Confessions of a Meteorite Hunter

IRA FLATOW: This is Science Friday, I’m Ira Flatow. When people ask me what I remember most about being on the Science Beat, well it has to be my trip to Antarctica. It was like being on another planet. Giant, ice blue glaciers, soaring mountains, and above all, the wonderful beauty but unforgivingness of nature. It changed my life forever.

And this week, I was transported right back there by some recordings Nina Lanza shared with us. She’s a scientist with this year’s Antarctic Search for Meteorites field team.

NINA LANZA: So right now we’re paused on this beautiful, white plateau. I guess it’s not really a plateau because we’re a little bit lower, but this is not something that you usually think of when you think of Antarctica. There’s actually these beautiful folded rocks that jut out of the ice. Imagine this blue slide of ice in between these beautiful, jagged, rocky mountains. Really a dramatic vista.

IRA FLATOW: Yes, I can remember back to seeing some of that stuff, but not quite what she remembered. And for the past six weeks, Dr. Lanza’s been in Antarctic mountain, the Miller range. She’s been on the hunt for space rocks. And I’m talking about chunks of asteroids, the moon, even Mars, all hand delivered– so to speak– to Earth, courtesy of gravity. And for the last 40 years, scientists have been scouring the Antarctic ice, searching for the celestial samples.

And when we heard that Nina was headed out into the field, we asked if she might make a few recordings for us of her journey. I’ll tell you how to listen to them a bit later, but I want to bring Nina on to this program. She’s back at home and at base at Los Alamos National Laboratory, where she’s a staff scientist. And she joins us now to debrief us on the 569 meteorites, Nina, that the team collected? Wow!

NINA LANZA: That’s right.

IRA FLATOW: Wow!

NINA LANZA: We’re very excited about that number.

IRA FLATOW: What a haul.

NINA LANZA: Yeah. You know, when you go out there, you’re not sure. I’m new to this project, so I wasn’t sure if I had what it took to actually find meteorites. But we did. As a team, we found 569. So we’re thrilled.

IRA FLATOW: Do you have one or two that stand out from the rest?

NINA LANZA: Oh, absolutely. I mean, I think we found some really interesting materials. I think probably my favorite one was, a sample– we can’t be sure, of course, where these came from just by looking at them– but we suspect it might be what’s called a howardite, and that’s a meteorite that we think has come from the asteroid Vesta. And so that’s really exciting, to be able to find a rock, just sitting there on the ice, that we know came from a very specific planetary body. And there aren’t that many pieces of Vesta here on the Earth, it turns out, so it’s a great find. That definitely stands out.

IRA FLATOW: Yeah. You’ve got to tell me, if we’ve never been to Vesta and got a chunk of it, picked a piece of it off, how do we know it came from Vesta?

NINA LANZA: That’s a great point. This is one of the triumphs of remote sensing and spectroscopy. We can observe Vesta using ground based telescopes. And we even sent a spacecraft there recently, as part of the Dawn Mission, where we actually were in orbit for awhile around that planet. So we have all this information about the geology from remote sensing, and we can connect that to the rocks that we see here on the Earth. And it’s one of the only bodies that we’ve been able to do that with.

IRA FLATOW: So, are the rocks just sitting out there on the ground?

NINA LANZA: They are, just waiting for us to come and find them. Yeah. If you can imagine that blue ice that you saw back when you were in Antarctica, and then you just look and there’s some dark spots on them, and those are rocks. And frequently those rocks are from space.

IRA FLATOW: And they get here how?

NINA LANZA: Well, they start off on their parent bodies, or just as a leftover rock in the asteroid belt. And a big impact may hit their parent bodies and be able to shoot pieces of it out off the planet and send them into an orbit that eventually intersects with that of Earth. So then they fall to Earth– and they actually fall over the planet at the same rate– but 71% of the surface of the earth is an ocean, so it’ll just fall to the ocean.

But we’re lucky with Antarctica that it’s this big, white sheet covered in glaciers. And so these meteorites just become embedded in the ice and start flowing with the glacier. And in some places, the glacier will run into something like the mountain range that we were in– the Miller Range– it will slow down. And then the winds, the very strong katabatic winds in Antarctica, will start to remove some of that ice, and that acts to concentrate the meteorites in these locations. So we can actually go there and find many more meteorites than you might imagine would fall in a single location.

IRA FLATOW: Now you’re taking me back, but I want to give our listeners who have never been there a sense of this. And you brought back some wonderful recordings. I want to play one from one of your very first mornings in the field.

NINA LANZA: I just want to describe some of this cold. I’ve done a lot of winter camping, but this is much colder and more sustained than anything I’ve ever done before. So for example, I forgot to take my contact lenses and solution into my sleeping bag with me before going to bed. And this morning I woke up, and they were frozen solid. Turns out, you can actually still wear contacts after they’ve been frozen in a block of ice.

IRA FLATOW: Wow. So your eye’s OK? Your eyes are OK?

NINA LANZA: They seem to be fine, I wore them for two weeks after that, so no problem.

IRA FLATOW: And you hear the wind. People don’t realize how powerful winds there are in Antarctica, they just ablate the ice away.

NINA LANZA: That’s right, that’s right. We actually measured wind speeds up to about 60 miles an hour one day, which was pretty exciting to be out measuring in, let me tell you, with it blowing me over.

IRA FLATOW: Let me play another recording you made from your first day out on the hunt.

NINA LANZA: So today we went searching for meteorites for the first time. And it was totally different than I expected it to be. I think part of it was because people had told me that it was going to be just driving around the ice and picking up rocks– which I think it essentially is– but we went searching in a moraine, which is a bunch of rocks that have been scoured by a glacier. And so, imagine if you are looking at a field of ice, and over all that ice is just a ton of rocks, of all different sizes, shapes, colors. And then you have to find the space rock in those rocks. It’s a little trickier than you might imagine.

IRA FLATOW: So, how do you tell the meteorites from the “meteor-wrongs”?

NINA LANZA: Great question! So I’ve learned a lot since I’ve started this work. You can look for certain characteristics, but of course, there’s always going to be ones that are different. But in general, you want to look for rocks that have what’s called a fusion crust. So that’s a very thin, shiny, outer coating which forms when the rock falls into the atmosphere of the Earth and heats up, so it melts a little bit. So it’ll have this very shiny exterior. And then sometimes it’ll break in half when it hits the ice or something, and you can see on the inside you can often see what are called condrules, which are these very round grains of material. Very common meteorites, so an ordinary chondrite would look just like that.

Of course, the meteorite from Vesta that we think we found didn’t look anything like that. So of course, rules are meant to be broken. So I’ve learned a lot from the veterans on the team, in particular a mountaineer John Schutt. He has seen– he’s been with this project over 35 years– he’s seen more meteorites probably than any person ever. So frequently, we’d say, hey, Johnny, is this a meteorite? If he says yes, then it is. if he says no, probably not.

IRA FLATOW: Is it possible to find, possibly, on any of these meteorites, forms that life might have lived on that place, where it came from?

NINA LANZA: It’s certainly possible, although with a big claim like that, it would require really big proof. A previously found meteorite from Antarctica was thought to actually have some potentially micro-fossils. This is the famous Allan Hills, I think it’s 84001. But you know, there are a lot of abiological processes that can make shapes that looks very biological to our eyes, so we need more than just a shape. We would need chemistry, we would need, I would say, a really complete fossil. So it’s not impossible, certainly not impossible, but I don’t think we’ve done it yet. We’ll keep looking though.

IRA FLATOW: If it’s not life that you’re looking for, or figure that there’s a high chance of finding, what are you learning from all of these rocks?

NINA LANZA: We’re learning all about the origin of our solar system. What were the building blocks? And then how the solar system evolved. And not just even the solar system, the specific bodies within the solar system. We’ve never done sample return from Mars, which is my planet of choice, it’s what I study. But we do have over 130 Martian meteorites that we can study here in the laboratory.

So we have great robotic missions. They are doing such a great job, but there’s nothing like having a rock in your hand and be able to analyze it in a laboratory, repeatedly, and with different techniques, and over time because that really gives you a lot more information. So that’s really telling us a lot about planets that we are studying right now and giving us more, and detailed information.

IRA FLATOW: You have such a niche job. I mean, you’re a geologist, but you’re only studying Mars. I mean, is there a name for exactly your job, of what you do?

NINA LANZA: I guess I’d say it’s the greatest job ever, but that’s probably not my job title. I would call myself a planetary scientist.

IRA FLATOW: OK, that’ll work. And you also zap Martian rocks with a laser, don’t you?

NINA LANZA: I sure do, Yeah. I’m part of the science team on the chemcam instrument that’s on board the Curiosity Rover that’s on the Mars right now, zapping rocks as we speak. We have a laser that will a little bit of material at a distance of up to about 23 feet away. And it’ll make a bright flash, and we’ll look at the color of light that bright flash emits and we can say what the chemistry of that rock is. So we do that probably– I’d say we do on average 400 to 800 zaps on Martian rocks every single “sol”, Martian day.

IRA FLATOW: Wow. You don’t actually push a button yourself.

NINA LANZA: I know. I wish there were a button. I was also hoping there was a steering wheel, but sadly it’s just typing.

IRA FLATOW: Let me go back to your last recording we have of you. I mean, this is terrific. It’s clear from your recordings that you’re in Antarctica, you have to make your own fun. I know from being down there. And here’s how you spent Christmas in the field.

NINA LANZA: Are you ready? He rules the world with truth and grace. And makes the nations prove. The glories of His righteousness. And wonders of his love. And wonders of his love. And wonders of–

IRA FLATOW: A Christmas Carol. You brought sheet music to Antarctica?

NINA LANZA: I sure did, and a pitch pipe. Apparently the first time in [INAUDIBLE] history that this has been done.

IRA FLATOW: Wow. There are also recordings of you guys reading aloud from Shackleton’s journeys. He, to me was– and I think to most Antarctic, people who’ve been there– is the great hero of Antarctica. Did any of that stuff he wrote about sound familiar to you?

NINA LANZA: Oh my goodness, absolutely. It’s really astounding how Antarctica has stayed the same over the last 100 years. He would describe these fogs rolling in, and we experienced that. The silence, and the solitude, and the sound of the wind, all of that is still true today. This is really still Shackleton’s continent in many ways.

IRA FLATOW: We’re talking with Nina Lanza on Science Friday from PRI, Public Radio International. Did you get to any of the huts that are out there?

NINA LANZA: I did get to the discovery hut, which is at McMurdo Station. So it was pretty easy to get to. And my goodness, I am so glad I didn’t have to live there for two years. It was good shelter against the storms, but that is not a luxury living.

IRA FLATOW: Do they still have the penguin sitting out there from a hundred years ago, that he was dissecting, Scott?

NINA LANZA: I only saw a giant, dessicated seal. Which I didn’t recognize as such until somebody told me. But the only penguins I saw were actually alive and well, thank goodness.

IRA FLATOW: That’s great. Now that you have all these meteorites, where does your collection go to now?

NINA LANZA: For right now, they are on a container ship that is bound for, eventually, Johnson Space Center. So the rocks will be kept frozen until they get there. And then when they get there, they will be slowly thawed in a dry atmosphere, so we can prevent any water from forming on them and then causing aqueous alteration change in the mineralogy And then the folks at Johnson Space Center will start doing the triage analyses. So they’ll try to say, OK, what did we bring back?

They can’t do in-depth analyses on every single one, but what they’ll do is they’ll do some analysis on everyone. And then they’ll publish a newsletter, which is put out twice a year, saying, hey researchers of the world, here’s what we found. Would you like to do additional research on it? And if somebody sees something they want to look at in more detail, they’ll submit an application to get a piece of that meteorite to continue to study.

IRA FLATOW: How long have these meteorites been in Antarctica?

NINA LANZA: Well, it’s hard to say. We don’t really know. They could be thousands and thousands of years, they could be last year. It’d be hard for us to know. Certainly, most of them have been there very, very long time.

IRA FLATOW: You mean thousands of years? And they’ve been covered with ice, and then the ice has been ablated and they just pop out?

NINA LANZA: Yeah. Some of them, right, they fall into snow, and that snow will get more snow piled up on top. And eventually that snow will compress into glacial ice, and it’ll keep moving as a glacier until it hits one of these places where the ice stops moving and the wind can ablate it. So it may have been locked in ice for thousands of years before we got there.

In fact, some of them we find are just sort of jutting out a little bit from the ice, and we have to very carefully chip them out of the ice because they’re still stuck in there. But we don’t want to touch them, so that’s actually quite tricky.

IRA FLATOW: I mean, they’ve been there for thousands of years. What more could you do, they’ve been exposed to the microbiome of Antarctica? Are you a little too careful about pulling them out of the ice?

NINA LANZA: You can never be too careful, Ira, especially because people are very interested in seeing what is the organic content of these materials. Some of them are very high– the carbonaceous chondrites have a very high organic component– so we certainly do not want to add any new organics because we want to make sure these came from space, so we really understand what the inventory of organics was in the early solar system.

IRA FLATOW: It sounds to me like you’re going back.

NINA LANZA: I think– if they’ll let me. If they’re not sick of me yet. I’d love to.

IRA FLATOW: And back to the same place, I’m sure there are a lot more meteorites left to be discovered.

NINA LANZA: Oh, absolutely. Although I think next year the field site will be different. They kind of rotate around, so I’ll have to talk to the PI to see where they’re headed next.

IRA FLATOW: Are you going to keep track of your favorite meteorites, what happens to them?

NINA LANZA: Absolutely, absolutely. I have my list, my personal favorites, so I’ll be very interested to see what the initial analyses are on those.

IRA FLATOW: Well, thank you very much for sharing your experience with us. It’s just been bringing back memories for me. And I have just a slight idea of what you went through, I can imagine how excited you must be. And how it probably changed your life, like it changed my life.

NINA LANZA: Absolutely. It’s hard to explain, but you understand exactly what I mean when I say, yeah, my life has changed now.

IRA FLATOW: Nina Lanza, staff scientist at Los Alamos National Lab in Los Alamos New Mexico. She’s also a member of the 2016 Antarctic Search for Meteorites field team, run by Case Western Reserve University.

And you can listen to a lot more of Nina’s Antarctic dispatches at our website, including her answer to our most pressing question–

NINA LANZA: “How do we go to the bathroom in the field? Great question, so glad you asked. ”

IRA FLATOW: If you want to know the answer, enquiring minds want to know, you can go to a website and find out. sciencefriday.com/nina.

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