977, Big Ear detected a strong signal that appeared to come from the direction of Sagittarius. Astronomer Jerry Ehman circled the data on his computer printout and wrote Wow! in red ink. This observation has been known as the Wow! signal ever since. A plot of signal intensity (averaged over ten-second intervals) vs. time shows it rising and falling smoothly over a 72-second window. The alphanumeric sequence 6EQUJ5 is simply its signal-to-noise ratio with E=15; Q=26; etc. Ehman never observed a comparable signal again, despite more than fifty attempts. Nothing remotely like the Wow! signal was detected during two decades of searching at several facilities, including the Very Large Array in New Mexico, which is much more sensitive than Big Ear. 6EQUJ5 remains, to this day, our strongest physical evidence for a possible extraterrestrial civilization.
Indeed! BigEar Destroyed In late 1997, after almost 40 years of operation, the Ohio State University Radio Observatory, with its "Big Ear" radio telescope, ceased operation. The land on which the observatory was sitting (owned by the Ohio Wesleyan University, Delaware, Ohio) was sold by them in 1983 to land developers who later claimed their rights to develop the land. The telescope was destroyed in early 1998. An adjacent 9-hole golf course was expanded into 18 holes and about 400 homes were planned for construction on the nearby land owned by those developers. This website is meant to serve as a memorial to that unique radio telescope, to its designer and builder (the late Dr. John D. Kraus) and the many persons involved with the telescope, and to the discoveries made with that instrument. http://www.bigear.org/
The Ohio State Radio Observatory was a survey instrument which lacked both sensitivity, selectivity, and a symmetrical beam, compared to other facilities. This meant that its primary purpose was ended at the completion of the survey. For a while the reflector was used as part of a near-field range. The demise of the facility was two-fold: a delay was allowed to give astronomers time to find resources to keep it open. The community was not behind that and it indeed was dismantled for a golf course. The absence of redundacy --repetition or independent measurement --means that the 'wow' signal must be discounted as a noise phenomenon. "Noise is unique, signals are redundant". Then, and now. BTW, 1420 MHZ is not, and was not 'reserved for SETI'. It is a protected band because the 21cm hydrogen spectral line falls there, and much NON-SETI research is undertaken. It is odd that we 'celebrate' an anecdotal noise feature. 73 Chip W1YW
A sad day when the land was sold off and the whole establishment was got rid of to build a golf couce and housing. History down the drain. I no doupt wonder if any of the golfers today even ever think about the history of the site. ?. 73 de John - G0WXU.
The system used was a 50 channel correlator with 10 KHz resolution. The sky basically 'transited' through the beam, which gave the profile made from the letters and numbers. It's a Gaussian, which is what you would expect with that beam for a 'point' source that is celestial in nature, that transits through. A few channels away you see a weaker signal transiting with the same timing. The second 'noise or signal' is suspicious because it could just as easily indicate an intermod from overload, for example. Which makes you wonder if the 'wow' itself is overload from some other source, such as a satellite, transmitting at some other frequency outside the correlator passband. To wit: 'circumterrestrial'. Today we see similar types of issues with PIM at cell frequencies. There is no evidence supporting the unique explanation that the WOW was an intelligent transmission of extraterrestrial origin. 73 Chip W1YW
I grew up in the shadow of Big Ear. First licensed as a teenager at 15 (WN8BCU/WB8BCU) I was a member of the Columbus Amateur Radio Association. Though a bit young to appreciate it at the time, I was blessed by the regular participation of Dr. John Kraus (W8JK) and Dr. Robert Dixon (W8ERD). One of my most memorable moments was a private tour of Big Ear they gave. I still have the photos I took that day with my Instamatic camera. Fast forward...the Big Ear is demolished to make room for housing and a golf course. Why? Because money talks. Adjacent to the Big Ear site is Perkins Observatory. Built in 1923 it was at one time the home of the largest telescope in the world (69" aperture mirror). Now its existence is being threatened because once again money talks. It is disappointing and sad. 73, Mark WB8BCU
Mark, That's not what's going on at all. Astronomers decide their own priorities on equipment and that means leaving almost all legacy instruments 'unfunded'. Believe me, if there was 'angel' interest in keeping these telescopes open, then they would still be around and used. Mount Wilson is a great example of that. The Perkins facility simply is the wrong location for any optical telescope. In fact, these days, there are few acceptable locations for optical observatories in CONUS, because of light pollution. It's not as if greedy commercial interest want to buy the facility, demolish it, and build a mall and a SONIC next door. That, at best, is a plan B when no astronomer wants to support the scope. The OSRO radio observatory was closed for the same reasons--no 'angel support' at the level needed to keep it. The fact that 'Big Ear' could not verify the WOW in real time or otherwise, is indicative of why it was the wrong instrument to pursue the SETI question. 73 Chip W1YW
Important to understand that the early OSRO facilities were arrays of helices, not the 'Big Ear'. That came in the early 1960's. No doubt JK's early work in radio astronomy is amongst the most important of that era. 73 Chip W1YW
