There are 100 billion stars in our galaxy alone. Perhaps it will never happen. Perhaps the unfathomable distances between worlds means that we will always think that we’re alone, at least in our corner of the cosmos. But it’s possible that, one day, a radio observatory pointed toward a constellation of diamantine specks glinting in that deep, dark ocean above will pick up something that will change everything.

Maybe it’s a radio signal, one not coming from the death of a star, or a distant planet’s aurora. It sounds technological. It’s not an accidental interception of one of Earth’s myriad broadcasts. And it has a purposeful structure to it. Astrophysicists cannot identify the meaning of the signal. But at that stage, the cryptic content doesn’t matter as much as the source: it came from a planet 40 light-years away, which meant that, 40 years ago, someone on a technologically advanced world decided to send Earth a message.

The search for extraterrestrial intelligence, or SETI, has succeeded. We are not alone; someone, whoever they are, is reaching out. What happens next? And how might we decide to respond to our enigmatic galactic neighbors?

The possibilities feel infinitely variable. It is a canvas upon which countless science fiction authors and screenwriters have applied their paint. But the question of what happens after this, and other, first contact scenarios, is being increasingly treated as a non-fiction event by diverse groups of experts across the world—including astrobiologists, astronomers, linguists, zoologists, artificial intelligence programmers, sociologists, psychologists, lawyers, and philosophers. Very little certainty is possible; after all, first contact with an alien intelligence has never happened before. But their work Is grounded in novel and ongoing research—and it’s already teaching us how to ask the right questions about a genuine encounter with an off-world intelligence.

These scientists and thinkers are preparing the world for first contact; they are sketching out the blueprints that may navigate us all through the most dramatic moment in our species’ history. “If you don’t have a plan for when you do discover something, you’re gonna be in a right mess,” says John Elliott, coordinator of the SETI Post-Detection Hub at the University of St. Andrews in Scotland. “This needs to be done.”

Intercepting a directed radio signal from a distant world, or moon, or star, isn’t the only version of first contact. A powerful space telescope might see a giant alien superstructure obscuring a star. We may find archaeological evidence of alien technology buried on a distant comet. A reconnaissance probe may zip through our solar system and send out a klaxon. Or aliens might park a spacecraft on someone’s lawn. But the radio signal scenario is intuitively thought to be the most likely because, to put it crudely, space is big, and direct radio waves travel across vast distances at the speed of light. It’s a decent way to communicate.

SETI involves looking for any signs of an alien intelligence, and a lot of that work involves scanning the universe for radio signals that aren’t coming from natural sources, like black holes or dying stars. The SETI Institute in California may be the most famous place partaking in this quest, but independent SETI groups all over the world with adequate funding and observatory time play major roles in the hunt for alien intelligence too.

It’s painstaking work. But if a radio signal is being transmitted toward Earth on a narrow range of frequencies, if it’s coming from a point moving across the sky, and if the signal’s structure shifts during the transmission – signifying the presence of encoded information – then the only explanation is that it’s coming from a piece of alien technology.

There is already a protocol that spells out what should happen immediately afterward. Adopted from a preexisting tome in 2010 by the SETI Permanent Study Group of the International Academy of Astronautics (IAA) – a United Nations-recognized body – the Declaration of Principles Concerning the Conduct of the Search for Extraterrestrial Intelligence is, on paper, quite clear about next steps.

Once a SETI signal has been verified, ideally by a consensus of many astronomers and astrophysical institutes, then this conclusion, and all its data, shall be shared “in a full and complete open manner to the public, the scientific community, and the Secretary General of the United Nations.” In addition, signatories should not respond to the signal without seeking guidance and consent of a body like the United Nations.

Transparency, patience, and a democratic approach to the world’s response, are all key tenets to the protocol—and SETI groups across the world have embraced it. But I’ve yet to talk to anyone who thinks the document is anything more than aspirational words. “That was so cute. That was such a nice idea,” says Kathryn Denning, an anthropologist and researcher of the social and ethical aspects of SETI and space exploration at York University in Canada. “It was never gonna work then; it’s never gonna work now.” 

Such a global effort to detect and then validate a signal would have been difficult to cover up prior to the age of social media. Today, “it’d be really hard to keep this a secret,” says Bill Diamond, the president and CEO of the SETI Institute. “We’d want people to know.” But it won’t happen in the orderly, UN-announced manner many would hope for. Instead, anything could happen. 

How do experts help the world prepare for – and mitigate – that chaos? This is the monumental query that an increasing number of think tanks around the world are tackling. The IAA has a SETI Permanent Committee. The venerable SETI Institute is now in the process of setting up a its own post-detection working group. 

The newest and most notable group is the SETI Post-Detection Hub at the University of St. Andrews. Although inaugurated only in late-2022, it already boasts 50 experts. “We’re meeting every month, as a general assembly,” says Elliott, the Hub’s coordinator. Their goal? To assess the impacts of discovering alien life – whether that be microbial, or a technologically advanced intelligence – on human society, and to set out procedures for a responsible reaction. The Hub wants to become “a trusted conduit to the rest of humanity” for when first contact occurs, Elliott explains.

Denning, who is a Hub member and part of the SETI Institute’s science advisory board, makes no bones about the difficulty of this endeavor. You just have to say, “okay: what kind of things would be in our control, what kind of things wouldn’t?” she says. “It’s extremely overwhelming” to research. But “with sustained effort, we can actually try.”

One thing that would be in their control would be explaining to the world what they think the alien message says. But how do you talk to an alien if you’ve never met one?

A radio transmission directed at Earth could come from a probe voyaging close to the fringes of our solar system, or it could come from thousands of light years away—or anything in-between. Depending on the distance, humanity’s reaction, and our ability to understand the content of the message, will varying considerably. 

For simplicity’s sake, let’s say the signal came from a star system 10 light-years away. That means that the message was sent to us 10 years ago, and any message we send would take 10 years to reach the source. In cosmic terms, that’s practically a conversation—and it gives humanity some time to attempt to decipher our first interstellar email. How do we begin?

Some zoologists think that the best way to practice this is by trying to converse with highly intelligent animals. And in recent years, Whale SETI has become a real, almost magical-sounding endeavor. 

says Fred Sharpe, a whale biologist at the Alaska Whale Foundation. Humpback whales are undeniably intelligent, they communicate over long distances, and they are inquisitive, often interacting with people. Does that make them good proxy for a back-and-forth with alien life?

A team of scientists from the SETI Institute, University of California Davis and the Alaska Whale Foundation, set up the Whale-SETI project, to find out. In 2021, they had an encounter with a female humpback named Twain that left them shaken. Using two hydrophones on the bough of a boat to monitor her responses, and an underwater speaker to talk to her, they began issuing several ‘whoop’ calls, the noises whales can make to essentially greet other whales.

“After the third one, Twain began vocalizing back,” says Lisa Walker, a whale song theorist and member of the Whale-SETI project. To make sure this wasn’t a fluke, they reduced the time between calls to see if Twain’s responses also came back quicker to match that new pattern. They did, meaning there was clear turn-taking: humans, then Twain, humans, then Twain.

“There was definitely engagement going on,” says Walker. “How do you quantify that engagement?” They are currently distilling the data down to try and answer the most basic queries: “Are we actually having a conversation?” By identifying non-human means of conveying complex information, if it’s there, the Whale-SETI team hope to essentially practice conversing, in a rudimentary way, with an alien intelligence.

Other zoologists aren’t sure if this approach will yield results. “I don’t think whale song is a language. I don’t think we’ve got any behavioral indication that it is. It’s all a little bit speculative,” says Arik Kershenbaum, a zoologist and animal communication expert at the University of Cambridge, and Hub member.

Another major issue is that both the aliens, and humans, will lack a lot of context when decoding each other’s radio messages. “What do you reference?” he says. Think about trying to explain the concept of a dog to a disembodied alien. Even if you show an isolated image of a dog, without any additional context, it could just be a meaningless shape an alien—just as much of what they may say will be meaningless to us.

Kershenbaum hopes that any directed message coming from aliens will come from scientists hoping to reach other scientists. In that case, he suspects they would make it easy for us to identify patterns in the signal—and maybe not by just including elementary mathematical patterns, like prime numbers, that all technological societies should recognize. Ideally, they’d send a video, and we could send one back, solving the context problem. You could show a dog in motion, interacting with its environment—and also include written words for dogs alongside it. This would be “like a Duolingo course for aliens,” he says. And using that, we can begin to have a conversation. 

But whether the message is comprehensible or mostly mysterious, it’s very likely that people will wish to respond. And that raises another tremendously challenging question. “Who gets to speak for planet Earth?” says Diamond.

Not everybody individual will get to send their own separate message to the aliens. But many agree that as much of the world’s human inhabitants as possible should be able to voice their opinion on how Earth should respond, if we choose to do so. 

Chelsea Haramia, a philosopher and ethicist at the Center for Science and Thought at the University of Bonn, Germany, and Hub member, is working on how to obtain global consent for actions in the post-detection world. How do we get informed consent on, say, a response to an alien signal, from people who aren’t yet alive? “That’s what I’m working on,” she says. 

Her aim is to do something philosophers don’t often do: fieldwork. She hopes to travel the world and talk to and survey people from a huge range of cultures. She is also planning to engage in active philosophy: to get groups to chat about first contact, and use their own reasoning and internal logic to reach their own conclusions. Perhaps that vast pool of data, once obtained, could be used to start projecting how future generations may react in a post-detection world. 

“Why not start now?” says Haramia. “If we wait until there is a real candidate detection, or some kind of contact or message, then I think things will move really, really quickly. And I think powerful people might start to manipulate information or narratives.”

Haramia is also interested in how artificial intelligence may bolster global preparedness. AI has its problems, including the inherent biases (racism, sexism) programmed into it by its human creators, and its capability to state mistruths confidently. But it could be used to quickly gather and process an immense amount of information related to perceptions about first contact – either by directly soliciting it, or indirectly, by sweeping up information from news outlets, social media, literature, art, scientific output, and so on. “What kinds of trends or values do we see in this data?” says Haramia. It’s not necessarily an ideal way to go about it, but it’s better than nothing.

In any first contact scenario, “people are not going to agree what to do.,” says Denning. So what do we do then?” Consent in a post-detection world matters. But public opinion is not always the ultimate arbiter of our world’s fate. “If the general population of Earth got to vote on absolutely everything, I’m actually not confident that all those votes would be well-informed,” she says. With that in mind, “what things should be more in the domain of experts? What things should be more in the domain of generalized democracy?”

The Hub is an example of an expert-driven group—but a first contact scenario may need more than just experts voicing their data-driven conclusions. Ian Crawford, a planetary scientist and astrobiologist at Birkbeck College, University of London, and Hub member, recently wrote about the need for a single political voice for a range of space-based dilemmas—issues that affect all of us, from the problem of space junk in near-Earth orbit or defending the planet from killer asteroids. Crawford reckons that, in the future, a federal world government would not only be tasked with handling these problems, but they would also handle key decisions about first contact.

In the present moment, such all-encompassing unity feels impossible. Even a federal body within the UN, one that can make enforceable decisions about human actions in space, seems deeply unlikely. “We have this distrust between nations that consider themselves to be sovereign,” says Crawford, putting the current state of geopolitical affairs mildly. 

says Andreas Anton, a sociologist at the Institute for Frontier Areas of Psychology and Mental Health in Germany, and Hub member. “It is conceivable that a scientific committee of experts from various disciplines could be set up to draw up concrete recommendations for action, which could then be discussed at United Nations level,” says Anton. But if nothing is legally enforceable at the international level, then when it comes to the question of who speaks for Earth, the answer would be everyone—but in a cacophonous, not harmonious, manner. Any technologically capable nations, research groups, companies or even individuals could, should they fancy it, message back.

Some already are. Take METI International, an organization that, among other things, sends directed transmissions into space, hoping to ping an alien society. (METI stands for Messaging Extraterrestrial Intelligence.) “We advocate sending intentional messages, and not just listening,” says Douglas Vakoch, the president of METI International, and an elected member of the International Institute for Space Law. 

In the past, the group has used radio observatories to beam out messages – those trying to explain the concept of music, for example – to various exoplanets. Future messages may involve pulsing messages so that the rhythm matches up with the yearly orbits of the planets—a way of communicating what a year is without using words. Another idea is to transmit various elements of the periodic table to convey Earth’s environmental crisis.

Several SETI researchers are deeply wary of METI. “I don’t want to overdo the risk. But there is a risk, because we don’t know what the aliens, if they’re there, what their response will be,” says Crawford. “There is a risk that it…wouldn’t be in our interests.” Why take a chance and illuminate our planet when there is a possibility that an alien society might want to overtake or exterminate it?

Although some fret about this risk, a more common issue researchers have with METI is that they see their actions as undemocratic: those engaging in it aren’t seeking permission from the rest of the world. But proponents of METI opine that they are doing what will happen in a post-detection world anyway, so they might as well be proactive about it.

“What if they’re waiting for us?” Vakoch says. An alien society might aspire to see who’s out there first before sending out a message. “We’re trying to show we have some skin in the game.”

METI participants aim to be as sensible as possible. “I don’t think we should be sending messages that threaten other civilizations,” says Vakoch. “I don’t think we should send a message that claims to be a message from the people of planet Earth.” But why not message now, he says—and why not be honest about the planet, its triumphs and troubles, and the fact that we are a multitude of societies and individuals with divergent opinions on, well, almost everything?

“I think it’s great that there’s going to be a cacophony of voices speaking for Earth,” says Vakoch. “That’s the best representation of humankind.” 

Although aspects of the signal’s interception, translation and response can be managed in various ways, it’s difficult to see how the broader social upheaval will be anything other than uncontrollable. 

A recent study, of which Elliott and Anton are co-authors, attempted to game out several different first contact scenarios. A radio transmission from thousands of light-years away would be a shock, but generations later could become a somewhat normal part of human history. The aliens that sent it would be so far away in time and space that they might have moved on or died out by the time their initial message reached us. This scenario is almost akin to archaeology. But a signal emanating from just a few light-years away – i.e., from somewhere very close to home – would trigger unpredictable, and unprecedented, pandemonium. “The nearer the discovery is, the less time there is to deal with anything,” says Elliott.

“Our scenario analyses show that such an event could have catastrophic consequences for humanity,” says Anton. “Even if the aliens have no evil intentions, first contact could cause a massive cultural shock with far-reaching consequences.” Political paranoia is a major concern.

But that doesn’t mean the situation is hopeless. Research by post-detection experts suggests there are practical things they can begin to do now to change the way people think about first contact—to make it something less fearful and less likely to devolve into internecine strife. 

One promising avenue is to start getting people to think about space as an environment we affect. Start asking people: “What do we want to do about Mars?” says Denning. The future of the Red Planet may rest in the hands of private corporations. Do we want that asymmetric power dynamic to still be prevalent in the future? By getting societies to think like this in public forums, experts can hope to alter the way societies contemplate space—which, in time, will make them more receptive to considering first contact to be something less abstract.

Post-detection researchers are also aiming to remove unhelpful biases about how first contact may play out. A lot of popular culture on the subject involves the subjugation or decimation of humanity—and much of this stems from an overreliance on historical analogies, like those involving the Old World colonizing and slaughtering New World societies. The late Stephen Hawking once said: “If aliens visit us, the outcome would be much as when Columbus landed in America, which didn't turn out well for the Native Americans.”

Steve Dick, a former NASA Chief Historian and Hub member, is also a prolific author. One book assesses the utility of using moments in human history to inform us about how first contact with alien life may unfold. And he thinks we are focusing on the wrong historical analogies. “There are a lot of culture contacts that aren’t catastrophic,” he says. The Age of Enlightenment, for example, didn’t come out of nowhere in Europe; mathematics and astronomy arose long before in (among others) the ancient Greek, Indian and Babylonian realms. Many cultural first contacts involved the exchange of ideas and materials, not societal destruction.

Denning suspects that historical analogies are essentially useless, in part because many misunderstand those historical flashpoints. The oft-cited Columbus/Native American analogy – which implies that the technological prowess of the aliens (Columbus) means they will inevitably squash us (the Native Americans) like bugs – irks her. “That is fucking not true,” she says. The oppression and tribulations of the Native Americans “is a story of epidemic disease, and it’s not a story of technological superiority as much as it is of brutality.” 

In other words, a technological disequilibrium between species doesn’t inexorably lead to violence. It is a major feature of plenty of first contact science fiction stories, though—and that’s a problem. “The assumption that someone’s going to try to conquer or take advantage of the other as a default assumption…I think that’s so baked in, it’s hard to unthink it,” says William Lempert, an anthropologist at Bowdoin College in Maine, and Hub member. “We understate how much of a projection of our own history that is.” 

One way to combat this? Tell more diverse science fiction tales. Lempert got connected to the SETI side of his academic research when he volunteered at some Native North American film festivals, and discovered that Native movies were extremely different to what many would expect from the genre. 

One movie, The Visit, involves a Cree man communicating with a flying saucer on a Canadian First Nation’s reserve via a hand drum. Why not? Sometimes curiosity is all that drives two different species to interact. Just watch humpback whales, or octopuses, interact with humans. They do it just because they are curious. Why should aliens be any different?

Stories like The Visit also matter because they also challenge a common assumption that alien intelligences would target Western-centric ideals of power centers. Why should we assume extraterrestrials would be most interested in messaging, say, the American President, or any of the leaders of the world’s most economically or technologically advanced nations? 

If we want the world to be better prepared on a psychological level for a genuine first contact scenario, Lempert reckons that one of the best things to do is offer a wider range of pop culture possibilities for people to consume. “Space is a mirror,” he says. No matter how first contact unfolds, it will be, in part, a reflection of humanity’s own values and mindset at the time.

It's vital to emphasize that post-detection research is in its infancy. At this stage, the only thing that’s certain is that, if a first contact event happens, nothing will ever be the same again. The new normal will be pervasively strange. And, frustratingly, no matter how we respond, we may never know the intentions of our distant messengers. We may never be able to reply in a comprehensible manner. 

But for some, just knowing someone else is out there, waving hello, is sufficiently exhilarating. In a galaxy riddled with planets, one alien intelligence implies that life, from the complex kind to the simplest, is all over the place. It isn’t a fluke, or a glitch, but a feature of the universe. “The most remarkable thing we may discover about life is that it’s not remarkable at all. It happens everywhere,” says Diamond. 

And with that revelation upon us all, perhaps we won’t fall fatally back on our most base, primeval, fearful, self-destructive instinct. Instead, says Diamond, “maybe we’d start thinking beyond ourselves.” He pauses for a moment. “I don’t know.” Then a smile. “One would hope so.”