“It’s always exciting any day you’re getting information back from another planet.”
“If life was on Mars, it would likely be below the surface and it would want to be near some sort of water.”
Tanya: Hi everyone and welcome to Ask-a-Scientist, a Science Journal for Kids podcast where we explore what it’s like to be a scientific researcher. I am Tania Dimitrova and I’m here with my co-host Dr Miranda Wilson.
Miranda: Hi there.
T: We are super excited about our guest today. Dr. Jennifer Stern is a space scientist at NASA’s Goddard Space Flight Center in Maryland. Here, she studies the chemical composition of the atmosphere and surface of Mars. She’s a member of the science team for the Curiosity rover that landed on Mars in 2012. Some of the results from this research on Mars were published in the prestigious journal, Proceedings of the National Academy of Sciences, last year. And here at Science Journal for Kids, we just adapted them for school students in an article called, What can we learn from carbon on Mars? Today, we will talk with Jen about her work, but we will also get to know, at least a little bit, the person behind the professional scientist. Hello, Jen, and welcome to the podcast.
Jen: Hello, thanks for having me.
T: So you work at NASA, and your mission is to study Mars. We can hardly imagine anything cooler. Please tell us the truth: do you brag about your job when you meet new people? Or conversely, do you keep it a secret so you don’t have to deal with adoring fans?
J: Well, I love talking about science and about the science we do. My husband actually calls me a NASAvangelist because I’m really, you know, devoted to the mission that NASA has. And a big part of that is educating the public about what we do. So I do tend to talk quite a bit about Mars if given the chance and about all of the work that we do here.
M: That’s awesome. So there are lots of kinds of popular things going around about space and space research. Do you have a favorite space-themed movie or TV show?
J: I have to think for a minute. Well, of course, I loved the book The Martian and the movie was really good too and it was actually pretty scientifically accurate so that made me happy. I definitely am drawn to space-type stuff, particularly anything having to do with Mars. I’ve always loved the movie Dune. I actually haven’t seen the newest incarnation of it, but the old one is like super campy and I’ve always liked it.
T: So let’s play a movie game. We say a space or a NASA-related movie and you say “Yay” if you liked it or “Nay” if it sucked.
T: Hidden figures.
M: The Martian. You probably already answered this.
T: Apollo 13.
T: That wasn’t very convincing.
J: I had to think about it for a second because it’s been a while since I’ve seen it.
J: I didn’t see that.
M: I haven’t seen it either. Tanya, have you seen it?
T: Yes, I have. It’s a Nay for me. For all mankind.
J: Did I see that? Is that a show?
T: It’s a show, yes.
J: Yay, I think I saw it.
T: For All Mankind is about an alternative past when the first person to land on the Moon was a Russian.
J: That is on my list. I haven’t seen it yet, but it seems really cool, so I do want to see it.
T: It’s a yay for me.
J: Okay, good.
M: Next up: Deep Impact.
J: Eh, I don’t think I saw it, but I’m going to guess based on what I think it is, a nay.
M: And last but not least: Stanley Kubrick’s 2001 A Space Odyssey.
J: This is so embarrassing. I’ve never seen it.
M: Oh wow!
J: I know, I know. It’s very embarrassing.
M: I’ll admit, I’ve only seen parts of it.
T: So let’s talk a bit about how one becomes a space scientist at NASA. And let’s start from the beginning. What kinds of subjects did you take when you were a school student and what passions and interests did you have back then?
J: Yeah, so it’s interesting because when I was younger, I never really once thought about space science as a career. I wasn’t one of those kids who wanted to be an astronaut or study other planets. I loved a lot of different things, including art, including reading. I read a ton. And I also love the outdoors. And that was sort of my way into all of this – geology. We used to go skiing with my family as a kid and we would drive up to the Rocky Mountains to the ski resorts and we would see these outcrops of rock that were all really different than anything that we had back on the East Coast. And so I always wanted to understand why do different parts of the world look different. And that all goes back to the geological setting.
So when I went to college I decided I wanted to be a geologist. At least I wanted to study geology and better understand just sort of how the Earth was created. And I also wanted the opportunity to do fieldwork and be outside studying the planet. And so I did that. And in graduate school, I continued to study our planet.
I studied how carbon is cycled in the Everglades and I studied methane emissions from landfills.
So I got really into the modern Earth and especially some of the things that we as humans are doing to change our Earth. Which is really fascinating.
And it turns out that the tools that I used to do that, the chemical tools, the trace metal and trace gas and stable isotope tools that I used in chemistry were really applicable to looking at, for example, the signatures of the first life on Earth in rocks.
And from there, it’s not that far of a leap to think about the signatures of life on another planet.
So my way into sort of what happens on other planets was looking at how life may have originated on this planet, in the oldest rocks, and then looking at different experiments in my postdoc that might have formed organic molecules abiotically, which means ‘not by life’. And then I continued to study these molecules in meteorites.
And then I was hired to work on this Mars project, the instrument that Goddard was developing for Mars called Sample Analysis at Mars that was going to go on the Curiosity Rover, which is where the data comes from for the paper I published.
M: So it sounds like your academic journey was kind of a straight logical path from your undergrad at Brown to your PhD at Florida State and then postdoc at NASA. Did you feel like it was a straight logical path for you or did you feel like it meandered a little bit?
J: Yeah, no, not at all. I don’t, because I really didn’t even consider NASA until, like, the very end of my PhD research. I had thought, you know, if I worked for the government, maybe the U.S.
Geological Survey or the Environmental Protection Agency. And, you know, to this day, I still do care a lot about using these tools to understand our impact on the Earth. And I think that, you know, it just becomes more and more important. And so I always thought I would be doing that kind of research.
And I’ve been really lucky to study what is interesting to me, and then be able to follow that path. When I came out of Brown undergrad, I was actually interested in coastal geology, and in how we’re changing the coastlines and you know what we can learn about that. And when I first got to grad school, that’s what I studied before, you know, some other doors were open to me to understanding some of the other stuff about carbon cycling. So I feel lucky to have been able to follow these paths and go where things interest me.
T: So what advice would you give to a young person who wants to work for NASA?
J: So I think it’s always good to have that basic science under your belt, those basic classes of physics and chemistry, and I never liked chemistry until late in life.
T: No way!
J: Yeah, it’s really funny how these things work. But if you arm yourself with all of that information, then you have the basis from which to work, and then you can pivot between your interests. But you have to have the basic science.
I also think it’s really important to know how to write and communicate and that’s something that is not always stressed as much as it should be. And like like anything, you develop that ability over time.
The last thing I would say is also just, you know, let yourself get excited about things and follow those interests and then see how you can pursue those interests. If you like being outside, find ways to be outside. If you like studying dinosaurs, you know, find ways to study dinosaurs. So follow your passions.
M: That is fantastic advice. Thank you for that for all of our students out there listening. It sounds like in your day-to-day, you get really excited about what’s going on. What do you do in a normal day? And maybe let’s start in the lab and we’ll get to the field later.
J: Well, every day is a bit different. Because I’m at a certain point in my career, I don’t get to go into the lab and do sort of the hands-on work myself as much as I would like to. But I have folks that I direct in the lab. And I like to go in and check in with them and look at their data and make sure everything is going as it should be.
I work on a lot of different projects so a lot of the time I’m pivoting from maybe working on looking at data from caves in Italy to then looking at data from Mars to then thinking about developing instruments for other planets. For example I’m working also on a Titan instrument, an instrument for the Titan mission Dragonfly so there’s a lot of fast-paced changes during the day.
And you know, sometimes I will end up doing stuff like this where I’m talking to folks and doing some outreach. So it’s never boring – that’s that’s what I will say.
T: So I’ve heard that we, humans, know more about the surface of Mars than about the bottom of the ocean. Would you say that’s true?
J: So that may be true in terms of mapping the surface, in terms of the physical characteristics of the surface. However, chemically, I’m not entirely sure if that’s true. We understand the chemistry of the surface of the Earth, I think, a bit better than we do of Mars.
And the other thing I will say about Mars is while we do understand the way the surface looks, we know so little about, you know, anything below the first few inches of soil. So I think that while it’s really important to study, I think, the bottom of the ocean because there’s so much information there, we also need to study Mars still.
T: So, we know that in addition to your work at the lab, you also get to go on some really cool field expeditions to places on Earth like the Arctic and the Atacama Desert in Chile. What makes these good field locations from Mars research?
J: So that’s a great question because scientists argue a lot over what makes a good, we call it ‘an analog’, for an extraterrestrial environment. So it really depends on what you’re studying.
In some cases, it might be a place that’s completely devoid and absent of life. And so you’re going there to understand, for example, how what little life there is can be detected, how it uses and cycles nutrients that are in, you know, short supply.
Or you may go somewhere where the geology looks similar to Mars so you’re going and you’re looking for sandstones and mudstones and gypsum and you’re really not focused as much on sort of the life aspect of it. So it really depends on what you’re studying. Sometimes we go to caves to understand how life, you know, survives and cycles elements and gets its energy when there’s no sunlight. So there’re a lot of different environments and it depends on what you want to study.
M: What does a typical day on a field expedition look like for you?
J: So usually you get up pretty early, especially if it’s hot. I was just in New Mexico where it was quite hot during the day, so our goal was to get up early and get out and do our work and then get back. So you pack your lunch, you definitely want to have food. Even when you’re going into caves and other places, you want to have some supplies. And then you head off to the field site.
Usually, you’ve got to drive a bit of the way and park the car and you may have to hike in. Usually, the hike may be shorter if you’re carrying large instruments and things to deploy in the field or coring materials. But if you’re just taking a look at what’s there and doing a little sample collection, the hikes could be longer.
You know, again, it can be specific to where you’re going. When I’ve been in the Arctic, sometimes we’ve been on a boat where we use the boat to get to the site. And when I’ve been in caves, you have to suit up into these cave suits and sometimes even put rock climbing gear on because some of the caves require repels to get into. So everything’s a little different. Usually, the field day can be long at times, especially in the Arctic where the day is long. But usually at the end of the day, you have a meal with the folks that you’re out in the field with and just sort of, you know, enjoy a hard day’s work and good company.
M: And are you doing any kind of data analysis while you’re out in the field or is it mainly just collecting the data?
J: So there’s a variety. I usually collect samples to analyze back in the lab, but there are plenty of folks who have handheld instruments and they can go and literally zap the rocks. Like one of the instruments makes like a pew-pew zip-zip sort of noise. So they can get some real-time information which helps us then pick better samples to take home from the field.
T: Can you think of a specific day that was really exciting for you at work? What did it look like? What happened that day?
J: One of the most exciting days was way back in 2014 when the data from this combustion experiment that was recently published came down…
T: Down from Mars?
J: Down from Mars, yes. So the experiment happens on Mars but then there’s a little bit of a delay in terms of when it gets, the information gets back to Earth. And so I was at work when the data came in and we started looking at it in real-time and the first thing we realized was that this was a multi-step experiment and that we didn’t have data on one of the instruments for the very first run. And we discovered that we created so much gas during the experiment that one of the instruments just turned itself off. So that was exciting and maybe a little scary, you know, because you don’t want to damage your instrument on Mars. But we did get enough data to make sense of it. But it’s always exciting any day you’re getting information back from another planet, especially when you spend some time developing and designing the experiment.
M: Let’s shift a little bit and talk about your work-life balance. So one question we always like to ask professional researchers is how you manage to balance your work and your personal life. And we know that this is a challenge for all working people, but we’re especially interested in how that works out for scientists.
J: It’s definitely a challenge and I have one four-and-a-half-year-old daughter so it’s challenging sometimes, especially with the travel that I do. And she, you know, she gets sad when mommy goes away but I always bring her back things like rocks and stuff. That can be tough, you know, long hours at work and commuting and everything can be tough. And you know, I can’t imagine not doing this job.
I don’t work on weekends unless I absolutely have to so that I can give a hundred percent of my time to my family and I try to you know really sort of turn off the work mode when I get home, but still, you know, it’s a challenge.
And I’m lucky that my husband doesn’t travel for work, so he can, you know, be really the one who stays home when I’m gone. We trade pickup from daycare, etc.
And I’m actually able to still have a hobby, which is dragon boat racing, which many people have not heard of.
T: What is dragon boat racing?
J: So dragon boat racing is it’s a 20-person boat. It’s paddling. It’s like outrigger canoe, except it’s a really big boat. And there’s two people per row, 10 rows, and you all paddle in sync and you race and it’s becoming more and more popular. And in fact, our team in DC went to nationals this year and next year we’re going to Worlds.
J: Thank you. But what it is, is it serves a couple of purposes. It’s a good release, so it gets me outdoors, it gets me exercise, and it’s social. In the past where maybe I would have had three different activities or hobbies to address each of those needs, now I just, I’m more efficient with the way that I address those needs with just one hobby. So I try to get that in at least two days a week, and it sort of keeps me sane.
T: Is there a dragon on the boat? Is that why it’s called dragonboat racing?
J: Yes, when you do race, they put a dragon sort of at the front of the boat, sort of sticking off the dragon head. And it originated in East Asia. There are many different kinds of dragon boats.
There are some boats that are really long, some boats that are shorter, and it’s become adopted here in the States and in Europe and all over the world as a sport. In fact, I think it was a demo sport in the Olympics last time around. So, yeah, it’s a lot of fun. And again, it just gets me out. I think it’s really important to have physical activity to get yourself away from thinking too much and to get into your body.
T: We actually understand that you also dance and you’re a big art fan.
J: Yeah, yeah. So I used to. I haven’t done it as much recently and in particular since having a kid and having my life change a bit. But I used to do Middle Eastern dance and I did that for about 10 years. I took classes and I performed and you know that was another thing that was really interesting in terms of sort of what it gave me. The movement is great and also I enjoy performing. I mean there are a lot of parallels between performing as a dancer or as any sort of performer and giving a talk to an audience. So I think in some way those activities were really helpful to each other. So I think it gave me better confidence and stage presence while still allowing me to have some art and some, you know, fancy costumes and stuff like that.
M: So let’s talk a little bit more about the Curiosity Rover and the research we adapted for students. For this paper, your team used the Curiosity Rover to sample a location on Mars where there might have been a lake a long time ago. You looked at the carbon in the samples to see how much there was and try and figure out where it might have come from. And you found that there was more carbon there than you expected. And in your paper, you discuss that most of the carbon probably came from meteorites and volcanic rock, but that it can’t necessarily be ruled out that some of it came from living things. Is that a fair summary of your research?
J: I think so.
T: So we actually received some questions from students who read your article. And the first one is from Adyant.
Adyant: Hi, Dr. Stern. I’m Adyant Bhavsar, an eighth grader from San Jose, California. I’m actually the one who suggested your article to Science Journal for Kids for adaptation. So I’m so excited to ask you some questions today. How does the Curiosity Rover’s sample analysis at Mars, or SAM, tool work, and how did you use it in the experiment?
J: So Sample Analysis at Mars is basically a lab in a box and it’s very capable. It does a lot of the things that, you know, a much larger instrument suite in a lab can do. But the first thing that happens is we have on the end of the rover’s arm there’s a drill and that drill drills down into sediments and takes some of the sediment that’s drilled and puts it into something that portions it out and it also shakes it through a sieve to make sure that we get that the instruments get all the same grain size. So then it gets dropped down a tube into the SAM instrument and the SAM instrument has a carousel with 72 cups and the sample will drop into one of those cups and then the carousel turns and puts one of the cups up into an oven. And what we do is we seal that oven and heat the sample and then look at the gases that come off with the mass spectrometer or the tunable laser.
Now this experiment was special and we did it in a bit of a different way than we usually would. We actually introduced oxygen to the sample and we closed the oven because we wanted to drive the combustion of all of that carbon in there to CO2 and then measure the CO2 that came off out of that sample. So it’s a little bit different, and that’s how we sort of over-pressurized the instrument on the first run. This experiment gets performed in the lab on Earth all the time, and what you get is the total carbon in that sample.
T: Cool. Another question from Adyant.
A: How does the amount of organic carbon on Mars compare to that of other stellar objects and what could this mean for its past?
J: Thanks for another great question. The organic carbon on Mars appears to be similar to or maybe a little bit more than that in carbonaceous chondrites.
M: What is a carbonaceous chondrite?
J: It’s a classification of a meteorite, and what it means is it has a certain amount of carbon material. There are lots of different organic molecules in there. And we see a lot of the same kinds of organic molecules on the surface of Mars as we see in those carbonaceous chondrite meteorites. And so what we see on Mars looks very similar to meteorites, which is not unexpected because we think that, you know, meteorites represent the most ancient pieces of our solar system and Mars contains that same material.
Now on Mars, you know, the question is how much chemistry has reworked that material or, you know, performed some sort of active organic chemistry either in the atmosphere or in the subsurface of Mars.
And so, you know, it’s really hard to tell how much chemistry Mars has done to this material versus, you know, sort of what it was in a primordial form. But we do see some suggestion that there could be atmospheric organic chemistry going on that’s taking the CO2 in the atmosphere, performing photolysis and other atmospheric reactions, and then precipitating carbon that comes to the surface. And it’s also possible in past Mars that water-rock interactions in the subsurface could have altered some of the original carbon in the Mars mantle.
T: But do we have these type of data from other stellar objects as well, other planets?
J: So we don’t have, for example, the total organic carbon of say Venus or Mercury or other rocky planets.
The only thing we do have is these different meteorites, which represent what we see in asteroids. And what’s exciting is with the OSIRIS-REx mission to the asteroid Bennu is that that mission went and sampled that surface of the asteroid directly and is now bringing back and about to basically drop to Earth the sample from that asteroid. And so I think we’ll learn a lot more when we look at that material, which represents, again, what everything in the solar system, what all the rocky bodies would have started with and also what carbonaceous asteroids would have.
T: That will be one exciting day at work.
J: Yes, so it’s actually happening on a Sunday, but there’s also going to be a lot of activity on, you know, before that. So everybody’s very excited and we’ve got a lot of scientists here at NASA Goddard who are going to get to actually analyze the material.
T: We actually have a couple more questions from an even younger reader.
Hi, I’m Aili and I’m six years old and I have a question for you. Why is Mars red?
J: So, a couple of reasons. Mars is very dusty and there’s a lot of particles in the atmosphere that reflect light. And it’s sort of like when we get haze here on Earth and the sunset makes everything sort of red or pink. So that’s what’s happening on Mars with the dust in the atmosphere and it’s just reflecting that kind of light.
T: One more.
A: Why do some people think that aliens live on Mars?
J: So way back long ago when people started looking through telescopes and were able to see the surface of Mars through telescopes, they saw what they thought looked like canals.
We really know now that these were channels cut by water. But there was the thought that these canals had been built by aliens. Of course, you know, many years later, when we actually went there with our rovers, we saw that these canals were cut by water and not by, you know, life-like or human-like aliens. So, but I think it’s persisted in the consciousness of the world that, you know, if there is life on another planet, it’s, you know, Mars is so much like our planet in terms of it’s made of rocks and we know that there was water. And so, you know, it is a good candidate for a place that some sort of, you know, alien species like us might live. And, of course, we think about, well, humans going to Mars and how they could possibly live.
T: Would you say that there might have been life on Mars? And if yes, how long ago and what sort of life?
J: If there ever was life on Mars, it’s highly likely that that would be like single cellular life, like bacteria. And, you know, we haven’t certainly found any evidence that life ever did originate on Mars. But if it did, it would have done it a very long time ago, it would have done it, you know, 3.8 billion years ago, which is actually when the very first single-celled organisms arose on Earth. So, so far we haven’t found any evidence of that but we do know that Mars at that time would have been what we call habitable. It would have had water and it would have had the energy sources and nutrients available for life to use had it been there.
T: Do you get tired of this question, is there life on Mars?
J: No. I think, you know, it’s difficult because the most habitable parts of Mars are places we haven’t explored. What I mean is the most modern-day habitable environment. So places under the subsurface where there could be water and we know that there’s at least water in the form of ice and those are areas closer to the poles and just like we have permafrost here on Earth there is that sort of permafrost on Mars and you know that is a potential if life was on Mars it would likely be below the surface because the surface is really harsh with radiation and it would want to be near some sort of water. Although the water would have to be liquid in order to support life as we know it.
Also, like the deep subsurface of Earth also has life, and so that’s a place that we haven’t looked yet on Mars. But there are people developing really deep drills that could get down to deep levels of Mars to start looking down there.
T: Would you say that that is probably an important question in the mind of most researchers at NASA? Is there life outside of Earth?
J: I think that it is one driving question and scientists think about the origins and the evolution of the solar system and, you know, because we are life, it’s very natural to also think about how life evolved. I’m interested in sort of also, how did chemistry evolve on different planets? And then also, if chemistry evolved, but life didn’t, why is that? What makes it so special for life to evolve? What happened on this planet that was so different than other planets?
But I think, you know, not only to NASA scientists, but to most people, the question of is there life, you know, somewhere that’s not Earth is a very fundamental question – Are we alone? – and an interesting one with a lot of different repercussions. Should we find life that’s not on Earth?
M: So we always like to end with a fun kind of pie-in-the-sky question. We know that space exploration is super expensive, but if you had an unlimited amount of funds, what is one burning research question that you personally would like to try and answer?
J: That’s a good question. I think some of the most fascinating places in our solar system that might be habitable are the oceans of Enceladus in Europa. And I think that it would be amazing to be able to go down there, drill in the deep hole, or go down the plume on Enceladus and see what’s around. Even if there’s not life there is there active you know hydrothermal venting and is there what’s going on down there are the oceans like our Ocean or are they very different you know that again gets at the Deep subsurface of a planetary body. But I think those are the places that honestly are currently the most habitable environments
M: So, would you want to build another rover to send there or send some astronauts or probes or satellites there to kind of look at stuff or what would be the plan?
J: So, I don’t think astronauts would fare very well on Enceladus Europa, but they’re, you know, way in the future. There might be the possibility of sending some sort of autonomous submersible into these oceans, which would be super cool. And people study the oceans of Earth and use them as a testbed for developing these sorts of things. I think that astronauts on Mars could enable scientific research for sure. Because, you know, making the decisions real-time and pick samples, etc., I think is very valuable. But I wouldn’t want to send astronauts somewhere so dangerous, like those outer moons.
M: Future astronauts, thank you for that, I’m sure.
T: Jen, thank you so much for your time today. We learned a lot about chemistry on Mars, about your typical workday, and about dragon boat racing. We really appreciate you taking the time to be with us.
J: Happy to do it.
M: Did you know that you can directly read one of Jen’s scientific papers, stripped from its complex scientific jargon, and made understandable to readers as young as fourth grade in school? It’s available in two reading levels and in Spanish. You can also just Google its title, What can we learn from carbon on Mars? Or directly go to www.sciencejournalforkids.org and search for Mars.
T: That’s all for today. This podcast was produced with help from our research assistant,
Adyant Bhavsar and Natalia Torres Behar, sound engineer Maria Mihailova and hosts Miranda Wilson and me, Tania Dimitrova. Thank you for listening. Subscribe to this podcast to receive notifications about the next episode of Science Journal for Kids Ask a Scientist. Till then!