Still waiting for ET to call After 35 years looking for signs of extraterrestrials, Jill Tarter is stepping down as Earth’s top alien hunter. She takes Stephen Hawking to task for thinking aliens will be aggressors, and tells Maggie McKee why considering ET might make us better people
SETI, the search for extraterrestrial intelligence, has been going on for 50 years. What fraction of the universe has been searched so far?
I think a pretty accurate comparison is to consider the searchable space as being like the oceans of the Earth. We have scooped one 8-ounce glass out of the ocean, stared at it and said, is there a fish there? Well, gee, no fish? Does this mean there are no fish in the ocean, or does that mean we haven’t sampled it very well yet? I certainly think it’s the latter. A glass of water out of the ocean?
That sounds bad! But the good news is that the tools we have now are getting better, faster and bigger. We are finally acquiring a set of tools that is perhaps adequate for the task. How do you actually hunt for aliens?
SETI is an attempt to detect evidence of someone else’s technology from a distance. We are looking for signals that are obviously engineered. In the radio spectrum, we look for signals that happen to be at only one frequency. At optical signals, we’re looking for outbursts of light that last only a nanosecond or less – lasers can do that. We’re using technology as a proxy for intelligence. What will you do if you find a signal coming from a distant planet?
Drink champagne – we keep champagne on ice because we plan for success. But the first thing you want to do is worry about a hoax. You want to get an independent confirmation with equipment you didn’t build, and software Profile Jill Tarter got hooked on hunting extraterrestrials in the 1970s, eventually becoming director of the SETI Institute’s Center for SETI Research in California. Last week a “SETIcon” was held to mark her retirement from this post. See a gallery of messages humans have sent to space at: bit.ly/N9Aqw
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you didn’t write. Our team at the SETI Institute has signed an informal protocol developed back in the 1980s, which simply says, do good science: get independent confirmation, and then tell the world. We go on to say that we, the signatories, will not transmit a reply until there has been some global consensus on whether we should, and if so, what we should say and who should speak for Earth.
whenever Freeman Dyson, who’s a wonderful physicist, is in the room and I say this, he kind of chuckles. He says that as soon as you announce the detection of the signal, anybody who can get their hands on a transmitter will do so. And they will transmit whatever the heck they want to, and you’re not going to be able to control that. There will be this great cacophony emanating from Earth.
It sounds sensible to wait for consensus on a reply to an alien signal, but is that realistic?
Stephen Hawking thinks that broadcasting our existence to aliens is too risky, as they might come and plunder the Earth. You disagree?
Intellectually, this is the high ground. But
Stephen may be right – neither of us are experts in extraterrestrial psychology. Humans haven’t treated each other well in the past, I agree with that. But I can imagine another scenario: if aliens can get here, they must be significantly more technologically advanced than we are. They will be older than we are. I don’t think you get to be old unless you outgrow the aggression that was probably so helpful in developing your intelligence over evolutionary times. By the way, if they do come here, they will be calling all the shots.
“If aliens do come here, they will be calling all the shots”
If we did decide to reply to ET, who do you think should speak for Earth?
For years we’ve been pondering that question and we’ve had a bunch of meetings. But the meetings involved first-world people, usually white males – not a large cut of the world’s cultures, traditions and religions. I’m now beginning to think that the way to get this conversation going is by taking advantage of social media in all of these emerging countries. That might get the job done. You want to crowdsource how to answer aliens?
I think that discussion will be good for the planet. The more we can talk about SETI, the more we can get individuals involved with that thinking, maybe we are only one of a number of civilisations in the cosmos. That means all of us humans, we’re all the same compared with somebody else out there. We’re all Earthlings. So this global conversation is one way to push this concept out into the world and perhaps trivialise the differences between us that we’re willing to shed blood over.
it’s something I can’t put off any longer. We don’t want to see the Allen Telescope Array [the SETI telescope which was forced to close for seven months last year because of funding problems] shut down again. We want to build more antennas. We only have 42 but if we grow them to 350 or 500 we would have an amazing world-class telescope. Have you ever seen any signals you thought might be from ET?
It doesn’t happen very often, but it’s pretty amazing. You get so excited. The latest was in 1997. The bulk of our equipment was at Green Bank, West Virginia, but we always observed with a second telescope to distinguish between signals coming from our technology and those that might be coming from alien technology. On this occasion, the second telescope got hit by lightning, so for a few days we had only one telescope. A signal that came in kept us intrigued for the better part of a day. It was clearly artificial. On the screen, it looked kind of like a picket fence. Clearly, that’s not something Mother Nature is fabricating. It took many hours to figure out that the signal was actually coming from the SOHO spacecraft. If we’d had the second telescope, we would have known it instantly. In Carl Sagan’s Contact, the main character, Ellie Arroway, is said to be modelled on you. Is that right?
Ellie Arroway is Carl. Her thoughts are Carl’s thoughts, aspirations and dreams in a female character. But the experiences she had as a young person in a male-dominated field – those are experiences I had. The fact that her dad died when she was young was an important factor in shaping her career, as it was with mine. That is the most difficult way to learn this carpe diem lesson. Before I read the book, Annie [Druyan, Sagan’s wife] and Carl had me up to their house for a cocktail party. Annie said: “You may recognise someone in the book, but I think you’ll like her.” I said: just make sure that she doesn’t eat ice cream cones for lunch, then nobody will think it’s me. That was kind of a defining characteristic of mine at that time.
Seth Shostak/SETI Institute
Do you have plans to start this discussion?
It is on my to-do list. But the first thing on my list is to find some money to keep the Center for SETI Research going, now that I’m retiring. How do you feel about searching for funding rather than aliens?
Fundraising is not my favourite thing, but
Aside from fundraising, what will you do when you step down from leading the hunt for ET?
My husband and I have a plane, we like to fly. We love to dance the samba. I’d like to find time to take a percussion course at the jazz school in Berkeley. But mostly I’m going to be working until SETI is funded for all the ages. n 30 June 2012 | NewScientist | 29