A conversation with Chris McKay, senior scientist at the Planetary Systems Branch of NASA’s Ames Research Center who works on projects from Cassini to Curiosity.
Host (Matthew Buffington): Welcome to NASA in Silicon Valley, episode 57. This week we’re talking to Chris McKay, a senior scientist in the Planetary Systems Branch of NASA Ames. Chris has spent his whole fascinating career here at Ames, focusing on the evolution of the solar system and the origin of life. He studies the way planet Earth interacts with life forms here – especially in extreme environments, like Antarctica and the world’s driest desert – to help us search for life elsewhere in the solar system. Chris is also involved in planning future missions to Mars, including human exploration programs, and others that will visit the ocean worlds of the outer solar system. It’s quite a menu of topics, and here to tell us more about his work is Chris McKay.
Host: Most of the listeners have either watched and seen you on a NOVA documentary or a BBC thing, so it’s not your first rodeo. But for everybody who hasn’t really gotten into, “Who is Chris McKay?” talk a little bit about how you joined NASA, how you came to Silicon Valley.
Chris McKay: I came to NASA as a student on a summer internship. And it was a transformational event. It was a long, long time ago. I drove my car out here from Colorado.
Chris McKay:And came here for eight weeks working with one of the leaders in the field of planetary science. And it was really exciting. It was great to come to a NASA center. It was great to meet the people here. And what I really liked was the work that was being done here, the research focusing on planets and life. And, also, what you might call the people culture. I really liked the scientists here and their approach to things, and they are easy going.
And, to me, it was such a contrast with the university. I was at a good university, great, but things were much more relaxed. There wasn’t any hierarchy of, “Me professor, you student.” It was all, “We’re all researchers, we’re all working together.”
Chris McKay:Yeah. And so when they suggested I come back on graduation, I just jumped at it. I didn’t apply anywhere else.
Host: Oh, wow.
Chris McKay: I came right here. I don’t know what I would have done if I hadn’t gotten the position. And I’ve been here ever since. They haven’t been able to get rid of me.
Host: Were you working on a doctorate by then?
Chris McKay: I was doing my Ph.D. research, and I came here for a summer as a graduate student. And then two years later I finished my Ph.D. and came here as a postdoc. And I really like what we do, obviously. I like planetary science and I like the idea that we’re searching for life on other worlds and trying to understand the Earth better. And I really like the people that I worked with here. And it’s been a good fit and I’ve really enjoyed it.
Host:I’m guessing your Ph.D., was that actually in planetary science and that just was what you started working on when you came over?
Chris McKay: No. My Ph.D. was more on atmospheric science, more on Earth atmosphere.
Chris McKay: And my migration toward planetary came in the middle of my Ph.D. program. And coming to Ames was part of that migration. And it was partly triggered by Viking landing on Mars. So I’m in grad school. Viking lands on Mars, the first landing on another planet. And its goal is to search for life. And I just thought, “Wow!”
Host: I’m in.
Chris McKay: I’m in.
Host: You got me hooked.
Chris McKay: That is really amazing. And I’ve been sort of in that orbit ever since.
Host: And so when you first came, you just picked up on that work, or just continuing what you were already working on? How did that kind of morph and change once you were now in the federal government and you’re a NASA employee?
Chris McKay: Well, what happened was, I continued to do what you might call planetary physics. And the guy I worked with, Jim Pollack, was a leader in the field in planetary physics. And working with him was really a pleasure and I continued to do that, and I still do some of that now. But as I came to Ames –– and Ames’ strong background in astrobiology even then, although we didn’t call it astrobiology, there was a strong background here –– I picked that up, as well.
And more and more of my time was spent studying life in extreme environments, interacting with people who were working in the labs studying life, and pulling in more and more biology into my planetary physics background. So I still can do the planetary physics, but I’ve become more and more focused on the search for life in the astrobiology, and Mars and Europa and Enceladus and all these worlds that look like they may have had water and, hence, may have had life.
And the search for life has become the focus, but I use my training in planetary physics to support that focus.
Host: So, basically, understanding Earth and how our atmosphere works.
Chris McKay: Correct.
Host: And then how can you extrapolate that to other worlds.
Chris McKay: Right. Earth is the big teacher. Earth teaches us about life. It teaches us about planets. It teaches us about how they work together. And so everything we think about in terms of searching for life is rooted on the studying of Earth. And so a lot of my time is spent going to places on Earth that are at the edges of the habitable zone, if you will.
Going to the Antarctic dry valleys, going to the driest place on Earth, the Atacama Desert, Death Valley, the top of mountains in the equator, places like that, and trying to understand life on the edge. Now, this is the edge literally. Not the cultural edge, but the literal edge of survival.
Host:Yes, exactly. Not Aerosmith.
Chris McKay: Yeah, right.
Host: So talk a little bit about that. When you first joined NASA and you’re working on this stuff, were you able to just leverage that into going to Chile, going to Antarctica? How did you start working that in?
Chris McKay: Well, the way we do it, the realities of being a scientist is you have to write proposals. So let me take a particular example, the work we were doing in the Atacama Desert. It was clear that this was the driest desert on Earth. It was on my list of places that we had to go. So what I had to do is write a proposal. I write a proposal, send it to [NASA] Headquarters: thumbs down.
I revise it, send it again: thumbs down. I revise it, send it again: we got funded. We got five years of funding, big team involving people from Ames, from [University of California,] Berkeley, from Louisiana State [University], a big expedition to the driest place on Earth. We find and understand it and it’s now a significant ongoing research activity.
So there’s always the challenge of getting your ideas accepted and getting going. But the interest in these places is real, and I don’t mind writing the proposal three times if it means that we can get the program going. And every iteration the proposal is better.
Host: Even as you think of NASA’s Ames Research Center, it kind of goes into almost the fundamental difference between within NASA a space flight center versus a research center. If you think of Kennedy [Space Center] as launching the rockets and [Johnson Space Center in] Houston is training the astronauts, at the end of the day, all that science has to start somewhere.
Whereas, Houston you see all over the place, “failure is not an option.” For us, at a research center, especially in the startup capital of the world, it’s like failure is almost like a feature. You have to be able to fail as that price of innovation.
Chris McKay: Sure, sure. And we see this, for example, in the Atacama Desert. We go there thinking we’re going to find a certain set of things. And we get there and it’s really different. And so I wouldn’t so much call it failure as surprise.
Chris McKay: We go there and we have a certain set of expectations. We go there with a certain hypothesis in mind and we’re surprised. And my first big surprise, for example, in the Atacama, was we went there and put out a state-of-the-art weather recording station. So this will record very, very tiny levels of rain. And our colleagues in Chile are emailing us back the results. And after a year-and-a-half I think something is broken because we haven’t seen a single drop of moisture for a year-and-a-half.
Now, we had been studying dry deserts for decades. And even in places where people say, “Oh, it never rains here,” I know that with our instrumentation we would record lots of rain events. So I went back to Chile with a whole new set of kits to replace the broken station. I got down there and tested it and it was working fine. It was just that dry. It was drier than the next driest place we’d ever studied by a factor of 50.
And it was a complete surprise. We just hadn’t appreciated how dry “dry” can really be, until we had taken that to data. And we were the first one to put a weather station in this dry core. People aren’t that interested in dry deserts because you can’t do agriculture there, and there’s not much human activity there. And so we were completely off-guard in terms of what to expect.
But that was interesting. And then we followed up on that trying to understand, “How does the biology in these soils react to this fundamentally dry place that is so much drier than anywhere else on Earth?” So we are often mistaken, and we often try out a certain line of research and we realize that we’re wrong and we have to change. And, like you say, that’s a feature. It’s not a problem. That’s a feature because that’s how we learn, that’s how we prepare for surprises.
Host: And no humans are being harmed in the process.
Chris McKay:Exactly, exactly.
Host: You’re not blowing up multimillion dollar equipment.
Chris McKay: That’s right. It’s not big expenses. Now, I did drag a bunch of equipment there needlessly. But the costs and the implications of that learning process are small. So it’s a lot of fun. I enjoy it.
Host: And the Atacama Desert is particularly interesting now with journey to Mars, and trying to understand Mars. How is that an analog?
Chris McKay: Well, the Atacama Desert and places like it are interesting in two ways, I think. One, they’re interesting scientifically. If we’re going to search for life on Mars, well, let’s go search for it in the Atacama. If we can’t make things work and figure it out in the Atacama, we’re not ready for Mars. Right?
Chris McKay: So it’s a good test of our biology and our technology. But it’s also an interesting comparison in terms of the human factors. We spend a lot of time in a little camp in the Atacama, or spend a couple months in a field station in the high mountains in Antarctica. And we get a sense for what it must be like to be an astronaut on Mars. It’s not at all like in the movies. It’s much more challenging and much more difficult.
And the big lesson for me, personally, was how much it depends on the team working together. If the team works together, obstacles can be overcome. If the team fragments in the face of obstacles, it’s hopeless. And, actually, one of the things I liked about the movie “The Martian,” is that the way that it was portrayed was as a team working together. Even though there were problems, even though things went wrong, they worked together. In adversity they came together.
That, to me, is the most important lesson that I personally learned from working in these extreme environments. And I hadn’t expected it. As an engineer and a scientist I expected that what determined our success in these environments was how good our gadgets worked and how good our gear was, and whether our tents were rated to minus 20 [degrees] or not.
That stuff is secondary. What matters most is how well the team comes together when things go bad, and they always go bad. Something is always going to go bad.
Host: And I know NASA Ames has worked on other kind of analogs or tests like BASALT or other mock simulations and stuff like that. Are you working on some of that stuff?
Chris McKay: That’s right. I’m involved in those, but the whole effort has expanded considerably. I couldn’t possibly go on all the trips that are now being done. I’m a co-investigator on BASALT, but I haven’t been involved directly in the field work at the site in Hawaii. And I’ve worked at the site in Idaho. Again, going to these places is both a scientific investigation, as well as a human factors investigation; learning how the crew will work together and how they will do their research.
And the people’s work in this area is getting more and more sophisticated. When I first went to the Atacama and first in the Antarctic, our approach to the human factors was rather anecdotal. We were all just five scientists in a tent. Now it’s much more systematic and made much more relevant to future planetary missions. And that’s a good thing, as we learn more.
Host: And one of the biggest advantages of doing it here on Earth is you can breathe the air. There are so many logistical challenges. Just thinking of the logistical challenges of being in one of those worlds where there’s a delay between Earth and us, and then you can’t breathe the air if something goes wrong. You’re just trying to survive, let alone do science.
Chris McKay: Right. There’s a few places that I have been involved in, where the risk to death is immediate. Working under water in ice-covered lakes. We cut a hole in the lake, and then dive underneath the ice in a dry suit.
Host: Oh, wow.
Chris McKay: And it’s somewhat analogous to being on the surface of Mars, where if you do something wrong, there’s not much option, not much margin. And so you have to be extremely careful. And another example, we’re working in a cave in Mexico that’s extremely hot; temperatures of 55 centigrade and 100 percent humidity, and life support systems that are cooling us down. And if that breaks down, we’ve got five minutes to get out of the cave before we fall over.
So the occasional time when our fieldwork has taken us to really life-threatening environments, we get a glimpse of what it might be like on Mars. Now, we’re only doing it for a day, maybe an hour. But we get a glimpse of what it must be like and what you’d have to face for a whole year on the surface of Mars. And it’s going to take some mental discipline to deal with the situations like that.
Host: You see the mix of the science and almost, for lack of a better word, the thrill-seeking, that adrenaline rush. But then I’m sure a big part of it is like controlling that adrenaline when you’re like, “Whoa! This is going down,” but keeping your cool to work under pressure.
Chris McKay: Right. And making sure that your team is coordinated. The biggest safety feature are things like that, is the team is coordinated. So if somebody is having a problem, other people are there and they realize it. And it really goes back to the human factors. The most important safety feature I’ve found is the team and the human factors of the team.
And I’m sure that’s going to be the case on Mars. If the team works together, it’s going to be good. If the team doesn’t work together, no amount of gadgets or technologies are going to be a replacement for that teamwork. And that’s been the lesson, in some sense, the higher level lesson that I’ve picked up from my limited experience in these extreme, deathly environments and from these Mars-like environments, in general. It is make sure you’ve got a good team.
Host: Talk a little bit about your day-to-day now. What are some of the projects you’re working on, have your hands in that are exciting and fun?
Chris McKay: Well, right now I’m involved in two things. One is I’m a part of the Curiosity on Mars, the rover on Mars. The data comes back. We’ve been there four years and there’s still surprises. We still have long telecons and we still have big arguments. And that’s all out of fun. “We’ve got to go do this.” And, “This means this.” “No. It means that.” So that keeps me active and interested.
But new opportunities are coming up in the outer solar system. Discoveries of oceans on Europa and oceans on Enceladus have motivated NASA Headquarters to call for new mission ideas to go out to the outer solar system and search for life there. And so I have jumped into that fully.
Host: Oh, I bet.
Chris McKay: And I’m now spending the other 24 hours of the day working on projects that will go to Enceladus and Europa. And that’s a really new and exciting opportunity. It’s a little more challenging than Mars. You can get to Mars in six months.
Host: Yeah. We’ve proven it.
Chris McKay: Yeah. And that’s not bad. A trip to Saturn and to Enceladus, you’re in space flying for 9 or 10 years. So it’s a whole different perspective of mission. We are now planning missions to the outer solar system, say Enceladus, where the data won’t come back for 20 years. And that forces us to think intergenerational.
So we are recruiting, as part of our teams on these missions, people who are just starting their career. And we’re putting in place plans to recruit people that right now are in middle school. But by the time we get there, they’ll be completing their graduate work, and then we will recruit them a couple of years before they arrive, train them and bring them up-to-speed. And they’ll probably be the ones that will be using the latest tools and the latest approaches and bringing the innovative thinking to analyze the data.
So it’s kind of interesting to be forced to plan a mission that’s intergenerational and know that your success depends on students that are in middle school now coming through the pipeline, getting their degree, and being available to be part of our mission in 20 years. It’s neat. So when I go and give talks to middle school students, I look at them thinking, “Some of you may be analyzing the data of the mission that I’m working on now. So get to doing your math.”
Host: Well, that’s kind of almost how NASA has been. I think of during the Apollo, the space race to get to the Moon, and how many baby boomers were inspired by that. And then that led into the shuttle program and continuing now.
Chris McKay: Right. NASA and space, in general, has always been an important motivation for kids. And I’ve always been pleased that NASA has taken that view and seeing contributing to science education and math education as an important part of its mission. And that’s not what I do. I’m not an educator. I’m a researcher.
But I’ve always been happy to help whenever the Education Office or the Public Affairs Office has needed to outreach to students. Because I think it’s incredibly important. And here on this mission I see it specifically. I can’t do this mission that I’m trying to do without recruiting students who right now are in middle school, basically.
Host: Yeah. I imagine even just the whole NASA mission process of writing the proposals, getting some rejected, some coming back. And then once it’s even approved, all the time it takes to create it, let alone to get there.
Chris McKay: Right.
Host: You mentioned Enceladus, you mentioned Europa. Talk a little bit about Enceladus. What makes that interesting, as opposed to other targets, like Ceres or other things.
Chris McKay: The reason Enceladus is so interesting to me is that here is this small moon of Saturn. It’s only 500 kilometers across. But evidence from Cassini clearly shows that it has an ocean underneath the ice. And even more interesting, there’s cracks in the ice and the ocean is leaking out. So there’s a jet of water coming out. Think of it as a geyser, coming out from Enceladus. And the Cassini spacecraft was able to fly through those jets, analyze them, and found that there were organics in those jets.
So here we have an ocean with organics. I like to call it a soup. This is a soup. So my question is, is it a prebiotic soup? Is it a soup that life could emerge in? So what we want to do is build a spacecraft that will fly through that plume and search for evidence of life. Is there life in the plume? And NASA headquarters has now put out a call for mission concepts to do exactly that. That is extremely exciting.
But it’s very far away. And the mission will, as I said, take a long time. But all the more reason to work on it now.
Host: Wow. I remember following up and reading some stuff on Cassini as it starts hitting its end of life. And they’ve really stretched that out. But even when it gets to the point of running out of fuel when it’s done, it’s not a matter of just letting it float out there. They’re purposefully having it burn up in the atmosphere of Saturn so that it doesn’t hit Enceladus or somewhere else and it inadvertently disturb what we’re hoping to find in the future.
Chris McKay: Right. The Cassini spacecraft has microorganisms on it. We know it. There are bugs from Earth on that spacecraft. We don’t want to contaminate that ocean on Enceladus. We know that that ocean would be habitable. If you were to take a little bit of dirt from Earth and put it in that ocean, the organisms in that dirt would be very happy to live there. We don’t want to do that.
So as the Cassini spacecraft ends its really successful, wonderfully successful mission, it will be purposefully steered into Saturn. And you say, “Well, isn’t that a loss.” Well, it’s not really a loss. Even if it was just allowed to go derelict, eventually it would spiral into Saturn, as well. People in the public had asked me, “Well, couldn’t we just steer it off to the outer solar system and head to the stars like Voyager or Pioneer?”
But we can’t. Cassini is trapped in Saturn’s gravitational well. There is no way it can escape. Its ultimate fate will be to go into Saturn, unless it crashes into –
Host:Whether we do it on purpose or not.
Chris McKay: Right. Or just wait for it to happen. And the risk is, if we wait for it to happen, it might, small chance, but it might crash into Enceladus and contaminate it. So to avoid that risk we’re going to purposefully crash it into Saturn. But there’s really no other choice. Cassini, once we put it in orbit around Saturn, there was no return. We do not have the technology to bring it out again and fly on the way Voyager did.
Neither the Voyager nor the Pioneer went into orbit. They just flew by. And so they were never bound to Saturn. But Cassini is bound to Saturn just like Galileo was bound to Jupiter. And so, ultimately, it would go into Saturn’s atmosphere.
Host: Talking about Enceladus this has got me thinking. It’s really far out there, out of what we would consider the habitable zone of planets.
Chris McKay: Right.
Host: But, yet, there’s clearly some seismic activity if these plumes are getting thrown up in the air. And organics and like water. How is it that there is that activity out there in a place where you would assume would be a frozen rock?
Chris McKay: This is a really good point. When I first got interested in astrobiology and life on other worlds, the scope of our investigation was limited to Earth-like planets around the stars. So Earth and Mars and Venus were the only game in town. And as we explored the outer solar system, we realized that that was not the case. We were surprised.
We discovered oceans on Europa, oceans on Enceladus. And we struggled at first to understand how could there be oceans out there so far, so cold? And the answer turns out to be tidal heating. As those small moons go around these giant planets, they get squeezed by the gravity of these giant worlds, and that squeezing generates heat.
So their oceans are warmed not by sunlight, like the Earth, but by gravitational heating. And that has enabled large oceans on many moons. And, in fact, it may be that the oceans in the universe, there’s more oceans in the universe driven by tidal heating, than driven by sunlight. So our ocean may actually be the oddball, rather than the typical case.
So it’s very exciting to understand these possibilities and to have the possibility of doing missions to follow-up these discoveries and explore these oceans, and to see if these oceans, like our oceans, are cradles for life, as well.
Host: Yeah. It’s like we have the tidal thing and pulling back and forth. The first place I’m thinking of is when you look at the Kepler data, you look at these future exoplanet telescopes, always trying to focus on the habitable zone. The Venus too hot, Mars too cold, Earth just right in that Goldilocks zone. And it’s been exciting to see how every single star has a planet, and some of them are in that habitable zone. But planets that are outside of that, these tidal forces could have – could possibly harbor life.
Chris McKay: Yeah. And that opens up the question, could we see moons like Europa and Enceladus around giant planets? How would we detect them? And it’s an interesting question because the way we would detect Earth-like planets is by looking at the atmosphere. You see oxygen and carbon dioxide and water in the atmosphere, ah-ha, Earth-like planet. But on Europa and on Enceladus the interesting stuff is buried under ice. So how do you detect it? Well there may be a way. And what’s different about Europa and Enceladus, if you were cruising through the solar system looking around, Earth would look odd. Oh, look at all that oxygen. Europa and Enceladus would look odd because they are so bright. They look like a fresh snowpack. And the reason is, because of these geyser activities, fresh snow is falling all the time.
Host: Oh, wow.
Chris McKay: So they are as bright as a fresh snowfall. And they are very unusual. All of the other moons out there are darker, but Enceladus and Europa are extremely bright. And so if we were looking around another star with a telescope and we saw a giant planet and we saw a moon around that planet, and that moon had a reflectance of very close to one, very, very bright, then we’d be able to say, “There’s a good chance that there’s an ocean in that world and it’s coming out and resurfacing. There’s snowfall. And that’s what’s making it so bright.” And, hence, it would be a good target for an ocean.
Host: Wow. If we fall into the realm of you’re a NASA administrator for the day, or you have all of these possible worlds, if you had to pick one, where is Chris McKay going to go?
Chris McKay: The way I think of that is, if somebody came to me with a little rocket ship and said, “You can fly this anywhere you want to go. Where do you want to go?” I would head straight for Enceladus. I would fly through that plume, collect a bunch of that material, and bring it back to Earth and put it in the lab and say to the lab scientist, “Is there life in this stuff?” I just flew out to 10AU, hopefully, it didn’t take more than an afternoon, got back to Earth, and put this stuff in the lab. Is there life? I think that is the most compelling target right now. Fly through the plume of Enceladus. We know it’s got water and it came from an ocean. It’s got organic material. It’s got biologically available nitrogen, biologically available sulfur. It’s got all the elements needed for life. It’s got energy sources. It’s perfect. Is there life in that? That’s the question I’d like to know.
Now, if I could recharge my rocket ship and go to somewhere else, the next place I’d go would be to Mars. I’d land at Gale Crater, where Curiosity is. But now I would go with a really deep drill. I’d drill 10 meters down below the ground, grab some of that gooey dark stuff, bring it back to the lab, too, and say to the lab folks, “Is there life in this stuff, too?” And if you’d give me a third trip –
Host: Yes, let’s keep going.
Chris McKay: I would head out to Europa, get through the ice somehow, and get a sample of that water, and bring it back to Earth. And then if I could get a fourth trip, I would be out to Titan and bring back some really strange stuff, and hope that there is life that’s living in a liquid there. It’s not water, it’s liquid methane. Really strange. But that’s why it’s at the bottom of my list, because we understand life can be in water, but could it be in liquid methane? We don’t know. At the end of those four trips I’d be willing to say, “Okay, I’ll retire that spacecraft. I’ve done enough.” So you gave me one and I want four.
Host: Hey, that works. Excellent. So for folks who are interested and who are following you, where can they look up more information on the stuff that you’re working on?
Chris McKay: Well, NASA has a website page. So I think if you type “Chris McKay NASA” it pops up. It lists the papers that I’ve published. Most of my work is put out into scientific literature. I don’t post it directly. But we post it through published papers. And NASA has a policy of making all of its research publicly available, so everything I’ve published is available, not only through the scientific journals, but also at the NASA information site. And so all the work we’ve done, everything we do is published, it’s all in the public domain, and it can all be accessed anywhere. And I encourage people to look at if they’re interested. And to those students out there, I’d say apply for summer internships at NASA because it could change your life.
Host: They could come over here and work for you for a little bit.
Chris McKay: There you go, yeah. I need some help.
Host: And then the circle of life continues, bringing another person in.
Chris McKay: That’s right.
Host: And, also, for anybody listening who may have a direct question for Chris, we’re using the hashtag #NASASiliconValley, and we’re on Twitter at NASA Ames. That’s a quick way they can jump start and kind of get around. Before the internship they can go ahead and ping you.
Chris McKay: Sure. And you can forward on those questions to me and I can help answer them.
Host: Absolutely. I have a feeling you’re going to be one of our returning Jeopardy champions as we do this.
Chris McKay: Okay, great.
Host: But thanks for coming over.
Chris McKay: You bet. My pleasure.