Astrobiologist Nathalie Cabrol was born in 1963 and grew up near Paris. She completed a PhD at the Sorbonne on the evolution of water on Mars and moved to the US in 1994 as a researcher at Nasa Ames. She has worked extensively in the Atacama Desert and the Chilean Andes, studying how life adapts to extreme environments similar to those on other planets. Cabrol, who lives in Northern California, is now director of the Carl Sagan Center at the Seti [Search for Extraterrestrial Intelligence] Institute. Her latest book, The Secret Life of the Universe: An astrobiologist’s search for the origins and limits of lifewill be published on August 15th.
How did you become interested in heaven?
It’s not hard to be interested in heaven, we are in heaven! I can remember when I was five or six years old, I would look up at the sky and start asking myself, “What’s this all about? Why does this exist?”
Is it a mistake to only look for extraterrestrial life when looking for extraterrestrial life? Earth-like planets and life as we know it?
It’s not necessarily a bad thing to look at our biochemistry and the kind of environment that got us here. Astronomy tells us that the stuff we’re made of is so common, and we’re learning that carbon came into existence much earlier than we thought. And with the discovery of exoplanets [planets outside our solar system]we also realize that while there probably isn’t an exact copy of Earth anywhere in the universe, there are environments that are probably just as suitable for life, or even more so. But from that standpoint, we’re blocking ourselves from looking for another version of ourselves. I’m looking more at the universal markers of life – markers that would apply everywhere in the universe, regardless of biochemistry.
Enceladus [a moon of Saturn] is definitely my favorite…we could do incredible things on Enceladus
What makes you so sure that there is something, and not absolutely nothing?
The easy answer is Carl Sagan’s answer: “That would be a terrible waste of space.” We’ve been looking for life intellectually for thousands of years, but we’ve only been looking for it in a meaningful way with technology for 60 years, so this is a very young search. You have to look at the distances. Even if by some miracle [alien life forms] think and communicate in a similar way to us and are interested in what is going on around them, our radio bubble is barely 200 light years in diameter. That is small. Then there is the fact that we are looking for life, but we don’t really know what life is, or intelligence, or even less consciousness. We have no idea what those three things are. We are still looking for them, which is fine, because otherwise you won’t get anywhere.
Where in our solar system would you most expect life to arise?
I think Mars still has some big surprises in store for us. They won’t be on the surface, but unlike a lot of people, I don’t think it’s going to be that far down there. There’s still volcanism on Mars, and we know there’s water and lots of nutrients – magnesium, potassium, and so on. Elsewhere in the solar system, Europa [a moon of Jupiter] could have an oxygen-rich ocean that would provide an opportunity for more complex life to develop. It also has sources of carbon.
We’re talking about oceans beneath miles of surface ice.
Yeah. And the thing is, you don’t have to invest in submarines to explore it; you can let Mother Nature bring the stuff to you. Because of the gravitational tides on Europa, you have this convective motion and a kind of slush that comes to the surface periodically. You land next to it, grab that stuff and see what’s in there. You let the ocean come to you.
But Enceladus [a moon of Saturn] is definitely my favorite. I love it because it just throws stuff at you in geysers or plumes [shooting up from the surface]Obviously, slowing down a spacecraft to collect samples is pretty complicated, but we could do incredible things on Enceladus.
Related: Is There Life on One of Saturn’s Moons? Scientists Are Planning a Mission to Find Out
Do other planets teach us lessons about what to expect from Earth? global warming?
If you look at what happens to a planet when there is a greenhouse effect, that is Venus. And the planet that is too hot and loses its water, that is Mars. We have that right in front of our eyes.
What is your view on people? like Elon Musk talking about colonizing other planets?
Well, first of all, I hate the word colonize. And the idea of setting up outposts on another planet because we are escaping our own is an insult to the spirit of exploration. Migrants usually move because they are desperate for better conditions. That is not the case on Mars. It is much worse. I think we should go to Mars not because it is an easy escape, but because we have grown up and are using it as a training ground for a much more mature civilization to take the first steps towards becoming interplanetary, and later interstellar. But we should also use all that technology to look back at Earth.
Projecting ourselves into space challenges our brains to find solutions that we otherwise wouldn’t look for on our planet. Sure, sending a Tesla into space [as Musk did in 2018] was not the right message when trying to create space policy and prevent planetary pollution.
There has been a lot of excitement about UAPs [unidentified anomalous phenomena] recently. Do you pay much attention to it?
As a scientist, I find UAPs interesting because we first have to see them for what they are: unidentified phenomena. The leap I don’t make is that they are necessarily extraterrestrial phenomena, like flying saucers and the like. We know that 96% of them will have a natural explanation. Something to consider is that we are seeing a lot more unusual atmospheric phenomena because our planet is changing. And then there is the undisclosed government activity that you shouldn’t have seen. And then there is the half percent or so that is unexplained. Of course I am interested.
But Seti is not interested in aerial phenomena – our instruments are aimed much further away. I always say, jokingly, that we are looking for ET in its own habitat, while people who are looking for UAPs are trying to see ET in ours. But if you tell me tomorrow that you have irrefutable evidence of an alien spacecraft caught on video somewhere, I will be the happiest person in the world.