Joel McKinnon: Where did you go to school prior to your PhD studies at the University of Colorado in Boulder?

Chris McKay: Florida. You know Penny Boston?

JM: Yes, the microbiologist who is a member of the Mars Society board?

CM: She and I both came from Florida and we both ended up in Colorado by coincidence. I knew her as an undergraduate. I went to grad school in Colorado and got there in ’76. Left in ’82. Carol Stoker was there when I was there and Bob Zubrin came for “The Case for Mars” conference, I forget which one, II or III I think.

JM: You were there in the “Mars underground” days. How did that come together?

CM: It came together after Viking landed. Viking landed on Mars in 1976 and Carol and I were sharing an office at the time with a couple of other people and we decided to form a little study group looking at Mars based on the Viking results. That’s what generated what we called at the time the Mars study project. Then Leonard David suggested that it would be a good idea to have a conference. He said there’s a lot of people interested in Mars, why don’t you guys have a meeting? So we said, OK, not knowing any better and put together the first Case for Mars meeting. It was originally called “The Case for Man on Mars,” which was taken identically from the title of a paper that Ben Clark wrote. We were doing it together with Stan Kent who was down here at Ames. On the phone one night he said we can’t call it the Case for Man on Mars. And so we thought humans and later on no, I said let’s just drop it and make it The Case for Mars. And that’s how it became called that.

JM: More poetic.

CM: Yeah. And it’s also more general. We were just amazed at how much interest there was. That was 1980 and that’s when Leonard David started calling it the Mars underground and a lot of people said we should form a society- like the Mars Society. I said no, I don’t want anything to do with a formal society. I don’t have time to do fundraising and membership and all the things that are causing Bob and Maggie a headache. Nobody else wanted to do these things either, so we ended up resisting any attempts to become organized and that’s when we started getting called the Mars underground. That was in the late seventies- well really the early 80s- the first meeting was in 1980. Then it continued every three years. We weren’t as ambitious to try to do it every one year. That was something else that contributed to the underground idea is that there were not enough people willing to work to do it every year. It’s a lot of effort, you think of the Mars Society; they almost have to start planning the next conference the day after the end of the previous one. It’s a lot of effort to host a conference like that. All of us had day jobs and that’s why it ended up being once every three years.

JM: When did Robert Zubrin get involved?

CM: I forget exactly. He came to one of the conferences and sort of jumped in. He had some good ideas and continued to develop them- then he wrote the book “The Case for Mars” more about his specific plan called Mars Direct. Then there was a lot of enthusiasm generated by that book. So he said let’s form a society. I said if you want to form a society go for it. If you’re willing to do that- that’s great- I’m happy somebody is. He’s now struggling with all the issues that reinforced in my mind why I didn’t want to do that. I don’t want to spend my time worrying about membership roles and board of directors.

JM: In your travels, what are some of your favorite places you’ve encountered?

CM: Well my favorite place is really the dry valleys of Antarctica. That’s really the most amazing place I’ve been to. It’s really like another world in terms of its interest and its connection to things I’m interested in like Mars. It’s like a frozen desert- that’s why I imagine it’s sort of like Mars. It’s isolated and far away and you really get the sense of being out there.

JM: I hadn’t thought about the lack of jet contrails prior to your talk the other day.

CM: Yeah that’s another thing. Just those small little things you take for granted.

JM: I know you’re extremely busy with your science. Do you get a chance to read much recreationally? Do you read science fiction at all?

CM: I read occasional science fiction. I read a lot. I read an enormous amount. Most of what I read is science though- magazines and articles, Scientific American and National Geographic. I read a lot of magazines. The stack of magazines I read a month is about up to my chest. I read on planes a lot when I travel. That’s when I devour most of my reading.

JM: Mostly oriented towards the area of your research or more general?

CM: About a half is specific to my research, magazines like Icarus or Journal of Geophysical Research.

JM: What, other than planetary science do you find the most interesting?

CM: Everything I do could come under the category of planetary science, but it includes life in extreme environments. I’m doing it from the planetary point of view, but some of the things I read like about Antarctica and the Arctic- the people who are in those fields don’t think of themselves as planetary scientists. I work there as a planetary scientist but everybody else is a glaciologist or a geologist with more traditional views. I’m looking at the same things with the view of applying it to Mars. A lot of what I read doesn’t have Mars in it or Titan or any of the planets directly, but it’s indirectly connected. Then another quarter of what I read is general science and about a quarter is not science- Time, Atlantic Monthly, National Geographic…

JM: Have you read any Mars science fiction?

CM: No, I haven’t read any of them. I have them. Mars Crossing by Landis, Martian Race by Benford, a couple others. I read Zubrin’s book (First Landing)

CM: I think I did read his first one- a draft copy, but I haven’t read the others yet.

JM: I won’t ask you what your favorite is then.

CM Dune is my answer. Dune is my favorite science fiction novel. It’s gotta be a classic.

JM: Where are you specifically focusing your research right now?

CM: Right now, what I’m working on mostly is life in extreme environments- deserts. Cold deserts like the dry valleys- hot deserts like the Atacama and Death Valley- places like that.

JM: What is the most intriguing unanswered question that might be answered without leaving the Earth?

CM: Maybe the origin of life- we might answer that without leaving the Earth. How life got started.

JM: How close do you think we are to the answer?

CM: It varies. Sometimes I think we’re really close. Sometimes I think we’re missing something fundamental- that we’re no closer to it than Leonardo Da Vinci was to building a flying machine. It’s hard to say. The other fundamental question of course is are we alone? That one will probably only be answered by going away from the Earth. In a sense those are the two fundamental questions that I work on; the origin of life, and are we alone? There’s a third issue that is where are we going? That’s not a fundamental question as much as it is a decision- not a scientific inquiry as much as a decision of what we want to do.

JM: As in, do we leave this planet?

CM: Right. How do we do that and whom do we take with us? [laughs]

JM: And what do we do about this planet when we leave?

CM: Right. Do we leave it or do we just expand? I’m not a fan of thinking of this planet as disposable in any sense, I think that’s a big mistake. I don’t think it’s possible. With any foreseeable technology I can’t see abandoning this planet. People have this concept based on an analogy to the European migration to the new world that people can leave in a significant amount. That was true with what happened then- something like one third of the population moved to the United States. But you can’t move one third of the population of the Earth off the planet- the numbers just don’t work. With a small population like Ireland and big ships you can imagine moving a lot of people across. But the number of people on Earth is way up and the capability of moving people through space compared to a ship is way way down. The numbers just don’t work out by about 5 or 6 orders of magnitude.

JM: It would seem that the mass emigration idea somewhat undervalues the Earth as well?

CM: There’s no point in doing it. There’s nothing to be gained. And it can’t be done. All of those reasons argue against thinking of it in that way. Such as we leave when there is a disaster.

JM: I believe you already answered my next question- what the biggest unanswered question is presuming we can leave the Earth, which would be are we alone?

CM: Right. I think that’s a question that everybody thinks about. Some people think we already know the answer. They think the answer is no.

JM: Can you describe your ideal Mars exploration mission scenario with no budget constraints?

CM: If I was in charge of the Mars program and had no budget constraints I would do first a sample return mission. Then I would go after Gusev crater looking for fossils. Follow that with drilling in the south polar region looking for organisms preserved in the permafrost. That would be the near term. In the long term, establishment of a base. I would use the Antarctic as a model. United States put a base in Antarctica in 1957 with the intention of it being a permanent base and there have been people at that base since then continuously.

JM: That’s McMurdo?

CM: Yeah. No one person has been there all that time. People move in and out but there’s always been someone there- it’s never been abandoned even in winter. So I’d take that sort of model initially. Antarctica never expanded into a settlement in the sense of families living there- maybe Mars would- maybe it wouldn’t. I would start with a research outpost like Antarctica and see how it goes- see how it goes- see if people stay. A lot of people assume that the first people who go to Mars are going to be like settlers to the new world- a wagon train, there to homestead and build a farm- but I just don’t see that happening. It’s hard to imagine. The new world was easy- it wasn’t really new- there were already people living here. It was already a place that was user-friendly compared to Mars. I don’t see how the hardy pioneer striking out for the open frontier is going to work on Mars- so I think the Antarctic model is a better one. A small research base…

JM: Something highly dependent on Earth?

CM: Yeah, just the way Antarctica is highly dependent. Everything we eat gets shipped in from Seattle. Nothing is made or grown there.

JM: Do you think that would be the way it is done on Mars? It’s a lot more expensive to ship things there.

CM: Right, so there’d be some compromise. Probably life support would be there. There’d be the need to grow some things locally. That’s why, in a sense we don’t know. That’s why we should start with a research base and see how it goes. It could be that indeed people will want to settle. It’s hard to predict. No one has expressed any interest in settling in Antarctica. It could be that it’s too close- so they’re willing to commute. I’ve been working with people in Antarctica for twenty years- but I certainly wouldn’t live there because I could come home. I’d much rather live here and commute there, just like I don’t live in this office. I commute to this office. But if it were far enough away, where the commute took two years- maybe I would live there for a longer period. It’s hard to predict. I think it’s one of the things we’ll just have to wait and see.

JM: With real world budget constraints what would you ideal mission be?

CM: The same thing- only slower. I think that what’s the right thing to do isn’t any different in my mind- it’s just how fast you do it. Do you do it quickly or do you do it slowly. The advantage to doing it slowly is that technology allows you to do it cheaper and cheaper and cheaper if you wait. If Columbus had waited long enough he could have flown to the new world. That’s kind of a silly statement, but the point is that the longer you wait the more capable technology becomes and the cheaper it becomes to do things. So I think that will eventually be true in space. Eventually we’ll be able to send humans to Mars for the cost that we now send robots to Mars. We’ll have better computers, and better machines and better manufacturing- better processes in general. But that’s the slow route- if you have more money you can go faster.

JM: Zubrin in Entering Space talks about the Ming Dynasty and how they were once poised to take over the world but pulled back and never were a serious force again. Gregory Benford talks about how if you don’t do it while you’re able you may lose the chance to ever do it. Does this possibility concern you?

CM: I don’t know. I don’t see those arguments as compelling. I don’t think that the chance to do it will go away. It may be true, but I don’t think that space exploration is that fragile that we’ll stop doing it if we don’t go right away. People who follow that logic sometimes say that if we don’t go in the next five years we’ll never go. I don’t find any of those arguments compelling. Obviously I’d like to go sooner than later, but I think that later will happen. I don’t think that there’s any window that will close. In fact I see everything pointing to the opposite- that it gets easier and easier- better and better to go. You can even imagine nanotechnology and micromachines making it easier and easier to go. Self-repairing mechanisms and feedback controls based on computers will make it simpler to imagine building a base for people. I don’t think it’s going to get to a point where we can’t go.

JM: What’s your gut feeling on where life on Earth came from?

CM: I guess I don’t have a gut feeling. The data is too conflicting. There’s some data that says it started here and some data says it couldn’t have started here. The data that says it started here comes from the tree of life. If you look at the tree of life and you look at the branches- they all, deep back, clearly originated together on Earth, but at the same time life starts so quickly. I think it’s really a mystery. If somebody had asked me ten or twenty years ago I would have said on Earth. But it’s now less certain that it started on Earth.

JM: What’s the evidence that it couldn’t have come from Earth?

CM: The evidence against it coming from Earth is the speed with which life appeared on Earth. It seems likes it’s there fully born- poof- it’s already alive. The easiest explanation for that is it fell in. As we look further and further back we see evidence for life as early as we can see. It’s now 3.8 billion years ago that we see evidence for life. I think there is data pointing us in both directions.

JM: You’ve said that phylogenetic analysis of life shows that all life had a common ancestor. Doesn’t this argue against there being a second genesis on Mars, since that life would inevitably have found its way here and be represented in the tree of life?

CM: It’s a good point. If you trace life on Earth it seems to go back to a single point. One could take the view that that was a Martian- that point. So why didn’t it come again and again? That is a good point and we don’t have an answer for that. That is one of the arguments for life starting on Earth. It may be used as an argument against repeated introduction of life from Mars. It can’t be used as an argument against an early, single incident of life coming from Mars.

JM: If life on Mars terminated at some point several billion years in the past you wouldn’t expect to have repeated introductions, would you?

CM: That’s right, but if the earliest ancestor is as old as we think it is- it’s before Mars died.

JM: If you had several repeated introductions of life from Mars in that general time period might it not be resolvable as separate introductions?

CM: It might not. Especially if they all ended up merging effectively into one type.

JM: If it turns out that Mars is and always was completely barren, assuming this could be determined conclusively, where would you direct your research?

CM: Probably to Europa. It would be bad news for Mars- that’s for sure. Europa is the next best bet. After that it’s a long wait- for interstellar travel. The nearby stars are not nearby. They’re a long, long way away. So I think if we have no luck on Mars and no luck on Europa we’re going to have no luck for a long time.

JM: You say that Earth’s polar regions are a good analog for the situation on early Mars. It seems that there’d be a big difference in that these regions exist within the context of a thriving biosphere, unlike the situation on early Mars. Can life originate in these kinds of places or does it have to migrate there?

CM: We don’t know. The part of Mars that we see that was like Earth’s polar regions was Mars 3.8 billion years ago. We don’t see what Mars was like before that. The geologic record that we see on the surface of Mars doesn’t look backwards before that because that was all erased by the late bombardment. As far back as we can see it was like the polar regions. The question of the origin of life was key. How did life get started? It is hard to understand a whole planet that’s like the polar regions versus the polar regions of a planet that’s rich in life. We don’t even know how life got started on Earth, so we have no idea how it got started on Mars if it did. These are questions that are beyond what we can do right now. As a result, our research has only been focused on the question of how does life survive in the polar regions today. You can’t ask the question of how does life originate in the polar regions because we don’t know how life originated at all. That’s the weakness of our model for Mars.

JM: Do you know where the organisms found today in the dry valleys originated?

CM: Oh yeah, they come from the rest of the biosphere- carried by the wind.

JM: So you’d still need to know where the source of life would be…

CM: …on Mars, right. We don’t know the source of life on Earth ultimately. It’s a big problem- on Mars it’s a little more extreme.

JM: You said that life on Mars would have had a head start relative to the Earth due to the Moon-forming impact. I hadn’t been aware that that was common knowledge- that the Earth’s moon was formed from an impact?

CM: I wouldn’t say it’s common knowledge, but it’s becoming an accepted scientific hypothesis for the Moon formation.

JM: How did it happen?

CM: A Mars-sized object slammed in to the Earth and knocks a chunk of material off which condenses to form the moon. It’s a major cataclysm that hits the reset button on life, for sure.

JM: That would have sterilized the Earth and set back the time when life could begin by how long?

CM: It would have reset the clock at 4.5 billion years ago.

JM: When did the planet finish accreting?

CM: The planet is accreting up until 3.8, so this is during the accretion phase. We see evidence for life at 3.8 billion years ago, so at 4.55 who knows what was happening? On Mars we have rocks that are 4.6 Billion years old, so clearly Mars went through this time period with a relatively stable surface. So if life started earlier than 4.5 on Earth it would have been wiped out by the Moon-forming impact.

JM: You think life could have started that early?

CM: We don’t know. We don’t have any record of it because it’s all destroyed.

JM: Would one idea for why it took so long for life to appear is that it would have taken that long?

CM: One idea is that life starts very quickly- life only takes ten million years. Sounds like a long time but in the geological record that’s very small. The other possibility is that life comes in from elsewhere. Either way, life could have started before 4.5 billion years ago, subsequently to be eradicated by the impact. So the Moon-forming impact may have been bad news for life and Mars did not have such an impact. Maybe it had a better initial condition for life.

JM: How big is it assumed that the object was that created the Hellas basin on Mars?

CM: As a rule of thumb, the object is about one-tenth the size of the crater. Hellas is about 300 kilometers or something.

JM: That’s puny compared to what made the moon.

CM: Yeah. The Moon-forming impact would have been about one-tenth the mass of the Earth.

JM: I wonder how close that would have come to demolishing the Earth?

CM: Well, it does demolish the Earth. But the Earth just re-accretes because everything is gravitationally bound.

JM: Is it a matter of timing? If the collision had happened long after accretion there’d be a different story?

CM: No, I think you’d have the same story. The whole Earth becomes molten from the energy released. But it doesn’t blow up as in pieces flying away and Earth is gone because all the pieces are gravitationally bound. You can’t shatter the pieces. In the original Star Wars they destroy a planet and the pieces go flying like a hand grenade. The hand grenade is not gravitationally bound, so if you start off with some initial velocity the pieces just keep going away, whereas with the Earth if you smash something into it the pieces just come back together.

JM: The other thing that seems to provide an advantage for life to be created on Mars would be that it could have oxygenated much faster- in ten to a hundred million years?

CM: That’s not for creating life, that’s for life to develop into advanced forms.

JM: With that advantage, how advanced could life have become before Mars died?

CM: It could have been as advanced as small animals and plants- if evolution was faster on Mars. It could have gone up to the precambrian level- trilobites and palm trees; fern trees would have been possible. That’s not saying that they’re there, but theoretically it’s possible.

JM: So we shouldn’t be shocked if we find those kinds of fossils?

CM: To put it a different way, we should include in our research to be able to see things like that.

JM: Supposing it got that advanced, and the surface of the planet later becomes uninhabitable, could that life have migrated to the subsurface and continued to thrive and develop further?

CM: We don’t really know. On Earth there is subsurface life, but most of it is based on a connection with the surface life. So whether there can be subsurface life when the surface is dead we don’t know. But that’s something we’ll look for to be sure. Subsurface life is a possible source for life on Mars.

JM: I recall Penny Boston talking about life laying dormant within the deep rocks waiting for an environment to develop for it to occupy.

CM: These are all things we don’t really understand, so the only answer is to go look. If there is subsurface life on Mars, we have to go and try and find it.

JM: Thanks for taking the time to talk with me about all this.

CM: You’re welcome.

Joel McKinnon currently works as a User Interface Engineer for a software company in Half Moon Bay, California. In 2001, he helped to organize a fundraiser for the Mars Society which attracted filmmaker James Cameron, Robert Zubrin, Pascal Lee, and Chris McKay and raised well over $100,000. Joel has had a deep fascination with the planet Mars since childhood.