What if alien life is everywhere, but we've been looking for it in all the wrong places? We assume life needs water, carbon, a warm little pond as Darwin said. But what if life doesn't care about what we assume to be necessary? There's a scientist who spent her career exploring the strangest, harshest, most brutal places on Earth. High altitude lakes in Chile that freeze solid at night and boil by day, toxic salt flats that look just like you'd expect an alien landscape to look, an environment where life should be impossible. And yet, as you know, we're not afraid to go into the impossible. Her name is doctor Natalie Cabral. She's the director of the Carl Sagan Center at the SETI Institute right here in Northern California. And what she writes about life in the universe shattered everything I thought I knew about it.

How can we communicate with the alien species? This is not a trivial thing.

We're going to talk a lot about alien life and why Earth might be a cosmic accident. We'll explore whether civilizations out there may stay silent on purpose and what it would take for humanity to survive its own future based on what we know about the deep secrets of the universe. But first, we have to ask perhaps the hardest question in all of science. Natalie, thank you so much for joining us.

Well, thank you very much for having me.

I wanna take this conversation in a very different place than I usually go because everybody thinks they know what alien life would look like. But your work really made me rethink our assumptions and then the assumption that we know what we're doing. I came out of it questioning whether or not we might be completely lost. And I wanna ask you today about the biggest blind spots in the search for extraterrestrial intelligence. How we might be missing alien life that's already here on Earth and whether humanity itself is ready for first contact. And we'll get there. We'll get there soon. But first, I wanna start with the most important, most uncomfortable question in all of science.

Are you ready, Natalie?

I'm all ready to go.

What is life?

We don't know. We don't know. That's the beauty of the whole thing, you know. And then you have to wonder how can you write 300 pages about something you don't know. Well, that's the whole thing. And I think that a lot of, you know, what you said about, you know, rethinking life and how we search for it, this is exactly it. I think we're coming at a time where we realize what we don't know, but we have a bunch of, you know, data that has been coming from forty years of planetary exploration right now. Maybe the most important thing is for us to rethink how we address those questions, how we ask them.

And you will see, as the discussion goes, that really, it's sometimes maybe only about rearticulating those questions.

Eventually, I wanna get to what we might make of biosignatures that we're missing and how we might actually detect life beyond our imagination or at least the limits of our imagination. But first, I wanna ask you, in your, you know, vast expertise, what do you think is the most dangerous assumption that members of your community are making in the field of astrobiology? Which assumption has the most biases whether intended to be prejudicial or not? What is the most dangerous aspect of the assumptions that are being made in your field?

I don't think we can say that any of them are dangerous. Not in the sense that, you know, the only dangerous danger is the intellectual danger where you are sort of bottlenecking yourself. In fact, when we are honest with ourselves, we follow hypotheses and we, you know, we develop experiments and we get more data and then that forces us to rethink. So I don't think there is a danger. There is the bias is just that we are learning. And, you know, the better our instruments are becoming, the more different the reality of the universe and how the universe looks for us, you know, change. And this is what gives us the possibility of changing our perspective. It's not really a bias.