In 1974, Frank Drake continued his search for life in the universe. But this time, instead of listening, he decided to send a message.
Drake used the powerful Arecibo Radio Telescope in Puerto Rico to beam out an intentional message to the cosmos.
The message was 1,679 bits. It was arranged into lines of 23 characters. The ones and zeros of the binary message were transmitted by shifting the frequency of the broadcast. The message was an image — encoded in those ones and zeros – that drew a pixelated diagram once decoded.
It contained a representation of the radio telescope, a stick figure of a human, a representation of DNA and a map of our solar system.
It was sent to a cluster of stars near the edge of our galaxy, some 21,000 light years away.
This made quite a few people very angry,” said University of Nottingham radio astronomer Emma Chapman. “They kind of said, ‘we didn't give permission to do this.’ There's a lot of argument, especially in [science fiction], which is that you should stay quiet if you think there's something out there.”
The idea of transmitting a signal to potentially other civilizations is controversial.
And it leads us to more questions. Who should be speaking first? What happens if someone calls us? And just how soon might that happen?
Call and respond?
Should we or shouldn’t we be actively sending a message into the cosmos to signal we are here and want to talk is a controversial question.
“There are opposing views about a phenomenon or a technique that is referred to as METI,” which stands for messaging extraterrestrial intelligence, said SETI Institute president and CEO Bill Diamond. “That is the idea that if we really want to find the aliens, let's call them. Let's send signals out.
Diamond said that’s not happening right now “because that is highly controversial, and it raises questions like,Who gets to speak on behalf of humanity? What do we say?”
Michael Michaud is a former U.S Foreign Service Officer and worked on the first set of protocols on what to do if there’s a confirmed signal of extraterrestrial intelligence.
The concern for him is less on who gets to speak for us. It’s the safety of our species that’s at issue.
“Almost everybody who deals with this assumes we're going to send signals, so we're going to announce ourselves. We're going to tell them we're here,” he said. And that’s a bad thing and a reason he urges caution.
What if they’re violent? What if they want to conquer our planet? We don’t know the answer, he said, “which is [why] we don't know what their reaction to us will be."
Diamond believes that at the heart of those concerns is misguided fear. He said any civilization that might have the technology to hear that signal — or interpret that signal — is one that developed in a way that is not threatening to us.
They’d have to advance technologically. Diamond argues that for them to have overcome existential challenges on their own planet, say climate change or widespread pollution, they surely would be harmonious by this point in their history and their motives should be good.
“One can imagine this is a universal phenomenon that any civilization that gets to our point is going to be facing the consequences of their technology,” he said. “If they are successful in overcoming those risks, that's probably going to mean that they ultimately evolved into a fairly benevolent, very socially and culturally advanced civilization that probably has no motivation or interest in going around and killing other civilizations."
Putting aside the alien invasion argument — will they or won’t they —Chelsea Haramia, a philosopher at Bonn University and co-director of the Discovery and Futures Lab at the SETI Institute, argues there’s another consideration. It’s an ethical one: Who gets to speak for us? All of us?
“This idea of communication and what should you say – that's morally loaded, and it comes with the morally loaded question of how to represent humanity, our planet, other species, future generations,” she said. “There is a risk of misrepresentation. There's a risk of harm. There's a risk of acting without consent. These are all moral issues we can think about when we think about communication."
And what if they call us first?
The protocols for dealing with the detection of an extraterrestrial signal say that in the event of such a finding, the scientists are — at least a first — asked to stay quiet.
University of Manchester astrophysicist Michael Garrett led the committee that wrote the most recent set of protocols released in 2026.
“You're an astronomer, just do your astronomy job, but you need to leave it to other people to decide whether it's in the interests of basically the entire planet to send the response,” said Garrett. “If we do decide that it would be good to send the reply, then what will the reply be and how can we make sure that it's really [a representation] of the planet as a whole and not just some kind of subset of all the cultures that are here on Earth."
Regardless of who makes the call first, there’s another issue to consider, says Michaud: time.
“We'd have to develop a system in which there would be a huge delay between question and answer, and cultures on both ends could change drastically in the interim,” he said. What was once a curious, friendly civilization could easily evolve into something else over a period of 1000s of years.”
Because of the vast distances between places in the galaxy, conversations would take decades, even centuries, between responses.
“What this delay does is it changes communication from like a Zoom call – an immediate conversation – to more like a pen pal with your grandma's pen pal,” said Chapman.
And what would we even say?
“In terms of sending messages, I think I'd probably embarrass myself if I gave you an honest answer, said Garrett. I might send my favorite football team or something."
For Chapman, and many other astronomers like her, the focus is on looking for incoming signals. Not sending them out.
“I don't put much thought into sending stuff, because I get writer's block as to what I would send,” she said. “I think I just listen."
So when it comes to listening and looking, what comes next?
Getting closer
When it comes to the search for life in the universe, we’re closer than we’ve ever been before. We talked about the three main avenues of the search: listening for signals from far out civilizations, peering into the atmospheres of exoplanets, and searching the surfaces of planets and moons closer to home in our own solar system.
It’s these efforts that give astrophysicists like Garrett hope for a finding and one soon.
“I don't think there's been a time really in the history of SETI, where the field has been in such good shape,” he said. That includes the work of SETI looking across the electromagnetic spectrum beyond the radio frequency.
Advances here on Earth are helping, too, including the work of Artificial Intelligence.
There’s an enormous amount of data coming back to us on this search. Space observatories like NASA’s Nancy Grace Roman Space telescope will send more than a terabyte of data back per day. While Roman isn’t primarily on the search for extraterrestrial life, future observatories may have that same data capability.
AI allows scientists to sift through enormous datasets, looking for clues to life out
One observatory that is planned to look specifically for signs of life out there is the Habitable World Observatory.
It’s not launching until the 2040s, but University of Central Florida physicist Josh Colwell says it will be worth the wait because “one of its primary objectives would be to directly image at least 25 potentially habitable worlds, and be able to detect spectroscopically if there are signatures of life as we know it in the atmospheres of those worlds."
A picture of an alien world. The ability to peer into the atmosphere and search for chemical signs of life. The possibility of finding an Earth-like world.
It could happen in our own lifetime.
When will we find them?
We started this podcast with the premise of when it comes to finding life in the universe, it’s not a matter of if. It’s a matter of when.
For all the people I interviewed for this podcast I asked: When will we find evidence of life elsewhere in the universe?
“I am convinced it's there. I am really pessimistic that in my lifetime we'll ever find something that we could be definitive about. That doesn't mean we shouldn't try, but that's kind of where I am with this. I'm like glass half full, and the glass is smashed open."
- Paul Byrne, University of Washington in St. Louis
“I think we're getting increasingly close to that event, and we may make a discovery of that kind even within our own solar system."
- Bill Diamond, SETI Institute
“I’m prepared to say that the probability of this happening in my lifetime is slender. There may not be contact in that short span of life."
- Michael Michaud, former U.S Foreign Service Officer
“It could be that just like one day all of a sudden there's a signal there. So as for [the] prediction of will it happen in our lifetime? We want to say yes, but maybe it'll just pop up. It could be tomorrow and it could be in 300 years.”
- Addie Dove, University of Central Florida
“As a scientist, I got to say ‘I don't know’ because the bar has not been met for me yet. The optimist, the hopeful person in me, though, says that we have come so far if you look at the rate of discovery, [it] makes me optimistic that we will reach that threshold maybe in my lifetime."
- Amy Williams, University of Florida
“I think that's very doable by probably about 2080. So not in my lifetime, but it's certainly in the lifetime of my granddaughter, Olivia."
- Michael Garrett, University of Manchester
Through this podcast I learned that when it comes to finding that evidence, we’re really close. Closer than ever before. But what happens next is still uncertain. We don’t know how we’ll react, but we’ve got a pretty good idea of what may change.
Like all good journalism, working on this podcast has led to more questions. How will AI reshape or refine our search? And if we’re looking for intelligent life in the universe, does alien AI count? Should we be looking for a more digital sign of life?
And if we do get a message from someone out there, how are we going to know what it says? We’ve sent bits and bites out into the cosmos, and even a golden record with images of Earth and humans to the edge of our solar system — could an alien even decipher our message to them?
What about the idea that they’ve already been here? In 2023, NASA, under the Biden administration, created the Unidentified Anomalous Phenomena independent study team to examine — scientifically — reports of UAPs. Earlier this year, the Trump administration directed the declassification of files related to UAP sightings.
We’ve received incredible feedback from our listeners about this podcast. It’s clear there’s an appetite and a curiosity for more exploration into these questions.
So we’ll keep asking. That’s next season on When We Find Them.
