Sean Collins
So, Noam, where are we with our attempts to contact aliens?

Noam Hassenfeld
There have essentially been three stages. 

The first stage was a demonstration of capability: Scientists shot a message from an observatory in Puerto Rico to a star cluster about 25,000 light years away. Obviously, it’s going to take a long time for that message to get there, and a long time for anyone to send anything back.

Then, there was the Voyager probe, which had a golden record full of information on it. We just sent this thing floating out into space, hoping someone would stumble across it, which is very unlikely.

More recently, an organization called METI (Messaging to Extraterrestrial Intelligence) International asked whether aliens would be able to understand the messages we’ve sent so far, and decided to try something different. 

METI’s president, Doug Vakoch, tried to go much simpler, sending a message where the signal itself was the reference point. The message was in binary code and contained a mini scientific lesson on the basics of counting and basics of frequencies, with the idea that aliens would sort of decode the message step-by-step, working their way up to this big idea of, “You've just received a radio signal. It’s from this place, Earth, and we sent it to you.”

Sean Collins
Why did METI structure the message that way? 

Noam Hassenfeld
They started from a basic perspective of aliens being…alien.

Sheri Wells-Jensen, a linguistics expert who works with Doug, made the point that people often imagine aliens as like us, just a little different. But why would they be? Maybe they communicate through smell. And what would that mean for how they conceive of communication?

So if we want to talk to them, we can't say, “We come in peace. We are humans. This is our culture. This is what we believe in.” 

We have to start with the most basic thing possible.

Sean Collins
Does METI think there’s a good chance they’ll hear back from some…being?

Noam Hassenfeld
They understand they have a very low chance of success. 

But researchers — both at METI International, and others doing this type of work — are interested in thinking through what it means to communicate with someone that can't necessarily understand you. Thomas Lu, who led Unexplainable’s reporting on this topic, told me there’s an entire field called xenolinguistics, which is focused on how to communicate with aliens. And the major question: What is a language? 

On Earth, humans have common experiences and our bodies have evolved in a pretty uniform way — most of us have tongues, and our mouths are similar. We understand how sign language works. 

But xenolinguistics tries to factor in about all of the potential hurdles we have to get past in order to make ourselves understood if we don’t have that in common.

Sean Collins
Given that barrier, do scientists think communicating with aliens is even possible?

Noam Hassenfeld
Thomas asked Sheri, “How can we ensure that what we're sending will mean the same to whoever receives it?”

Sheri ultimately said she didn't know if it's possible. But she also told us that xenolinguistics is about understanding ourselves as much as it is about trying to connect with aliens.

Sean Collins
You mention at the start of your Unexplainable episode that if you could send a message to aliens, it would be, “Don’t hurt us.” Now that you’ve learned about xenolinguistics, would that still be your message?

Noam Hassenfeld
Now I feel like aliens would have no idea what that means. The concept of “hurt” feels so complicated. The concept of “us” feels complicated.

Looking at Doug’s research, I think those three words could easily be misinterpreted and also just probably not understood. Which makes me compelled by Doug’s strategy of sending a little bit of math. If we could send out two plus two and get back four, that would just be an earth-shattering day in the history of science; if there was some type of connection, that would just be incredible.