The movie Contact thrust Jill Tarterıs research into the limelight. As the director of the Search for Extra-Terrestrial Intelligence (SETI) Institute, Dr. Tarter has devoted her life to collecting signals from space.

In this interview with CEM, Jill discusses her movie portrayal, operations of SETI, and the future of extra-terrestrial searching.

CEM: What are the most common sounds you ³hear² from space?

JT: The common sources of what we call radiofrequency interference are satellites and overflying airplanes with distance measuring equipment (DME). We call it interference because it does in fact block the spectrum; you canıt listen through it. But in fact, formally, itıs not interference because these are technologies and products that are operating at frequencies that have been allocated to them. They are doing their thing, it just interferes with us. It illustrates the problem that the so-called passive services like radioastronomy have: they have a few very widely spaced and very narrow bands of the spectrum which have been ³protected² for passive use. Radioastronomers canıt observe there. However, our windows are closing because of increased use of the spectrum.

We also donıt police very well. There may be no transmitters in those frequencies whose actual fundamental frequency of transmission falls within the protected bands, but we get harmonics and ³out of band² spurious emission from transmitters that donıt have filters that restrict the frequency range into which they radiate. The FCC regulations and the international ITU regulations are just not stringent enough to protect them. And the only way itıs going to happen is when all these different allocations become so numerous that they begin to interfere with one another. Then the marketplace will demand that good engineering hygiene be practiced, and transmitter A does not pollute the spectrum thatıs allocated for transmitter B. We hope that when the commercial systems begin to interfere with one another they will again adapt good engineering hygiene and we will benefit. Itıs not good for radioastronomy, itıs facing a diminished future in terms of spectral access.Itıs being sold at auction for a billion dollars a Mhz.

CEM: When you do SETI, you are ³listening² to many different frequencies. Why does measuring the strength of signals at a small 1Hz (frequency) interval denote intelligent life?

JT: You can take a look at astrophysics and ask, ³what is the narrowest absorption or emission you can find in the sky?² It turns out itıs 300 Hertz wide and is associated with an absorption feature in an OH maser, which is something that is narrower than thermal. But thereıs nothing below that. Nature doesnıt appear to be able to generate coherent pure tones, very narrow-band signals. But technology does all the time. Itıs a really cheap way to get a high signal to noise ratio (just put all your transmitted power into one narrow frequency range and you get a strong signal relative to that noise). Thatıs the idea that this particular aspect band-limited frequency domain would be indicative of a technology. Either that, or a whole new brand of astrophysics that we donıt know about‹that nature can be more coherent than we currently expect. So thatıs why we chose to look for narrow band signals.

CEM: What types of signal processing are you using at SETI?

JT: What weıre currently using is custom hardware that we built‹essentially special purpose supercomputers. We started with FFT chips that we built ourselves because there wasnıt anything commercially available at that time (early 1990ıs). So we built it all, full custom hardware and weıre going to get rid of it as soon as we can...because it is ancient now. This is four generations of Mooreıs law! Itıs very difficult to maintain custom things that you built because you canıt even buy products. We built special purpose supercomputers, very highly parallel processed (we sort-of scale it at 75 Gflops).

When I said Phoenix was going to die in 2000 itıs because weıre developing the new generation of signal processing equipment, it is based on commercially available products, itıs not custom at all. It will reduce cost and increase maintainability. Mooreıs law is great, but it also means you canıt stand still. You always have to make your system better and thatıs what weıre doing.

CEM: What are the future plans for the SETI

JT: We have just moved our equipment from Greenbank, West Virginia and Woodbury, Georgia to two other telescopes, the largest telescope in Puerto Rico at Arecibo Observatory and the 76-meter telescope at Jodrell Bank in England.

Starting on the 10th of September we will begin an observing campaign using these two large telescopes which are just about the biggest interferometers you can form with existing telescopes on the planet. It is our most sensitive configuration. We will eventually begin an observing campaign every six months for the next 6 years.

Sometime around 2000, Project Phoenix will formally die when the NASA derived signal processing equipment is replaced with our own new generation processing equipment. At that point itıs time to let the name which signifies ³rising from the ashes of congressional termination² go away. The searching will still continue. While weıre doing this, we continue running workshops for the next 6 months with external scientists, engineers and technologists to figure out where we should be 10-20 years from now. Two things have come out of these workshops. One: where weıll start searches with very fast optical pulses. And two: how to build a telescope that has a collecting area of a million square meters (about 100 times the size of Arecibo [telescope]) and do it for something like $400-600 a square meter so that itıs affordable to the world community. It obviously means breakthrough technology so we canıt build telescopes like we did in the past, we have to do something new. Our idea has been to use consumer market products, where the price has been driven down by competition to an absolute minimum and where many are produced so the reliability is very high. Weıre trying to see whether you can economically build a very large array by using small satellites, tv dishes and build mounts with parts made out of truck axles and universal joints. Out of all of this workshop activity the thing that will probably happen next is to see if we can build not a million but 104 which we call the one hectar telescope. It will be an array of hundreds of TV dishes which will be equivalent to a 100-meter class telescope (world class). This instrument will allow us to do SETI all the time and provide a prototype for an economical solution. Thatıs the future as I see it beyond the tip of my nose.

CEM: Turning to your recent brush with fame, how accurate is the role of Ellie Arroway (played by Jodie Foster) in the movie Contact?

JT: The experiences that Ellie had were similar to experiences that Iım familiar with...up until the time when the signal is detected. All bets are off at that point. Carl [Sagan] did a very reasonable portrayal of experiences that Iıve had, experiences that women in science have had.

CEM: Did Carl consult you before he created the character, or did he create the character then show you his book?

JT: We talked about it in advance and I joked that if Ellie didnıt eat ice cream cones for lunch, nobody would think it was me. But indeed, I was startled when he sent me a pre-publication copy and I saw so many experiences that I personally had. He wasnıt really basing the book on me, but what he knew of me. It was the fact that Iım very representative of women my age in science and that there are a lot of common themes in our histories. Carl was writing about all of us.

CEM: Is the pursuit of truth really the goal of science and theology?

JT: You can deal with theology, Iıll just work on science. But thatıs what I try and do. I certainly donıt try and pursue falseness. Actually itıs just trying to figure it out. Thereıs a lot we donıt know, weıre all looking for answers.

CEM: Shifting gears, with our increasing dependence on technology, will America be shut down when something goes wrong? (i.e. the Year 2000 problem)

JT: Well, it does remain to be seen how much the Year 2000 problem does us in. Someone told me about a CNN report yesterday morning about the fact that the Soviet Union simply doesnıt have the money to update their technology and that it can cause problems with their weapons systems...I donıt know...

CEM: You donıt know but do you think that‹

JT: Sure, technology is becoming increasing complex and inter-related, itıs a lesson weıre having to learn. What we will hopefully take away from it soon enough is that redundancy leads to cost of survival. Itıs important to educate the folks that are growing up about the fact that they need to deal with a technological world.

CEM: For you, what is the definition of success?

JT: I would feel personally extraordinarily successful if, at the end of my life, this pursuit of scientific evidence of extra-terrestrial technologies were established with a funding mechanism that would enable it to go forward over a generational time-scale. I think itıs a question that is so big and we know so little that itıs going to be something thatıs going to take a while to be successful. I know I will have considered myself a success if I could contribute to the establishment of an endowment or some other resource base that will enable this to go forward into the future in whatever mode it needs to.

CEM: What do you consider the most important thing in your life and why?

JT: Learning something new everyday that I didnıt know the day before. And that can be from watching my daughter grow up and marveling at how children learn and become formed into adults to understanding exactly how the galaxy formation started to learning a new dance step. Not standing still, growing old, learning something new every day‹that is, to me, the most fun. Thatıs why I have the best job in the whole world because it lends itself to the acquisition of some new knowledge in some diverse field every single day.

CEM: Would you give a bit of advice to the readership of Colorado Engineer Magazine?

JT: The important thing to do is to do what youıre passionate about. And if youıre lucky enough to end up being able to do that, in a real job, then youıre fortunate indeed. And thatıs what you ought to try and make happen.