The Search for Extraterrestrial Intelligence: Dr. Peter R. Backus of the SETI Institute
Interview by Henri Béhar and Mayra Langdon Riesman

Henri Béhar: What did you think about being almost a star in "Independence Day"?

Dr. Peter R. Backus: I was rather surprised. I found out about it on a trip to the east coast, I ran into a cousin I hadn't seen for a few years and she said how she had taken her daughter to the movie. During the opening scene she said to her daughter, "You know, your cousin does that," and my little cousin said "No way!" That was my first clue that we were actually included in that movie. So I went to see it the following week...

HB: And then sued?

PB: No no, fun movie. Much of what they showed was fairly accurate about the way we do our search. We don't have an array of antennas, we use national facilities in this and other countries, and bring our equipment to the site, but in terms of how the observations are conducted, it was fairly accurate. The computers do most of the work. We tend to catch up on e-mail or play computer games rather than practice our putting. We don't have flashing lights, the computers ring their bells if they think they've found something that deserves attention.

Mayra Landgon Riesman: Has that happened?

PB: Well, we set our analysis software at a level where even noise alone - just the background static hiss from the universe - will trigger a possible detection approximately once a day . At that point an astronomer has to perform some further tests. When we were in Australia, on a 16-week long program, we had 39 signals that required some astronomer's attention and further tests. Unfortunately, all of them turned out to be either noise or unusual satellite signals.

HB: This year, from "Independence Day" to "Mars Attacks", there seems to be a resurgence of the alien movie, which was prevalent in the 50s and 60s, symbolizing just about everything from the Russians to McCarthy, right?

PB: Yes, I think many people have pointed it out and speculate that it's the change in world politics. Where we once had the evil empire as our enemy in the world, we no longer have that threat, and the rebirth of the alien invasion movie is kind of a response to that - to fill in the void left by the departure of the Soviet Union.

HB: To what would you attribute the rebirth or new popularity of the alien films this year?

PB: I think it's like the entire horror genre that releases something in us, it's kind of a cathartic experience to have this seemingly extensible enemy that is eventually defeated by the spirit and determination and unity of the human race. I think there's kind of a nice moral feel there that if we all work together it's possible to achieve great things. I think in many ways these alien invasion movies fill that role.

HB: Did "Independence Day" generally describe what you do accurately?

PB: "Independence Day" was pretty close, the way they had the control room with all of the computers monitoring for signals. That was pretty accurate. Some of the details were not accurate, but that's part of dramatic license. Having the signal come up on the speaker so you could hear it, that's somewhat unrealistic. That, and the fact that they were able to determine that the signal was coming from roughly the distance of the moon. Our computers would automatically reject that signal, because we are looking for something that's coming from outside of our solar system. And anything internal to our solar system would be classified as a spacecraft or satellite signal. In some ways "Independence Day" was very good, but I suppose to make the story more interesting they had to stretch things a little bit.

HB: What about the use of the word "parsec" in Star Wars?

PB: Yes, [I remember] the use of the term in the first Star Wars movie. It was a memorable experience, the movie was quite a breakthrough film in terms of science fiction. I was in graduate school at the time and went to see the movie with about 15-20 other graduate students. We basically occupied about a row and a half of the theatre. In the scene where Han Solo was bragging about his piloting abilities and that he made the Kessel run in 12 parsecs, our entire row just groaned, because it was a misuse of a standard astronomical term for distance as a time frame instead. So, for us at least, it stuck out like a sore thumb. Most science fiction writers are careful not to use standard terms in ambiguous contexts. I think the Star Trek movies and series do it rather well. They have kind of a technospeak or technobabble that, if you watch the series often enough, you kind of know the performance of the warp drive, and you understand that if the plasma inducers or whatever are malfunctioning, that's not a good thing. It isn't anything in our known technology, but they can get away with it because it doesn't have a reference in our current technology.

HB: Most of the doctors I know who watch ER find it to be completely faultless and accurate in terms of the depiction of technology. I wondered whether in any of these movies there were any instances when you just had to go "ouch!"

MLR: When you had a giggle between the science fact and the science fiction.

PB: Well, you have to allow some license in the storytelling both in fiction and in non-fiction. I remember watching Carl Sagan's TV series "Cosmos" back in graduate school. We would have a "Cosmos" night at our house where a bunch of graduate students from the astronomy and biochemistry departments would come over, and we would watch it, and the astronomers would start to find fault with all of the astronomical graphics: "Oh, it's not really that way. It really wouldn't look like that." But all the biochemists were just fascinated and would say "Oh, so that's how it works!" Then it would come to a point where he's describing biochemistry or cells, or something about life, and all of the astronomers were saying "Oh, so that's what the inside of a cell is like. I always wondered what that was like." And the biochemists would respond "Well, you know it's not really like that..." So the more you know, the more you can find fault with a film that is either trying to be entertaining or instructive. I think for a show like ER, which is trying for a high degree of realism as part of their drama, they're able to bring in doctors as advisors to make sure that all of their procedures and conversations in the emergency room are accurate. So I think in that case the high degree of realism is a plus, because it's not really trying to instruct, but it's trying to make it more real.

MLR: What's your reaction to all of the recent fuss over the possible discovery of life on Mars?

HB: Other than the film "Mars Attacks!"

PB: I think it's very exciting. Scientifically I'm quite skeptical about whether in fact they have found fossilized life on Mars. But much of the evidence that they have so far does indicate that it's at least a possibility. I'd say one thing that is confirmed is that there were organic molecules on Mars, which is a big step towards life. Since we do know that Mars has had a warmer, wetter climate in the past, it is entirely possible that the forces of chemical evolution could have eventually caused those organic chemicals to react and form simple life. I think over the next year or two we will hear solid evidence one way or another as to whether or not those are Martian organisms that were found in the rock. But in any case, it's an exciting discovery, even if it's just organic molecules it opens the possibility that life could evolve near other stars.

HB: But for the moment, you are skeptical.

PB: Most scientists are very skeptical. Whenever a big discovery is announced, there is a lot of excitement, but a lot of that excitement is housed within skepticism. Because whenever you make an extraordinary claim, the evidence that supports it also has to be extraordinary. In this case the claim is the existence of fossilized organisms, and the chain of evidence is very complex and there are some links in that chain which are, I wouldn't say, weak, but less solid than others. If the evidence continues to build, over the next year or so you'll see scientific opinion moving with the flow of the evidence.

MLR: Do you think they'll wind up doing a mission to Mars?

PB: Well, I think if in fact these are proven to be the remains of Martian life, I would say most certainly. NASA has a whole series of missions to Mars planned over the next decade or so, about a dozen in total. Not specifically designed to look for life, as the Viking missions were in the 70's, but certainly these missions could be tailored to look for more evidence of Martian microbes. As we gain more knowledge of Mars, more experience building these smaller, cheaper, faster type missions, it might become feasible to have a mission.

MLR: How long would it take someone to get there?

PB: Someone? Well, current space probes take about a year, a little less than a year to get to Mars. But these are small spacecraft. A crewed mission which would probably have a few people, would require a much larger vehicle, much more in terms of life support, supplies and a lander. That would be a more complex and much more expensive mission than the type currently being run.

HB: This may sound silly, but what do you guys do all day if all you have to do is listen? If that's the core of what you do, why don't you transmit?

PB: Well, we don't transmit for the reason that it takes so long and it requires quite a bit of effort in terms of the power and building an antenna structure. We also don't know where to transmit and how often. Within 100 or 200 light years of Earth there are roughly 1000 stars that we consider to be like the sun in terms of age and temperature, and they would be likely candidates to have a planet like the Earth. But to transmit messages on a more or less continuous basis to these thousand start would be a tremendous expense, both in terms of time, effort and the technologies to build all of these antennas and all of that.

HB: It's more a question of expense than choice?

PB: Well it's also a choice. Say we were to send a message to Alpha Centauri, that's 4 light years away, that message would take 4 years to get there, then - assuming they received it - a response would take another four years to come back, so it would take a total of 8 years or a little more before we would know the answer of whether or not anyone is there. However, we can use sophisticated radio telescopes and apply sophisticated digital processing to the signals that we pick up, and perhaps answer the question right away. If there is a technological civilization on a planet orbiting Alpha Centauri, and they're using radio technology, if we make our equipment sensitive enough we can point our equipment at that star and have an answer in minutes. So it's partly that it is more efficient in terms of money, but it's also more efficient in terms of time. We can answer the question in the near term without waiting years and years or even decades for a response to a message.

MLR: The question is also what would we transmit?

PB: That's true. Many people have come up with schemes. In fact there *have* been a few deliberate transmissions. The most famous was 1974 when the air and sea observatory was rededicated; they transmitted a message in the direction of a star cluster, M13. The star cluster is about 25,000 light years away, so the message was largely symbolic. But within the string of digits that was sent was a picture that depicted the major elements that make up life on Earth, the rough shape and size of the human body, and the size and shape of the antenna that sent the message. We have also sent other types of messages attached to the sides of spacecraft. Again, this is largely symbolic, but perhaps millions of years from now some space-faring civilization will stumble upon this relic of our civilization that has travelled across space to be discovered by them and on the plaque or on the record on the side of the craft they'll see depictions of what humans look like and where we're located in the galaxy.

HB: So basically what you do all day is sit and listen?

PB: We don't really sit and listen much. In many ways it's like what the movie "Independence Day" showed. It is the computers that do most of the work. We run checks, we examine any signals that the computers think are interesting, but a good deal of our effort is directed at making our computer algorithms more efficient and more sensitive, making the computer hardware more reliable, and planning towards a much larger system. Our current system listens to roughly 56 million channels simultaneouslly across a part of the spectrum that's equivalent to the FM radio dial. What we'd like to be able to do is listen to maybe 10 to 50 times that amount of radio spectrum and multiply the channels correspondingly. We'd also like to have computers that can listen to each of those channels with perhaps 2 to 5 times as much sensitivity.