ScienceMatters - Season 3, Episode 3: The Search for Life at Earth’s Extremes

September 30, 2019
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The search for life elsewhere in the Solar System can start at the most inhospitable regions of Earth, like Iceland’s volcanic landscape, or frigid Antarctic waters. Amanda Stockton, assistant professor with the School of Chemistry and Biochemistry, talks about her astrobiology work for NASA.  

S3 E3 ScienceMatters Amanda Stockton Script Transcript 

(Upbeat music) 

Renay San Miguel:  Hello and welcome to ScienceMatters, the podcast of the Georgia Tech College of Sciences. I’m Renay San Miguel. 

Does life exist elsewhere in the universe? 

If so, how would we know? 

What conditions would signal that life exists in some distant planet outside our solar system, or on the moons of Jupiter and Saturn?  

You don’t have to be an astrobiologist to ask these questions, but they are questions that the NASA Astrobiology Program is trying to answer, with the help of educational institutions like Georgia Tech.  

NASA video: Right now we’re trying to get mapping so we can get a three-dimensional digital model of the entire area on this side. 

Renay San Miguel: That’s Amanda Stockton, an assistant professor in the School of Chemistry and Biochemistry. This is from the first in a NASA video series called Astrobiology in the Field, which premiered in late 2018. 

Here Stockton is in Iceland, studying a famously extreme environment of fire and ice right out of a Game of Thrones episode: we’re talking volcanos and glaciers. Her work there could tell us more about the prospect of habitability – developing and sustaining life -- in extreme environments elsewhere in our Solar System – like Mars or the moons of Jupiter and Saturn.  

She’s there as part of a NASA program called FELDSPAR, or Field Exploration and Life Detection Sampling through Planetary Analogue Sampling. And yes, FELDSPAR is also the name of one of the minerals Stockton finds a lot in her field work.  

Amanda Stockton Georgia Tech lecture: Since flying to these areas around the Solar System is rather expensive, it’s a lot cheaper to use locations on Earth that are terrestrial analogs of these extremes, in order to better understand whether those systems could actually be habitable. 

Renay San Miguel: That’s Stockton back on Georgia Tech’s campus during a lecture appropriately titled “Searching for Habitability at the Extremes.” 

While they conduct that search, Stockton and other scientists are helping the space agency determine possible landing sites for the next phase of uncrewed and crewed space missions. Her team will also help determine what scientific instruments should be on those missions, like the Europa Clipper, set to leave for one of Jupiter’s most intriguing moons in 2023. 

Amid the most extreme locations on Earth, Stockton searches for fossils, biomarkers, and other evidence of past or present life -- just as space probes, and astronauts, will do during future missions to other planets and moons.  

If probes and on-site analysis work on Earth, then maybe they will work on dusty Mars, or the frigid-yet-watery Enceladus, one of Saturn’s moons.  

Because if life could find a way in unforgiving Earth environments, then maybe it could find a way..somewhere out there. 

(Upbeat music) 

NASA video: So we now have our samples back in the lab, and everyone who comes in this room has to wear a face mask, so that we don’t spray all of our bugs on the samples when we talk. 

Renay San Miguel: That’s Stockton once again from the NASA video, in a clean room near her Iceland camp, getting ready to analyze geological and biological samples.  

That analysis will include looking for signs of extremophiles, or any organism that has adapted to life in an extreme environment.  

If Stockton and her researchers are helping NASA figure out what scientific instruments should be on future space probes, then how do they determine what needs to be analyzed?  

Also, where in space are the best locations for exploring? 

Amanda Stockton: So it's not like you're flying blind. We have lots of information about many interesting locations in our solar system from flybys to orbiters et cetera. That is not to detract from the fact that we still need more missions to better cover very exciting targets, particularly small bodies in the asteroid belt, in the Kuiper belt, and just the Jupiter Trojans. There are just a million small bodies out there that we don't have very much good information on. But for the larger planetary bodies, we do have some information to help us. Most of it has been remote sensing where basically, based on the colors of light that's reflected off of the planetary surface, you can tell—you can have some information about what it's made of—I don't want to say you can tell. For example, Europa, one of my favorite icy moons, we can tell based on its reflectance spectrum of that light that comes off of it from the sun that it’s mostly water, and then we can say that there's some areas that are not water. And whenever we go in the lab and we try to duplicate that spectrum of reflected light from those areas that are not water, it looks like we could be looking at like hydrated sodium calcium sulfates. But we don't know that for a fact. And in order to know that for a fact, we need to land. 

Renay San Miguel: You need to be there. 

Amanda Stockton: We need to be there. And so we need to bring the right tools that can detect, is it sulfate? Is it calcium? Is it sodium? What if it was also a mix of chloride? You know, sodium chloride irradiated can get you more in the reddish regime as well. What about organics? What if there are microbes underneath that icy surface of Europa living in that subsurface global ocean? 

Amanda Stockton: So we're not flying completely blind, but we need more information. So Europa Clipper—just to go back to my favorite moment here—will help us get more of that information so we'll have a better idea of what tools and techniques to land. But the other thing that we do is use our own Earth and locations here to try to figure out what instruments work well, what analyses work well, what just gives us horribly messy data that we can't figure out stuff which, you know, that happens, too. So we've got the analogs and we have some— 

Renay San Miguel: — analog environments that might match up to what you will find out there? 

Amanda Stockton: Right. So icy regions, ocean regions, and that's the whole goal of that Oceans Across Space and Time. 

(Upbeat music) 

Renay San Miguel: Oceans Across Space and Time: A romantic, very sci-fi-sounding name for an international team of interdisciplinary scientists, including Stockton and several other Georgia Tech scientists. It’s part of the Network for Life Detection funded by the NASA Astrobiology Program.  

The focus is indeed on ocean worlds, and whether life was or is there.  Georgia Tech Associate Professor Britney Schmidt is OAST’S principal investigator.  

But really, what Schmidt calls her “robot oceanographer,” Icefin, does the investigating. 

(Icefin underwater sounds)  

Renay San Miguel: That’s Icefin, a torpedo-shaped robotic autonomous underwater vehicle, with plenty of instrumentation to analyze any life under the Ross Ice Shelf of Antarctica. This audio is from Icefin doing just that in 2015. If everything goes right with testing and modifications, it could be doing its analyzing in other worlds, such as the waters of Europa.  

Stockton and her team have been developing microfluidics instrumentation – that is, devices that can control and measure microscopic amounts of liquids – that could join the instruments of Icefin. But the original robotic vehicle is already providing some new info about life there.   

Amanda Stockton: With under-ice submarines, my group is building a microfluidic cell counter to go on Britney Schmidt’s submarine—unmanned underwater vehicle; it's not a submarine. The distinction between whether there's people on it or people driving it from the bottom. (Laughter) 

Renay San Miguel: Understood. 

Amanda Stockton: So now we're learning a lot more about the under-ice environment. And beautiful pictures from these little like sea anemones, but they grow down off the ice rather than up off the floor. 

Renay San Miguel: That's weird. 

Amanda Stockton: It's absolutely amazing. And then with some of the other technology that my group has been building, we now have the ability to build an instrument system that can survive hitting an icy moon without having to slow down first which saves you an awful— 

Renay San Miguel: You can hit it at full speed — 

Amanda Stockton: Full speed! 

Renay San Miguel: Oh my gosh! 

Amanda Stockton: Five kilometers per second. That's a 50,000-g impact. We've tested up to that and almost everything has survived. 

For the price of one Europa lander you could fly maybe a hundred of these little guys. They’re like the size of a Coke can, about the same weight, too. 

(Upbeat music) 

Renay San Miguel: There are other tempting, warmer analog environments on Earth that could duplicate other potential planetary targets, such as Mars. One of them is the Atacama Desert in northern Chile. 

Amanda Stockton: So there's lots of excellent analog environments, but there's no one, perfect analog environment. Each thing that you want to mimic about an extraterrestrial location, you can find something on Earth to mimic that one thing, but you're not going to mimic it all because we can't do reduced gravity and high radiation and really, really cold ice, really, really thick ice above a completely sterile ocean. Like these are not options on Earth. So for Mars, there's lots of excellent analogs. The Atacama Desert is the oldest, driest desert on Earth. Very low biomass there, but still things grow. Even in some of the driest regions there have been detection of organic compounds, plenty of them indicative of the last major rain events in the area. 

There's El Tatio, which is a hydrothermal system in the Atacama region, that's another one of these good analogs.  

When you're looking at trying to find something with like absolute lowest biomass that's still spectroscopically similar, you're looking at really new volcanoes in Iceland.  

Iceland is very active—new volcanoes roughly every four years-ish, which is awesome because that's about the length of a standard NASA grant. 


Renay San Miguel: Very convenient how that worked out. 

Amanda Stockton: Yeah. So you may remember Eyjafjallajökull, the eruption that shut down European air traffic? 

BBC News report: Our airports are at a standstill tonight as volcanic ash from Iceland drifts across the region, leaving air travel too dangerous. 

Amanda Stockton: We've been going to that since 2013. Actually the rest of the group was there in 2011—I didn't join until 2013—and studying that volcano as microbial diversity recovers as a Mars analog in order to understand what are the little microclimate parameters that help dictate habitability. And by using a cold volcano in a remote area without much human traffic, we can start to nail that down.  

Renay San Miguel: Stockton also appreciates that a new volcano in Iceland has been reserved just for scientific study: No tourists allowed. 

Amanda Stockton:  More recently Holuhraun erupted and that—I think we were one of the first teams out on the lava after it stopped out-gassing enough to be safe for travel. And that one's a really valuable volcano to be studying because they don't allow any travel to the site of the eruption except for with scientific permits.  

(Upbeat music) 

NASA video: So without further ado let me welcome today’s guest, Dr. Amanda Stockton, an assistant professor in chemistry and biochemistry at Georgia Tech. Dr. Stockton, hi and thanks for joining us on the show. 

Amanda Stockton: Hi, thanks and thank you for inviting me to be here, I’m really excited to participate with you. 

Renay San Miguel: Stockton is getting a lot of camera time lately thanks to NASA video projects. 

In addition to the Astrobiology in the Field video, Stockton also took part in the NASA Ask an Astrobiologist video series. This particular episode is from 2018. In it, she talks about growing up on a cattle ranch in Oklahoma, and earning a dual Bachelor of Science in chemistry and aerospace engineering at MIT.  

Her studies obviously prepared her well for astrobiology research, but the real spark for that happened much earlier in her life. 

Amanda Stockton in NASA video: I was always interested in space, and I was always wanting to go into space and look for signs of life. I grew up on Star Wars and Star Trek, and just the whole idea of being able to find life beyond Earth was incredibly exciting to me. 

Renay San Miguel:  Stockton tries to pass along that fire to her students. She also connects the dots between the sci-fi obsessions of her youth to her microfluidics research. 

Amanda Stockton: Well, you know, there's just so many fun little discoveries and excitements that happen every day. And getting to work with my team of students that—there's always something new and exciting that happens. And it's that bit of discovery and seeing that spark of discovery from a student. That's pretty nice. 

A large part of what my group does is microfluidics. And the goal of microfluidics for a long time has been to make Spock’s tricorder. 


(Star Trek tricorder sound) 

Mr. Spock: Captain, our information on these people and their culture was not correct. There is no evidence of any progress as far back as my tricorder can register. 

Amanda Stockton: The way that we have framed our science fiction helps frame how we talk about our science and helps us communicate what our goals and hopes and objectives are across various scientific pursuits. 

Renay San Miguel: Stockton is also trying to make things easier for anyone who needs microfluidics analysis. She and her team have a provisional patent for a method for building microfluidics testing devices that could bring down costs and make them more accessible.  

Amanda Stockton: You can do it at home with a bit of equipment of about maybe $300, and then you can play microfluidics at home.  

Producing custom microfluidics has been expensive because of the time required. But this can make it to where you basically have the foundry setup to accept orders and get some things out. 

It could be an enabling technology. 

(Upbeat music) 

Renay San Miguel: I thank Amanda Stockton, assistant professor in the School of Chemistry and Biochemistry, for chatting with me about her astrobiology work.  

Check out her lab’s website at 

I also want to thank NASA, the BBC, and Paramount for the use of TV clips. 

Siyan Zhou, a former research associate in the School of Psychology, composed our theme music. 

If you enjoyed this podcast, please subscribe to ScienceMatters. We are on Apple Podcasts and Soundcloud. 

This is ScienceMatters, the podcast of the Georgia Tech College of Sciences. I’m Renay San Miguel. Thanks for listening. 

(Upbeat music)