NASA's Our Alien Earth: The Lava Tubes of Mauna Loa, Hawai'i

0:07 Hawai’i, a tropical island in the Pacific Ocean, forged from volcanoes,

0:14 and teeming with diverse ecosystems, climates, and creatures.

0:19 And for some, a laboratory for studying environments that could

0:23 hold potential signs of ancient life on our neighboring planet, Mars.

1:29 Four teams of scientists awake in the town of Hilo on the Big Island of Hawai’i.

1:35 They're not here for the beautiful beaches,

1:37 the stunning waterfalls, or the lush rainforests.

1:42 These astrobiologists are journeying to the volcano

1:44 known as Mauna Loa to investigate lava tubes,

1:48 caves formed by molten lava of past eruptions,

1:51 to test a suite of instruments for future missions to Mars.

1:56 After arriving near the summit,

1:58 the team set out on foot across the barren lava fields towards their field site.

2:14 So this is a lava tube, which is a subterranean kind of environment.

2:21 And so it's analogous potentially to sites

2:23 on Mars that we've identified from orbit.

2:28 Mars is also a planet with a lot of basalt and obvious volcanism in the past.

2:34 And we can see with imaging from space that there's things,

2:37 kind of like this skylight behind me,

2:39 that might be an entrance to a subterranean cavern.

2:43 And so, if life potentially exists there, that would be a great place to live,

2:48 because it's isolated from the surface,

2:50 which is very hazardous for anything to live.

2:53 Here, these tubes are actually teeming with life.

2:56 And so they could potentially be relevant to what we might see on Mars.

3:01 While all four teams have the same destination,

3:04 they're all here for different reasons.

3:06 Let's meet the teams.

3:13 My name is Dina Bower.

3:14 I am a research scientist at the University

3:17 of Maryland and NASA Goddard Space Flight Center.

3:19 So, our role is to look at the relationships between microbes and minerals,

3:24 to understand better what signatures are left

3:26 behind by the microbes in the minerals,

3:28 because on other planets, we're more likely to see minerals,

3:32 as opposed to actual, living microbes.

3:35 I'm Heather Graham from NASA Goddard Space Flight Center.

3:38 We're actually trying to look for life by the geology itself.

3:42 We're looking for mineralogical complexity on surfaces.

3:46 We're also looking at elemental abundances,

3:48 just the patterns and distributions of elements on those surfaces.

3:53 And we're trying to use those two pieces

3:55 of data to build up an “energy landscape”.

3:58 So by looking at those minerals, and those elements,

4:01 we can calculate how much energy would be available for certain

4:04 kinds of metabolism that microbes in these caves might use.

4:09 Over long periods of time,

4:11 microbial life leaves a chemical footprint in the rocks.

4:15 While it's unlikely that modern Mars has living microbes today,

4:18 future missions can seek out these footprints

4:21 to determine if there once was Martian life.

4:28 Yeah, so this is a really classic spectrum

4:32 that you would hope to see on another planet, because these are pigment peaks.

4:37 So, you're not necessarily getting specific in terms of species,

4:40 but you can at least say there's definitely a microbe here.

4:45 So, we're doing a suite of measurements,

4:47 a combination of what a rover would be doing and return sample analysis.

4:51 Very quickly, Raman spectroscopy is a vibrational spectroscopy technique.

4:55 Basically, you're firing a laser at your target and that excites the bonds.

5:00 Each mineral has its own signature because when the light hits those bonds,

5:04 they excite differently and produce a spectrum.

5:06 And so I use that spectra that I collect to tell me what minerals are there,

5:10 as well as what organics are there.

5:12 So when we find them together,

5:13 it kind of helps us to understand their relationships.

5:15 If the microbes are actually part of the precipitation of those minerals,

5:20 we can infer that from looking at the Raman data.

5:23 And on the flip-side,

5:24 if the minerals were there first and we do see signatures of the microbes,

5:28 we might say that maybe those microbes are taking advantage

5:31 of the elements and the energy present in those minerals.

5:38 Okay, look at that.

5:39 Got me some cave water.

5:41 Got me some cave juice.

5:44 Hey, Dina, I found water!

5:46 You did?

5:47 Yeah, I'm getting your drips.

5:51 We take all of these data that we're doing with field instruments,

5:54 and we're mapping this in a co-registered landscape of the surface.

5:59 So, I hate to admit that I actually learned

6:02 about this technique by watching an archeology television show,

6:06 but this is a common technique that people do in caves so that they can have

6:10 these co-registered maps of all of their different

6:12 data types that they take for their measurements.

6:14 And we're doing the same thing here.

6:16 C dash five...

6:18 one.

6:19 So, that guy right there.

6:23 and we have all of that information for all of those grids in the same place.

6:26 Then we take that rock.

6:27 We know each of those grid sections and all of that information about it.

6:31 And then we're also taking portions of those mapped surfaces back

6:35 to the lab to do measurements

6:37 with much higher resolution laboratory instruments,

6:40 so that we can understand also,

6:42 not just testing the hypothesis of these patterns is a way to detect life,

6:47 but also understanding if it would be possible to use a technique like

6:51 this with the kind of instrumentation that we

6:53 have flown on rovers and things like that.

7:04 I'm Dr.

7:05 Allie Fox.

7:06 I consider myself the anti-astrobiologist because I'm looking

7:09 for biological patterns that are being produced by abiotic chemistry.

7:14 The thing that keeps me up at night, my like 3 a.m.

7:16 wake up thought, is that abiotic chemistry, so,

7:18 no life involved at all, can look a lot like biotic chemistry.

7:22 And so, when we're sending these rovers or these probes to these other planets,

7:25 and we have limited field instruments that we can use in those environments,

7:29 we need to be really careful on how we can distinguish biosignatures.

7:32 So, a lot of the work that I do is trying

7:35 to understand how abiotic chemistry can mimic those types of patterns.

7:48 So, I'm doing a combination of techniques that we can do in the field,

7:51 and then some techniques that we'll actually do back in our laboratory.

7:53 So, in the field we're using an XRF, that's X-Ray Fluorescence,

7:57 and that gives us an idea of what types of elements are present.

8:02 So, now it's switching to another beam

8:03 that can actually see other types of elements.

8:05 So, it's adding a bunch in.

8:07 So, it's really helpful for me, because it's not always clear from just looking

8:11 at a rock that it's going to have really different mineralogy.

8:13 But the difference in those elemental compositions,

8:16 that tells us a lot about how that mineralogy is changing.

8:18 So that's a quick, easy way for me

8:19 to know that I'm getting the samples I'm interested in.

8:22 And, you know, maybe in a couple of years,

8:24 once I've recovered from being outside for this much,

8:26 I'll be able to come back out and collect more samples.

8:28 [Laughing] Understanding the chemical makeup of these rocks will bring Dr.

8:32 Fox and her team one step closer

8:35 to identifying true signs of life from false positives.

8:44 My name is Bethany Theiling.

8:45 I am a planetary research scientist at NASA's Goddard Space Flight Center.

8:49 We are trying a technique that has been often considered,

8:52 but not explored as much.

8:55 Can we identify life using the gases that we collect from the environment?

9:01 Basically, all life breathes,

9:03 and life gives a particular signature of CO2 versus geological processes.

9:09 So, we can come down here,

9:11 and we can make a bunch of measurements of the ambient area,

9:14 and back in little crevices, and get an idea whether there is life

9:18 in the crevices or whether this is just ambient CO2.

9:21 One of the things we recognize is that it's a lot easier to sample gases.

9:25 I mean, if you think about it,

9:26 if you have to take one of these rocks around here,

9:28 you have to crush it up and probably put it in acid and do a lot of stuff,

9:32 a lot of chemistry, before you can actually analyze it.

9:34 With a gas, you can send it directly into an instrument and get,

9:38 hopefully, some results.

9:39 So we're trying something new here.

9:40 We're trying to figure out if you can use the isotopes of carbon dioxide

9:44 and methane to see if we can identify the life that we know is already here.

9:50 [sound of rushing air filling the sample container] So,

9:54 we've come up with a few unique and very new [laughs] sampling strategies.

9:58 One that I think is very fun, is called the “lasso” technique.

10:02 So, we have this incredibly long tube.

10:04 I have gotten pretty good over the past few days at lassoing.

10:07 I'll take a few coils in one hand and throw it into the back of an alcove,

10:11 because I don't want to go back there and breathe.

10:14 So, this is one technique where I can stay back,

10:16 turn my head, and just throw it into the darkness.

10:21 Oh my god, [laughs] I’m actually getting pretty good at this!

10:25 We also have a simple ambient measurement,

10:27 so we can just pull from the air right next to us,

10:29 and that gives us a sense of what it looks like with all of our team here,

10:33 and how that could affect everything.

10:35 So, we were fortunate enough to get in here before any of the other teams,

10:39 and so we were able to sample, hopefully very quickly,

10:42 in order to get the sense of what it looks like in a more pristine environment,

10:46 or at least constrained with just my colleague Jennifer and I, yea.

10:55 My name is Dr.

10:56 Steven Scheidt.

10:57 I'm an associate research scientist at Howard University.

11:00 I'm working with NASA Goddard Space Flight Center.

11:04 One of the things we're trying to do here is not just understand this lava tube.

11:07 We're not just trying to understand the minerals, the life, or the geology.

11:11 We're trying to understand the whole system.

11:13 What we've done is we sort of started from the top and worked our way down.

11:17 We took unmanned aerial vehicles, we've mapped the surface,

11:20 and we've come inside the tube and we've mapped with LIDAR.

11:24 And now we have a physical model of outside and inside.

11:27 That's a really cool way of combining data to understand the system.

11:30 You, you know, 18 around to here...

11:33 Yea, or we can start, Want to start here...?

11:36 My name's Zach Morse.

11:37 I'm a postdoctoral research scientist at Howard University,

11:40 and NASA Goddard Space Flight Center.

11:42 So we're mapping the interior of the tube

11:44 using a specialized camera that collects long exposure shots of the interior

11:47 of the cave while it's illuminated in UV light.

11:50 Once we find a site, we set up a tripod and we have a special device

11:54 that allows us to rotate the camera at known set angles,

11:57 and the geometry is set up so that when we

11:59 take these pictures that they will stitch into a perfect photosphere,

12:04 where you have an environment where you

12:05 can virtually stand and rotate your environment around.

12:09 So, in that process, Zach first collects the LIDAR from that point.

12:12 We have a quick mount that detaches.

12:14 We put on a lighting system which shines white light and has the camera.

12:18 And then after we do that photosphere,

12:20 we take that LED panel off and we add this UV system.

12:25 And this helps us identify minerals or some biology that might

12:28 fluoresce in UV that is hard to see with the naked eye.

12:31 And our end goal is to create a full map

12:33 of the tube that can also be viewed in augmented reality.

12:36 So you can walk through the tube and see that data in situ,

12:38 as if it was projected on the walls with our light.

12:41 One of the things that's really cool about this is

12:43 once we have this full model of the tube,

12:45 we can add digital assets anywhere in the tube.

12:47 So, if another team has collected samples or collected data in a location,

12:51 we can add a virtual field flag,

12:52 so we don't have to leave any physical markers in the tube.

12:55 We can come back next year, and as long as the morphology is still the same,

12:58 hold up the tablet and see exactly where samples are collected,

13:00 where data was collected, and help guide future expeditions to this location.

13:05 Building this full virtual system will take time,

13:08 but even the raw data was already paying off in collaboration with other teams.

13:13 It's interesting, because we weren't entirely sure how

13:16 those collaborations were going to happen before we came.

13:19 There's someone who's looking for ATP,

13:21 which is a tracer for biological material,

13:24 and we were able to hand her an image that she could put on the iPad on her arm.

13:28 It was so close to AR, augmented reality, that she could look at the colors,

13:34 zoom in and look at features on the scale of millimeters to be

13:39 able to tell whether or not she wanted to sample them or not.

13:42 Oh, I can find it, yeah, so...

13:43 This is the only one that I can actually see.

13:45 But only after you guys pointed, your technology pointed it out.

13:49 So, on the screen, here’s this green...

13:52 bright green areas, these two.

13:54 Yeah.

13:54 So, they're right here and right here.

13:56 Yeah.

13:57 I'm going to concentrate right in the middle here.

14:01 So, they were able to target specific colors in the UV, get different swabs,

14:05 and measure the amount of biological activity on different

14:07 colors that showed up that are visible in UV,

14:09 but you wouldn't see with the naked eye.

14:12 It was a really great moment for all of us.

14:24 I love being underground.

14:27 I think I'm deep down inside, you know, one of the dwarves.

14:30 I'm just missing a giant beard.

14:33 I love rocks, I love minerals, so I mean,

14:36 it's just fascinating to be here for that reason.

14:38 But I think the really cool thing about these environments is,

14:41 it is isolated from the surface.

14:43 It's so quiet.

14:44 It's a really chill kind of place to be, and there really is a lot going on.

14:48 So, there's just always something to see, always something to sample.

14:53 Well, I think just being out in the field is great,

14:55 just to be able to collect your own samples.

14:58 And this is super important because you need to see the environments,

15:02 you need to see where they were collected,

15:04 and not just a little crushed sample that they give you.

15:06 And, I can collect what I want and much more to do my analysis in the lab.

15:11 It's definitely a change.

15:13 I'm normally sitting in a room of humming

15:16 mass spectrometers by myself in the dark.

15:18 It's still dark, so it's not that different.

15:21 The main difference is I'm used to being able to get my results quickly,

15:25 but it's really cool to actually be on the side of, like,

15:27 collecting my own samples.

15:28 That's not something that I've done in the past.

15:30 So, it's been cool to make the decisions in the field myself,

15:33 and what we're hoping is that we'll get

15:35 a really solid pilot data set from this work,

15:37 and then we'll be able to come back and do a really in-depth expedition.

15:40 You know, you always hear about field sites and you see pictures,

15:44 but there's nothing like actually coming to the site and taking

15:47 your own samples and then being able to measure them.

15:49 It's just, you can't replace that.

15:51 It's been fun, and challenging at the same time.

15:53 I'm super grateful to get to be here and explore this crazy environment.

15:57 It's tough to bring everything in and out of the cave every day,

15:59 but it's totally worth it.

16:00 We get some really cool science that we've been sharing all week,

16:02 and hopefully help other teams with their science, too.

16:13 It's a reasonable analogue for Mars because,

16:15 if you're looking all around you, this is all made out of basalt.

16:19 This is all volcanic rock.

16:21 Mars was very much volcanic in the past,

16:23 and so this could be a really good area for that.

16:26 We know that there are skylights, we know there are lava tubes on Mars,

16:30 and so, this is a really great area to try to test that.

16:34 When we think about geologic timescales, so like, hundreds of millions of years,

16:38 that's a long time for an organic molecule to survive.

16:41 And for the most part, how they do it is by interacting with mineral surfaces.

16:45 And some minerals, especially clay minerals,

16:47 make a much better home for organic material,

16:49 and it can protect them from a lot of different things.

16:52 We've also done experiments in the lab that shows

16:54 us they can also protect them from radiation,

16:55 which is a big problem on a place like Mars.

16:59 So for a long time, we used to think about “follow the water”,

17:02 because we have this understanding that most

17:04 life is probably going to need water.

17:06 It certainly does here.

17:07 And so, we thought that if we just follow the water,

17:09 that's the most likely place to look for life or look for habitable places.

17:14 But really, we're coming to this understanding

17:16 that there's really a need to understand energy potential.

17:20 Are there the kinds of materials in there

17:22 that would provide nutrients and energy sources for microbiology?

17:28 So I think there should be a lot more work done,

17:31 and hopefully a lot of sharing of data so we can have a really solid data set.

17:36 So like, when we do land on Mars, eventually,

17:38 we'll have a wealth of information to work with.

17:41 These kind of instruments that we're using here

17:43 in the field are what we call high-heritage,

17:46 which just means we've had a lot of practice building them,

17:50 and sending them places, and making measurements on other planets with them.

17:55 We’re trying to find new ways,

17:56 new strategies of looking for interesting information,

17:59 with just that kind of data.

18:01 We could use the similar instruments, say, on Perseverance rover,

18:04 in a place like this, we might be able to use those same

18:09 patterns and the same tools and techniques to identify the presence of life,

18:12 past or present, on another world.

18:17 As NASA looks towards a future where

18:19 human astronauts land on the surface of Mars,

18:23 difficult environments like these Hawaiian lava tubes

18:26 will be prime candidates for human exploration.

18:31 And the data collected from expeditions like this on Earth,

18:35 may one day lead to a discovery of past life on the red planet: Mars.