It's called xenolinguistics: Looking at the science of extraterrestrial language.
Biologists, anthropologists, linguists and other experts specializing in language and communication have begun to explore what non-human, off-Earth language might look like.
Arguably, such thinking sparks thought about the fabricated Klingon language, the cosmic "Klingonese" chatter spoken by one the alien species on "Star Trek." There's even a thriving Klingon Language Institute, which was founded in 1992.
But you can put sci-fi aside, for scientists in the real world are investigating the possible forms that alien languages might take — and whether we might be able to understand them.
Related: The search for alien life
Off-Earth intelligence
Astrobiologist Douglas Vakoch is president of Messaging Extraterrestrial Intelligence (METI International) in San Francisco. He's co-editor with Jeffrey Punske of a new volume, "Xenolinguistics: Towards a Science of Extraterrestrial Language" (Routledge Taylor & Francis Group (2023).
The book is anchored in what is known about human language and animal communication systems, but it offers suggestions about what we may find if we encounter non-Earth intelligence.
For over six decades, researchers have been engaged in the search for extraterrestrial Intelligence (SETI), listening for signals with radio telescopes — and they could succeed tomorrow, Vakoch told Space.com. (METI, as its name suggests, concerns the possibility of communicating with alien intelligence — making meaningful contact.)
"We might be faced with understanding a message from an unknown civilization, and linguists could provide the key to cracking the code," said Vakoch. "The recommendations coming out of our new book are directly shaping how we will say 'Hello, universe.'"
Vakoch highlighted the importance of communicating our intentions as the hallmark and rationale for METI messages. "Another key question is whether universal grammar of the sort we see across languages on Earth will also hold true more broadly in the universe," he says.
As noted in the volume, one major point is that communication involves more than getting across the content of your message. "You also want to communicate your intention," said Vakoch.
Related: If aliens have visited the solar system, here's how to find clues they left
Start a conversation
One of the common objections to METI, Vakoch pointed out, is that we may alert hostile extraterrestrials to our existence and provoke an alien invasion.
"In reality, any civilization with the capacity to travel between the stars also has the technology to pick up the accidental radio and television signals that have been leaking off into space for the past century," Vakoch said.
So any aliens picking up our targeted messages won't be surprised to know we exist, Vakoch added. "But what will surprise them is that we're attempting to start a conversation. That's the whole point of METI — to get across our intention of making first contact."
Universal principles
Vakoch said that the aliens he is most interested in are the ones we can make contact with.
"Those are the aliens who have developed the technology to transmit and receive radio signals. In the past, when scientists have sent interstellar messages, this shared technology has provided the foundation for crafting the messages."
The messages we've sent into space so far have relied on possibly universal principles of math and science as a starting point, said Vakoch. "But maybe there's something more basic. Long before humans had math and science, we had language. Maybe the same is true on planets orbiting other stars."
In the end, Vakoch thinks, the idea that we must choose between either math and science, on one hand, or language, on the other, is itself too simplistic.
Core of language
Co-editor of the new xenolinguistics book is Jeffrey Punske, an associate professor and the director of undergraduate studies in linguistics at Southern Illinois University in Carbondale.
What we define as the core of language may be fundamentally constrained by external considerations. If so, then it is almost certain that a linguistic, non-human intelligence would have the same core of language, Punske suggests.
"However, there are many aspects of language that are universal to human language that cannot solely be attributed to such externals," he said. "Those aspects are likely products of the structure of human cognition. There is certainly no guarantee that a non-human intelligence would share our cognitive systems. Thus, while the underlying structure of language might be the same, the message might not be interpretable."
New perspective
Excited that scientists are beginning to think seriously about xenolinguistics is Bridget Samuels of the University of Southern California (USC).
Samuels is conducting research in two areas that address where universal grammar may fit in the universe: How did language arise in our species, and what are the limits of variation in human language?
"The study of animal communication has exploded in recent years, and it's given us a new perspective on how human language is, and isn't, unique," Samuels, the project director at USC's Center for Craniofacial Molecular Biology, told Space.com. "Also, how communication systems are shaped by the unique cognitive abilities of the organisms that use them, as well as by the environmental niches they inhabit."
Invariant laws of physics
Those lines of inquiry, combined with a "third factor" in language design — factors that shape language beyond our genetic endowment and experience — have set the stage for theorizing in entirely new ways about universal grammar, Samuels said.
That theorizing has helped Samuels shape and share a prediction with Punske: "Some aspects of language syntax and externalization may even be shared by extraterrestrial languages, as they are constrained by invariant laws of physics."
By pondering language and animal communication in a cosmic context, Vakoch said, we are forced to rethink just how unique language is, even on our own planet — whether or not we ever make contact with extraterrestrials.
"Xenolinguistics shows that human language may not have the privileged position we've always assumed," he said.
