Asteroids, supervolcanoes, nuclear war, climate change, engineered viruses, artificial intelligence, and even aliens — the end may be closer than you think. For the next two weeks, OneZero will be featuring essays drawn from editor Bryan Walsh’s forthcoming book End Times: A Brief Guide to the End of the World, which hits shelves on August 27 and is available for pre-order now, as well as pieces by other experts in the burgeoning field of existential risk. But we’re not helpless. It’s up to us to postpone the apocalypse.
SETI — the Search for Extraterrestrial Intelligence — is passive by nature, a human ear cocked towards space. The hope is that there are extraterrestrial intelligences out there trying to message us, and we just need to be ready with our radio telescopes to hear, ready for that moment of contact.
But listening isn’t just a search method — it’s a philosophy. Early SETI advocates like the astronomer and author Carl Sagan took it for granted that any alien civilization we might come into contact with would be more advanced than us, likely far more advanced, technologically and even ethically. (The universe, after all, had been around for nearly 14 billion years before human beings showed up, which means plenty of time for older life forms to arise.) Given our assumed place as a young species in the cosmic hierarchy — and given all that we might hope to learn from our alien betters — a core SETI belief is that we should listen before we speak. Shouting into the cosmos, Sagan said, was “deeply unwise and immature,” the act of a toddler calling attention to themselves.
Proponents of what is known as Active SETI, however, believe it’s a mistake to assume that any technologically mature alien civilization will automatically take the first step to establish contact with us. If we’re not making an effort to signal them, after all, maybe they won’t signal first. It’s possible that extraterrestrials are no longer using radio, and that sifting through radio waves while searching for alien life is like trying to find evidence of other people in 2018 by looking for smoke signals. Perhaps they assume our silence is a sign that we just don’t want to talk, which means it would be up to us to start the conversation.
Shouting into the cosmos, Sagan said, was “deeply unwise and immature,” the act of a toddler calling attention to themselves.
Despite the beliefs of people like Sagan, however, SETI has often included the occasional effort to send a message into space. The first known attempt was undertaken by Soviet scientists in 1962. Using Morse code, they transmitted the words “MIR,” “LENIN,” and “SSSR” to Venus, on the assumption that any advanced life-form would obviously be communist and would get their references. Laugh now, but that’s really no different than Carl Sagan assuming alien civilizations would have the same values as Carl Sagan.
The Soviet attempt was interplanetary, but the SETI pioneer Frank Drake — he of the eponymous Drake Equation, which tries to calculate how many alien civilizations might exist — was responsible for sending the first deliberate interstellar message, on November 16, 1974. To commemorate the rechristening of the Arecibo Observatory in Puerto Rico, then the largest radio telescope in the world, Drake blasted 168 seconds of two-tone sound toward the star system M13. It was noise to the listeners in Puerto Rico, but any aliens who happened to receive it might have noticed a clear, repetitive structure indicating its origin was non-natural. Also encoded in the message were the numbers one to 10, the atomic numbers of several basic elements on Earth, and a graphic of the solar system indicating the planetary origin of the transmission.
Given that M13 is 25,000 light-years away from Earth, it’s going to take thousands upon thousands of years before Drake’s message ever reaches its destination, and at least another 25,000 years before a reply would ever reach us. Yet just days after the message was transmitted, Martin Ryle, then Britain’s Astronomer Royal, sent an angry letter to Drake. It was “very hazardous to reveal our existence and location to the Galaxy,” Ryle wrote. “For all we know, any creatures out there might be malevolent — or hungry.”
To this day, mainstream SETI has eschewed active messaging in part out of the concern, however remote, that something malevolent or hungry might be on the receiving end, and that they might come for us. The editorial board of the journal Nature has cautioned that “the risk posed by active SETI is real,” and in 2006, when the International Academy of Astronautics convened a committee on SETI but refused to push for a ban on active messaging, two prominent members resigned. Before his death, the cosmologist Stephen Hawking was on record saying he didn’t think it was a very good idea to invite extraterrestrials to come calling. “I imagine they might exist in massive ships… having used up all the resources from their home planet,” he said. “Such advanced aliens would perhaps become nomads, looking to conquer and colonize whatever planets they can reach.”
It was “very hazardous to reveal our existence and location to the Galaxy,” Ryle wrote. “For all we know, any creatures out there might be malevolent — or hungry.”
But those fears haven’t stopped a breakaway group of space scientists from launching the new group Messaging Extraterrestrial Intelligence (METI), led by the former SETI staffer Douglas Vakoch. The Israeli-Russian billionaire Yuri Milner’s Breakthrough Initiatives — a new attempt to jumpstart the search for intelligent life — has a Breakthrough Message component, with a crowdsourced competition to devise a letter to the stars. The interest in active messaging is in part a product of the exoplanet revolution, which has seen astronomers discover scores of potentially habitable planets outside our solar system. With so many potentially life-supporting planets out there, the thinking goes, why not target them and begin beaming out messages of greetings?
If Drake’s Arecibo message was like shouting at random in the middle of a forest, METI can direct signals to where there’s a chance of life, including some planets that are as few as 100 light-years away. Given the vastness of space, METI advocates believe, anything that increases the chances that we might make contact is worth trying. And they argue that the risk of active messaging is overstated. After all, humans have been leaking radio and TV signals into space for decades that could be picked up by sufficiently advanced extraterrestrial intelligence, so it’s not as if we’ve been keeping quiet.
The deeper debate about METI isn’t necessarily the act of messaging, but the content. If there really are ETs out there silently listening, the signal from METI or one of the other active messaging groups may be the first thing they ever hear from Earthlings. That’s an enormous responsibility. Why should any single group get to decide how Earth says hello — or whether it says anything at all?
“What’s just so interesting is the assumption of the right to do this,” Kathryn Denning, an anthropologist at York University in Canada who studies the strange tribe of alien hunters, told me. “To make these choices on behalf of all humanity. And a refusal to look carefully at the potential consequences. The idea is that all innovation is good, and let history sort it out.”
Why should any single group get to decide how Earth says hello — or whether it says anything at all?
There’s something of the move-fast-and-break-stuff ethos of Silicon Valley in the METI movement, a willingness to disregard risk if risk gets in the way of potential reward. That might be acceptable if the reward is a new search engine or social network. It is considerably less acceptable when innovation brings with it the possibility, however remote, of a world-ending threat. This is the debate over anthropogenic existential risk, played over again. If an act carries even a minuscule risk of human extinction, shouldn’t we err on the side of safety, given the ultimate stakes at play? And if that’s the case, shouldn’t we pause before sending an unknown alien civilization of unknown technological capability and unknown intentions Google Maps directions to our home planet?
Olle Häggström, a mathematician at Chalmers University of Technology in Sweden and the author of the existential risk book Here Be Dragons, thinks so. “There are optimists who say that good things can come out of establishing communications,” Häggström told me. “We could learn wonderful things from them. But an extraterrestrial civilization of very advanced technology might be a threat — and they might want to get rid of us before we become a threat to them. There are real evolutionary-style arguments pointing in that direction. Maybe we’d be better off observing exoplanets for 10 or 20 years until we’re in a better position to assess the risk of communication. The risk is too great.”