Nathalie Cabrol: Search for Alien Life | Lex Fridman Podcast #348

"My friend is telling me that the volcano seems to be starting to erupt. If that volcano goes off, we have nowhere to go." That got my attention. So, if you say scared, I would say that I got the realization that what that meant. I went cold for, like, a fraction of a second. But that meant that just my adrenaline started to kick in. And it was a very, very strange experience because now you have tunnel vision. It's about survival.

The following is a conversation with Nathalie Cabrol, an astrobiologist and scientist at the SETI Institute, directing the Carl Sagan Center for the Study of Life in the Universe. She explores some of the harshest places on Earth, including free diving in volcanic lakes, all in the pursuit of understanding living organisms beyond Earth. For this, she holds the woman's world record for diving at altitude, both scuba and free diving. She's amazing. This is the Lex Fridman Podcast. To support it, please check out our sponsors in the description. And now, dear friends, here's Nathalie Cabrol. You are the director of the Carl Sagan Center For Research at the SETI Institute. SETI, of course, stands for Search for ExtraTerrestrial Intelligence. One of the things you do as part of that is travel to some of Earth's most extreme and dangerous environments in search of organisms that live in conditions analogous to those on Mars. First, let me ask what the job posting for the work you do looks like. Is it like Shackleton's ad in, uh, 1900 that said people wanted for hazardous journey to the South Pole?

(laughs)

Small wages, bitter cold, long months of complete darkness, constant danger? And also, where do I apply?

(laughs) That's funny because there was not really a job application. In fact, when you're a scientist, you have questions in your mind and you have hypothesis, and you start to list the kind of thing you need to answer. Um (laughs) , and then when you, you see the kind of thing you have to answer, then you kind of know the places where you need to go to do that. As far as science is concerned, started with analyzing data from the Mars missions. And, uh, I had written a PhD about water on Mars, first looking at, uh, channels and the history evolution of, of water. Uh, but then during my postdoc, I started to look where that water was ponding. Interestingly enough, everybody was about channels and water and whether catastrophic or whatnot, or seepage. But when you are talking about ponding water like lakes or ocean, people were starting waving their arms a little bit. So, it was a little bit of a happy battle, interestingly enough. Yeah. But that got us on track with my husband. Uh, we were working together and, uh, we started developing the idea, the concept of lakes in impact craters. So, why in impact craters? Just because the Viking, uh, mission at the time, which is what we were working with, uh, the resolution and the topography were so poor that there was really no way of telling where you had a real low in the topography. The only thing you knew was a hole in the ground was an impact crater. So, when you saw valleys.