Since time immemorial, humans have looked to the heavens above to make sense of life below, right here on Earth. What else is out there among all the countless galaxies, stars and planets? Are we truly alone in the universe? Such questions are crucial for establishing humanity’s cosmic context and have inspired a variety of speculative answers from a wide range of philosophical and scientific traditions. Buddhists believe in different Buddhas living in different worlds. The Greek anatomist also believed in the plurality of worlds. And as early as the 19th century, Western scientists postulated ways to detect and communicate with putative Martians on the Red Planet. In each case, preexisting cultural biases served to profoundly shape prevailing ideas about the nature of life beyond Earth.

Today, under the auspices of the search for extraterrestrial intelligence (SETI), astronomers seek out space aliens by using some of the world’s most powerful telescopes to look for clearly artificial electromagnetic transmissions emanating from interstellar or even intergalactic sources. So far, no convincing evidence of otherworldly messages has been found. Perhaps that’s simply because there isn’t anyone else out there to talk to. But increasingly, SETI scientists are grappling with the disquieting notion that, much like their intellectual forebears, their search may somehow be undermined by biases they only dimly perceive—biases that could, for instance, be related to the misunderstanding and mistreatment of Indigenous peoples and other marginalized groups that occurred during the development of modern astronomy and many other scientific fields.

For years, science historian Rebecca Charbonneau has been exploring this possibility in the context of SETI. She earned her Ph.D. at the University of Cambridge studying the history of radio astronomy, and is currently a historian in residence at the Harvard-Smithsonian Center for Astrophysics, as well as a Jansky Fellow at the National Radio Astronomy Observatory. Her most recent paper, “Imaginative Cosmos: The Impact of Colonial Heritage in Radio Astronomy and the Search for Extraterrestrial Intelligence,” appeared last year in a special SETI-themed issue of the American Indian Culture and Research Journal. To weed out biases and enhance the quest to find life somewhere among the stars, she argues, SETI’s practitioners must find a way to “decolonize” their field. But what exactly does that mean?

Scientific American spoke to Charbonneau about decolonization, SETI’s feedback loop with its own context and history, and how combating cultural biases in the search for alien life can be a case study for similar reforms in other STEM fields.

“Decolonization” seems to be a problematic term, in part because it carries so much historical baggage and is used in many different ways across many different fields. Finding consensus about what it actually means is challenging, to say the least. So, to start out, what does decolonization mean to you?

It’s something I think about a lot because it is a very difficult problem. Some of the major problems with the term decolonization is that it has been watered down to mean any kind of conversation about colonialism. That really weakens the term. There was a paper written by these two great scholars, Eve Tuck and K. Wayne Yang, called “Decolonization Is Not a Metaphor,” where they make the argument that when we’re talking about decolonizing, it shouldn’t be about just speaking in metaphors. This is actually a real-world process that has to happen—actual, physical colonization which needs to be undone.

How does this apply to SETI?

Oftentimes when we think about colonialism in SETI, we do think of it primarily in metaphors, right? Space being “the final frontier,” first contact with aliens as a stand-in for encounters with Indigenous peoples—that sort of thing. But it actually is much more than a metaphor. Because space exploration is also an extension of our imperial and colonial histories. We know that space infrastructure, including SETI infrastructure, exists in remote locations, with places that often have colonial histories or vulnerable populations, particularly Indigenous peoples. And then space, despite our best efforts, is highly militarized. Nations talk about becoming space superpowers, building new empires and colonizing other planets. So it’s not just a metaphor. It’s actually happening in the world and off the world, and that’s why I think it’s a useful term when we’re talking about SETI. And SETI in particular carries a lot of intellectual, colonial baggage as well, especially in its use of abstract concepts like “civilization” and “intelligence,” concepts that have been used to enact real, physical harm on Earth.

If decolonization isn’t just a metaphor but rather a process, that implies it’s about reckoning with history and striving to fix past mistakes. That’s something easy to say but much harder to actually define, let alone to do. In the context of SETI, what might decolonization’s “reckoning” look like?

It’s a great question. Ultimately, in Tuck and Yang’s interpretation of decolonization, this would look like prioritizing the sovereignty of Indigenous cultures and respecting their wishes regarding settled scientific infrastructure. And while that is critically important, we shouldn’t entirely discount the symbolic, dare I say metaphorical, nature of colonialism at play in SETI. Fundamentally, SETI concerns listening to alien civilizations, ideally, but we also have to get better at listening to Earthlings! We’re not very good at that right now, but we’re starting to move in that direction. There are members of the SETI community, myself included, who are very interested in listening to marginalized and historically excluded perspectives.

A lot of SETI scientists start their research from the technical search perspective, without deeply considering the implications and impact of their listening. They are simply interested in finding evidence of intelligent extraterrestrial civilizations, which is valuable. I think that to do that, however, without thinking critically about how we conceptualize big abstract ideas, such as “intelligence” and “civilization,” and without considering the ethics of the search and its cultural implications, would be a huge mistake. These ideas are tightly bound with the histories of racism, genocide and imperialism, and to use them haphazardly can be harmful. How we use these symbols of the past when thinking about alien civilizations also says a lot about how we view Earth’s civilizations, and this is where Indigenous Studies scholars, such as those who contributed to the special SETI issue of the American Indian Culture and Research Journal, can make great contributions. They have a unique perspective on the impact of contact, and how concepts like “intelligence” can be weaponized.

It does feel ironic. SETI is built around listening for something out there but perhaps at the cost of ignoring much of what is right here on this planet. For instance, you’ve repeatedly mentioned the cultural implications of terms such as “intelligence” and “civilization,” but how about the word “alien,” too? All of these terms have very different connotations—even destructive ones—as historically applied to Indigenous peoples or, for that matter, as applied to all the other sentient beings that live on Earth. Even now some people don’t consider nonhuman animals to be sentient, let alone possessing any real intelligence. And throughout history, building empires has come at the cost of discounting and dehumanizing Indigenous peoples as lesser beings, incapable of sophisticated thought and societal organization. Yet “intelligence” is right there in SETI’s name. Should we reconsider that framing?

SETI is designed to listen outward, but as you said, it’s not always so great at listening inward. And I should preface this by saying that there are members of the SETI community who are very interested in doing this work. And oftentimes these missteps are not made consciously—we’re all operating within our own cultural frameworks. And so, of course, when we are thinking about the “other,” the imagined alien, we’re going to project our own understanding of what that looks like onto this blank slate. In fact, some people even call SETI a mirror. Jill Tarter, an eminent SETI scientist, famously referred to SETI as holding up a cosmic mirror, where we’re looking for the “other,” but in the process of doing that, we are really learning about ourselves.

As for “intelligence,” that’s certainly a dangerous word, and it has been used in very harmful ways. Eugenics, for example, used the limited concept of “intelligence” to justify genocide. I’m therefore sometimes troubled by the word intelligence in SETI. For one thing, we might not even be able to identify what intelligence is. And because of this, maybe we [will] someday make contact and [won’t] even recognize that we’ve done so. But it’s also important to think very critically about why we search for intelligence. Is there something special about intelligence? Does intelligence deserve more respect than whatever we might perceive to be nonintelligence? We might perceive microbes as nonintelligent life, for example. Does that life have a right to exist without us bothering it? Or is it just germs—just bugs that we are going to just bring back and study and pick apart?

We may not be able to recognize intelligence when we see it, and we may not respect or honor things we don’t perceive to be intelligent. That is what we did in many colonial interactions. Certain countries in Europe made “first contact” with Indigenous peoples, perceived them to be nonintelligent and therefore not worthy of life, not worthy of respect or dignity. And that is troubling to me. What’s going to be different next time?

Agreed. But what would be a solution, then? Just using different terminology seems insufficient.

Right. I’ve talked to a lot of scientists about examining the colonial legacy at play in SETI, and I’m sometimes met with resistance. I’m told, “You can’t just cut words out of the dictionary” or “Obviously microbes on Mars are not the same as Indigenous people, and you can’t offend a germ.” All of which is, of course, probably true. But I think we would be foolish to not think carefully when we project our troubled concepts of intelligence and civilization onto the universe. It’s not necessarily as ephemeral as you might think. SETI scientist Jason Wright once wrote, “Even more than thinking like an alien, we need to be sure we are able to identify what it means to think like a human.” Decolonization may not be a metaphor, but metaphors and symbolism are big parts of human thinking.

People in general get frustrated when they hear statements such as “concepts of civilization and intelligence are socially constructed.” It seems confusing and puzzling. It makes it seem like things aren’t real. But actually it’s the inverse. Words and socially constructed things are real because we are a verbal, social species. Things that are socially created still have a real-world impact; they’re not imaginary. So when it comes to “decolonizing SETI,” the metaphors do matter too. Maybe not to aliens, but to people on Earth. Being mindful of the histories and language we’re invoking is the bare minimum of what we can do. And this is why including Indigenous voices is so critical. As Indigenous Studies scholar Sonya Atalay told the SETI project Breakthrough Listen, “Intent ≠ impact, we must consider both.” It is not enough to just want to contact aliens and hope interaction will be friendly; we must critically examine our own history and words and stop assuming our good intentions will not result in harm. Columbus metaphors might not hurt an alien, but using them will hurt people on Earth.

Let me push back on one aspect here, though. Might there be a degree of incompatibility between openness to other ways of being and SETI’s core tenets? After all, SETI—all of astronomy, really—is built on the assumption of universality, that the laws of physics are the same throughout the observable universe regardless of one’s social constructs. A radio telescope, for instance, will work the same way whether it’s here on Earth or somewhere on the other side of the cosmos. Regardless of context, certain shared fundamentals exist to allow common, predictable, understandable outcomes. SETI takes this conceit even further by elevating mathematics as a universal language that can be understood and translated anywhere and by anyone. What are your thoughts on this?

So let me preface this by saying I am not a mathematician. But I do write about math. And there are many anthropologists who study mathematical systems in different cultures. They see that, even on Earth, among human cultures, there are different ways of thinking about math. And while mathematics is the language we use on Earth in our hegemonic culture to describe what we are seeing, we don’t know that another species will use that same language to describe what they are seeing. So while I don’t want to discount universality, I do think any assumptions about this are perhaps optimistic, to put it kindly. The core of what I’m trying to say is that we must critically interrogate our assumptions about life and universality, because we will all too often find that they say more about us than aliens.

Appreciating that some things can be too complex for universality to capture seems like a wise way to approach any human endeavor. You’re saying there’s never just one solution or one model that will be optimal for any given situation—multiplicity and plurality is as valid of a concept as universality, right? That seems to echo what you said earlier about listening.

Yes, I think one of the best arguments for making SETI more diverse and for including diverse sets of thinkers is that the worst-case outcome from incorporating those other perspectives would just be the expansion of our pool of what civilizations might look like. There’s really no downside. Not only are we being inclusive and trying to distance ourselves from historically oppressive behaviors—which I think is worth doing on its own—but we also may benefit SETI and other sciences because we can’t be hurt by expanding our ideas of what a civilization or culture might look like. It just makes sense—if you want to listen to, and understand, alien cultures, you might as well start with your own species and planet first.