From Earth orbit to the Moon and Mars, explore the world of human spaceflight with NASA each week on the official podcast of the Johnson Space Center in Houston, Texas. Listen to in-depth conversations with the astronauts, scientists and engineers who make it possible.
On Episode 279, a NASA planetary geologist describes the Mars environment, terrain, weather, atmosphere, and more that humans will face while living on the Red Planet. This is the ninth episode in a reboot of our series about a human mission to Mars. This episode was recorded on December 14, 2020.
Transcript
Gary Jordan (Host): Houston, we have a podcast! Welcome to the official podcast of the NASA Johnson Space Center, Episode 279, “Welcome to Mars.” I’m Gary Jordan, and I’ll be your host today. On this podcast, we bring in the experts, scientists, engineers, and astronauts, all to let you know what’s going on in human spaceflight. We our continuing with a reboot of our series that outlines a human mission to and from the Red Planet. The ninth episode describes the Mars environment, terrain, weather, atmosphere and more that humans will face while living on the Red Planet. This episode was recorded on December 14, 2020. Let’s get started.
(Transition to original episode)
What is it about Mars that makes a human mission so challenging? So on this episode, we’re exploring the geology, the weather, the atmospheric pressure, the environment that humans can be expected to live in for a human mission to Mars. Joining us to discuss the planetary science of Mars is Dr. Paul Niles, planetary geologist and analytical geochemist based at NASA’s Johnson Space Center. You want to know all about Mars, this is your guy. So let’s get right into it: what you need to know about the Red Planet on your next visit, with Dr. Paul Niles.
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Host: Dr. Paul Niles, thanks so much for coming on Houston We Have a Podcast today.
Paul Niles: Great to be here.
Host: Hey, so this is all about the Red Planet itself. We’ve been doing this series called “Mars Monthly,” really taking a journey on a human mission to Mars from, basically, launching off of planet Earth, everything it takes to rendezvous with planet Earth — sorry, with Mars — and then everything about the journey along the way. We’ve even, we’ve even addressed what it’s like to land on Mars and even live on Mars, but this, we’re going to take a step back from the human side of things, definitely considering it as we’re going through some of these different aspects, but today we’re going to focus on the geology, the weather. So if you were going to visit Mars, this was your vacation, let’s just call it, for, for the layman, but maybe for the astronauts, their mission, you know, what are some of those things that you can expect? Paul, I wanted to start off first, before we get into, just Mars in general, by understanding how you got to this point of being, I don’t if we should call you the resident expert here at Johnson Space Center for, for Mars, everything Mars, but how did you get into this field of really understanding and focusing your career path on understanding a different planet?
Paul Niles: Yeah, yeah, I’m by far not the only resident expert. We’ve got a really vibrant group of Mars scientists here who’ve worked on almost all of the, the Mars missions since the two rovers, twin rovers, landed in 2003.
Host: Wow.
Paul Niles: So, so we’ve got a great group of people who are experts in understanding the local geology of Mars. Yeah, so, for me, I just was, you know, in college was trying to find my way, and I knew that I liked science but I didn’t want to be a physicist or a chemist, and I liked the natural world and I liked hiking, and, and geology just sort of rang out for me. The other thing that I knew that I liked was space, and when I found out that there are, that people study rocks on other planets, it was like a perfect, you know, hallelujah moment, moment of clarity, I guess you call it.
Host: Yeah.
Paul Niles: And so, yeah, that’s, that’s what pushed me towards, towards doing this.
Host: Well, let’s just say you’re taking your extended hiking trip, right, for those hikers out there that want to enjoy the outdoors, and they want to take their first steps on this, on this whole new world, let’s just say we’re an astronaut and we’re taking that first step out of our landing vehicle. We’ve landed on the surface of Mars. We’re taking our first step out onto the Martian surface. What are going to be some of those first things that we notice about the terrain, the view, the weather, the, you know, just the composition, the way that everything looks? What are going to be some of our first things that we notice when stepping onto the Martian surface?
Paul Niles: Yeah, so Mars is the, one of the most Earth-like planets, and the first thing I think that everyone would notice is just how similar it seems. You know, the Mars’ day is almost the same as an Earth day, only 37 minutes longer. The year is quite a lot longer, but the axial tilt of Mars is really, really similar to the Earth’s. So, and that’s the thing that gives us our seasons. So, so any, on any spot on Mars you’re going to have, you’re going to be in a summer or a winter or something like that, and so it’s going to look just a lot similar. Two of the biggest differences that you’re going to notice right away is the gravity and the atmosphere. The gravity is about a third of, of what is on Earth. And so, I mean, no one really knows what that exactly is going to be like, but I imagine it’s not quite looking like when you’re bouncing around on the Moon, if you’ve seen the videos of the astronauts on the Moon, but yeah, I think you would still have quite a spring in your step. The biggest, the biggest difference is definitely the atmosphere. The atmosphere on Mars is very, very thin, and so you would need to have a spacesuit and wear, you know, protective clothing for, for the cold. It’s very, very cold on Mars.
Host: So, let’s focus on the gravity first. What do we know about the gravity of Mars, kind of relative, you talked about it’s just a little bit more than the Moon; you know, how, how, how it would feel, and then kind of blending that question into maybe how it shaped the geology of Mars, if, if at all?
Paul Niles: Yeah, it’s been really hard, I mean, as a geologist, without a whole lot of other examples, it’s hard to know what, how the gravity affects the geological processes. We may sometimes, for example, trying to understand how the wind affects things; well, obviously, the rocks and the pebbles and the sand are going to be lighter, but then you also have a lighter atmosphere. So, so it’s hard to know, OK, well, there was, you know, a lot of debate about, for example, whether or not sand would get blown around at all, or whether the sand dunes that we see on Mars are, are just, have been there for billions of years. It turns out that you can, in fact, the sand does get blown around in these wind, wind events, but it’s a lot harder than you think. And so people would try and simulate this in the lab, and they would use like walnut shells and stuff like that. So, so it’s really hard to get your handle on, because the gravity could affect, you know, any number of things…
Host: Yeah.
Paul Niles:…how water flows on the surface, you know, landslides, you know, everything that you can imagine.
Host: Now let’s, let’s focus on the, the atmosphere was the other thing that you mentioned. One of the first things you mentioned when talking about the atmosphere was, was it’s pretty cold. Is that because of the atmosphere, or is it because of the position of Mars? Give us kind of an example of, of what you mean by cold on Mars?
Paul Niles: Yeah, yeah. So, so the atmosphere of Mars is, it’s pretty cold. I mean, it’s not, it’s not, you know, unreasonably cold, if you imagine places on the Earth. So, one of the, you know, it’s, you know, it can get much, much colder than places on the Earth — so down to minus-80, almost at minus-100 degrees Celsius. But it can be quite warm on the surface, minus-20 — I call that warm – minus-10. But the, the surface can actually get above freezing. So, so it can be, you know, moderately temperate. The main problem with the atmosphere, because it isn’t so thick, is it doesn’t hold in the heat as well as the Earth, so you don’t get that, you know, nice thermal blanket effect. And then, of course, Mars is, is much farther away from the Sun than the Earth, so, you get less sunlight and warmth from, from the Sun.
Host: Yeah, so, you talked about the atmosphere maybe being maybe a little bit thinner. So when you say cold, are there large temperature swings from day to night? And then, you also mentioned something about seasons, too, so I guess there’s, there’s a difference there.
Paul Niles: Yeah, actually, the, the seasons can be pretty hectic. One of the interesting things about Mars is that the atmosphere is made up entirely of CO2 (carbon dioxide) gas. So, and it turns out we actually have almost the same, you know, amount of CO2 gas here on Earth and on Mars. On Earth it’s only 300 ppm (parts per million), 400 ppm parts of the atmosphere; on Mars it’s the entire atmosphere. And then, in the winter, the polar regions get cold enough that they actually start condensing CO2 on the surface. Basically, CO2 is dry, when it becomes solid, is dry ice. So, basically, you get snow, CO2 snow or CO2 ice forming on the surface of the planet. And so, the whole atmosphere starts to condense out of the air. So, you actually get big differences in pressure between the summer and the winter. The, the parts of the planet that are in the summer and are warmer, relatively, versus the parts of the planet that are in the winter. So, we actually sent a spacecraft called the Phoenix lander to the northern sort of polar, sort of the equivalent of the Arctic Circle, on Mars, and that, we, we knew was going to be a short mission, because after, once the winter hit, it became covered with almost up to a meter of ice and snow. So, so that is definitely a pretty alien aspect of Mars. In fact, one of, one of the best places to visit I would think would be the polar hood, sort of walking around on these CO2 ice deposits. I think it would be pretty amazing, although pretty difficult to do with the current technology as far as what we need for warmth and, and spacesuit technology.
Host: Yeah, so when you’re looking at those pictures of Mars, and you see those, what looked like ice caps, the white parts, that kind of are little, you know, they’re just on the caps of Mars, that is mostly, you know, the red planet, orange planet, that, that is CO2. Now when you’re talking about temperatures, I mean, you talk about it being difficult based on the current technology; is it really, is it really that cold that now you’re going to have some engineering challenges if you wanted to explore those polar regions?
Paul Niles: Yeah, absolutely. It’s pretty cold to be able to do that. It’s not crazy. I don’t think — and I’m not an engineer so…
Host: Yeah.
Paul Niles:…and certainly, this isn’t one of the places that we’ve been talking about going to because it’s just not, not one of the places that’s got the highest science output. But, yeah, absolutely, dry ice is super-cold, and if you were walking around on it, it would be pretty intense. And to be clear, the, it turns out that the poles on Mars actually are mostly made up of water ice. So in the summer, when the atmosphere then, the dry ice goes away, you still are left behind with water ice at the poles. That’s the white, small white thing that you see in most pictures. And then you also have a lot of water ice under the surface, in permafrost. So, so there’s a lot of water ice, which is much more Earth-typical involved as well. And in fact, you can get layering of dry ice underneath water ice on the poles, and one of the interesting things that happens is you see these geysers that erupt. So basically, the sunlight filters through the water ice and heats up the dry ice underneath it, and that becomes CO2 gas that’s pressurized underneath the surface, and then it would, it will erupt through cracks in the surface and blow these giant, and what they look like are these sort of black spidery-looking things on the surface where dark sand has erupted on top of, of the brighter surface.
Host: You’re making a case for visiting these polar regions. A lot of cool stuff happening up there. The water ice is very, very interesting. You mentioned, though, that it would be, there’s a lot of engineering challenges that come with seeking out some of these polar regions, and then you mentioned that there are possibly more scientifically interesting areas. So if you were to focus maybe on landing at these scientific, scientifically interesting areas first, would you, would you have, you know, water ice that you can go and check out? What, what are some of the other interesting science, I guess interesting parts of science that you would have at this landing site?
Paul Niles: Yeah, so, so the, there are a lot of interesting targets that we would want to tar, target with human, human missions, and different things that have been discussed, and we’ve also explored several of these places with rovers and spacecraft already. So one of the kind of like really interesting places that you might want to go are similar to where the Curiosity rover is today, these mountains or large mounds of layered material, which are made up of hydrated sulfate, among other things. The hydrated sulfate is interesting geologically because it indicates past presence of water. And so, that’s a really interesting target to try and understand the history of water on Mars. The other thing that people have talked about using it for is if you get a lot of the sulfate you could, and you know, pile it into an oven, you can heat it up and recover the water from there, and if you’ve got the right kind of sulfate that can be a pretty effective way of harvesting water on Mars. Now, we think that there are actually a lot of older relics, ice deposits, that might be accessible in the mid-latitude, sort of not quite the equator but, you know, about 45 degrees or so, a little bit less, 30 degrees, where there’s ice underneath the surface that would be accessible if you drilled down into it. So, so there’s actually a lot of places where you can, if you can combine the presence of ice and scientific targets, it can be really good for human explorers.
Host: Yeah, so…oh, I was just going to kind of chime in and talk about the water thing, because one of the things going through my head is, you know, you’re talking about there is this presence of water, we can dig for it; I’m sure there’s some scientific value to understanding more about this water, but you said there’s value to it being for human missions. You know, is it, is there enough? I’m trying to kind of quantify how much water we’re talking about. Is there enough to support, say, you know, having enough drinking water and I guess you could separate hydrogen and oxygen to generate oxygen for a habitable environment. Is there enough water where the water in situ can support a human mission? You know, just, kind of trying to get the idea of the quantity of water you’re talking about.
Paul Niles: One, one of the things that we really want to figure out in the next ten or 15 years is exactly how much water…
Host: Got it. OK.
Paul Niles:…is there. We’re talking about a couple of different options for trying to understand what the buried ice looks like. How, what if, you know, how pure is it, and how far away from the surface? We sent several radar instruments in the past ten or 15 years that have given us a really tantalizing idea about what the ice looks like, and we definitely have strong evidence that shows that this ice is present in these mid-latitude regions and can be fairly close to the surface, so within, you know, ten meters or so, which wouldn’t be too difficult to try and drill into. There also have been, you know, several discoveries showing that there is pure ice exposed in cliff faces in these regions as well. So, so you can see these exposed cliffs with relatively pure ice exposed, and then, near the top, a layer of, of sediment, regolith, whatever you want to call it. So, so, it, it seems like, and definitely in particular areas, we can identify, yes, there is a place where you could do this, where you could drill not too far and reach pure ice, which then you could set up something called a Rodriguez well, which is, basically, a well where you drill down into pure ice, and then you just pump hot water down there and the hot water melts the ice into like sort of a bulb and gives you a bulb of liquid water, and then you would get that liquid water and pump some of it back up again. So you would be continuously pumping hot water down to keep it liquid, and then be recovering some of that water for, for your base. We hope that the base that we, or the habitat that would be there, would not use too much water. It would be recycled, most of it. It’s not going to do 100%, but so the main use for water is definitely for the propellant, as you mentioned.
Host: That is very interesting. Now, you talked about it being pure. Let’s kind of dive into the soil a little bit. I’m trying to get a better understanding of this dirt, or I think you said maybe regolith, I don’t know if it’s dirt. I think, you know, we’re all speaking the same language, the Martian dirt. [Laughter]
Paul Niles: Dirt, just call it dirt. [Laughter]
Host: [Laughter] Yeah, let’s just call it dirt. So, what is it? What’s inside of it? What’s it made of? Understanding more about the soil there.
Paul Niles: Dirt, dirt on Mars is mostly just ground up volcanic rock. So, something similar to what you would find in Hawaii if you went to Hawaii, or Iceland. You basically, on Mars, you have the main source of rocks is volcanic eruptions, and those can either be lava flows or they can be ash deposits, and then, and then those, those rocks get ground up and redeposited in different ways, by the wind and by water. And so there is some evidence for other kinds of minerals, these secondary minerals we call like sulfates or carbonates, that are similar to the sedimentary rocks on Earth, but we don’t see real just pure versions of that like we see on Earth. So, that, on Earth, we have the oceans that help deposit large sedimentary rock exposures. If anybody’s been driving, driven through West Texas, you drive through these rolling hills and it’s just all carbonate deposits that are left over from a sea, that inland sea that was in that region millions of years ago. And, you know, it’s just, you know, hundreds of meters of it, and it’s just pure carbonate, and we hoped to find something like that on Mars and we just haven’t found it. So, so it looks like Mars is pretty much made up of this dirty regolith. And now one thing that, another thing I wanted to mention since we were talking about melting water and, and dirt on Mars, is that some people think that there’s poison, that the Martian dirt is poisonous, and that’s based on the discovery that was made by the Phoenix lander, which I mentioned before, which discovered that the, Mars has perchlorate in it. It’s about 1% in some places, maybe less in others, but certainly higher levels than what we see on Earth. And perchlorate can be poisonous to humans if, if, you know, we ingest it, and it’s used, actually, as rocket fuel, can be very reactive when you heat it to higher temperatures. But on Mars and in the dirt, it’s really quite not going to be a problem, because it’s very soluble so you could wash it away with water. So, any kind of dirt that you want to use for growing plants can easily be treated for perchlorate by just simply rinsing it, and then this perchlorate can be filtered out of any drinking water using just typical water filtration, which you’re going to be using anyway. And so, the perchlorate situation really isn’t a problem. And even if none of that works and you still have astronauts getting a little too much perchlorate in their system, you can take iodine tablets and that helps, helps relieve the effects. So, perchlorate, really, among the challenges, you know, to human astronauts on Mars, the perchlorate’s really not, not a big one.
Host: So, let’s just say you’re washing away the perchlorate on the soil there. What can you use the soil for? Can you use it to grow plants? Can you use it to, I don’t know, to split apart and make rocket fuel? What can, what can you – or to build habitats, I don’t know; what can you use the soil for? What’s inside of it?
Paul Niles: Yeah, like I said, the soil is volcanic rock. So if you go to Hawaii or someplace like that, it’s a really good example of what you’re going to find on Mars. And you’ll notice that in Hawaii the soil there is excellent for growing plants. Volcanic soil is extraordinarily fertile. So, you have a, with Martian soil you have an excellent base for growing plants, and you know, the main problem just being you don’t have the bacteria and the life that we have on Earth. So, so in order to really develop the soil you’d have to also bring in that microbial mass to help make it be the best soil that it could be. But, you know, that’s certainly something that you can grow alongside the plants in your, in your habitat.
Host: Nice. So, there’s enough that it’s kind of rich, but you just need to supplement it with a couple extra microbes, and you can actually use it to sustain like farming on Mars; that’s pretty cool.
Paul Niles: Yeah, absolutely.
Host: Now, let’s see, another, when thinking about Mars and sort of how it is as a planet, I know one of the items is, is radiation. You know, what, you talked about the atmosphere being thin, so what’s the radiation environment like on Mars for humans that are exploring its surface?
Paul Niles: Yeah, there are a lot of dangers on Mars to human explorers. We talked about perchlorate just a second ago. The, the other ones are the radiation that you mentioned, and dust is another major one. And sometimes people think about wind as a problem, like the movie, “The Martian.” But yeah, none of these things are really that bad if you are talking about visiting Mars so, if you’re only going to be there for a little while. The, the, one kind of interesting way to think about Mars is, is similar to Mount Everest. So, if you go to Mount Everest the, the atmosphere at the top of Mount Everest is about 30% as dense as it is at sea level. So, so if you are at sea level on Earth, our atmosphere is something we call one bar, and then, or 1,000 millibars. On the top of Mount Everest, we have about 350 millibars of atmospheric pressure, and then on Mars it’s about ten to 15 millibars. So, we’re still about a factor of ten or 20 less on Mars, but you kind of get the impression that it’s not that much different in the end. And we talked about the temperatures: the temperatures at Mount Everest are similar, minus-20 into minus-80 Celsius. So, that is a really similar thing. The one difference is the radiation, like you mentioned. On Earth, we have a magnetic field that protects us from a lot of the magnetic radiation, and the denser atmosphere is another thing that really, really helps out. But if you go to the space station, you’re still within the magnetic field but you get a lot more radiation than you would on the surface, and we think that the radiation, in fact, we know the radiation on Mars is very similar to what we see at the space station. So, that is, you know, that gives us a lot of confidence to say that, you know, astronauts visiting Mars aren’t going to be impacted by radiation too much. I mean, you certainly get more radiation traveling to Mars and back from it, so the faster that you can go to and from, the better, as far as radiation goes. And another huge difference between Mars and the space station is, would be galactic cosmic rays. So, the, the radiation, the magnetic field of the Earth really protects us pretty well against galactic cosmic rays. The higher energy ones, they don’t care about anything, they just go through, so, so we get that. But you’d definitely be exposed to more galactic cosmic ray radiation on Mars than you would otherwise. So, so that’s one of the interesting things that we’re going to help, we’re going to learn about with the Artemis program, sending people to Gateway, which is going to be an orbiting outpost around the Moon, and sending people to the lunar surface. That’ll give us a lot of information about what that radiation environment is. And then once you’re on the surface of the Moon or Mars you have that whole body protecting, you know, half of you, half of the, it’s blocking the radiation coming from half the solar system. So, so that provides a lot of protection, and it’s really quite manageable in the end. But, if you were going to live on Mars long term, it’s certainly something that you would have to deal with.
Host:We were talking about radiation, then you said some of the things for people to watch out for when on the surface of Mars are, of course, the radiation, and then, the other thing you mentioned was, was dust. So, what’s the dust environment like on Mars?
Paul Niles: Yeah, dust is really challenging, I think. It’s very, very thin, or small, so it could pose an interesting challenge to mechanisms, seals, spacesuits. Certainly we have had rovers on the surface for long periods of time, and those rovers have dealt with the dust pretty admirably. So, so we know that it’s definitely a problem that is tractable, but it’s definitely something to keep in mind. The other major issue with the dust is that you have these global dust storms that happen every ten or so years, and that can be pretty substantial as far as blocking out the Sun. So, if you are planning on using solar power for your mission, having these global dust storms that might kick up, and essentially the whole surface of the planet becomes clouded, then that’s a real challenge. So, a lot of our solar-powered missions, we have to plan for particular seasons for when we think there won’t be dust storms, and we’re also heavily considering using nuclear power for the human mission to save us the, to sort of help alleviate some of that risk. Although, you know, finding the right mix of different power is definitely something that we’re going to want, because we want to have a happy, you know, mixture of different options available in different times.
Host: Yeah.
Paul Niles: One of the things we’ve actually talked about is using perchlorate, if you can actually use perchlorate in a fuel cell to help power things. So you could conceivably, you know, this isn’t going to power the whole habitat, but it could be something that, you know, for a rover roving across the surface you could harvest your perchlorate and throw it in your, in a fuel cell and help do some extra range boosting.
Host: [Laughter] So, you talked about these global dust storms, they happen, you said, every ten years. How long do they last?
Paul Niles: Yeah, I mean, it’s not on a regular schedule. It happens when it wants to happen, and there’s certainly dust storms every year that are smaller and more regional, but the global dust storms are more dangerous because they are longer-lasting. So, you know, they can last up to a month or even a little more than that. So, it’s definitely something that you’ve got to watch out for.
Host: Got it. OK, and the reason you would want to watch out for it is because of the impacts to potential power systems where you’re gathering power on the surface, but in terms of the dust itself, you know, blowing around on the Martian surface, from what I understand it’s not like, you already referenced this was that scene from “The Martian” where the dust is blowing real hard and the astronauts are crouching through because of the thin atmosphere, even though the dust is kind of flowing around, would it be, feel more like a gentle breeze so it wouldn’t really impact structures that much?
Paul Niles: Yeah, the, the lower gravity, one of the impacts of lower gravity is the wind speeds actually can get pretty high. The Viking lander got all the way up to about 70 miles an hour. But like you said, the density is so low that it turns out that it doesn’t really feel like much, so it’s almost like a tenth of what it, so, so 70 miles an hour would feel more like a seven-mile-an-hour breeze. So, it doesn’t, yeah, so the wind isn’t really a big factor. In fact, you know, scientists spent a long time trying to figure out if the wind was even powerful enough to lift dust, I mean, lift sand grains. So, so we definitely aren’t going to be challenged by the wind speeds on Mars, even though they sound scary because they can be pretty, pretty fast. Things are traveling fast. The air is traveling fast, but the power isn’t quite there.
Host: Yeah, right, when you say a 70-mile-an-hour global dust storm, I mean, my first reaction is fear, but if you say it’s like a seven-mile-an-hour breeze I guess it’s not all that bad. So, more about the Martian planet. Now, you said, you talked about the day/night cycle. It’s a little bit similar to Earth, maybe a little bit longer by just a matter of like 30-something minutes. Now, how about like an Earth year? You mentioned that it’s, did you say that a year is significantly longer?
Paul Niles: Yeah, because Mars is farther away from the Sun, it takes longer to get around. So, so the year is, is about twice as long as the Earth year. And so, so all the seasons are a little bit longer, or longer than an Earth season, as a result.
Host: But the day/night cycle is kind of similar enough where astronauts could have just a near-regular sleep schedule. In fact, they get a couple extra minutes in their day, it sounds like.
Paul Niles: Yeah, actually for the, for some of these missions, we, the scientists, were actually operating on the Martian day/night cycle to operate the rovers, because the rovers would wake up at the same time, Martian time, every morning and, to receive commands, and then, and then, it would broadcast back the data at the end of the day. And so we would use the Martian nighttime when the rover was sleeping to create new commands to send in the morning. And as a result, we were working on a Martian day/night schedule. Now the Martian day/night, I mean, day is 37 minutes longer. So, it turns out that it’s really hectic to try and do that while you’re working, while you’re living on the Earth because, you know, pretty soon you’re waking up at, you know, when you start waking up at 6 a.m. it’s not long, you know, a couple weeks later, you’re waking up at 3 p.m. and then, you know, a couple more weeks and you’re, you know, waking up at midnight. So, and that’s really, really tough to maintain with the sunlight schedule. But if you could figure out a way to stay away from the Sun and create your own sunlight schedule, the 37 extra minutes a day is pretty nice. When you think about you have 40 extra minutes to sleep every night or 40 extra minutes every day to do something different, it’s pretty nice.
Host: That would be a really interesting experiment on the surface, because for, for the teams working the Martian rovers you were adjusting to the Martian day but you still had the day/night cycle of Earth that maybe, you know, tripped you up a little bit because it was constantly changing, but maybe without the awareness of, of the shift in change in Earth time, and you still have the sunrise and sunset approximately the same time, you know, plus 37 minutes on the Martian surface, it would be a really interesting experiment to see how humans adjust. Will they be completely fine? They’ll just, you know, get used to the 37 extra minutes? Or will they kind of start getting a little bit fatigued as time goes on, like you’re saying, you know, because their body, their internal clock is telling them that it’s 3 p.m. not 6 a.m. or something. You know, that’ll be interesting.
Paul Niles: Yeah, I found it really, because I wasn’t living at home, I was, I was living in a hotel and I found it really nice. I’m also a night owl. So, you know, it’s not hard for me to stay up an extra 40 minutes every night. So I’m getting the same amount of sleep. You know, I was able to pretty much, I could just stay up as late as I wanted to or as I could, basically, and I would always have, you know, I got to the point where I was basically going to bed right after my shift instead of staying up another four or five hours, right, so, like you’d normally do. You usually get off work at like five, and then, you go to bed at ten. You know, I would be getting off my shift and going to bed, but I would try and stay up as late as I could, but then I’d wake up and have, you know, a few hours before going to work. It was, you know, really, really nice, and as long as you could sort of, you know, keep, stay inside and stay away from the Sun, yeah, without letting, because after a while, that definitely does mess…
Host: I figure, yeah, for sure. Now on this topic of day/night cycles on Mars, it gets me thinking about a Martian nighttime. You know, I think we see a lot of pictures of Mars from the surface, thanks to some of the rovers that had been there. A lot of them take place during the daytime, but I wonder what the Martian nighttime would be like. You know, are the skies clear enough where you can see a lot of stars? Could you, could you be able to make out the Earth from the naked eye? What are some of the things you would see in a Martian nighttime?
Paul Niles: We’ve been able to, I mean, there’s been some just great imagery taken from the rovers where you can wake them up in the middle of the night and take pictures. And yeah, I mean, the Earth looks like, sort of if you imagine, it’s sort of like Venus, I guess, that would look like looks from the Earth. So it’s brighter than Mars is in our sky, but, you know, since the Earth, we can see Mars from here, you can see the Earth from Mars. The other really interesting thing that you would see at night is the moons of Mars. So, there’s two moons, and they have really weird orbits, compared to what we’re used to, right? Phobos orbits every eight hours, and Deimos it goes every 30 hours. Phobos is sort of like a mini-moon, so you could sort of like, you imagine what the Moon looks like to us; sort of 1/10 of that or less. And, and it, it’s zooming across the sky every eight hours. So you might see it pass, maybe you could potentially see it pass, you know, you could see it set and then rise again all in the same night. The, then Deimos is every 30 hours. So, but you definitely, instead of, you know, just moving across the sky as the planet rotates, you would see it move across the stars, as well. So, it’s pretty neat.
Host: So, for Phobos, you said every eight hours. Could you see it during the daytime too? Because that’s enough time where you might be able to, I feel, I feel like you could maybe catch it during the day.
Paul Niles: Yeah, I mean, you know, it’s just like trying to see the Moon during the day, but, you know, it’s usually, if it’s lit well, then yeah.
Host: If the conditions are right, yeah, but you could possibly. That’s interesting. You talked about some, let’s see, when you were talking about just way at the beginning of our talk the different landing sites, and we talked about some of the things that were scientifically interesting. If you were to land on Mars, you would want to land at some of the spots that were more scientifically interesting. We talked about water ice a little bit, but let’s investigate some of the geological science. What is interesting about Mars? What are some of those things that we can’t wait to get human hands to do on the surface of Mars, the, the scientific missions that we would want to accomplish for the Mars geology?
Paul Niles: Yeah, every time we sit down as scientists, we try and come up with, you know, what are our science objectives for exploring Mars: finding evidence for extant life and past life, that’s almost always near the top of our list. So, when we think about humans exploring Mars, we’re looking, we’re probably going to be centering that around looking for life, either life that’s living there now or whether or not, or evidence for life in the past. So, so one of the things that we target when we’re looking for life is evidence for water. So, if we know that water was some place on Mars in the past, hopefully a long-lived water, that’s the kind of place where we want to go and look for life. So, that focuses on several different kinds of targets, like I mentioned a couple of them already: the, sort of the sulfate minerals is evidence for past liquid water; the other place, and then the lava tubes are really interesting for potentially protecting little damp areas and places where you might get ice forming in these lava tubes that could also be a haven for, for life. The, the other place that a lot of people are interested in is going to a delta. So, there are places on Mars where we see where past rivers have flowed sort of out of the mountains and into these craters, and they create these delta deposits, just like the Mississippi River Delta. But if you imagine the Mississippi River Delta with all the water drained away, it sort of rises; it would be a positive feature. It would be sticking out of the ground, and that’s what we see on Mars is, so, in these craters the water’s drained away and you see these, these deltas, these stacks of layered materials that are sinuous, a lot of sinuous riverbeds. And, and that, people are really interested in going to places like that because that’s the place where you might preserve a lot of material, because what happens is in a delta is stuff gets, you know, is coming down the river, and it gets quickly buried by the next stuff that comes. So, you don’t have a lot of time to have it be eaten or, you know, annihilated by radiation or something like that. Now, one of the objections to that is that, you know, the river is sampling just material at the surface. So, that material at the surface might already not be the kind of stuff that you want to look for because that might be, you know, already that’s radiation, you know, exposed material that doesn’t have life, potentially. And so, so the delta is definitely a place to look for stuff that’s sitting at the surface. One of the other places that people really want to go look is underneath the surface. We think that there’s a lot of evidence for hydrothermal activity, warm water, lasting for long periods of time underneath the surface, and you see exposures of these rocks at the surface. So, you don’t actually have to drill down to get there, and those, those are really interesting rocks. They’re called, one of the interesting minerals to target there is serpentine, which is something that we know forms in sort of warmer, wetter environments, and that’s, that’s the, something that we might target with the extended mission for Mars 2020. So, Mars 2020 is actually going to Jezero crater, which is the next Mars rover mission; it looks a lot like Curiosity. It’s got different instruments this time, but same kind of rover chassis, and it’s going to this place, it’s going to investigate a delta deposit, and then, as an extended mission, it might be able to explore some of these serpentine sort of clay-rich, hydrothermal deposits, so, from the deeper subsurface. So, hopefully, we’re going to get a little bit of both with that mission, and it’ll help us really understand where to send humans as the most promising kind of target.
Host: Yeah, I’m sure you’re looking forward to, to Perseverance landing here. I mean, at the time that this episode comes out, we’ll just be a few short weeks away from landing there. So, will you be part of the teams there? Will you have some, something that you’re going to be looking after for the Perseverance mission?
Paul Niles: Yeah, I mean, as a Mars scientist I’m definitely interested in the results and will be, will be analyzing the data when the science teams release it, but I’m not on any of the rover science teams this time.
Host: Yeah, but I’m sure you’re definitely going to want to get a hold of some of that stuff. Now, understanding, I guess, we’re talking about human missions here, and I think there’s a lot of excitement for, for the rover landing that’s coming up here shortly, but understanding the human aspect of things, what is nice about having humans on the surface of Mars to accomplish some of these scientific objectives?
Paul Niles: When we have humans there, there’s just so much more that you can do with regards to the kind of science activities. So, one of the things that the rovers really struggle with, it takes them a long time, is just any time you interact with the surface, because you have to wait a whole day to find out what happened, so any time you interact with the surface you really need to just do it one step at a time. So, you, you know, contact the surface., then you wait to see if you actually contacted the surface correctly, you know. Then you could drill. You would drill a little ways and stop, see, OK, wait, how far did we go? You know, you have to do this all in a, you know, each-day cycle, you have to wait for the data to come back, in order to understand what happened, you know? And then if you’re moving rocks around and, you know, you’ve got to figure out where the rock landed before you keep going. So, there’s so much that takes such a long time when you’re interacting with the surface. With regards to humans, there’s so much they can do so quickly. Just, you know, one of the things that we do all the time in the field as geologists is take a rock hammer and crack open a rock to look at what’s inside. And that takes, you know, less than a minute. But it’s just something that we can’t do with a rover effectively. So, you know, something like that, it makes things so much easier. And then likewise, just any kind of sampling that you’re doing on the surface can be extraordinarily speeded up with a human there or just having a human nearby. You can do a lot with teleoperations if you are worried about contamination in certain areas. So, we certainly talked about in areas where we don’t want any of the human contamination to enter, you could send a specially cleaned robot, and because you got humans there you, the light delay would be small, and you could, you could operate pretty effectively.
Host: Is there anything we can learn from Artemis to kind of help out with some of these operations, making sure we don’t contaminate different areas, you know, just working through those surface operations, those geological expeditions on the surface of the Moon, developing the right tools? Is there something we could look forward to in Artemis that can help us out for, for the geological expeditions on Mars?
Paul Niles: Yeah, I hope Artemis is an opportunity that we see used to really advance what human exploration of outer space looks like with regards to, you know, planetary science. You know, we’ve got a lot of examples of tools and techniques they used during Apollo, and, you know, a lot of that is shovels and rakes and hammers and stuff like that, you know, we’re going to want to use again. But with the kinds of new technology that we have available to us, there’s just an enormous number of really interesting things that you might do to supplement and advance planetary science exploration of Mars or the Moon, and these are things that you could try out on the Moon and, you know, and make sure that they work before taking them to Mars. And a lot of this is, you know, robotic-human interaction. So, trying to make sure that you, so trying to design robots to do the kinds of things that robots do well, and then, allow the humans to do the things the humans do well, so that you get, really, the most efficient exploration that you can get, because the amount of time that you have on the surface during an EVA (extravehicular activity) is very, very limited. And so, we’re going to have to use the robots to do, and on many things as we think, you know, they can do most effectively, while we save, save the kinds of things the humans can do most effectively for the humans. And, you know, we’re still trying to iron out all of that information. I mean, we’ve got a lot of examples of what that looks like with regards to the robotic exploration we’ve already done. But there’s still a lot more to learn about how robots and humans could, could operate effectively together. And so, you know, I’m really looking forward to Artemis as being a time when we start to test out some of these ideas and start to make big strides with regards to how, how we explore planetary surfaces.
Host: And that time is coming up real soon, too. So it’ll be a nice teaser for when we see those astronauts on the surface of the Moon conducting, you know, all kinds of science with brand-new tools. It’ll be a nice teaser for when we finally see those boot prints on, on the Red Planet. Dr. Paul Niles, thank you so much for coming on Houston We Have a Podcast. What a great conversation. I learned so much about the Red Planet, and you got me really excited for what’s to come and a lot of the things that we still need to find out about working on the Moon, or on Mars, that we can learn on the surface of the Moon. So, Paul, I really appreciate your time. Thanks so much.
Paul Niles: Yeah, thanks for having me. I enjoyed the discussion, as well.
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Host: Hey, thanks for sticking around. Hope you’re enjoying our Mars reboot of the entire series. Of course, if you want to skip ahead, you can go to NASA.gov/podcasts and check out our collection of episodes on Mars, and these are of course a reboot of episodes that were originally aired, you can check out the last couple of episodes, if you want, but don’t worry, if you don’t want to, you can just stick around for next week, we’ll bring the episode right to your feed. While you’re there at NASA.gov/podcasts, make sure to check out some of the other shows that we have across the whole agency. If you want to talk to us specifically at Houston We Have a Podcast, go to the NASA Johnson Space Center pages of Facebook, Twitter, and Instagram; just use the hashtag #AskNASA on whatever platform you want to submit an idea show, maybe ask a question, make sure to mention it’s for us at Houston We Have a Podcast. Thanks to Will Flato, Pat Ryan, Heidi Lavelle, and Belinda Pulido as well as Jaden Jennings for their part on this podcast as always. Shoutout to former podcast team members, Alex Perryman, Norah Moran, and Jennifer Hernandez for their help in the original episode. The episode originally aired January 8, 2021, as Episode 177. Thanks again to Paul Niles for taking the time to come on the show. Next week, for Episode 10 in our Mars series, we chat with Natalie Mary about what needs to be considered in the design and operation of a spacesuit that will be used to explore the surface of the Red Planet. Give us a rating and feedback on whatever platform you are listening to us on to tell us how we did. We’ll be back next week.