(light music) - [Announcer] This program was made possible by contributions to your PBS station from viewers like you.

Thank you.

- [Announcer] "Now That's A Good Question with Phil Oldham" was produced under an agreement with Tennessee Tech.

- You can't predict the future, but you can count on Tennessee Tech always putting students first.

Our faculty, staff, and students have shown strength, compassion, patience, and kindness during these trying times.

I'm a college president, and Kari and I are also the proud parents of a Tennessee Tech student.

We want every student to be treated as we want our own son to be treated.

We understand today's challenges and put the focus on students' success.

For us, it's personal.

That's what you can count on at Tennessee Tech.

(upbeat music) Hello, I'm Phil Oldham, president of Tennessee Tech University, and welcome to "Now That's A Good Question," a show devoted to exploring the power of asking good questions.

It's said that a picture's worth a thousand words.

This show believes that a good question is worth at least a hundred answers.

So today I'm joined by Dr. Evan Hart, and after the break, I'll be joined by Dr. Jeannette Luna from the Department of Earth Sciences here at Tennessee Tech, to explore everything from caves and sinkholes to Mars.

So first of all, help me welcome Dr. Evan Hart.

Evan, you've been here at Tennessee Tech for a number of years now.

You're a professor in the Department of Earth Sciences here, and research interests focus on flood hydrology and the effects of caves and sinkholes on the whole hydraulic process.

Most recently, Evan has been the lead consultant overseeing the installation of flash flood monitoring system at Cummins Falls State Park.

Thank you, Evan, for being with me today.

- Thanks Phil.

- Yeah, so first of all let me just ask you, what all is involved in earth science?

- Well, we have about 50 student majors, undergraduates.

It's an undergraduate department.

And we have four concentrations that they can select from, geology, environmental geology, GIS, which is a popular one, that's geographic information systems, which is if you've ever used Google Maps or Google Earth or something like that, it's similar to that technology.

And then we have a geography concentration.

- So that's what we offer here, I mean, in terms of earth science, you could include meteorology, I guess, as well as atmospheric sciences?

- Yes, yep, often we do have a few climate and meteorology courses too, so yeah.

But yeah, earth science is really broad, so it includes, could include even planetary science, you're gonna talk with Dr. Luna about that.

So it's a broad field from everything from earth science, hard rock geology, you know, to surficial processes, hydrology, and even crossing over with atmospheric science and climate.

- This is really a pretty interesting region here, isn't it, for the study of earth science, particularly caves and those kinds of formations?

- Right, so I tell the students it's like Swiss cheese geology.

So the limestone is the state rock of Tennessee.

(chuckles) And because of its properties, it dissolves away and it leaves these, you know, openings like Swiss cheese.

And it creates interesting hydrology and environmental problems sometimes.

- Yeah.

But also beautiful nature in this area.

I mean, it's fun to explore and great to look at as well.

So I would assume that students really enjoy this kind of a study.

- Right, yeah, so having it so close to campus, they can get out and, you know, go to Virgin Falls, you know, go to all the great state parks that are just close by.

And that's really kind of our laboratory for our students is right outside their backdoor there.

- So Putnam County, where we're sitting now, is pretty well known for caves and sinkholes.

There's gotta be, I don't know how many caves, you may know how many caves there are in Putnam county, but.

- [Evan] Well, in the state, there's over 11,000 caves.

- Wow.

- Yeah, and it keeps going up every year as cavers find new caves.

- Yeah.

So from that standpoint, how does the general population, why should the general person in Tennessee or Putnam County, why should they care about that?

- Right.

So you know, it does come into play.

Most people think of sinkholes and caves, you think of something like the Corvette Museum in Bowling Green, Kentucky a few years ago, caved in in a big sinkhole and swallowed some of the nice cars, and it's this kind of sudden collapse.

And that's kind of the dramatic environmental effect that affects people, a collapsed sinkhole, but those are pretty rare.

You know, the other thing that happens with sinkholes, because they're low, is they flood.

And it may be a subtle thing, you don't know that your building's in a sinkhole, just a closed depression, and you get a heavy enough rainfall that it backs up in these little local floods and we've got that problem in Cookeville, in several places, out on Melrose Avenue, on Byrne Avenue, right here north of the Hooper Eblen Center, just repeated times, it just kind of fills up and floods.

The other thing that is, for the general population, is you have a lot of weird stuff that goes on with groundwater.

So for example, the city of Monterey, they discharge their wastewater in the Falling Water River but it actually sinks and goes over to the Calfkiller River, all the way under the interstate on the other side.

And so you get these underground connections that you don't know about until you get out there and figure it out with-- - So how do you trace this?

How do you follow that?

- Right, so there's people that specialize in that in our department and in the caving community and they do dye tracing.

So there's non-toxic dyes, they're fluorescent dyes.

And you just basically have to guess where it might come out and then you set up a few locations and then you put the dye in and you have to, you get out, you have to get into some pretty wild places.

- I bet.

- To see where the dye might come out or in a cave or in a sinkhole somewhere.

- That's interesting.

So I guess you can actually do some underground mapping just by tracing how the water flows, is that?

- You can.

You can determine how fast it gets there.

You can't always determine where it went.

You can determine it went from point A to point B and it took a certain amount of time and it may have moved a little bit in that time, but it's hard to see what's under your feet unless you can, you know, get some, if you could strip away all the rocks and look down under there, but we can't do that, so.

- Right, so since these are caves and sinkholes are low spots, I guess they collect a lot of debris and all too.

Is there some interesting things that get found in these locations?

- (laughing) Yeah, I joke with my students that I'd go down before Christmas, when my kids were little and get some, you know, basketball, bicycle, things like that you might find.

(both laughing) - So you did your Christmas shopping in a sinkhole.

- Yeah, just clean it up a little bit.

Yeah, but unfortunately, that's where a lot of the trash ends up.

Some of, our student Geoclub does sinkhole cleanups.

And, you know, that's a good thing to, 'cause they do, the other theory about sinkholes, you may have heard this, is that they are formed by refrigerators.

Have you heard that one?

- I have not heard that.

- Yeah, so every sinkhole, when you find a refrigerator in the bottom, so there must be some connection that probably formed.

- There's a correlation between refrigerators and sinkholes, that's interesting.

So flash floods, typically when I think of flash floods, I actually think maybe out in the western states or something like that.

I don't really think in this part of the country, but we do have some issues here with flash floods, right?

I know you've been involved at Cummins Falls and it's a very popular spot, it's a very beautiful spot but there can be some danger associated with it.

- Right, yeah, Cummins Falls is kind of a perfect storm for, we found out in these last few years, for flash flooding, just the way that the waterfall drops off there and into the, from the highland rim to the central basin.

And, you know, there's our, we have pretty rocky soils, not a lot of soil.

And so a heavy rainfall, if it's centered over that watershed, it can act like these flash floods that you see kind of in the western states.

And unfortunately there've been some tragic events at Cummins Falls.

But we have established the warning system there and the state parks have, they invested in that and it should really help people be safer at Cummins Falls now.

There's also a quota on the number of people, you have to have a permit to go down into the canyon at Cummins Falls.

So that's helpful to reduce the pressure.

And when another flash flood does come, it should be easier for people to kind of get out of the way.

- So in terms of the early alert system or monitoring system, how exactly does that work?

- So there are a series of rain gauges and stream gauges.

So the rain gauges catch rain and they tell you what's falling out of the sky.

And then there's a little bit of a delay between that and then the water gets into the streams and then we also have gauges in the stream.

And it's all a wireless system and so the rangers at the park, and this is also true of Window Cliffs State Park.

They have, the warning system covers that state park as well.

The rangers can sit in their office and read now their, on their screen, what the water level is in real time.

Upstream.

- So can somebody who's in the area, hiking or whatever, can they actually get that on their phone or something as well?

- Yes, yes.

- Okay, well that should be a tremendous help to help prevent problems in the future.

So how do you get students involved in this kind of work?

- Students love to get out and do, you know, tromp around in the streams and get their feet wet, literally.

One of the things they have to do is go out, you can measure the stream water level but you really don't know the velocity of the water.

And so that's one thing that you still have to really go out and do by hand.

And so we get students to help us with that.

And sometimes, you know, if you're doing, if you're trying to catch a flash flood and it happens in the night, you might have to go out at different hours of the day, too.

- So they're ready to go anytime, huh?

- They're supposed to be.

- Yeah.

(laughs) That's interesting.

Well, what do you see coming?

What are the things that you think earth science should be looking at for the future?

Anything comes to mind that says that, "Wow, that's the question we really need to be answering"?

- Well, I'm probably biased, but I always go with water.

You know, water is the most important resource.

And we don't typically have a deficit of water in Tennessee.

We have, you know, we can have droughts.

- We're very fortunate, aren't we, to have good water resources.

- We have good water resources and they need to be protected and we have good state agencies doing that, I think, and working on that.

But there's always room for improvement.

- Mhm.

That's great.

Water.

Keep that in mind.

Thanks to Evan for being with me on this segment.

- Thank you.

- After the break, I'll be joined by Dr. Jeannette Luna to talk about, was there water on Mars or not?

So stay tuned.

(upbeat music) Welcome back to "Now That's A Good Question".

I'm excited to be joined for this segment by Dr. Jeannette Luna of the Department of Earth Sciences at Tennessee Tech, where she's an associate professor.

And Jeannette's research focuses on petroleum geology and planetary geology, and her students actually helped name two craters on Mars.

Most recently, Jeannette's been following the results of the 2020 NASA rover Perseverance.

Welcome Jeannette and thank you for joining me today on the show.

- Great, thanks.

It's nice to be here.

- Yeah, so I gotta start out, petroleum geology and planetary geology.

Those two seem very, very different to me.

Is there some overlap there?

- Yeah, so, you know, when people think about petroleum geology, a lot of times you think of, maybe Exxon or Shell.

And then you think about planetary and you think about, you know, NASA or SpaceX.

And the thing that they overlap on is really the search for organic materials.

So if you're looking for, you know, buried organic material that's been heated up, you're searching for oil and gas.

If you're looking for organic material that might be preserved on another planet or a moon in the solar system, then you're looking, you know, that would be planetary geology.

So I love teaching here at Tech, I get to teach a little bit of both of them.

- So in terms of planetary geology, I mean sometimes you hear about, one reason we might go back to the moon or to other planets is for the natural resources that might be available, the minerals and all.

Is that true?

Is that something you would look for?

- Well, I'm more on the science side so I would look more for what it tells us about the history of the solar system and planetary evolution and those really big questions, like was there ever life elsewhere in the solar system or could there be life elsewhere in the universe?

So I don't go quite so much on the resource side of it, but there are, you know, really exciting developments looking at mining asteroids or potentially, you know, in the future, looking for those resources like you mentioned, so yeah.

- Well, it's all fascinating to me.

So tell me a little bit about this latest rover mission to Mars.

What's going on there and what's the scope of that?

- So this mission is the Perseverance mission.

This rover is just so exciting, right?

So it launched this past July and then it landed in February.

And this is the first part of a goal to bring samples from Mars back to Earth.

So you might remember back in the late 60s, early 70s, we had the Apollo missions.

And the Apollo missions, you know, astronauts went to the moon, they collected samples, and they brought them back.

We've never had a mission go to Mars yet and bring samples back.

So this rover, on the front of the rover, it's kind of about the size of an SUV.

And on the front it has a big arm and the arm actually has a drill on it.

It drills down, it collects a sample, and then it holds the sample in the rover and then the rover will drop out multiple samples and those will be collected by a future mission.

So sometime in the late 2020s, maybe 2030, 2035, we hope to have robotic missions that go back to Mars and collect those or maybe even a crewed mission where it's astronauts out on the surface of Mars collecting the samples and bringing them back to Earth.

- That's fascinating.

So is there any instrumentation on this rover that can actually do some analysis onsite or is that in the future?

- Oh yes, yeah.

So this rover was built on the success of the 2014 Curiosity rover.

So that rover design was extremely successful and had, ooh, I'd say eight to 10 different instruments on it.

So it has instruments to look at the mineral spectra, it has lots of cameras, I think there's over 20 cameras on this new rover.

There's engineering cameras that are looking down at the ground, there's cameras up on top.

And you might've seen last week or a few weeks ago, the most recent stuff was, you know, the flight of the Ingenuity helicopter.

So this rover had a helicopter mounted underneath it, right?

It lowered it to the ground.

The rover drove away.

And then the helicopter launched and flew around on Mars.

And that's a technology demonstration because that tells us that we can have drone technology even in a really thin atmosphere like we see on Mars.

- That's amazing.

So there must be a lot that goes into, I mean, 'cause Mars is a pretty big planet.

There must be a lot that goes into selecting a site where they want to land and explore.

How does that go about?

- The site selection process is probably a four to five-year process, it takes a really long time.

And, you know, Mars has so many exciting things.

It's got the biggest volcano in the solar system, Olympus Mons, it's got canyons like the Mariner Valley, it's got polar ice caps.

So you're absolutely right that, you know, there's a lot of exciting places.

If you could set an SUV on a planet, where would you set down the SUV?

And so there was a series of workshops that NASA had to go through.

They started with 16 potential sites and they had a workshop and narrowed it down to eight potential sites.

Then they narrowed it down to four.

And then ultimately the rover has landed in Jezero Crater which has the Jezero Delta deposit in it.

- So one thing I find incredibly exciting and very proud of is you and your students have been able to be involved in naming a couple of the craters on Mars.

How did that happen?

And what have the students thought about that?

- The students, it's been really exciting.

So we're really honored at Tech to be able to put a name on a crater on a different planet.

That's just a really wonderful scientific moment and to share that with students has been really a thrill.

We were mapping in two different craters, and at the edges of those craters, there were some fan-shaped features.

So when we're looking at orbital data, you know, kind of getting back to what Dr. Hart talked about, you know, looking at water resources.

One thing that our group looks at are fans.

So we see a feature where you have, I'm gonna use my arm as an example, right?

You have sort of a narrow confined flow and then it opens up and we saw that on the margins of these craters.

And we kind of got tired of saying crater one and crater two.

(laughs) So we applied to, there's an international group that manages all of the formal scientific names and they gave us permission to name the two craters.

So one crater is named Garu Crater and that one was named by my colleague Joseph Asante, he's also in earth sciences.

And then the other crater is named by one of our alumni.

She's an alumni now, she was a student then, Allison Bohannon, and Allison is now at Mississippi State doing her masters in planetary geology.

- Oh, that's fantastic.

What a proud moment for everybody.

That's really cool.

So, I mean, you brought this up earlier, it's sort of the ET moment, you know, everybody's curious, you know, we hear a lot about UFOs and everybody's always curious about, is there life out there somewhere?

But you actually sort of play with that question, right?

I mean, you really look into that question.

- Yeah.

- So what do you look for?

- The big theme, right, and there's a slogan for it, is follow the water.

We're looking for water.

And so actually, I brought a sample, I'm a geologist so I brought a sample, a rock sample here to show today.

This one is, this is an Earth sample, remember we haven't had any samples yet that came back from Mars when we would be following water on Mars.

So this is called a stromatolite.

This is a fossil sample that has layering in it.

It's been slabbed, so it's cut and polished so we can see the layers.

But the layers tell us that at some point, there must have been cyanobacteria that was growing, right, sort of in a shallow marine environment where the water would come in and bring nutrients, and then it went back out again, it would calcify and leave behind these layers.

If we found something like this on Mars, that would be real key evidence that there used to be, you know, there used to be bacteria on Mars.

That would be exciting.

- So water is really key to existence of life, right?

So you're really looking for evidence that either there is water or has been water at some time or another.

And there is, is there some evidence that there may have been on Mars?

- Yeah, here's lots of good evidence.

I mentioned before the channels, right?

So, you know, having that, the only thing that can really make a fan shaped feature is water.

So we have that confined flow that changes to unconfined.

We see that maybe in like the, like I mentioned, the Mississippi Delta.

Other things that we can look for, though, are branching channels.

We haven't been looking yet for sinkholes but maybe in the future.

But branching channels, what we call valley networks, those dendritic patterns, they almost look sort of fractal.

Those would also indicate that there was something collecting in the highlands and flowing down to a basin.

- Well, that's amazing.

And it's fascinating to be on the front edge of that kind of science.

It's gotta be, maybe exploring things or seeing things that nobody's ever seen before.

- I feel like I have the world's greatest job.

It's really, really fun and it's fun to get to do that with students, too.

- So they get excited about it?

- They do.

We were wrapping up this past spring our planetary geoscience class, which is part of a new minor at Tech, the astronomy minor.

And so we had 25 students this spring who, they all selected different planets and moons in the solar system to look at the processes there and have just finished wrapping up their papers.

And, you know, I'm a big space enthusiast, I love space exploration.

So it's a lot of fun to share that passion.

- That's good.

So what are the next steps in the Mars program?

- So Mars is, we have several missions that are still ongoing.

So there are some orbiters that are still in orbit around Mars.

There's so many, I'm gonna give you two that I'm really excited about.

One is the Hope mission and that one launched this past summer, right about the same time that the Perseverance rover launched.

And the Hope was launched by the United Arab Emirates, it's that country's first big space mission.

So really excited to follow the results that are coming back from that orbiter.

And then the second one that I'm really thrilled about is the Rosalind Franklin Rover.

That's a European space agency mission and they will launch, probably about a year and a half, and that'll be our next big rover landing, but it won't be NASA this time, it'll be the European Space Agency and we'll get to watch their success.

- So if you, real quick, if you had to ask, if you could get one question answered about outer space, what would you want to know?

- Oh.

Is there life out there?

- Okay.

That's great.

Well, thanks for being with me today.

I want to thank Dr. Luna and Dr. Hart for their participation in the show today.

I want to thank the viewers for joining us and remind everyone to keep your wings up and keep asking good questions.

(upbeat music) (bright piano music) - [Announcer] "Now That's A Good Question with Phil Oldham" was produced under an agreement with Tennessee Tech.

- You can't predict the future but you can count on Tennessee Tech always putting students first.

Our faculty, staff, and students have shown strength, compassion, patience, and kindness during these trying times.

I'm a college president, and Kari and I are also the proud parents of a Tennessee Tech student.

We want every student to be treated as we want our own son to be treated.

We understand today's challenges and put the focus on students' success.

For us, it's personal.

That's what you can count on at Tennessee Tech.

(light music) - [Announcer] This program was made possible by contributions to your PBS station from viewers like you.

Thank you.