It remains the perennial question of our ages, are we alone? Since time immemorial, this is a mystery that has kept us up at night gazing at the stars stoking the very heart of our very exploratory desires. What if there was another civilisation exactly like us out there, waiting for some type of signal?

It is only in the last century that we have had the modern tools able to make this search a practical reality. Allowing us to explore the far reaches of space that we never thought possible. One of those people responsible for this modern day search is Jill Tarter, the now retired former director of the Center for SETI Research of SETI, or better known as a real-life alien-hunting astronomer. She spent her career obsessed by tracing the faint signs of extraterrestrial life, her passion never going unnoticed, in 1997 she was portrayed on the big screen by a younger Jodie Foster in the universally praised film Contact. Now retired, Tarter looks back on a life fueled by near misses, human endeavour and figuring out what contact would really look like.

“I have no idea what that intelligence would be like and how contact would happen.” What would you say to people that think there has to be something bigger out there that maybe science alone can’t help us find? I would say that’s not a position I’m comfortable with. Science has been extraordinarily successful in explaining the world that we occupy and there are many things that science cannot explain yet, may never explain because it has to do with emotive interactions among humans and other species, but there is an enormous amount that science can explain. I find the scientific story far more comfortable than the cultural creation myths that have been so prevalent throughout our history, and for me, that’s enough. The awesomeness of the universe is plenty.

"We must figure out a way to stick around as a species long enough to be able to have a future in which we can get smarter." Jill Tarter on our own scientific hubris

I guess what I am referring to, rather than the cultural myths, is the fact that this extraterrestrial civilisation that may be out there and we have not communicated with yet, might not communicate through the means of science. So if not, how would we ever know that and how would we communicate, if they even communicate? But then you are postulating in a domain that has no evidence, at least among human species. Why that should be something that can propagate across vast interstellar distances is not something that I entertain lightly, and we have seen no evidence of any of that. Now, I will definitely agree with you that we may be looking in exactly the wrong way because we haven’t invented or understood yet some piece of physics or some technologies. The best way to communicate over interstellar distances may turn out to be zeta rays, and I haven’t a clue what zeta rays are – we haven’t discovered them yet. You have to understand that I am nothing if not pragmatic. It seems to me that our best strategy is to use the tools and understanding that we have at the moment, and to search every way that we can, but reserve the right to get smarter in the future. In addition, we must figure out a way to stick around as a species long enough to be able to have a future in which we can get smarter. The search for extraterrestrial communication seems like an incredibly intriguing area. You often talk about how traditionally we used to turn to priests and philosophers for such questions, so would you say that philosophy can still play a role in this search? I think that philosophy still has a place within our culture and civilisation, but it might not be best applied to trying to understand the physical reality of the cosmos. I think that observations and technology are key to understanding what is actually out there. I’ve spent my whole career trying to persuade people that, with respect to the physical reality of our universe, we should be changing the verb ‘to believe’ into the verb ‘to explore’. So that is why I talk about no longer having to ask the priest and the philosophers what we should believe about this question of the evolution of our universe; we can actually do some experiments and observations to find the answer. I think it is spectacular that a human brain can, in fact, puzzle out – with the help of a lot of tools – the story of 13.8 billion years of cosmic evolution. It’s quite astonishing. Why do you think we’re obsessed with this question, are we alone? I think your answer is already contained in what you just said. Long before there was the Internet there were people who walked out of caves and looked up at the sky wondering what was beyond the next valley and how we fit into it all? We are constantly trying to calibrate ourselves against something and it’s just a fundamental part of our philosophy or DNA, I don’t know what you call it – humans are curious, and amongst other things, we are most curious about ourselves. Do you feel like science fiction movies play a pivotal role in elevating public discussion around the topic of life in space? Yes, some of them certainly do. I am enamoured of Arrival. I really like the idea that if you write in circles you have to know the beginning, middle, and future. Science fiction has been a fantastic aid to humanity in terms of trying to think about something different. By painting us a picture of the ‘something different’ it helps us to see ourselves as all the same. It makes us all step back and have this larger point of view that trivialises the differences among humans that we shed blood over.

SETH SHOSTAK/SETI INSTITUTE Should we encounter an extraterrestrial civilisation, Jared Diamond makes the statement that “the most dangerous people are the naïve astronomers who want to send messages into outer space to come wipe us out, like a request for decimation”. What do you think of that? There is a controversy at the moment in the community over whether we should be transmitting, or passively listening, or both. I’ve tried, through the AAAS and other venues, to start a conversation around this existential question about whether we should transmit as well as listen, and it’s discouraging to me that within the SETI community people just shout their same message louder at each other, without a lot of changing of opinions. What I have been trying to implement in some fashion, is that the conversation takes place among people other than first world white males, that we find a way to get voices from other traditions and cultures into this discussion. It really is a global discussion, and one thing that I think is useful to bring to the table, and something that people very often don’t think about, is time. Rather than a 2 or 5-year plan, this has to be a 10,000-year project, because our galaxy is 10 billion years old and vast. So if you transmit a message for a short period of time – a day, month or year – that signal is going to wash past a potential recipient and be missed if they are not looking at us at exactly the right time and in exactly the right way. The rallying cry is that if everybody is listening and nobody is transmitting it’s not going to work, so we have to hold up our end of the bargain into the foreseeable future. I don’t think we are sophisticated, wise, and old enough yet to do this. I think the transmission is in our future when we ourselves have become an old and stable civilisation. That means when we have solved the problems of our planet like climate and food and water strategy, managing the planet systematically for a long future. When we get there, then we can plan a 10,000-year project. Technology is accelerating at phenomenal speed and a lot of experts that we talk to believe that we will be able to create a unique intelligence in the near future. What do you think about this idea that a unique intelligence could look at life in space from a different perspective? I’ve talked to and read a lot of people on this subject and I think that the neurophilosopher Patricia Churchland is probably one of the most sceptical about creating a generalised artificial intelligence that deals with emotive qualities and intuition. She’s not clear that we are ever going to get there; but does that mean that we can’t build something that learns and gathers information in completely new ways and therefore can think up methodologies of discovering other intelligence beyond Earth? It’s fascinating. We have seen this whole promise of AI not delivering for a long time and now we are seeing some spectacular successes with deep learning and neural networks that can be nested deeply enough to have complex behaviour emerge. So yes it is tantalising, and I don’t know who is right. I’m a big fan of IA or intelligence augmentation, as well as AI – developing tools that can help us do what humans already do but do it better.

"The best way to communicate over interstellar distances may turn out to be zeta rays."

In Voyager 1 in 1977, there were some messages sent out of artefacts from Earth of some kind, and you said that we lied through our teeth with those messages, leaving out all of the bad parts of life on Earth like war and bloodshed and that a correct portrait of humanity should be sent out. Yes, that’s correct. It’s not because I want the extraterrestrials to know what they’re in for should they decide to interact with us, it’s because the process of creating that message is a process for ourselves, and we need to see ourselves as we are today if we are going to change it in the future. There is a project going on right now called One Earth Message, led by Jon Lomberg in Hawaii, who was the artist that helped with the Golden Record for the Voyagers. His idea is that the message 2.0, whatever it is, should be crowd sourced so everyone on the planet should have an opportunity to submit things that they think are important to communicate. It will get people to start thinking about who they are, and what they are, and understand that we are not perfect, but we can get there.

“Message 2.0, whatever it is, should be crowd sourced so everyone on the planet should have an opportunity to submit things that they think are important to communicate.” [Voyager 1 pictured above] Did you ever have a point in your career where you had a false alarm or felt that you had come close to having contact? Yes, there have been a couple of them. The most spectacular of them was in 1997. We at the SETI Institute have spent a lot of effort in developing the tools that allow us to do our signal detection and analysis in real time, or near it, so that we can immediately follow up on any signals that we detect. This helps to discriminate between a potential extraterrestrial signal and a terrestrial technology. One of the ways that we did this during a 10-year project that we called Project Phoenix, was to use 2 telescopes on the planet, separated by hundreds or thousands of miles. In 1997 we used a 140-foot telescope at the National Radio Astronomy Observatory in Green Bank, West Virginia, and a telescope in Woodbury Georgia. On this occasion, lightning struck the telescope in Georgia and a surge of energy through the lines fried the disk drive, so we had a couple of days with only one telescope. And of course, that was when we found a signal. The signal was clearly artificial in the sense that you consider a pattern in frequency and time. This signal showed up as a picket fence, with lots of power at different frequencies with a constant spacing between them and it persisted in time. This isn’t something that nature can do so it was clearly engineered. What was it? Well, it took us the better part of 24 hours to understand that it was the SOHO spacecraft in orbit around the Sun. It was orbiting the Sun and it ended up at essentially right angles to the direction of a star that we had been tracking. This is what we call a side lobe because it is like having peripheral vision – it’s not as good as direct vision but you do have some kind of sensitivity there. When we looked at our target, the signal got into our telescope, when we tipped our telescope away from the target the side lobe also tipped and the spacecraft fell out of the side lobe so the signal went away. Then we’d move the target back and the signal was there. We were going crazy like this for hours because there was nothing we could do to discriminate without our second telescope. We were so incredibly excited, the adrenaline was unbelievable.

Image credit: Warner Brothers I can imagine. The way you describe it makes me think of some of the scenes in Contact. Well, that’s not a coincidence. We went through all of that, and when Ellie leans over and kisses the computer screen and says “Thank you Elmer”, she’s referring to the FUDD, which is the Follow-Up Detection Device on our second telescope. So yes, that scene should feel familiar because that’s the kind of thing we did go through. What do you think contact would look like? We are looking for some technology that modifies its environment in ways that we can sense over interstellar distances. To be able to do that I think the technologists have to have some way of abstractly representing their reality, so something like math. But would we recognise and understand their math, even if it is describing something that we are familiar with mathematically? I used to think of course. Now having listened to a number of neuroscientists and people who study how we actually think, it may be that our particular form of mathematics is informed by the geometry and topology of our brains. Therefore, it’s possible that someone else has an abstract mathematical framework that is quite different from ours. That has been one of my late recognitions. So in answer to your question, I have no idea what that intelligence would be like and how contact would happen. Do you ever talk with people at NASA and so on about a contingency plan? I imagine making contact would cause huge disruption? When we were a NASA project we had to have a post-detection protocol. Some of the things it talked about were which Associative Administrator of the Agency was going to inform the Administration and who was going to inform the Congressional committees that fund NASA. It also had to talk about steps to make the discovery information available and to hold a public press conference to release the results. Today as a private enterprise we don’t say who is going to call the President, that’s not in there, but we do actually go through the whole process of how to announce it to the public. We would distribute the discovery information to all the observatories around the world so that when a public announcement is made, or the whole thing just gets leaked out, there will be experts regionally around the globe who can interpret for their local media what has actually happened. In terms of disruption, there is so much global communication that I think it reduces the potential for panic. I mean, gosh, the Kardashians will be doing something stupid the next day right? That will grab the headlines.

"We don’t say who is going to call the President, that’s not in there, but we do actually go through the whole process of how to announce it to the public." On making contact