By David Jay Brown
For fans of the science fiction film Contact--where a scientist played by Jodie Foster establishes communication with an advanced extraterrestrial species, the SETI Institute has almost mythic status.
However, SETI, which means "Search for Extraterrestrial Intelligence"--is the acronym for a very real organization which scans the skies every night in search of some type of evidence for the existence of intelligent extraterrestrials-in hopes of establishing contact.
Becoming an official nonprofit corporation in 1984, SETI's mission is to "explore, understand and explain the origin, nature and prevalence of life in the universe." Using optical and radio telescopes, SETI's team of determined astronomers and communicational specialists seek the answer to one of mankind's most gnawing question: are we alone in the universe?
Allen Telescope Array (ATA) at the Hat Creek Observatory in Northern California scans known planetary systems for signals. Credit: Seti.org
Seth Shostak, Ph.D., is the senior astronomer for the SETI Institute, based in Mountain View, California. He hosts the popular weekly radio show "Big Picture Science," and is also widely recognized as a science educator. In 2004, Shostak won the prestigious Klumpke-Roberts Award by the Astronomical Society of the Pacific in recognition of his "outstanding contributions to the public understanding and appreciation of astronomy."
I spoke with Shostak on January 16, 2014. In conversation, Shostak combines open-mindedness and skepticism with a vast array of knowledge, and he is especially talented at seeing the "big picture." In the following interview of Shostak, he talks about SETI's current search for life in our galaxy, whether or not he thinks alien civilizations are benevolent, SETI's plans for the future, and what amateur astronomers can do to help in the search for extraterrestrial intelligence.
David Jay Brown: How did you first become interested in astronomy and the search for extraterrestrial intelligence?
Shostak: That all began as a kid, of course. I was interested in astronomy from the age of 8, since I was looking at a book that my parents had. It was an atlas, but in the back of the atlas there was a funny-looking diagram, which I didn't understand.
So I asked my mom about it, and she said, "Oh, that's a diagram of planets."
I had never heard the word "planets" before, but once I heard it, I got interested in that--and by the age of 11, I had built my own telescope.
As far as aliens go, well, that was also, I'm sure, from about the age of 8--because there were a lot of science fiction films in the movies those days featuring aliens. Aliens were always doing something terrible to humanity in these films--and I went to them all!
Brown: Can you tell us about some of the latest projects that SETI is working on?
Shostak: Our SETI projects are multiple. We use the Allen Telescope Array--with a large number of small dish antennas--so we're doing what's called "radio SETI." That's looking for the kinds of signals that transmitters would make.
We have another project where we're looking at the galactic center. That's something that I think is a good idea, because that's a special place in the Milky Way. Incidentally, my first published SETI experiment--in 1981--was to look at the galactic center, the center of our galaxy.
A really advanced society would know that everybody is going to be looking at the galactic center sooner or later--so they might put a big transmitter there to act as some sort of beacon. So we're doing looking there.
We're also looking at star systems that are known to have planets. Of course we do that. I wrote an article about this that's in the January issue of Astronomy magazine actually, about looking for signals from the neighborhoods of red dwarf stars.
I honestly think that that's a very good SETI strategy, because probably 1 in 5--certainly 1 in 6, at least--of red dwarf stars, will have a habitable planet orbiting around them, it seems. Red dwarf stars are also so numerous, and so old, that they're just perfect for a SETI search.
Brown: What research techniques do you think hold the most promise for establishing contact with a race of intelligent extraterrestrials?
Shostak: Of course nobody knows that. If we knew that, then we would put all our resources into the most promising techniques.
We're great fans of radio SETI, and that's the traditional form of SETI. That was used in the first SETI experiment, at least the first modern SETI experiment. It was a radio search in 1960 by Frank Drake.
Then we continued to do that, because--in terms of the energy required--it turns out, it's very easy and inexpensive to send bits of information from one star system to another using radio. So I do like that.
But it's also the case that optical SETI appeals to me, and I think that it will appeal to me more in another couple of years, when we have new detector technology that would allow us to survey the sky much more quickly, in the optical.
But there are also other things that are coming down the pike, if you will. These are the kinds of SETI experiments where you don't actually deliberately look for ET, as it were, but you mine data collected by other sorts of instruments. For example, large telescopes that are intended for other purposes, but might in fact reveal the activities of very advanced societies.
There could be engineering projects that are big enough for you to see. So those are, all to me, very interesting techniques.
Brown: Taking the recent discoveries of so many exoplanets into account, how common do you think intelligent life is in the universe?
Shostak: Well, that's a complete guess, but it's now looking like there are roughly a trillion planets in the galaxy. The current estimate is that 1 in every 5 stars has an earth-like world. If that's true, then there are on the order of 50 billion "Earths" in the Milky Way galaxy.
Now, what fraction of them have life? I bet most of them have life, actually. But what fraction have intelligent life? That is a different question. But even if it's one in a thousand, then that's still 50 million societies that have sprung up in the galaxy--a galaxy that we know for sure has supported intelligent life at least once.
So if intelligent life has any durability at all, if it can last for a million years, or something like that, then that means there are tens of thousands of worlds that are extant today, that are out there now with cosmic confreres, with intelligent beings.
That's a big number.
Brown: What type of patterns are you (or your computers) listening for when you search through the radio signals in the sky?
Shostak: It's actually very simple, because the searching is done by the computers. Of course there's a tremendous amount of data coming in. There's really a fire hose of data coming in, so you can't look for the Fibonacci series, or anything like that.
In fact, you wouldn't get it anyhow. Because you're adding up the signals coming in over a period of minutes, any sort of fast modulation or any sort of message would get smeared out anyhow.
But we're just looking for the kind of signal that a transmitter would make. A transmitter would make a signal that would have some narrow band component. It would have peaks of energy over a very narrow range of frequencies.
That's exactly what television, radar, and radio do as well. The energy is put into a narrow range of frequencies, although it is more narrow for AM than for FM. But it's still pretty narrow. So that's the kind of signal that we look for--narrow-band signals--and if we find one, and if the source is moving across the sky at the same pace as the stars, then you say, "That's not a bit of nature. That's not a pulsar, a quasar, or anything like that--it's too narrowband. That's some sort of artificial source."
Brown: Physicist Stephen Hawking has warned us not to attempt extraterrestrial communication, because he thinks that it makes us too vulnerable to the will of an advanced species, and in his new book, The Future of Mind, Michio Kaku says that you once told him that any battle between ourselves and an advanced civilization would be like a battle between Bambi and Godzilla.
How do you envision the friendliness of other intelligent species in our cosmos? Do you think that our science fiction films are paranoid, and that the universe is basically a friendly place, or do you think that we need to proceed more cautiously, and be concerned about the dangers of an intelligent extraterrestrial species, many years more advanced than ourselves, that may be seeking to exploit us or use our resources?
Shostak: To begin with, I don't think they would be interested in our resources. What do we have that they don't have much nearer by? But, aside from that, the facts are that we can't guess the sociology of the aliens.
A lot of people like that the idea of malevolent aliens, and in particular Hollywood likes it, as, of course, friendly aliens are a lot less interesting than hostile ones from a movie's point of view, so they have a vested interest in hostile aliens. As far as Stephan Hawking's point goes, I've written three articles on that. You can actually find one if you go to The Edge, for example. I wrote an essay last year about what I'm not afraid of, and I'm not afraid of that, largely because of the following:
You can't say whether the aliens would be friendly or hostile. I suspect most of them would be friendly, because, after all, I think advanced societies probably tend to be peaceful, otherwise they don't last very long.
But hey, I could be wrong. And in fact, if only 1 percent of them are not friendly, well that might still be dangerous. But my point is somewhat different. It's very easy to show that any society that has the ability to come here, and do some damage...(laughter) If they can do that, if they've got the technology to do that, they also have the technology to pick up all the signals we've been broadcasting into space since the Second World War.
So there's actually no point in being careful about this. There's no point in turning off the radar systems at the local airport. All that would do is kill people, and it's not going to make us any safer--because those signals are already on their way. And any advanced society, anyone that could ever pose a threat to us, could pick those up anyhow.
Brown: What does SETI plan to say to the first intelligent extraterrestrials that it makes contact with?
Shostak: I suppose we would just send a whole bunch of information, if we were to be responding to a received signal. Mind you, there's a protocol that says you wouldn't respond to a received signal without international consultation, and probably that means something like the United Nations... To be honest, I don't think that it matters. I honestly don't think it matters, because you could have said that maybe the natives of the Caribbean should have prepared what they were going to say to Spaniards in 1492, should their ships ever show up on the beach. It really didn't matter what they said actually.
Brown: Please tell us about the SETI Institute's radio program "Big Picture Science" that you host.
Shostak: Yes, it's a weekly show about science. We always try and put the show in the context of the overall picture of science, the overall picture of humanity, and what it means. We explore the scientific developments, and also ask how does that affect us in any way? So that's the kind of thing we do, and we try and make it fun. We have lots of very good scientists, lots of Nobel Prize winners, and so forth. We interview about 4 or 5 people every week. You can find us on the web at: www.bigpicturescience.org
Brown: What are some of the future research projects that SETI has in mind?
Shostak: Unfortunately, the future depends a lot on funding, but we would like to continue to increase the capabilities of the Allen Telescope Array, which is the instrument that we use.
This is because that would speed up the search, and speeding up the search means that, if there's going to be success, it's going to come sooner rather than later.
And as I say, there are these new approaches. I like the idea of optical SETI using two dimensional detectors.
I see that coming in, as something that right now is mostly waiting on technical developments that we won't make, but industry will.
Also, I have to say, I think that data mining would be a very interesting thing to do. There are some very big optical telescopes being built around the world, and they will provide enormous data sets that can be combed by anybody with a laptop and a little bit of time to look for anomalous features, things that aren't natural.
Brown: How can people at home get involved with SETI, using their personal computers?
Shostak: On our website we have something called SETI Live, where people can look at some of the actual data. People who are interested in participating should just look for interactive SETI programs with their internet browsers and check them out. It may be something that they want to do.
Brown: What excites you most about the search for extraterrestrial intelligence?
Shostak: That's a big picture question. I think that's the most exciting thing. This is something that everybody has some interest in. I mean, are we the only game in town? Are we the only kids on the block? Are there other kids? And if so, what are they like? I think everybody's interested in that. And of course no previous generation could answer this question, but we can--so, hey, that's exciting!
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David Jay Brown is a science writer whose work has appeared in Scientific American, Wired, and Discover magazines. He is the author of 14 books, and was voted "Best Writer" in Santa Cruz (in The Good Times & The Santa Cruz Weekly) three years in a row. To stay current with the frontiers of alternative science 'like' David's Facebook page.