Terraforming Mars is possible – planetary scientist
Interplanetary flights may be just decades away. But what will they be like, and are we ready to embrace the Interstellar Age? We ask NASA's planetary science researcher Professor Jim Bell.
Sophie Shevardnadze: Jim Bell, welcome to the show. It's great to have you with us. So, Jim, scientists say that the Sun will expand into a red giant and eventually destroy life on Earth. How much time do we have?
Jim Bell: Well, Sophie, that's actually true. But I wouldn't worry about it. It's going to take at least maybe five billion years or so. The Sun is a typical star. There are hundreds of millions of stars like that in our own galaxy. And so astronomers can monitor the life cycle of stars like our Sun. And we know the Sun is about four and a half billion years old and stars like the Sun last around nine or ten billion years. So don't lose any sleep over it. But it's true that someday the Earth will be destroyed by our own star.
SS: But look at the world we live in, Jim. I mean, the growing number of conflicts and the climate change is recognized as another existential threat we're facing. What makes you think that we’ll survive for even another thousand years, forget billions?
JB: That's a great question. I mean, fundamentally, I'm an optimist. I think that we've already seen... Well, I know that we've already seen just incredible advances in science and technology, medicine, communication, transportation just in the last few hundred years. And I think that, you know, that's what's going to help us survive as a species. That's what's going to help us learn to live in a sustainable way on this very precious and rare planet that we live in, to maintain the environment that is conducive for a good quality of life. So I'm an optimist. I believe in science and technology and that the scientific method can make our lives better. It has and will continue to do so as we go into the future.
SS: You know, I'm sure you know this astrophysicist and cosmologist, Martin Rees. So I was speaking to him recently and he told me that there was no Plan B for us. Do you think there is or there is not?
JB: Well, I mean, right now that's true. That's absolutely true. We are made for this planet, for this environment. We have evolved for this life around this star and this kind of an atmosphere with this temperature and this pressure and this composition. So, you know, Earth is our home and Earth will always be the home planet of the human species. And so there is no plan B, of course, you know. There's lots of interest in exploring the rest of our solar system and settling, you know, sending people to the Moon on a lunar base, sending people to Mars, maybe other places in the outer solar system, establish research stations and bases, maybe tourist destinations. But Earth is always going to be humanity's home. And everywhere else we go, we'll have to figure out how to carry the Earth's environment with us in a spacesuit or habitat or somehow figure out how to modify those environments, maybe underground caves or whatever to be more Earth-like. So I agree, there is no plan B for the species, but there is a plan to explore and to push our species right into our own solar system.
SS: Let's talk about that and we'll start with colonizing Mars. So the main problem with terraforming Mars, for instance, is that the atmosphere is too thin for us to survive there. And I've heard the idea that it is possible to thicken Mars's atmosphere by releasing the so-called greenhouse gases. Now, here on Earth, we produce these gases from agriculture and waste. But where do we get them on Mars?
JB: Right. It's a great question. And, you know, Mars has polar caps with water ice and carbon dioxide ice. It has composition very similar to the Earth, actually. All of the terrestrial planets have very similar composition. So there is methane gas and other kinds of greenhouse gases that are stored in the planet, just like inside of the Earth. So all that is possible. But the timescales, Sophie, are really long. You know, it's taken humanity 200 years or so, basically since the industrial revolution, to start to change our own climate with greenhouse gases like CO2. To change the climate of a planet like Mars, with a much thinner atmosphere would require a lot more time and some pretty industrial-scale processing and creation and release of greenhouse gases. We're talking hundreds, thousands of years to really terraform a place like Mars. So in the near term, we're really talking about people living in space suits and habitats and environments that we create on Mars that are little mini versions of Earth's environment.
SS: So we know that Mars lost its magnetic field millions of years ago and this amazing NASA physicist Jim Green came up with the idea of creating an artificial one. Is that feasible? Is this something that could work?
JB: Well, you know, the wonderful thing about science is that you can speculate, you can hypothesize, you can come up with ideas and models. And that's just an idea, it's a model. You know, if it were possible to somehow tap into Mars's internal heat, if there's enough left to create this kind of a magnetic field… Right now, my opinion, it's sort of science fiction because it requires a scale of planetary engineering that we're just not capable of as a species. But like all good science fiction, we can kind of imagine a future where we could change a planet's climate or, you know, locally change the planet's magnetic field, for example. So, possible? Sure. You know, one can imagine some scientifically developed engineering steps to head in directions like that. But is it practical? Probably not, and certainly not anywhere in the near term.
SS: All right. But scientists today already create artificial atmospheres in sealed testing chambers, right? So theoretically, is this possible to create an artificial atmosphere on Mars? Meaning like not satellite stations, but cities that could accommodate Earth's population? I mean, you're saying people should be walking around in special suits. But why can't we just create like special mini-cities?
JB: Absolutely. We could certainly do that with domes or covered structures or... You know, Mars has some natural environments like these lava tubes that volcanic lava used to travel through, like you see these kinds of lava tubes in places like Hawaii or Iceland on the Earth. And there are buried caves, basically. And if you just seal them off from the surface, you could create an environment in a place like that that is very Earth-like with oxygen and nitrogen and high pressure and normal temperature, shirts-leeve temperature. Or you can imagine dome structures or small habitats. You know, you're probably familiar with the movie ‘The Martian’ that came out a few years ago, the movie and the book. You know, they imagined some pretty decent-sized habitats and structures where they created an Earth-like environment. I think those are all very, very possible. The engineering is challenging, but not impossible. And I think it's going to be part of the future of people eventually settling Mars in the next few decades.
SS: So once again, Martin Rees, when we were speaking, he told me that the people who colonize Mars will have to be a different kind of species because they will need to adapt to this long-term travel in outer space and harsh radiation. Do you think that we'll have to sort of mutate if we want to get off Earth eventually?
JB: Well, I mean, you know, evolution is slow and it is forced by environmental changes certainly as well as mutations and we've seen that throughout the history of life on our own planet. So the first people who go out to live on Mars to stay or live on the Moon to stay or to go live on Jupiter's moon, Europa, to stay will sort of suddenly be in a very different environment than the one in which their ancestors were raised in. And so one can imagine that there could be favourable mutations to radiation that allow that trait to be built up over time. You know, we don't know. We don't know if women can have children in space. We just don't know what is the effect of gravity on the development of a child.
SS: Well, supposedly the radiation is way too high for a fetus to actually develop into a healthy human. It mutates so much inside the womb in space, so it’s supposed that it's not possible as of now. That's what I've heard.
JB: Well, it depends. I mean, there are more and less benign radiation environments in space. Around Jupiter, for example, huge, enormous radiation environment, very intense. It's difficult for our robotic spacecraft to survive in that environment, let alone living beings. Mars is kind of... it’s different. It's a different radiation environment than the Earth. It's not as protected as the Earth is. But there's a variety of calculations that show that people should be able to survive there. There may have to be some special shielding in their habitats or in their spacesuits, etc. But it shouldn't be too crazy harsh like other places in the solar system.
SS: But in general, what abilities or features should humans have to survive in this new habitat, be it Mars or any other planet?
JB: Yeah, I mean, I think probably the number one skill that we and they will have to develop is sustainability, it’s the ability to live off the land as much as possible to kind of break the supply chain of having to bring everything from the Earth and figure out, how do we extract water and oxygen from these rocks or from these polar cap deposits? How do we use the materials that are around us as building materials? How do we shield ourselves from radiation or just from the very thin atmosphere? How do we protect ourselves and keep our atmosphere in using materials around us? Where do we get our energy? How do we make ourselves completely self-sufficient? Solar energy, nuclear energy, other geothermal, wind, other sources — all of that that we think about when we think about pioneers settling new lands. They have to learn how to live off the land and going out into space, the Moon, Mars, other places will be the extreme test of that for the human species.
SS: So supplying the International Space Station, for instance, requires huge resources and it is located relatively close to Earth, which makes it possible to sustain it. How are colonies on Mars going to sustain themselves? I mean, would it be like in The Martian, the one that you know, the one that you mentioned, the movie, — growing potatoes and recycling waste?
JB: Right. Certainly, there will have to be... They will have to figure out how to live off the land. You know, initially one can imagine lots of building materials and water and maybe even oxygen coming with them in the pretty large spaceships it's going to take to get there. Even just to go to the Moon — it's a pretty big spaceship. And you can imagine there being lots of room for cargo as well as people. So food and water, oxygen — bringing a bunch of that initially is probably the smart thing to do. But then the first settlers there, the first towns and villages that are built up, small numbers of people, they're going to have to learn how to get construction materials and make bricks and structures out of the rocks. How do you pull the iron out of that and other metals that they might need? How do they get oxygen out of the CO2 or out of the water ice that they can find in the ground, breaking up the hydrogen and oxygen, you breathe the oxygen, you can drink the water, you can use the water as a shield against radiation if you build your structure the right way. So all of these things, and there's a lot of research being done here on Earth today by NASA, by the Russian Space Agency, by the European Space Agency, the Japanese space agency, many different countries thinking about how do we extract resources from those environments out there in space so that they will help us survive.
SS: So let's try to reverse that perspective. Once we colonize other planets and have a sort of a life ready in waiting, do you think it will devalue life on Earth somehow, make things like nuclear war more likely to happen, for instance?
JB: Look, I told you, I'm an optimist. I have exactly the opposite perspective. I believe and I truly believe that the ability to learn how to sustain ourselves in groups of people who have to work together out in harsh environments on the Moon or Mars or other places, learning how to live off the land, learning how to completely recycle everything and use everything to its maximum efficiency and maximum potential, I think all of those skills, all that engineering, all that knowledge will come back to the Earth and they will help us live better lives on the Earth. We can solve a lot of our energy problems. We can solve a lot of our waste problems. Maybe we can solve a lot of our social problems because we have to realize we are all living on a small, fragile spaceship together. And it's really no different than a bunch of people in a harsh environment trying to rely on each other to survive. We are interconnected on this planet and we rely on each other everywhere around the world to survive as a species. So I think all of that's going to come back. And in fact, that's why we explore space, in my opinion, to learn more about our home planet, how to sustain and better our lives here, because, of course, most of our species will remain here on this planet and only a small fraction will be fortunate enough to go out there and explore and settle.
SS: So I know you are an optimist, but I still want to bring up Ray Bradbury and what he once suggested that every colonization that humankind undertakes eventually entails destruction and devastation, whether it's here on Earth or anywhere else. What is your take? Will we destroy other planets just like we almost destroyed our own?
JB: Certainly, I don't deny that there is that potential and that makes for great science fiction, of course, because it is the history of our species and it's not a very pretty history, of course. We have to learn from it. We have to learn, you know, what we did wrong, what we can improve, how can we achieve that betterment of our species by learning from the past. So I think, of course, when we get to another planet or moon or elsewhere in our solar system, we don't think there's anybody living there right now. There could perhaps be microbial life deep underground in some of these places. We don't know, of course. There could be life in the oceans of Jupiter's moon Europa. We don't know. So, you know, there's the potential and maybe an ethical responsibility that we need to find that out before we go to some of these other places. But we're also going to have to exploit some of the resources. We need to find the water, find the oxygen, find the building materials, figure out how to grow food. You know, those have all been part of settlement in the past. And can we do it responsibly? Can we do it sustainably? Can we do it in an ecologically friendly way for that environment? I think these are big challenges for us. I'm an optimist. I think we will rise to the challenge.
SS: So you've been saying that you would actually take approximately 40 thousand years to get to the next star, and that means that tens of thousands of generations will die and be born during this trip. I mean, wouldn't it be easier to build like a new planet than to fly thousands of years without a firm guarantee of achieving the goal?
JB: Sure. No, I agree. And, you know, it's tens of thousands of years using current technology. Propulsion technology is always advancing. There are radical ideas that don't, you know, defy the laws of physics that could potentially get us out into interstellar travel faster than that. So, you know, but it's still hundreds, maybe thousands of years. So still many generations to do that. So you're right. We have in our own backyard, in our own solar system a number of places, planets, moons, asteroids, comets that we want to explore that could have the resources that could support a small human civilization, expansion of human civilization into our solar system. There's been, of course, a lot of science fiction books and television shows and movies that explore this theme and much of it's based in reality. There are resources out there that we can use to survive. And there are ways that we can travel around in our own solar system that aren't generational, that take years or decades maybe to go out to really distant destinations. So you're right that the prospect of interstellar travel is daunting, extremely challenging. But maybe that's what's causing us to focus mostly on our own solar system for near-term, next few centuries, thinking about settlement.
SS: Well, I've heard that a NASA engineer has recently come up with this concept of a revolutionary engine that could take us to the stars at the speed of light and without any fuel at all. Some scientists have already called this idea crazy. Is it?
JB: If somebody told me as a scientist, “Hey, you know what, I'm going to get you something for nothing”, I'd be sceptical. So I'm certain there's a lot of scepticism, especially if it's that “no-fuel” part. And we should be sceptical. But, you know, science doesn't work as a democracy. Science works on hypothesis and test. So let's see some tests of this engine technology, for example. And that's the kind of way to convince sceptics.
SS: Right, let’s move to the Moon for a little bit, because you've been saying also that the Moon is permanently moving away from the Earth. And that means that one day we will hardly be able to spot it in the night sky. How will this affect our life here, on Earth? I mean, if the moon's gravity affects the tides, will it also affect our ability to walk or fly, etc?
JB: Right. And the effect you describe is absolutely true but very, very slow. It's centimetres over centuries. It's really slow. We can measure it super accurately because of the mirrors that the astronauts left on the Moon. You can bounce a laser beam off of those mirrors from the Earth and get the distance to, you know, submillimetre distance. So it's really slow. And so we're talking about millions and millions of years for the Moon to move significantly away. And that will lower the tides, of course, because it's the gravity of the Moon, the sun a little bit as well that create the tides. It won't fundamentally change the gravity of our environment, et cetera. It'll be sad because there won't be any total solar eclipses anymore, because the Moon won't be big enough in the sky to completely block the sun. But that’s all millions of years in the future.
SS: So will the Moon become like a separate planet one day or be gravitated to another planet like Mars, for instance?
JB: No. What scientists, my colleagues believe will happen is that the Moon will... You know, it rotates around the Earth every 28 days now and the Earth spins once on its axis every day. It will eventually move away to the point where the Earth and the Moon are both locked into a rotation around each other. It's called synchronous rotation. And many moons in the solar system are exactly that way. They're locked with their parent planet. And so in millions of years from now, the Moon will stabilize and its position that is just locked in the same spin rate as our planet.
SS: I see. Well, what about the human exploration of space in general? Robots are getting better and superintelligence is almost there. Will there be any practical need for sending humans into space at all?
JB: Yeah, no, that's a great question. You know, the practical side of it has always been that the engineering, the technology, the science needed to get people into space has spurred all kinds of innovation. For those of us still here on the Earth, all kinds of amazing technology, advancements in propulsion and software and guidance and control and, you know, you name it. The space program has communications, the space program has had enormous influence in life on the Earth… But that hasn't been the real motivation to do it. Of course, you know, early in the space program in the 60s, it was the Cold War, right, it was the desire for, you know, “our way of doing it is better than your way of doing it kind of thing and demonstrate national prowess”. Today that’s still many countries getting involved in space exploration as a way to prove that they've reached a certain level of engineering and science sophistication. It's almost like becoming a member of an exclusive club and more and more countries are becoming members of that club.
SS: You wrote a tour guide about sightseeing opportunities and activities our solar system has to offer like hiking on the Moon or skiing on Pluto. So far, terraforming one planet for us seems to be a paramount endeavour. Will this require another giant leap for our civilization to tap into other planets, or terraforming one makes terraforming all the others a lot easier?
JB: Yeah, it's a great question. And of course, I don't know what the future holds, but I don't think we need to terraform the other places out there to become interplanetary tourists. You know, think about it. If you want to go scuba diving to an amazing reef in the Caribbean or something like that, you go, you find a guide, you get equipment, special equipment, because it's an environment that you're not going to survive in without special equipment, you get special training. And if you're not careful, you're going to get injured or die. But we do it even though we're not meant to be down there at those depths. You want to go climb Mount Everest or some other big mountain - we're not meant to be there and unless we have special equipment and unless we have a special training, special guides, we'll get hurt or we'll die trying to do that. And yet people do it. I think it's exactly the same when we go to the Moon and we go to Mars, asteroids, comets, all these destinations that we're learning about. We'll have to get special equipment. We'll have to get special training, special guides. And if we're not careful, we're going to get hurt or we're going to die. And so I think there's the adventure tourism model that I think will work for interplanetary travel. And it's just going to take decades to centuries, but not many, to get to the point where getting into space is relatively routine, like getting into an airplane and travelling around the world is today.
SS: All right. Thank you so much for this wonderful insight and all of our opportunities that we have in terms of interplanetary travels. It was great talking to you. We were talking about the possibilities of interstellar flights and colonizing the deep space with NASA's planetary scientist, researcher Professor Jim Bell.