Terraforming Mars: Experts Debate How, Why and Whether

At the Astrobiology Science Conference earlier this year, scientists and science fiction writers -- from NASA researcher Chris McKay to author Kim Stanley Robinson -- faced off on the promises and pitfalls of terraforming Mars. Their debate is recreated in these seven pages. The Mars Terraforming Debate was co-sponsored by NASA's Astrobiology Magazine, the SciFi Museum (Seattle), and Breakpoint Media. It is reproduced here in cooperation with Astrobiology Magazine.

See About the Debaters below.

Part 1: Giving Mars Back its Heartbeat
Christopher McKay advocates making Mars habitable for Martians.

Donna Shirley: Terraforming was once solely the province of science fiction. In the 1930s, Olaf Stapledon wrote of electrolyzing a global sea on Venus in order to prepare it for human habitation in "Last and First Men." Jack Williamson coined the term "terraforming" in the 1940s in a series of short stories. And in 1951, Arthur C. Clarke gave the concept wide exposure with his novel, "The Sands of Mars." Kim Stanley Robinson picked up the terraforming torch in the 1990s with his epic trilogy, "Red Mars, Green Mars, and Blue Mars."

Scientists began to think seriously about terraforming in the 1960s, when Carl Sagan published several articles dealing with the possibility of terraforming Venus. Terraforming Mars has been the major subject of research of two of our panelists tonight, Dr. Chris McKay and Dr. Jim Kasting, since the 1970s.

So the question is, can we terraform Mars? How would we do it, why would do it, when we do it, and should we do it?

Chris McKay: I don't think we can terraform Mars, if terraforming is, as it was originally defined, making Mars suitable for human beings. But what we could do is make Mars suitable for life.

Human beings are a particular subset of life that require particular conditions. And it turns out oxygen in particular is very hard to make on Mars. That is, I think, beyond our technological horizons - it's a long time in the future. But warming Mars up, and restoring its thick carbon dioxide atmosphere, restoring its habitable state, is possible. It's sort of a stretch of the word terraforming, but if you want to call that terraforming, that's possible. Bob McElroy coined the phrase "ecosynthesis" for that, and I think that's a better word.

So I'll answer, "Yes! We can bring Mars back to life." How? Well, the biggest problem is warming it up. We know how to warm up planets, we're doing it on Earth. In fact the same sorts of things would work on Mars.

Should we do it? Well, that gets down to a question that we've never had to face on Earth before: the distinction between nature and life. On Earth there is no meaningful distinction between nature and life, even in the remotest, coldest deserts.

We see that distinction for the first time when we look beyond the Earth, when we look at the moon. There's nature; there's no life. When we look at Mars, we also see nature, probably no life. It's different from the moon, and we lack the word that distinguishes between something that's dead, and something that was never alive. The moon was never alive. Mars is dead. The question in my mind is - should we bring it back to life?

Well, I vote for life. Nature's a great thing. Mars lived fast, died young and left a beautiful body - the Sylvia Plath approach to planetary science. We could play Ted and just ignore it, or we could do something better and bring it back to life. Mars is beautiful the way it is, but I think it would be even better if we could restore the biosphere that it once had. So I vote for life.

I apologize that I'll have to leave in about 15 minutes - as it turns out I'm giving a lecture at a class on ethics at Stanford on the same topic, of terraforming Mars. Who would think it would be so popular that I'd have a conflict like this?

Donna Shirley: Lisa would you like to respond to that?

Lisa Pratt: I'm afraid I'm going to have to violently disagree. I think we have no reason whatsoever to think that Mars is dead or sterile or even hostile to life forms.

I think it's increasingly evident that there is a large inventory of water on Mars. There may in fact be groundwater relatively close to the surface, meaning, within a few hundred meters of the surface. The kinds of chemistries that are suggested by the evaporite minerals indicate that the groundwater may be a brine with a perfectly habitable composition. In fact, it may contain a soup of molecules that would be delicious for any number of Earthly microbes. So I think until we successfully interrogate the martian subsurface, and adequately address the possibility of indigenous martian organisms, that we absolutely should not think about terraforming Mars.

Donna Shirley: So Jim, if we did terraform Mars, how long would it take? What kinds of things could we do to make that happen?

James Kasting: Well, Chris has hit the nail on the head. Of course I was a co-author on the paper we wrote on that.

In that Nature paper, we defined two levels of terraforming Mars: one was for humans and one was for plants. The one that seems potentially doable, although it's difficult by itself, is to do it for plants. To me, that's not that interesting. Co-authors can disagree on what the paper implies, and I personally wouldn't go to the trouble to terraform Mars just to make it habitable for plants. I'm more interested in humans.

But as Chris already pointed out, the oxygen is a major problem. If you think about oxygen in the Earth's present atmosphere, you have to bury organic carbon. It's not enough just to have photosynthesis, you have to bury the organic carbon that you've produced. On Earth, we bury about one-tenth of 1 percent of primary productivity in the oceans, and that gives oxygen about a 4 million-year lifetime, meaning you have to do that for 4 million years.

Now, if you're really optimistic, suppose you could get oceans going on Mars, and you had as much productivity as you had on the Earth. And let's say that instead of burying 0.1 percent you could figure out how to make that system bury 10 percent of the organic carbon. It would still take forty thousand years to build up oxygen. That's a daunting task which I hardly can envision us doing. So that leaves us with terraforming it for plants, and, well, we can debate whether that's worth doing or not.

Donna Shirley: So, Greg. If we only had terraforming to make things habitable for carbon dioxide breathers, as Chris suggests, would anyone be interested in doing it?

Greg Bear: That's an interesting question, but we have to look at our motivations for terraforming Mars. Is it because we want to transform Mars for the art of doing it, for the science of doing it, or for the economic necessity of doing it?

You know, at this point, it's kind of tough imagining doing that for any of these reasons, because it would take so darn long. And usually our economic basis of doing this sort of activity requires a two-year time span for delivery of goods, so unless we start thinking very far out, like the Japanese, but hyper-cubed, then we really have to think of, well, why would we want to get this started? To leave a legacy for the next species on the planet Earth? It's about how long it's going to take. And will we be around when it's done?

If we're going to do it for an experimental purpose, then we have to define the terms of the experiment. So, it's a huge question, and we just don't have the information about either ourselves or Mars to figure out the answer to it.

Donna Shirley: So John, what information do we need about Mars?

John Rummel: I think that we're talking about the trajectory for Mars, and not necessarily as some other kind of an opportunity. Mars in forty thousand years might be a wonderful place if we started now. The question is, we can't go back when we start with the wrong propositions.

The Earth a couple of billion years ago was not all that comfortable to humans. In fact, we had bacteria that were not really happy when other organisms showed up and started breaking water (molecules), and making oxygen, and releasing it into the atmosphere.

As it's turned out, over time organisms have been able to modify this planet, not only in the atmosphere itself, but also all the way down into the mantle. Cyanobacteria are the culprits involved here; these are the organisms that caused the demise of the original inhabitants of this planet. They didn't worry about the time scale; they worried about their trajectory.

Forty thousand or fifty thousand years is the time span at which Mars terraforms itself. Mars is a place that may be terraforming on a regular basis. So get in now and avoid the rush.

We need to know, before we go, whether or not, if we adopt a trajectory, are there martian organisms there? As we push Mars towards being more Earth-like, are there organisms there that will push back, that will do what we would consider to be socially unproductive things, like covering the planet with poisons? So let's think about whether or not Mars should be pushed in that direction. Once you make the decision, then I don't have a job anymore.

Donna Shirley: I'm going to give Chris the last word here since he has to leave. So anything else you want to say about terraforming Mars?

Chris McKay: I just want to add one more point about martian life. I think that we should make a biosphere on Mars, as I said earlier. I think the ingredients of the biosphere - the genome of that biosphere - if at all possible, should be martian. That would be the most interesting situation.

We have evidence that Mars had life - we have evidence it had water, from there we deduce that it had life. I think an objective assessment of the situation leads us to be very pessimistic that that life survived intact today. But for a variety of reasons I think we could find the relics of it - frozen and dead maybe - and reconstruct it if we had to, or find it living in some subsurface refuge, and let it once again control the biogeochemical cycles of that planet the way that life on Earth controls the biogeochemical cycles of our planet. In other words, give Mars back its heartbeat.

I'm not proposing to send life from Earth there. That's only the last resort. If Mars has no genome, then we could share ours with it. But I personally think that a Mars full of Martians is much more interesting than Mars full of Earthlings.

Next Page: Looking for Martian Life

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Part 2: Looking for Martian Life
John Rummel predicts that in our search for life on Mars, we probably won't find cows.

Donna Shirley: David, making a planet habitable is something that people have said is maybe a good thing to do, maybe not a good thing to do. And the question is, since your research is on climate evolution and habitability, can we do it?

David Grinspoon: Can we do it? I think that, in the long run, we probably could if we wanted to, from a technical point of view. But my concern is not over the technical difficulty, but the societal problems. I think that human technical ability increases fast; it increases exponentially. Human wisdom increases much more slowly.

But, to my mind, I think that if a hundred years from now, we decided that we wanted to terraform Mars, we would know how to do it. We already have some ideas, and we're getting smarter all the time about how planetary climate works from a technical point of view.

But whether we have the other abilities that we need, in terms of the collective decision-making that it takes to purposefully transform a planet, right now we're having trouble purposely not transforming our own planet. We're having trouble not veneraforming the Earth, in a sense. And I think if we get to the point where we demonstrate that we have the wisdom to take care of Earth's climate, and not haphazardly, but in a collective way, where we decide that we're going to make these decisions and we're able to control Earth's climate, then maybe we will have the wisdom to terraform Mars.

We should be thinking about terraforming Mars. I don't think we should terraform Mars now, but as we think about it, we work the problem of how do we purposefully take care of a planetary climate. So I think that this exercise of considering terraforming Mars is very good for us, and is maybe a first step towards attaining the kind of wisdom that we need to someday be smart enough - not just technically, but also ethically and in terms of collective decision-making - to terraform Mars.

Donna Shirley: Stan, you've written about all those things. One of the things that you've written about is the role of Antarctica in preparing us to go to Mars. What would you say about the question of should we do it, and what should we do?

Kim Stanley Robinson: I think that Antarctica will serve as a good analog for Mars. (Mars) will be a distant place that's cold. There will be scientific stations there. And it'll be interesting to the rest of humanity, but somewhat remote. Scientists will be rotating crews coming back after their stay. And what we learn there will teach us more about taking care of the Earth. So, if you want to think about what Mars can be compared to in the rest of human history, because in many ways it's entirely a new thing, I think Antarctica is a much better model than the Wild West or any other model that's been proposed.

But this question of should we terraform or not, I find it really interesting because the scientists are still split on the question of whether we have any good expectation of finding indigenous life there. So it becomes a kind of decision-tree that we have to answer - like forks in paths, we have to come to a fork, find a way to make a decision, and then move on to the next decision.

The first question we need to answer is, is there life there right now alive, or not? When we answer that, and if the answer's in the negative, we can then proceed with essentially a dead rock that's very big and really interesting, and bringing life seems the obvious thing to do. A project which the industrial capacities of humanity may grow in ways that are as surprising to us as (our technology would be surprising to) the people in the 17th century.

If we do find life on Mars, it will be very interesting to try to discover whether it is indigenous, which is to say a second start, and truly alien to us, a second genesis. In that case, I think we'll have to go and try to kill all the bacteria that are already there, inside the boxes that we've left, and try to clean up and really study it from a distance. That will be a really remarkable discovery, perhaps the major discovery in human history.

But if we find that the life there has the same DNA, the same patterns, and is clearly bacteria that got bounced up there from Earth, or vice versa, and that we're all martian bacteria that got bounced down here and then evolved - if they're cousins, in a sense, then I think you could go on for a few centuries and begin to feel that we could move to Mars and live on Mars. The local cousins would have their niches, and we would have our niches, and then let the two begin to interpenetrate again.

At each point we need to make these decisions without being able to say right now, "Oh, we should terraform Mars," or, "Oh, we shouldn't terraform Mars." We can't answer that yet. But I agree that it is a completely useful thought experiment. Because it's really the terraforming of Earth that we are now doing, in ignorance and by accident. And so we need to know more about it.

Donna Shirley: Lisa, you found cave creatures way down below the Earth. Can they co-exist with the creatures on the surface? Seems like a Mars analog to me.

Lisa Pratt: I think certainly on Earth, as we begin to look at greater and greater depths and into increasingly extreme environments, we realize that we are co-habitating with organisms that live very much in partitioned ecosystems, where organisms from one cannot survive in the other. So, in that sense, one can perhaps imagine a situation where there would be indigenous martian organisms that continue to reside in the deep subsurface, relatively protected and isolated.

But I think the problem for us as a scientific community, and the problem for the public as a whole, is that until we know enough about the subsurface of Mars to make an informed decision, it's really difficult to move forward. Right now, we barely know enough about the subsurface of Earth to make informed decisions. We're discovering, practically on a daily basis, organisms in places that we, as recently as 10 years ago, were absolutely certain were barren of life.

As we have begun to get samples back that are clean enough of surface contamination to think that we're actually looking at deep subsurface materials, what we realize is we know the organisms are there because we can identify their genes, but we can't culture most of these organisms. So we don't in fact know what their requirements for life are. In some cases, we know what their energy source is. In some cases we know what their carbon source is. But the vast majority of microbial organisms remain unculturable, even on planet Earth.

Donna Shirley: John, if subsurface microbes are unculturable, how do you know when there is life there or not? How do we know when we can safely assume Mars is dead and start terraforming?

John Rummel: Well, the good news is that life, when it's there, tends to leave little dead life around. So you can pick out the dead bug bodies. They play hell with organic chemistry, and that's a good thing. But they also change the environment around them. Basically, you're moving material and energy around, back and forth, to attain some particular end, usually the result is more microbes of one kind or another. And even if we can't grow them, it doesn't mean that they can't grow.

Our attempts to culture microbes are a little bit like trying to grow large mountain lions by feeding them wheat. It doesn't work very well, and it really ticks them off. I understand mountain bikers is a better diet, but that's a California joke.

I really think that eventually we will find out whether or not there is something there by their action on their own environment. But it will be critical to know these things before we attempt to modify the martian environment at all. And I think if we watch Mars for just a little bit while longer, even if there's nothing alive there, there are things going on. And those things may or may not lead you to a deduction that life is there.

We have people now reporting methane in the atmosphere. This is a detection from the planetary Fourier spectrometer. ESA, the European Space Agency, has put out an announcement that it's been detected at 10 to 20 parts per billion. Well, methane in the atmosphere on Mars can mean one of three things: either vulcanism, possibly microbial life, or maybe cows. We haven't seen the cows yet. I doubt that we'll find them. But one of the other two would be a very interesting thing to find out.

Whether or not we can find more methane on one part of Mars than another is going to take either more measurements from abroad or an instrument in-situ, perhaps in orbit around Mars, that can really make high-definition measurements. So these are things for people to propose for future Scout opportunities or future Discovery opportunities to really nail it down. Then we'll have to go to those places and find out what's going on there. When we do, we don't want to take our own bacteria there so that they do those things themselves. We want to find out about Mars life before we take Earth life to a place where it can be modifying the environment in a way that we can't control. We're not trying to control Mars and martian life right now. If we ever want to, we want to make sure we don't screw it up first.

Next Page: Should We Terraform?

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Part 3: Should We Terraform?
David Grinspoon says we have an ethical imperative to bring a dead planet to life.

Donna Shirley: Greg, what are the ethics of exploring Mars?

Greg Bear: You usually talk about ethics within your own social group. And if you define someone as being outside your social group, they're also outside your ethical system, and that's what's caused so much trauma, as we seem to be unable to recognize people who look an awful lot like us as being human beings.

When we go to Mars, we're actually dealing with a problem that's outside the realm of ethics and more in the realm of enlightened self-interest. We have a number of reasons for preserving Mars as it is. If there's life there, it's evolved over the last several billion years, it's got incredible solutions to incredible problems. If we just go there and willy-nilly ramp it up or tamp it down or try to remold it somehow, we're going to lose that information. So that's not to our best interest.

We were talking earlier about having a pharmaceutical expedition to Mars, not just that but a chemical expedition to Mars, people coming and looking for solutions to incredible problems that could occur here on Earth and finding them on Mars. That could generate income unforeseen.

If we talk about ethical issues on a larger scale of how are other beings in the universe going to regard how we treat Mars, that's a question for Arthur C. Clarke to answer, I think. That's been more his purview: the large, sometimes sympathetic eye staring at us and judging what we do.

We really have to look within our own goals and our own heart here. And that means we have to stick within our social group, which at this point includes the entire planet. If we decide that Mars is, in a sense, a fellow being, that the life on Mars, if we discover them - and I think that we will discover that Mars is alive - is worthy of protection, then we have to deal with our own variations in ethical judgment.

The question is, if it's an economic reality that Mars is extraordinarily valuable, will we do what we did in North America and Africa and South America and just go there and wreak havoc? And we have to control our baser interests, which is, as many of us have found out recently, very hard to do in this country. So we have a lot of problems to deal with here, internal problems. Because not everyone will agree on an ethical decision and that's the real problem with making ethical decisions.

Donna Shirley: David, you want to comment on the ethics of terraforming Mars?

David Grinspoon: Well, one comment I've heard about recently, partly in response to the fact that the president has recently proposed new human missions to Mars - of course, that's not terraforming, but it is human activities on Mars - and I've heard a lot of people say, "Why should we go to Mars, because look at what human beings have done to Earth. Look at how badly we're screwing it up. Look at the human role on Earth. Why should we take our presence and go screw up other places?"

It's an interesting question, and it causes me to think about the ethics of the human role elsewhere. What are we doing in the solar system, what should we be doing? But, it's very hard for me to give up on the idea. Maybe because I read too much science fiction when I was a kid, I do have, I have to admit, this utopian view of a long-term human future in space. I think that if we find life on Mars, the ethical question's going to be much more complicated.

But in my view, I think we're going to find that Mars does not have life. We may have fossils there. I think it's the best place in the solar system to find fossils. Of course, I could be wrong about this and I'd love to be wrong about it, and that's why we need to explore. If the methane observation is borne out, it would be, to me, the first sign that I really have to rethink this, that maybe there is something living there under the ice.

But let's assume for a second that Mars really is dead, and we've explored Mars very carefully - and this is not a determination we'll be able to make without a lot more exploration - but assuming it was, then what about this question. Should human beings go to Mars, because do we deserve to, given what we've done to Earth? And to me, the analogy is of a vacant lot versus planting a garden. If Mars is really dead, then to me it's like a vacant lot, where we have the opportunity to plant a garden. I think, in the long run, that we should.

We've heard a lot different possible motivations, economic motivations, or curiosity, but I think ultimately the motivation should be out of love for life, and wanting there to be more life where there's only death and desolation. And so I think that ethically, in the long run, if we really learn enough to say that Mars is dead, then the ethical imperative is to spread life and bring a dead world to life.

Donna Shirley: Jim, we can't prove a negative, so how do we know if there's life or not, if we keep looking and looking and looking. How long should we look? How would we make that decision?

James Kasting: I think Lisa put us on the right track initially. She's studying subsurface life on Earth. If there's life on Mars today, it's subsurface. I think it's deep subsurface, a kilometer or two down. So I think we do need humans on Mars, because we need them up there building big drilling rigs to drill down kilometers depth and do the type of exploration that Lisa and her group is doing on Earth here. I think that's going to take not just decades, but probably a couple of centuries before we can really get a good feel for that.

Donna Shirley: Well, I know, John, at Lake Vostok, one of the big issues is, if we drill into it, our dirty drilling rigs are going to contaminate whatever's down there. So how do we drill without worrying about contaminating something if it is there?

John Rummel: Well, you accept a little contamination probabilistically that you can allow operations and still try to prevent it. I mean, basically what we can do is try to prevent that which we don't want to have happen. We can't ever have a guarantee. The easiest way to prevent the contamination of Mars is to stay here in this room. Or someplace close by.

Greg Bear: That's known as abstinence.

John Rummel: [laughs]. I also want to point out it's not necessarily the case that the first thing you want to do on Mars, even if there's no life, is to change it. We don't know the advantages of the martian environment. It's a little bit like the people who go to Arizona for their allergies and start planting crabgrass right off. They wonder why they get that. And it may be that Mars as it is has many benefits. I started working here at NASA Ames as a postdoc with Bob McElroy on controlled ecological life-support systems. There's a lot we can do with martian environments inside before we move out to the environment of Mars and try to mess with it. So I would highly recommend that not only do we do a thorough job with robotic spacecraft on Mars, but we do a thorough job living inside and trying to figure out what kind of a puzzle Mars presents.

Donna Shirley: Stan, you dealt with this issue in your book with the Reds versus the Greens. What are some of the ethics of making decisions about terraforming Mars?

Kim Stanley Robinson: Ah, the Reds versus the Greens. This is a question in environmental ethics that has been completely obscured by this possibility of life on Mars.

After the Viking mission, and for about a decade or so, up to the findings of the ALH meteorite, where suddenly martian bacteria were postulated again, we thought of Mars as being a dead rock. And yet there were still people who were very offended at the idea of us going there and changing it, even though it was nothing but rock. So this was an interesting kind of limit case in environmental ethics, because this sense of what has standing. People of a certain class had standing, then all the people had standing, then the higher mammals had standing - in each case it's sort of an evolutionary process where, in an ethical sense, more and more parts of life had standing, and need consideration and ethical treatment from us. They aren't just there to be used.

When you get to rock, it seemed to me that there would be very few people (wanting to preserve it). And yet, when I talked about my project, when I was writing it, it was an instinctive thing, that Mars has its own, what environment ethicists would call, "intrinsic worth," even as a rock. It's a pretty interesting position. And I had some sympathy for it, because I like rocky places myself. If somebody proposed irrigating and putting forests in Death Valley, I would think of this as a travesty. I have many favorite rockscapes, and a lot of people do.

So, back and forth between Red and Green, and one of the reasons I think that my book was so long was that it was just possible to imagine both sides of this argument for a very long time. And I never really did reconcile it in my own mind except that it seemed to me that Mars offered the solution itself. If you think of Mars as a dead rock and you think it has intrinsic worth, it should not be changed, then you look at the vertical scale of Mars and you think about terraforming, and there's a 31-kilometer difference between the highest points on Mars and the lowest. I reckoned about 30 percent of the martian surface would stay well above an atmosphere that people could live in, in the lower elevations. So maybe you could have it both ways. I go back and forth on this teeter-totter. But of course now it's a kind of an older teeter-totter because we have a different problem now.

Next Page: Walking Naked on the Red Planet

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Part 4: Walking Naked on the Red Planet
Greg Bear ponders the evolution of humans into Martians.

Donna Shirley: Let's say that we've decided to go to Mars, we're going to terraform Mars, we're going to terraform it so people can live on it. What kind of people are going to go to Mars? Greg, you had people going to Mars (in your book). Could you talk about them?

Greg Bear: Well, my people weren't by and large genetically modified, although they did have biochemistries installed so they could survive the lower gravitational fields or weightlessness. Mostly they looked like me and you, but I think if we're going to go to Mars I think it's a cheaper option to fix ourselves up rather than fix Mars up.

We could generate ourselves so that we don't need that extra flora, that biota, that occupies our intestines and our skin and everything else, and that way we won't leak too much when we go there. But that might be a real fantasy. Humans leak - that's pretty much a universal truth.

So my people in "Moving Mars" are pretty much like you and me, as Mr. (Robert) Heinlein would imagine them. I think what we're going to see is that when we get to Mars in a serious way, we're going to want to change ourselves, just so we can do what Stan would like to do, and that's walk out on the surface of Mars and climb a rock, naked.

That's a pretty good idea, isn't it? Just your fingers - no suckers allowed; you can't put suckers on your fingers - just the few extra scales or whatever, to keep yourself from drying out, and a way to recover your oxygen quickly. The Maui effect. You just really want to get out there with nature and touch Mars directly. That's tough to do when you're in a NASA suit, but we've seen very skinny space suits being designed, and that might be adequate for Mars.

But that's getting off the point. The point is that I think we'll be genetically modified very soon after we get there. It'll be more economical. You could propagate faster. And if we're going to do this thing of being fruitful and multiplying, then we can multiply in a different form. And the question then becomes, will they be Martians, as Ray Bradbury says? I think they will. Will they be respectful of any other life forms we find buried tens of kilometers deep on Mars? Perhaps. But for economic reasons, almost certainly they'll preserve them and start studying them. And the whole process will go on. I don't actually think we've ruined the Earth. I think we're transforming the Earth. We're Earth's gonads, and we're about to do what comes natural.

Donna Shirley: So Lisa, when you're down in the mine somewhere...

Lisa Pratt: I can't believe you're going to ask me to say anything after that!

Donna Shirley: [laughs]. When you're down in the mine somewhere, how do you protect the life forms from leaking?

Lisa Pratt: Well, you try very hard, but the point of the matter is we've already done a very invasive procedure in these deep mines. We've already put in tremendous infrastructure, and we're pumping enormous amounts of air through those mines in order to sustain the miners who work down there.

It's very interesting when you walk around on Earth, three kilometers below the surface, every place there's the smallest drip or trickle of water, there's a luxuriant red biofilm of air-consuming organisms that are utilizing the chemical disequilibrium of these deep-Earth waters. In order to sample for deep-Earth microbes, you have to wait for the serendipity of the miners drilling into the virgin part of the subsurface and intersecting high-pressure water. And if the water that is intersected continues to come out at high pressure, and you can collect a sample before the aerobic organisms work their way back in, then, in fact, you have a chance to identify the indigenous life forms. What we find is there are many microbes at depths below two kilometers below Earth's surface.

Donna Shirley: Let's talk about the economics. If we're going to terraform Mars, what are the economic incentives? Will pharmaceutical companies be able to fly us to Mars to find new medicines? Stan, you had some economic things worked out in the trilogy.

Kim Stanley Robinson: Well, no, it will never be economic. This is the cool thing about it, and one of the reasons that people all around the world are so interested in Mars, is that it sits outside of the systems of current culture and economics. You can't make a profit from it. You can't make it make sense in religious terms. It's just a kind of a thing that humanity would do as a project for the sake of how interesting it would be. It would be an interesting story.

We would go there first the way we go to Antarctica, to do scientific studies, to try to help us understand the world better. And then after that, if it were to be terraformed, people would be doing it for itself, just in the way of gardening or building a cathedral. There is no analogy that really makes sense, because it's such a new and big thing. But I think that people are interested in all these little robotic missions and in everything about Mars, because it's so hard to get outside the economic trap that we're in, in our current culture. So it's best to think of it as being meta-economic, or beyond economics.

John Rummel: Well, at least it's not at the time scale of the typical investment. If we did have forty thousand years of burying reduced carbon, we'd have oil there, so we could get that.

Donna Shirley: For a long time, they said, we're going to do it for science. And then we say, no we're going to do it just because humans explore. So why would humans go to Mars? Anybody want to take a crack at that?

James Kasting: Yeah, I'll take a crack at it. I think scientifically, it's very exciting. It's not just looking for extant life and drilling down deep beneath the surface. There is a chance that there's fossil evidence for life on the surface. We want to understand the surface of Mars like we understand the surface of the Earth. We'll learn something by robotic missions, we're learning lots right now from the current missions, but we won't understand Mars like we understand the Earth until we get teams of geologists up there with rock hammers, clambering down Valis Marineris and looking at the whole stratigraphic sequence that is very difficult to get to robotically.

Lisa Pratt: Actually, I think there's an important step in-between, and that's to take the time to return samples to Earth. We take the risk of bringing samples back to Earth, where they can really be analyzed in a comprehensive way by many different laboratories around the world, using as many different analytical techniques as we can throw at them, before we get in a hurry and make what I think would be a titanic mistake to actually get up there on Mars and walk around with human beings before we're prepared for what we discover.

Greg Bear: That's a good use for the space station, too, if you don't necessarily want to bring those samples back to Earth.

John Rummel: If you bring it back to the space station, you've brought it back to Earth, but you've brought it back in an uncontrolled fashion. The fact is that there is nothing about modern biology that we know enough about in space to be able to do the kinds of tests you'd want to do. You bring it back to the space station, what goes up must come down, therefore any space station that's in orbit right now will eventually be part of this planet once again. If you do find life on Mars, you don't want to find it in a place where you can't control it adequately. So you really can do a safe job of bringing it back to a terrestrial laboratory and allowing it to be looked at to make sure that there's no biohazard, and then get it out to the people who can do the work. Finding a biohazard would be one of the greatest scientific discoveries of all time. So we're looking forward to that.

Back to your question, though, about why you would go to Mars. Essentially, ignorance is not bliss. Going in also may tell us about a future place where we could put at least part of this civilization to come back and clean up after an event like (a giant asteroid impact on Earth). So I would advocate, if not terraforming, at least solar system exploration, as a way of saving part of the history and the culture of humanity.

Donna Shirley: People say, "Well, we're going to mess up the Earth, so we're going to jump off of the Earth and go live on another planet." David, what do you think about that idea?

David Grinspoon: Going to Mars now with robots or even with human expeditions, which is very different from terraforming, is greatly motivated by curiosity, and part of the return from that is we get smarter about how planets work. This is knowledge that we really need, because whether we like it or not, we are at least partially running a planet now. Maybe we're running amok on a planet, but the decisions that we're making with our technical civilization are changing this planet. So we can't afford the luxury of ignorance about how planets work.

I think we need to explore the solar system, not just to satisfy our curiosity, but to get smarter about how planets work. In the long run, I think we will go to Mars to live - assuming again Mars is a dead world, which I think it is, probably - for the same reasons that human beings left Africa. Why aren't we still all living in Africa, which we were at one point? I think it's part of what we do; we wander and we explore. In the long run, I think we're going to continue that beyond the Earth.

Next Page: The United Nations of Mars

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Part 5: The United Nations of Mars
Kim Stanley Robinson wishes Mars (and Earth) would abide by the Antarctica Treaty.

Donna Shirley: If we want to do something massive, like terraform Mars or even go to Mars with a lot of people, is it going to have to be an international endeavor? If so, how do you do that? Is it going to be all U.S., is it going to be like the Star Trek universe, where it's all humanity? What's that going to look like?

John Rummel: Well, if you look at the front row of this audience now, it's not all U.S. Why would it be? I think everybody's going to be interested in this. And I think that the opportunities are there for all humankind to be able to go to Mars, to go other places in the solar system and learn together. If you take a look at any of the missions that are currently planned, they all have international participation, and that counts for everybody's mission. Not NASA, not ESA, not China - everybody's missions have international participation. It's the way of life in solar system exploration.

Donna Shirley: So, science fiction guys, what about you? You've postulated international groups going to Mars. What are some of the issues involved in that?

Kim Stanley Robinson: Oh, gosh. There's language problems. There's metric and foot problems. There's problems!

Antarctica provides a really good model for this. That's under an international treaty and nobody claims it, nobody owns it, there's no sovereignty there. It's a beautiful model and I sort of wish that the rules of Antarctica would just creep north by a degree or two every year until the whole planet was under the Antarctic treaty. The space treaty is based on the Antarctic treaty. If there's going to be a Mars treaty, I'm sure it's going to be based on the Antarctic treaty.

There are national stations down there. You know, the Italian station, the French station, the Kiwi and the Australian stations, and the American station. It's possible, I think, that Mars expeditions might be national, just because of the logistical reasons of one sort or another, and getting the initiative to go. But they will have international components to them, and it will just become international and be under international law and be a human achievement. It seems to me inevitable that it will work out that way.

But the idea of it being any kind of a space race - I mean, what if the Chinese suddenly say, all right, we're set to go. We're off to Mars and we're going to be there in 10 years. Although they wouldn't announce that. But if we came to that conclusion, would it then turn into another space race? It seems to me it would break down and fall back into internationalism before that actually transpired, that we no longer can get stuck in any kind of Apollo races. But this is more a hope than a certainty.

Greg Bear: I think that's probably what's going to happen. I think that there's more nationalism than we can think of out there, and there's more pride. There's pride of people who've come into a technological age after we have. They are going to exert themselves. They're going through the kind of adolescent fervor that we are still going through, but at a later stage.

I think that's going to happen. I don't think it's necessarily going to be a bad thing. It's going to be a conflictful thing, but in living systems, that's how problems are solved. Two different systems or more get together, clash and conflict, and there's a lot of casualties along the way. Is there a way of doing it better? I think there probably is. I think that we could sit down and apply ourselves to it, if we want to take that role of standing back from the space race, but you know we're still a pretty young country. I think we'd probably roll up our sleeves and say, "Hallelujah!" and jump into the fray. It's a wonderful place for novels, fortunately. But it may not be the best place for raising children in peaceful circumstances.

Donna Shirley: Okay, so now we've got this bunch of nations on Mars. You've got some experience, Lisa, in South Africa and other places. How does one set up a society where people are willing to collaborate and get around the national boundaries and work together? How did you get into South Africa and get into mines?

Lisa Pratt: The reason it worked in South Africa is we made a compelling argument for the joint benefits to the mine owners, the mine operators and the scientists. So if there is an analogy, I suppose it's that there will have to be a multi-front reasoning that moves forward incrementally until, as a society or as a planet, we all agree that there are compelling reasons.

Donna Shirley: John, planetary protection's a highly international endeavor. How does that work? Can we use any models there for living together on Mars?

John Rummel: Well, the 1967 space treaty is the basis of planetary protection law around the globe. We co-ordinate with the Committee on Space Research as a consensus where there is an international planetary protection policy.

Think about back contamination concerns: an international crew is coming back, and they've found life on Mars, and then they find that maybe they're infected by that life. Do you want to tell them they can't come home because they have Mars flu? You'll find that there's another nationality born right then, and that's called Martian, and they're going to want to come back anyway.

I think that we have general consensus throughout the international community, and a lot of concern internationally, about making sure that Mars is as we find it, until we decide to do something else with it.

Lisa Pratt: I might mention one other thing, that the thorniest issue in getting this deep subsurface research going was getting the agreement signed at very high government levels about who owned the genomes. That in fact it was concern about the value of the meta-genome that would come out of the mine in terms of its economic applications. The genome for anything that we bring out of the South African mines is owned by South Africa.

Donna Shirley: Do you want to have the last word, David?

David Grinspoon: Well, it occurs to me that one of the subtle benefits of the space age is that there is something of a planetary perspective that is spawned from seeing images of the Earth from space. Contemplating human beings going to another planet; there's something inherently global about that. I think that even if it is different national expeditions that go to Mars to live, that once they get there, they'll identify with being Martians.

One of my favorite science-fiction stories when I was a kid was by Isaac Asimov, the story called "The Martian Way." That is the story of the martian colonists eventually saying, "To hell with Earth. We're Martians, and we're going to do it our own way." I think that one of the benefits of thinking about all this, whether or not we end up doing it sooner or later, is that it does, in some sense, almost subversively foster a kind of global consciousness that can help us, maybe, get along here on this planet.

Donna Shirley: I think that's a very common theme of science fiction. Science fiction asks the question, "What if?" And what we've got here are some people who are actually working on these things, and thinking about what if there's life, what if there isn't life, how would we govern ourselves, and so on. And that's one of our major functions of the Science Fiction Museum and Hall of Fame - to show people how to ask those questions, and to show people how to think about what might happen. To use terraforming Mars, for instance, as a thought experiment that reflects back on ourselves.

Next Page: Audience Questions about Living on Mars

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Part 6: Audience Questions about Living on Mars

Q: In the broad sense of life, it doesn't matter what we do with Earth. What we have to think about is what we need to do if we want to preserve human life - not life itself, because life is going to be here until the sun dies. The U.S.A. uses most of the energy of the Earth. How much energy do we need to save in order to go to Mars and terraform Mars? And are we going to have enough energy in order to stay here on Earth?

Donna Shirley: So is your question, "Are we going to run out of energy?"

Greg Bear: It's a matter of focus, isn't it? We have to have discipline to do big things, and we seem terribly undisciplined at times. I hope that's what you were getting at there. And also as a culture, the United States is fairly dominant in the consumption of raw materials in the world today. And you know that there are some of us who think that that's a necessary thing and others who object to it. There's really no answer to this question.

It's a big question, because as I'm watching you ask your question, I'm seeing this entire planet learning to take baby steps. When you talk about things like, "Will we survive beyond the death of the sun?" you're talking about the very earliest thought processes of an organism that's going to be much larger than our solar system eventually. And that really is like watching a baby being born. So I hope that's not too abstruse, but, yeah, you ask huge questions there.

James Kasting: I thought what she was asking was, "Is it really worth spending the huge amount of money that it would take to terraform Mars, when we have so many pressing problems on the Earth?" And I would say no. I'm a pessimist about that. I think it would be too expensive and not a good economic enterprise.

Q: I understand from reading that between 50 and 70 percent of the mass of life on Earth is under the ocean floor. Is that valid or not?

Lisa Pratt: There are so many estimates out there now about biomass and the answer is: We really don't know, because we don't have an adequate inventory right now for the sub-sea biomass or for the deep-Earth biomass. We just don't know.

John Rummel: I would point out that 3 billion years ago, when life was abundant on this planet finally, that the Earth was a planet of microbes. Microbes ruled the Earth. That hasn't changed at all. We are still a microbial environment. We have a really nice skin coat of people and critters and plants. But effectively, the biomass is probably at least 50 percent microbes and if you count the ones we carry with us, maybe even more.

Q: You were talking about the potential that any current surviving native martian life might exist as far down as a couple of clicks below the surface. If it required us to drill to a great depth in order to encounter the native life there, if it exists, then would that leave us free to do what we pleased with the uncolonized surface, while leaving the martian ecosystem undisturbed?

David Grinspoon: I think it's a question of whether we're smart enough to know if we can have extensive industrial activities, or whatever kind of activities we're going to have on the surface, and not affect the subsurface. I don't know if we're smart enough yet to make that decision, but theoretically I would say that, yes, if we knew that we weren't affecting that subsurface life, then perhaps there isn't that much difference ethically between acting on the surface of a dead Mars and a Mars with life that's completely unaffected by our actions. Unless, I suppose, we think that subsurface life has some long-term potential to become surface life. But the way Mars is going now, and the way Mars's future looks, I would say that's not particularly likely.

Greg Bear: Yeah, we don't know about Mars, but I can tell you that on Earth there is a constant churning between the deep Earth bacteria and archaea and the upper surface. It's constant, but it's very slow. It's probably on the order of tens of millions to hundreds of millions of years for a complete turnaround, but it still exists. I don't know if that same turnaround would be on Mars.

Lisa Pratt: I think, in addition, the minute we talk about doing anything with the surface, we're going to lift the lid of the permafrost to get the liquid water. At that point we've probably opened holes and cracks into the subsurface world, so I think it's very hard to imagine that you could really have a barrier between those two worlds that would be effective.

John Rummel: I'm absolutely certain we don't know enough about Mars to know an answer to that question.

Q: You spoke earlier about three different aspects for looking at martian life: exploration, exploitation and, I believe, ecosynthesis was the term. The first two are certainly focused within the lifespan of an individual or even an individual society - How can I learn something? How can I use something? - where the final one, ecosynthesis, given the time frame of forty thousand years at the minimum, presents a challenge of changing human perspective into encompassing a task that not only goes beyond the lifetime of a person or a society, but well beyond the lifetime of human civilization. For Greg and for Stan, how do you see people learning to embrace that sort of change in perspective?

Kim Stanley Robinson: My teacher, Gary Snyder, the California poet, always dates his letters, I guess right now it'd be 41004. So he's saying that from about the time forty thousand years ago, humanity has been itself, dating it from the start of art, I believe.

I think taking the long view is a good thing. The idea that it's a hundred thousand-year project, of course, puts it on a different scale than anything else that we do and takes out the normal use values that we bring to bear. And yet, humanity was around forty thousand years ago, and it really ought to be forty thousand years in the future.

So it's good to think about these long-term projects just for the way it increases our sense of ourselves as a species, and also for planetary consciousness. It's not just our species, we are interpenetrated with all things, including the bacteria, on the planet. So it is a healthy thing to think about. It is not escapist. It's an interesting new lens to look at our current situation.

Greg Bear: Exactly. The existence of science fiction and of the Science Fiction Museum is a sign of evolutionary advancement on a huge scale.

Q: A couple of years ago, I was riding on BART through Oakland, and I ran into a gentleman who had a very different perspective. I don't know how we got from the subject of his love life, which is what he started with, to human exploration of space, but when I mentioned that I did, in fact, favor manned expeditions to Mars, he got very angry. In his worldview, this made him assume that I favored abandoning the Earth to pollution and ruin and going off with a technocratic elite and leaving everyone else behind. So my question is kind of two-fold: Who decides, when we talk about one country versus another country deciding these policies, we're a democratic country, at least in theory. I'd like to know how you get people involved in the decision-making? And second of all, how do you get them educated enough to know what the decision is?

Donna Shirley: I'd like to say something about that. That's what the Science Fiction Museum is designed to do, hopefully. It's the function of all museums to preserve knowledge. But it's the function of the Science Fiction Museum to speculate from that knowledge, to go forward from it, and to ask the questions about what might happen.

Thinking about the future is going to help you make those sorts of decisions. People do need to be informed, and one of the things we're trying to do is to get people interested in science. We want to use science fiction, frankly, to suck people in the way that some of us were sucked in when we were kids, into going into science and engineering, or at least appreciating science and engineering. We're also interested in promoting literacy, because if people can't read, they can't really understand things. They're not going to get everything they know from television. So we have an evil purpose. Our plan is to subvert children - heh, heh, heh. "Did you watch 'The Matrix?'" "Yes." "Did you like it?" "Yes." "Do you know that's science fiction?" "No, I didn't know that. What would be the science behind making that happen?" So we do have this evil purpose and I think that's at least one way that we're going to do these things.

Greg Bear: Yeah, this technocratic thing. I think science fiction has really come of age, because now we're starting to upset the Greens. And this is a good sign. The dialog is about to get really serious, because we've convinced enough people that this stuff is doable. Going into space is doable, building micro-machines is doable, taking over the genome is doable. Now they have to think in what used to be called science-fictional terms just to deal with current politics. And our present president has a very hard time thinking in science-fictional terms, despite giving an interesting pronouncement on the space program. His biological program is nothing. So we've got to deal with these issues on a larger scale. It's a little too late for people who are becoming president now. We've got to perhaps vote for them on the basis of whether or not they read science fiction when they were kids.

Next Page: Audience Questions about the Martian Future

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Part 7: Audience Questions about the Martian Future

Q: One of the main criticisms of astrobiology as a science is that our sample size is one - life on Earth. So, I've been hearing you guys talk about the merits of Mars, if it has life, and we