E23 – Between a Varnished Rock and a Hard Place

Nina Lanza (left) studying rock varnish in California. Credit: Nina Lanza.

Scientists have been testing whether life exists on Mars for over 40 years, ever since the Viking 1 lander touched down on the Red Planet. Researchers often perform experiments on Earth to better understand the context of data collected by Viking 1 and subsequent landers – data that gives scientists tantalizing clues about the habitability of the Martian surface.

In this episode, Los Alamos National Laboratory researchers Nina Lanza and Chris Yeager discuss their investigations into rock varnish in New Mexico, which could help them understand whether life is present on Mars. Rock varnish is a mysterious coating found on rocks in some of the harshest and most Mars-like landscapes on Earth, but no one knows whether rock varnish is created by living things. If so, finding it on Mars would be a sign that Martian life exists now or has existed in the past.

This episode was produced by Larry O’Hanlon and mixed by Kayla Surrey.


Shane Hanlon:              Hi, Nanci.

Nanci Bompey:             Hey, Shane.

Shane Hanlon:              So today we have a little bit of a different format, I guess, or whatever. But, we’re beaming in-

Nanci Bompey:             Beaming in.

Shane Hanlon:              … from New Mexico?

Nanci Bompey:             Yeah.

Shane Hanlon:              … one of our colleagues, Larry O’Hanlon.

Larry O’Hanlon:             No relation.

Shane Hanlon:              No relation, to me. Hi, Larry.

Larry O’Hanlon:             Hey Shane. Yeah, no relation. I have an O, you have no O.

Shane Hanlon:              Yeah, yeah.

Nanci Bompey:             So Larry-

Larry O’Hanlon:             You have O envy, I’ve heard. You told me that, once.

Shane Hanlon:              Oh, I do. Yeah, I know, that’s a whole other episode.

Nanci Bompey:             … Yeah, it would make, it would be cool. Yeah, like, it’s a whole other story. But, so Larry, New Mexico. So you told us a fun fact, about New Mexico. Can you-

Larry O’Hanlon:             Yeah, yeah. Well, many people, I mean New Mexico only has about 2 million people, in the whole state. So it’s not a very big state. I mean, people-wise. And a lot of people, it’s surprising, how many people don’t even realize it’s a state. There’s a very popular magazine called New Mexico Magazine, and at the end of the magazine, they have this feature called One of the 50 is Missing. And people write in their stories about how people don’t, you know, things they run across where people think they have to bring pesos here, or you need a passport.

Shane Hanlon:              Oh, so they really think it’s literally like New, comma, Mexico?

Nanci Bompey:             … Like, it’s a part of Mexico. Okay. Interesting.

Larry O’Hanlon:             Yeah. They just, people think there’s like Texas and Arizona. And they just kind of forget that there’s New Mexico, in between. So, yeah.

Nanci Bompey:             That’s funny.

Larry O’Hanlon:             It’s a weird state in that way. Right?

Shane Hanlon:              I mean, I guess like, Nancy and I both live in Virginia, but we can definitely at least relate because the District is not, like, DC is not a state. But it’s like the flip side. People always think that DC is a state. And when you tell them like, “District of Columbia is not a state,” they’re like, “What? What do you mean?” Like, “Yeah, yeah. Think about that for a second.”

Larry O’Hanlon:             Yeah.

Shane Hanlon:              Voting rights, representation. Yeah. Maybe, maybe opinions on DC and New Mexico could swap.

Larry O’Hanlon:             Yeah. It’s kind of backwards, isn’t it?

Shane Hanlon:              Right.

Shane Hanlon:              Welcome to the American Geophysical Union’s podcast about the scientists and the methods behind the science. These are the stories you won’t read in the manuscript, or hear in a lecture. I’m Shane Hanlon.

Nanci Bompey:             And I’m Nanci Bompey.

Shane Hanlon:              And this is Third Pod from the Sun.

Nanci Bompey:             So Larry, hi. So being down there in New Mexico, you have the opportunity to talk to scientists that we, up here in DC, don’t necessarily get to talk to, every day.

Larry O’Hanlon:             Yeah, we have a couple of National Labs, so I went up to Los Alamos National Lab. It’s about an hour from where I am, and talked to a couple of the scientists there about work they’re doing related to the Mars rovers, the one that’s there and the one that’s coming. As well as about life on Mars, and how you search for life on Mars, by looking at stuff on earth.

Nina Lanza:                   I’m Nina Lanza, and I’m a scientist at Los Alamos National Laboratory.

Chris Yeager:                 Chris Yeager, also at Los Alamos National Laboratory. I’m a microbiologist.

Larry O’Hanlon:             Okay. And this is Larry O’Hanlon, with AGU. So we’re here to talk about a few things, but primarily, I think it’s about looking for life on Mars. Right?

Nina Lanza:                   Yeah.

Larry O’Hanlon:             Okay.

Nina Lanza:                   We’re looking, we’ll let you know when we find it. Spoiler alert, we haven’t found it yet.

Larry O’Hanlon:             Now, but this has been a search that’s been going on for a long time. I mean, I remember, I think I was a kid, when the Viking landed.

Speaker 5:                    That was green for touchdown. AGS is green, 1.5 degrees per second, max. Point two Gs [crosstalk 00:03:38]-

Larry O’Hanlon:             I’m old enough to remember that.

Speaker 6:                    Touchdown, we have touchdown.

Larry O’Hanlon:             And there was a lot of excitement about, they thought they’d found something, but then they thought, well, maybe not, and it’s, it. Can you kind of talk about a little bit about the background of searching for life on Mars, to kind of get us into this?

Nina Lanza:                   Sure. Well, you know, Mars has really captured the human imagination, just because it looks so Earth-like.

Speaker 7:                    For hundreds of years, the planet Mars has been the subject of heated controversy among scientists, and imaginative speculation by science fiction writers.

Nina Lanza:                   Even before we ever landed anything there, we had telescopes that could show us these features on the surface. And in fact, some folks have misinterpreted some of those features to be grand canals and maybe cities.

Speaker 8:                    Obviously the work of intelligent Martians, the simplicity and symmetry cannot possibly be the work of-

Speaker 9:                    I think these are canals, massive engineering works, which provide water for irrigation and commerce.

Speaker 10:                  It will be possible, with larger telescopes, to see cities on Mars.

Nina Lanza:                   Which turned out, is not actually the case. But this is, you know, it has been very, in our imaginations, it’s a place where life could have existed. But we’re actually not that far off, because right now, even the way that Mars is now, which is pretty cold and pretty dry, there are life forms on Earth that would happily thrive there, right? It has all the ingredients for life. So now the question is, is it there? Was it there? How would we know? And so, we have sent some landers and rovers to the surface of Mars. And you mentioned Viking. You know, Viking was very exciting.

Speaker 11:                  It’s probably the most sophisticated spacecraft ever designed for any purpose. It’s going to Mars. It’s going to land on Mars, and it’s going to orbit around Mars, at the same time.

Nina Lanza:                   It was the first time we’d touched the surface of Mars. Unfortunately, we landed in some places that looked very desolate. We landed in the flattest possible places, just because that’s the safest place to land.

Nina Lanza:                   But we were really excited to see, I shouldn’t say we, because this is before my time. The scientist who landed the Viking landers were very excited to see, initially, they had this life experiment where they essentially added water and some food and, they saw what happened. And they got this huge release of oxygen and other gasses. And so at first, that seemed like a robust, “Yes, there’s life here,” right?

Nina Lanza:                   But as they looked at those data a little bit more carefully, they saw that the release was very fast, way too fast for microbes. You know, microbes get very excited when they get food and water, but they take a little time to actually digest that and produce signatures. And so the consensus now is that, even though there was a release, that was probably chemical, so that’s abiologic as opposed to biologic.

Nina Lanza:                   And that’s probably because, as we’ve learned from later missions, there is actually something called perchlorate in the Martian soils. And so, we like to think of this as probably, rocket fuel is the name that you would call it, if you were a non-scientist. But basically, it’s something that’s very, an oxidizing material that will react when you add water to it. And so, that’s probably what caused the Viking release. But that was something we didn’t know, when we sent that experiment.

Larry O’Hanlon:             Now, I’ve heard of that, perchlorate, before. I’ve heard about the soil there. Is it all over Mars, or is it just, do we, how much do we know about where it is?

Nina Lanza:                   It’s hard to say, right? So in the landing sites, where we’ve actually had instruments on the ground, we found that there is quite a bit of perchlorate in rocks and soils. Now, it’s not actually uniformly distributed. Right now, in the Gale Crater Curiosity rover mission landing site, we’re actually in a place where there aren’t any perchlorates. But, in a previous spot, where we roved from, there were perchlorates. So they’re everywhere, probably, but not homogeneously distributed.

Larry O’Hanlon:             Yeah. One reason I asked that is because I was watching the movie The Martian, a while back-

Nina Lanza:                   Awesome.

Larry O’Hanlon:             … and I remember the perchlorates, and I was watching it and thinking, “But wait a minute, what about the perchlorates? Would that kind of screw up this whole, potato farming?” I don’t know.

Nina Lanza:                   I mean, I don’t want to eat too much perchlorate.

Chris Yeager:                 I would guess so.

Larry O’Hanlon:             Okay. Well, but it’s possible he was in a spot where there wasn’t a lot of perchlorates. So maybe it was possible, right?

Nina Lanza:                   Well, they did have a big rocket launch there, too. So the soils in that area, probably were contaminated with perchlorate anyway, even if they weren’t there before.

Larry O’Hanlon:             Oh, right.

Nina Lanza:                   We’ll let it slide, we’ll let it slide.

Shane Hanlon:              Okay. Have you seen the Martian?

Nanci Bompey:             Yeah, of course.

Shane Hanlon:              Did you read it?

Nanci Bompey:             And I read the book, too.

Shane Hanlon:              Yeah, I would say like, The Martian is one of those books slash movie adaptations, whatever, that like, it tracked pretty closely and I really genuinely enjoyed both.

Nanci Bompey:             Agreed. I really liked it. I really liked The Martian.

Shane Hanlon:              I’m waiting for like the trifecta, where we send people to space the third time, to get Matt Damon.

Nanci Bompey:             Yes. I also love Matt Damon. So that was fine, too, by me.

Shane Hanlon:              But we’re not here to talk about the Martian. Larry did actually do, like, he went asking questions.

Nanci Bompey:             About real science, that they’re doing.

Larry O’Hanlon:             Now, what you guys are talking about now, this current work, it gets to the issue of biologic versus non biological, desert varnish. That’s the focus, right? So first, can you explain what desert varnish, I call it desert varnish because it’s rock varnish. I grew up calling it desert varnish. A lot of people don’t know what this is. Can you explain what it is?

Nina Lanza:                   Sure. Rock varnish is this dark, shiny coating that you see in deserts all over the world. You’ve probably stepped on it, if you’ve been in a desert. You can see a rock, and it looks just really dark and shiny. And it turns out that that is a material that is a mixture of clays and iron and manganese oxides. And what’s so interesting about it, and so intriguing, is that it’s the same all over the earth. No matter what rocks it’s on, it’s always about the same composition.

Nina Lanza:                   It’s really been this enduring mystery in geology. You know, “What is this coating that is ubiquitous, in these errant locations?” And there are places where there are no available iron, or manganese oxides, to make that, you know? Where is that material coming from? It’s something that has been an active area of study for at least a hundred years, if not longer.

Larry O’Hanlon:             How do they, what do they look like? Black?

Chris Yeager:                 I grew up in the West, and until about 10 years ago, I thought that that was just the color of what I considered volcanic rock. But what it is, is a coating that forms over the surfaces of the rocks over hundreds, thousands, tens of thousands of years.

Nina Lanza:                   If you were to take one of these desert rocks, you know, take a rock in the desert and break it in half, if you can. You would see right away that the inside is a totally different color than the outside, sometimes dramatically so. You can see the dark shiny, rounded black coating, which has all this manganese in it, doesn’t go very deep at all. You know, we’re saying microns, right? So 10 to 30 microns, even 500 microns, that’s half a millimeter. That’s very, very thin. You can immediately see that it’s not what the whole rock is made out of, if you break it in half.

Larry O’Hanlon:             And Native Americans have used this, right?

Nina Lanza:                   Rock varnish typically forms on surfaces that are not easily eroded, because it takes so long to form. It probably forms on softer rocks, but it gets washed away, by chemical and physical erosion. On harder rocks, it can actually build up. And as I mentioned, it’s a very, oftentimes very different color than the inside of the rock. This dark coating is much darker than the interior. And so, Native Americans have actually used this as a canvas for art and communication. You can see what are called petroglyphs carved into this varnish. You’ll see a very dark surface, with this lighter material uncovered, in sometimes very intricate pieces of art, on the rocks.

Larry O’Hanlon:             Do the petroglyphs have any scientific value, in terms of studying the formation of varnish?

Chris Yeager:                 Maybe the other way around. You can roughly get an idea of the date of the petroglyphs, if they have started to varnish over again, they’re older. Not so much varnish, if it’s pretty, just the color of the underlying rock, they’re younger. Say three, 400 years old.

Nanci Bompey:             So Larry, I mean, I will admit, I don’t think I know, I’ve ever seen this rock varnish stuff.

Larry O’Hanlon:             Yeah, well it’s, it’s super common in desert areas. So, I could probably walk outside and find some right here in New Mexico, in central New Mexico. But it’s not common in other areas. It’s, literally, we could take a light colored rock and if it’s, leave it out in the sun for hundreds of years, it’ll develop this coating. And-

Shane Hanlon:              So, why, but like, so there’s rocks everywhere, though. I mean, there’s rocks here on the East Coast. Why is it so prevalent, do you know why it’s so prevalent, out in the West, and out in your neck of the woods?

Larry O’Hanlon:             … Well, I think that’s one of the things these scientists are trying to figure out. Because it’s, I remember hearing about it as a high school student, when I first went on field trips to desert areas, from California. And saw it, but even then, no one was sure how it’s formed. And that’s sort of where, this science they’re doing, kind of, it’s an earth science as well as a Mars science thing. Because they hope, if they can figure out what’s going on here, it might tell them something on Mars, if they find a similar kinds of layers on the surfaces of rocks.

Shane Hanlon:              Oh. Well, that’s pretty cool.

Chris Yeager:                 Nina was talking about, where does the manganese and iron come from? There’s plenty of iron in most of these rocks to form that glaze or varnish, on the surface. However, the manganese it, that’s not the case. And it appears that a lot of the manganese and iron is coming from atmospheric deposition.

Larry O’Hanlon:             So that would be dust?

Chris Yeager:                 Dust, rainfall, and this occurs over hundreds and thousands of years, our best guess. Now, does this varnish occur in little spurts and pauses, or is it a constant growth over time? That we don’t know, either. But the interesting part is if, if that manganese and iron is deposited onto the surface of these rocks, how does it get immobilized there? How does it go from manganese and iron that are soluble in water, to an oxide form, that forms this very tough crust on the surface of rocks? And that’s where microbes might play a role.

Larry O’Hanlon:             This isn’t exactly something you can duplicate in a lab, it sounds like, because it’s such a long process, right?

Chris Yeager:                 And that’s been one of the reasons we’ve got a hundred year question.

Nina Lanza:                   Many have tried, but it’s also very hard to take microbes out of their natural environment and then make them exhibit the same behaviors in the laboratory. And especially, the microbial communities that we find on these rocks, which I’m sure Chris can tell you more about. These aren’t very happy, right, in the lab?

Chris Yeager:                 Right. They grow very slowly, so, they’re adapted to conditions of low water. Importantly. High irradiation. And that’s one of the reasons we’re interested in Mars, and varnish connection.

Nina Lanza:                   And so, another part of the connection that we’re trying to make is that, we’re not really sure on Earth, the origin of varnish, you know? Is it a biological product, or is it not? And so if it’s not, we might expect that in any arid environment you would form varnish, through these abiological processes. And so, then the question is, on Mars, would we expect to see varnish or not? Many have predicted that we should see varnish, because the surface of Mars is like the coldest, driest deserts on Earth, which do have rock varnish. So we haven’t seen ubiquitous rock varnish on Mars yet, but we have seen some very intriguing signs that manganese is being concentrated on Mars rocks, in some places.

Nina Lanza:                   This now leads to the question, “Okay, so what’s the origin of varnish on Earth? First of all, is life involved? And if so, does it leave behind signatures that we could see on Mars, with our rover instruments?”

Shane Hanlon:              I want to know, this is a very typical question, but how do they, how are they actually doing, like, how do they do this on Mars? Like, how do they find these?

Nanci Bompey:             ChemCam.

Shane Hanlon:              What are you saying?

Nanci Bompey:             ChemCam.

Shane Hanlon:              C-H-E-M-C-A-M?

Nanci Bompey:             Correct.

Shane Hanlon:              Like a chemical camera?

Nanci Bompey:             I believe that’s exactly what it stands for. Or, chemistry and camera.

Shane Hanlon:              Ooh, chemistry. You should know something about that.

Nanci Bompey:             Ugh.

Nina Lanza:                   ChemCam is an instrument that is on the Curiosity rover, which is on Mars right now, operating in Gale Crater. ChemCam was built by Los Alamos National Laboratory and it’s also operated by us here, in New Mexico. And it’s actually two instruments in one. So ChemCam is short for chemistry and camera. So the chemistry part is a rock vaporizing laser, that actually vaporizes a little bit of rock, at a distance from the rover. So, up to 23 feet away. And it creates this really bright light. And we can look at the light that that’s producing, back on the rover, and we can see what elements are in that target. It’s a really rapid technique. So every time we pulse our laser, we get another spectrum. So that’s the chemistry part.

Nina Lanza:                   And then we can put that chemistry into a geologic context by using our camera, which is a little remote micro imager, that gives us a very small scale image of where we shot on the rock. So we can say, “Hey, we shot that little white grain, or this little dark matrix,” and we can see the chemistry differences with the laser information, and then put that into the context, by seeing where on the rock it is.

Larry O’Hanlon:             Could you explain how you get the chemistry from the laser?

Nina Lanza:                   Sure. Yeah. Waving my hands, here. So the technique that we’re using on ChemCam is called laser induced breakdown spectroscopy, or LIBS. And the way that LIBS works is that it adds energy to the target. A lot of energy, right? We’re vaporizing material. It’s hotter than the surface of the sun. In this little tiny spot, which is only about half a millimeter in diameter, right? So it gets everything really hot. So everything breaks apart. You have no molecules, you just have atoms. And so, as they kind of cool and come back into a solid state and lower energy levels, they will emit photons at characteristic wavelengths. So you can look at the color of light that comes out and say, “Ah, this element is in this target.”

Larry O’Hanlon:             You’re zapping it and you’re picking, you’re also reading the light coming off of it.

Nina Lanza:                   That’s right. And so we have this, we have a telescope back on the rover, because this is a really small spot, right? I said half a millimeter. So it depends on how far away you’re shooting. It can be a little bit bigger, but not by much. So you’re making a little burst of light, which you can actually see with your eyes. If you were standing on Mars, next to the rover, you’d be able to see it. And so, the Rover can actually collect that light during the daylight, so there’s all kinds of sunlight, too. And then we can actually look at that light and say, “Okay, what does the spectrum look like?”

Nina Lanza:                   And you’ll see that it’s not a continuous spectrum, right? If it’s continuous, you would have all wavelengths. But instead, we see peaks at very specific places. And that’s what tells us what the rock is made out of.

Nina Lanza:                   We have an engineering model of the ChemCam, it’s cemented right here in our laboratory. So we can play samples in our Mars chamber, and get data that are equivalent to Mars. So we can say, “Okay, here is, here’s our rock varnish, that we collected. What would it look like, if we saw it on Mars?” Because, that’s the thing, on Earth, we have all instrumentation available to us. And we can use the gold standard measurement techniques. On Mars, we’re limited to what we bring with us. And sometimes, you can’t bring everything. And until we do sample return, we’re limited to the few experiments that we send.

Nina Lanza:                   So part of what we’re trying to do here, we’re trying to answer these two questions. One, what are the, you know, what’s the relationship between varnish and life? And what are those signatures, in terrestrial laboratory techniques? But then how do we translate that knowledge to the more limited instrument suite that we have on a Mars rover.

Nina Lanza:                   So we were lucky enough to have been selected to build another instrument, for the upcoming Mars 2020 Rover. And this instrument is going to be called SuperCam, because it’s similar to ChemCam, but it has some super capabilities. And so the biggest difference is that, so we have the LIBS laser technique, but we’re also going to have Raman spectroscopy. So, this provides us with structure. So the LIBS technique gives us chemistry, and chemistry is awesome. But for a geologist, you need more than just chemistry. You need to know what are the elements, but you also need to know how are they arranged? That’s mineralogy. So, what Raman does, is it provides that structure information. So it’s a lower power laser. We don’t vaporize things, we’re just exciting the molecules, the bonds. So we’re seeing what the bonds are, so we can use the LIBS to find out the chemistry, and then use the Raman to find the mineralogy. And therefore, we can get a full picture of what these rocks are.

Shane Hanlon:              SuperCam.

Nanci Bompey:             SuperCam.

Shane Hanlon:              I know, it’s, but I think ChemCam’s funner, more fun, more fun to say.

Nanci Bompey:             ChemCam, SuperCam.

Shane Hanlon:              CamCam.

Larry O’Hanlon:             When is this rover scheduled to, that this will go on?

Nina Lanza:                   Mars 2020 is going to launch in 2020.

Larry O’Hanlon:             Launch, okay, that’s pretty soon.

Nina Lanza:                   It’s very soon. Terrifyingly soon. But we’re going to be ready. We’re going to do it. Yeah, so we should launch, let’s see if I can remember. We’re going to launch in July of 2020 for a February 2021 arrival.

Larry O’Hanlon:             Have they chosen a landing site or anything, that’s going to be kind of feed into what you guys are doing at all? Do we know?

Nina Lanza:                   Yes. I have been quite involved in the landing site selection process, and essentially, the scientists get together over a series of yearly meetings to hash it out. Basically say, “Here are some sites, based on what we want to accomplish with the Rover, which sites can address those mission goals?” And it can be very contentious, very exciting meetings, a lot of raised voices. But it’s all for the good of science. And eventually, at one point we had our final meeting, in which we made our recommendation to NASA headquarters. And then NASA headquarters, decided. But luckily for us, they went with our recommendation, and that is Jezero Crater.

Nina Lanza:                   So, Jezero is a crater that is, at it’s very surface, seems very similar to Gale Crater, where we are with Curiosity. It is a middle aged crater. So that’s, if you knew your geologic timeframes on earth, that’s the Hesperian, so that’s about 2 billion years old. That’s pretty young for Mars, because there aren’t very many young terrains on Mars. So this is a place that is a reasonably, relatively young place that can contain some ancient bedrocks but has a whole bunch of features on the inside, that are much younger. And in particular, it looks like there is a Delta deposit, that was deposited into a longstanding lake. And that’s very similar to Gale Crater. But, the reason we’re so excited to go here, is because the mineralogy is totally different from orbit. So we can see that there are actually carbonates, here. Carbonates have never been seen on Mars, in situ.

Nina Lanza:                   And so you know, we’ve seen some really intriguing hits of carbonates from orbit, but we’ve never seen them on the ground. So this is going to be our first opportunity to see that. And carbonates are really interesting because they, I mean on Earth, most carbonates are actually made by microbes, right? All the lime stems you see, are just the dead bodies of sea creatures from the past. On Mars, we might expect, okay, maybe it’s not sea creatures. But, we might expect there to be a lot more carbonate, given that it has a carbon dioxide atmosphere. And if there was a lot more water in the past, where are those carbonates? We don’t know. We don’t really understand how they form. So this will give us our first glimpse of, what does that carbonate look like? And that will also help us ascertain if that is made by life, or not made by life.

Nina Lanza:                   But also, this sort of lake environment, it’s just a perfect environment for life. On Earth, an environment like that, would be inhabited. On Mars, we don’t know if it was, but this is a great place to look. And from Gale Crater, or from our studies with Curiosity, we know that manganese is actually much more abundant on the Martian surface than we had previously thought. So I think this is going to be another place for us to test hypotheses about high manganese concentrations, such as rock varnish.

Larry O’Hanlon:             And Mars, where you guys are going to do this, when you zap the rocks, you’re not leaving any marks on the rocks. I mean, you’re not doing petroglyphs on Mars, are you?

Nina Lanza:                   In fact, we are, leaving little marks on the rocks. So every time that we zap our laser, we actually ablate micrograms of material. So that’s not very much, but we do multiple pulses in one location. So typically, we’ll do 30 to 150 little zaps and that actually digs a little hole into the rock. So we are leaving little holes, on rocks, all over Mars. And in fact, we can see those images. We can see those in images, we can see the little holes where we did the analysis, in our remote micro imager images.

Larry O’Hanlon:             I have to ask Nina, have you left your initials on Mars?

Nina Lanza:                   I can neither confirm nor deny. No. No, no I have never. Because it turns out, it’s really hard to move the mast. So our instrument, is on the rover mast. And so it is really hard to come up with fine control, for that mast. And we’re actually limited by the gear size, right? We have like, specific motor positions. We can’t go smaller than that. So we can do, side to side and up and down. But it actually gets really hard, if you want to try and do something that’s diagonal. And so, I am actually on engineering operations, so I have to make these spacecraft commands. And I, as much as I would love to write a big N on there, that would take forever. It’d be so annoying.

Larry O’Hanlon:             Sounds like you’ve thought about it, though.

Nina Lanza:                   I’m not going to say I haven’t thought about it. Right now, we limit ourselves to lines, or like, a box, a grid, because that’s a lot easier.

Larry O’Hanlon:             I think I’ve seen some pictures from Curiosity, showing a little line of holes. You could do Morse code.

Nina Lanza:                   We could, we could, if we just space them. And sometimes we accidentally do, you know, we try to keep it even spacing, but because we’re doing such a fine pointing, you know the wind can actually blow us off course a little bit. Or thermal expansion, or contraction. So in fact sometimes our point is a little bit off. It’s really, it’s actually much more challenging than I anticipated. But that’s fieldwork, right?

Shane Hanlon:              I would love to have my initials in a rock on any planet, I guess. [crosstalk 00:26:59].

Nanci Bompey:             Oh, would that make you like space, then? If your-

Shane Hanlon:              Maybe.

Nanci Bompey:             … if you had a personal imprint on-

Shane Hanlon:              Did you ever like, put your initials in cement or carve them in a tree, or anything like that?

Nanci Bompey:             … I was never that destructive of human, of nature.

Shane Hanlon:              Concrete is not nature.

Nanci Bompey:             No, that’s true.

Shane Hanlon:              All right. The thing I can remember is my dad, when I was like in second grade or something, he got me a little pocket knife. I was in Cub Scouts, it was a big deal. You get like a whittling chip. It’s a, whatever, it’s a thing. But he also got a Dremel, like right when Dremels first came out.

Nanci Bompey:             I don’t know what that is.

Shane Hanlon:              Oh, sorry. It’s this little, it’s like a tiny, tiny little drill that’s very like, micro fine. And so he literally initialed like into this little thing, my pocketknife-

Nanci Bompey:             Oh, like your name.

Shane Hanlon:              … my name, and I still have it. It’s hilarious. But every time I show him that, I’m like, “What were you doing?” He’s like, “I don’t know. I had a new toy. I thought it was kind of cool.”

Nanci Bompey:             That’s cute.

Shane Hanlon:              So, not quite as impressive as like lasers on Mars, but you know, shout out to my dad. All right, folks. Well that’s all, from Third Pod from the Sun.

Nanci Bompey:             Thanks so much to Larry, for bringing us this story, and to Nina and Chris for sharing their work with us.

Shane Hanlon:              This podcast was produced by Larry, and mixed by [Kayla Surrey 00:00:28:05].

Nanci Bompey:             We’d love to hear your thoughts on our podcast. Please rate and review us. You can find new episodes on your favorite podcasting app, or on thirdpodfromthesun.com.

Shane Hanlon:              Thanks all, and we’ll see you next time.

Shane Hanlon:              (music)

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