Space Plants

Can you actually grow potatoes on Mars? On this episode, Neil deGrasse Tyson and comic co-host Paul Mecurio explore how to grow plants in space and whether we can farm on the Moon and Mars with space biologists Anna-Lisa Paul and Robert Ferl.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:01Neil deGrasse Tyson?

  Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now.

• 0:14Neil deGrasse Tyson?

  This is StarTalk. Neil deGrasse Tyson here, your personal astrophysicist. And I got with me Paul Mecurio. Paul, dude.

• 0:23Paul Mecurio?

  Howdy. Good to see you, my man.

• 0:24Neil deGrasse Tyson?

  Bit too long.

• 0:25Paul Mecurio?

  Yeah, I know. I know. We gotta get up for lunch again soon.

• 0:29Neil deGrasse Tyson?

  Yeah, we'll do it. We'll do it.

• 0:30Paul Mecurio?

  With our buddy.

• 0:31Neil deGrasse Tyson?

  Stand-up comedian, and I just love the fact that every time I'm on Colbert, you're there warming up the crowd before anything else happens. So that's why they're laughing and they're always in a good mood.

• 0:43Paul Mecurio?

  Or if they're not, it's my fault.

• 0:45Neil deGrasse Tyson?

  I forgot I could blame you as well.

• 0:48Paul Mecurio?

  Or you get like, why were they so excited but not laughing enough? Why weren't they laughing? Why were they not? Oh my God.

• 0:54Neil deGrasse Tyson?

  So today's subject is something I've been, it's been eating away at me because I've been thinking about it ever since I've been thinking about it, right? And it's like, can you grow plants on other planets, right? I mean, we think of putting seeds in the ground and then it grows. And all you need is a little bit of water and a little bit of sunlight. And nobody's thinking about what role the soil is playing. I mean, no, I mean, regular people aren't thinking this, of course. Experts think about it all the time. And so there's a word they use for the, the, the quote soils of the moon. It's called the regolith, right? It's a geology term and we'll learn more about that in a minute. So, so this whole show is gonna be, if we're gonna go to another planet,

• 1:38Neil deGrasse Tyson?

  either our moon or Mars or wherever, and we're gonna feed ourselves without having, you know, supply chains keep us alive, then, then like, what do you do and how do you do it? And I have no such expertise in this. So we combed the world and we found two people who, who this is what they do. Let me first introduce Annalisa Paul. Annalisa, welcome to StarTalk.

• 2:05Speaker 02

  Thank you. So happy to be here.

• 2:07Neil deGrasse Tyson?

  Excellent. So you're the director at the Interdisciplinary Center for Biotechnology and researcher at the University of Florida, okay, and a research professor at Horticultural Studies?

• 2:19Speaker 02

  Horticultural Sciences, yep.

• 2:20Neil deGrasse Tyson?

  Horticultural Sciences, very good. And so you think about your plant, you've had a green thumb from early on. Is this what you're telling us?

• 2:29Speaker 02

  Yeah, yeah, yeah, kind of. But I also would describe myself as, you know, simple country molecular biologist.

• 2:35Neil deGrasse Tyson?

  There you go. I love it. Country molecular biologist. We need more of those.

• 2:39Paul Mecurio?

  Yes, exactly. Just got a quick question. How good are your tomato plants at home? Are they good or are they?

• 2:46Neil deGrasse Tyson?

  That's the litmus test, because if you've got crappy tomatoes, we're finding another guest.

• 2:51Paul Mecurio?

  We've done some research and we have photos that are...

• 2:54Speaker 02

  That's right. But my Arabidopsis crop is pretty good.

• 2:59Neil deGrasse Tyson?

  All right, we'll get top people worth looking into that. And we've got with us also one of your collaborators in this effort, Robert Furrow, professor and VP of Research in Horticulture. Is that, am I saying that right, Robert?

• 3:13Speaker 03

  I'm Vice President for Research at the University of Florida.

• 3:17Neil deGrasse Tyson?

  There it goes. Thank you. You happen to have an academic specialty of Horticulture, but if you're VP of Research, you're overseeing all the research in the science there, correct?

• 3:25Speaker 03

  Well, I have a role in enabling the research overall at the University of Florida.

• 3:30Neil deGrasse Tyson?

  That is so politely tactfully said. Okay, you don't want to make any enemies just by how I describe what you do. Very good. And you, I have here your interests are environmental regulation of gene activity in plants. So I love this combination of expertise because it's not just, let's find a seed on earth and then grow it somewhere else. You might have to do some serious gene editing to make that happen. So I just, I'm ready to sort of jump into this. And so could one of you just start us off?

• 4:09Neil deGrasse Tyson?

  And tell me, um, do we have experience trying to grow things on moon soil? Did the Apollo astronauts, I know they brought back rocks, but did they bring back bags of soil too?

• 4:21Speaker 03

  Yeah, so you're talking on one of the really interesting parts of sort of Apollo history that drew us into this business. We're, we're space biologists. We're very used to sending experiments to the International Space Station and understanding the role of gravity in terrestrial biology. And in fact, trying to think about how we would feed astronauts as they're, as they're traveling between planetary bodies in our solar system. But it turns out that this whole notion of whether plants, whether biology interacts

• 5:02Speaker 03

  with lunar samples is one of a pretty deep historical note. The Apollo astronauts, to answer your question, they sure did bring back lunar dirt. They brought back all kinds of rocks. They brought back all kinds of samples of the dust and the dirt that was in and around their sampling sites.

• 5:23Neil deGrasse Tyson?

  But so Paul, you notice he can't call it soil. Notice that?

• 5:26Paul Mecurio?

  Yes.

• 5:28Neil deGrasse Tyson?

  He just used four different adjectives.

• 5:29Paul Mecurio?

  I know. And all I'm thinking about dirt is like they walked, somebody had it on their boots when they walked into the laboratory and you just started screaming, hello, it's so much. That's why we have a mat at the door. You're an astronaut. You can't figure that out.

• 5:44Speaker 03

  Until biology touches it, it really can't be called soil. So

• 5:49Neil deGrasse Tyson?

  All right.

• 5:50Speaker 03

  So we have, we have, because of our work, we actually have lunar dirt, lunar soil in our laboratory now because it's been in contact with biology. So to, to round out your question about dirt, Apollo astronauts did bring soil, did bring dirt back from the moon. They kept it. They NASA, they, the lunar sample curators and the lunar sample community kept it under tight wraps at Johnson Space Center for the purposes of, of studying lunar geology primarily. But it's one of the great untold stories, unremembered stories, underappreciated stories of the Apollo era is the role that biology played, including plant biology.

• 6:36Speaker 03

  In determining that the samples that came back from the moon were not dangerous, did not have lunar pathogens.

• 6:45Neil deGrasse Tyson?

  Okay, so let me ask you, Annalisa, if we know in advance that it's not earth soil, and whatever it is, if, by the way, I'm glad somebody, your professional brethren from a previous generation, did decide that there was no bug that was brought back from the moon, you may remember the novel, The Andromeda Strain.

• 7:09Speaker 02

  Oh, yeah.

• 7:10Neil deGrasse Tyson?

  Which came out right around that time, which was a bug from space that totally wreaked havoc. And of course, I think that was Michael Crichton's first novel, before he wrote Jurassic Park and a whole lot of other things. So he had some good sort of bio chops to give us fun thrillers. But, Annalisa, if we already know there's nothing living, or we suspected and confirmed, nothing living in the soil, then isn't it a challenge to grow plants in something that doesn't have living organisms? And who cares if it's regolith or anything else?

• 7:45Speaker 02

  Well, so, there's a lot of, there's two layers of stuff there. First of all, they never grew plants in it, even back in the Apollo days. All they ever did was a scientist biologist called Charles Walkinshaw just sort of rubbed the surfaces of the leaves, you know, sprinkled on the surface just to see if there are any pathogens or anything. But nobody ever actually grew it in the dirt, in the regolith, to see if it would actually support plant growth and development. So, we had no idea whether there wouldn't be something toxic to plants, or something too reactive to plants, that would be able to support it. So, if you're going to go someplace else, you have to be able to have plants as part of the equation to support long-term goals. You have to have plants

• 8:29Speaker 02

  to recycle your air, water, in addition to providing food. And the best way to do that is if you can use in situ resources, something that's already there, so you don't have to carry it with you. So for the moon or Mars, most logical thing to grow plants in is of course the regolith.

• 8:45Paul Mecurio?

  Yeah, and you and you want to be able to you want to be able to have grow your own food. I mean, if there's an alien civilization, they may be price gougers, you know, you can.

• 8:53Neil deGrasse Tyson?

  You want to you want to protect against inflation.

• 8:56Paul Mecurio?

  Well, how are you gonna you can't haggle with an alien. You're 2,000 light years away from home. You don't have any leverage, so whatever they're going to charge you. So you want to have your own.

• 9:04Neil deGrasse Tyson?

  But just to be clear, Paul, the moon is one third of a light second.

• 9:09Paul Mecurio?

  This is where you don't have to be so smart and correct me. Just go along with it.

• 9:12Neil deGrasse Tyson?

  No, one and a half light seconds. Sorry, I got the wrong number there. No, but but if so, I hadn't considered that, of course, it's not whether there are microbes that could help it, but whether there's something that would actively destroy it. That would be that'd be bad, too. Right, very good. Okay. And NASA, correct me if I'm wrong, I remember this 20 years ago. Do they still have a branch of themselves called that specializes in in situ resource utilization, ISR U?

• 9:42Speaker 02

  Yep. Yep, absolutely.

• 9:44Paul Mecurio?

  And why did it? It was 50 years, right? With that before you actively started trying to grow things in the regolith. Why was there such a long period of time? Or if I'm off on that a little bit, it was a long period of time before you started trying to grow things in the soil. Why? Why was that? I mean, Neil Armstrong had to be upset because he must have been calling like every other week on, hey, all that dirt I brought back, you guys using it?

• 10:11Neil deGrasse Tyson?

  For anything?

• 10:13Paul Mecurio?

  Because I took up a lot of space for tang on the ship and I was. Is there a reason that you guys it took a while to start to use some of that?

• 10:22Speaker 03

  Well, there are several reasons and many of them are, I think, tied up with the simple fact that until.

• 10:32Speaker 03

  The collective we decided to go back to the moon with the Artemis program. Those lunar soil samples that were at Johnson Space Center kept under nitrogen and controlled conditions were the only ones that we were gonna have. And so they were very, very careful. NASA was very, very careful with how much and what kinds of samples they put out to the, to the community to study. And by and large, the questions that needed to be answered was things that associated with the age of the moon and the geology of the moon. Biology going to the moon, interacting with the moon was not as important.

• 11:12Neil deGrasse Tyson?

  It's down the road.

• 11:13Speaker 03

  It's down the road.

• 11:14Neil deGrasse Tyson?

  Yeah, yeah. So, and Elisa, tell me about the Florida Space Plants Lab. Like, what do you guys do?

• 11:21Speaker 02

  Well, so it's a, directed by Rob and myself, and we do mostly what you think of as orbital science. So we do a lot of plants to the space station and ask the very simple question is, how do plants respond at the molecular level to the novel environment of spaceflight? So we look at patterns of gene expression and things, what molecular tools plants are pulling out of their toolbox. But we also do what we call sort of exploration science and suborbital science, so we can test what kind of things we can learn about plants in any of these kind of environments that we may face ourselves with in the future.

• 11:56Neil deGrasse Tyson?

  Right, so the, the environment, just to be, be clear, Rob, when I think of the space environment, of course, as an astrophysicist, you're in zero G, but you're, there's also a high-energy flux of particles from the sun that could affect DNA, I suppose. I know at low Earth orbit, we're a little bit insulated from that, but in terms of, quote, "space environment," it seems to me it's, it's more than just a zero-G proposition, correct?

• 12:24Speaker 03

  Absolutely, and much like the previous question about lunar soil samples, most of our space biology research for the last 20 years has been in low Earth orbit. The opportunities to study biology beyond the Van Allen belts, biology on the moon or biology in deep space, basically didn't exist. It wasn't an option. And so, to drive back to the question, many, many of our scientific questions are about

• 12:56Speaker 03

  What happens in microgravity and the absence of unit gravity here on Earth? That's something that's been a driving evolutionary presence for all of biology forever. But again, going back to the moon now opens up sort of the intellectual floodgates. And we do have to come to grips with the question, what happens to biology when it's not protected by a magnetic field? So absolutely, solar flux is an important thing.

• 13:26Paul Mecurio?

  Are there layers here? In other words, once you establish you can grow something in the regolith, like, so you have to factor in cosmic rays, solar winds and how you can, and the substrates? And how do you, have you started to look at, I guess, what Neil was referring to as the environment and the effects on the regolith? If you're going to do this going forward? Or is that farther down the road to try to figure some of that out?

• 13:50Speaker 02

  So there's a couple of layers of questions there as well.

• 13:53Paul Mecurio?

  Really? Wow, I'm pretty smart.

• 13:54Speaker 02

  I mean, tons of layers, like an onion. So, but if you think about anything, you're going to be growing on the moon.

• 14:01Neil deGrasse Tyson?

  The horticulturist says it's layers like an onion. You've got food references to everything here.

• 14:06Speaker 02

  I was thinking more of Shrek, actually, but yeah.

• 14:09Neil deGrasse Tyson?

  Okay.

• 14:11Speaker 02

  But you have, you're going to be growing in a habitat. So you're not going to worry so much about things like the solar wind because you're going to be as protected, the plants will be as protected as the humans inside a habitat. However, the solar wind does affect the regolith itself from before you've collected it. And that's one of the things that we found in the work that Rob and I did is that the older regolith stuff that's been exposed to the solar wind longer is actually more hostile to plant growth than the quote younger. We're talking a billion years younger regolith of other sites.

• 14:49Neil deGrasse Tyson?

  Interesting. And of course, the solar wind just embeds in the surface of the moon, and it just stays there. It doesn't erode, it doesn't wash away with the streams. So you've got quite the record there. And just to make sure, because Rob mentioned the Van Allen Belt, I want to make sure we're all on the same page here. The, um, but I hadn't heard a reference to the Van Allen Belt in decades, so thanks for bringing that up again. Um, so the, the, the Earth has these sort of magnetic zones that can actually trap particles and prevent them from coming lower and funnel them to the poles and give us the Roerbo Realis, this sort of thing. And so if you are orbiting within that, you're basically protected. But once you go beyond that, you don't have these repositories, these protective

• 15:31Neil deGrasse Tyson?

  layers and zones, protective because it otherwise would be hostile to life as we know it. So, yeah, thanks for that bit of memory lane there.

• 15:40Paul Mecurio?

  Well, I gotta tell you, this is gonna be great for me because I, you know, trying to grow something in harsh conditions, if I'm gonna give you my situation, I, if you, I mean, it's similar to me, I can't grow a philodendron. I guess I keep fricking watering it. And my watering process is terrible. So if you can help me with the harsh conditions that I put my plants under, I think we'd be in all

• 16:00Neil deGrasse Tyson?

  Paul Mecurio-proof plants. That's what they're, they're gonna put that ahead of the space plants, Paul.

• 16:05Paul Mecurio?

  Please, please. I feel like I'm a common man and they all have the same problem. If someone could just remind me to put some water on the plants, but, um, but, yeah.

• 16:14Neil deGrasse Tyson?

  So we're gonna take a break. And when we come back, we'll get deeper into what kinds of seeds are being used and what kind of modifications to them are necessary, and what kind of food is produced. Because I hope it's gonna be something other than kale. Okay. Because I ain't going into space. All right. So nothing against kale.

• 16:33Paul Mecurio?

  Right. But if you blanch it, it's fine. No, it's not. No, it's always bad.

• 16:37Neil deGrasse Tyson?

  So, uh, we'll, we'll be right back. We're talking about growing food in space on StarTalk.

• 16:50Speaker 04

  Hey, I'm Roy Hill Percival, and I support StarTalk on Patreon, bringing the universe down to Earth. This is StarTalk with Neil deGrasse Tyson.

• 17:07Neil deGrasse Tyson?

  We're back, StarTalk. We're talking about growing plants not only in space, but in destinations in space, such as the moon and perhaps Mars and beyond. And you can't just plant the seeds. You need a little more than that. And I've got with me two experts, two folks who are colleagues at the University of Florida, who are horticulturists with special interest in biotechnology and show, not quite astrobiology, that would be life forms that develop somewhere else. We're talking about developing Earth life elsewhere. And both of them are totally into this, published papers together on it. And that's why we got them both here for this program. And I got with me, of course,

• 17:49Neil deGrasse Tyson?

  Paul Mecurio to help me out. And so let me just ask you guys, what studies have you done with what seeds? And why did you choose those seeds instead of others? And what's the thinking behind your experiments?

• 18:04Speaker 02

  All right, that's an easy one. We mostly work with the model organism for plants. It's called Arabidopsis faleena. We just call it Arabidopsis for short. And it's a tiny plant, the genome's been completely sequenced. It's been used all over the world for all manner of types of experiments. And so why we chose it for growing in lunar regolith is both its size, it can grow just a teeny tiny thing, can grow in a quarter teaspoon of material. It's also completely sequenced. There's a lot of reference material on growing it in other types of harsh environments and stress responses. And so we have a huge compendium of information that backs up all the stuff that we will find

• 18:45Speaker 02

  about growing it in regolith, as well as grown it in space a number of times over the years.

• 18:52Neil deGrasse Tyson?

  You know, and Elise, I'd never thought about it. Of course, you guys would want to do the same thing that sort of people who use laboratory animals do, right? I've looked, it's completely freaked me out, opening up a catalog of mice. You can short order mice that are identical to thousands of other mice that are distributed around the world, so that when you compare your research results, the full genome is identical, so that you can remove the variables and only look, you can remove things that you don't want to vary and look at the things that you do. And that's what you're doing with this seed, isn't that correct?

• 19:29Speaker 02

  Yep, exactly.

• 19:31Neil deGrasse Tyson?

  That is, I'd love it. I'd love it. Now, did you guys create this? Oh, it's sequenced, but did anybody genetically create it or engineer it? We just found one that everybody just agreed would be good for this purpose.

• 19:43Speaker 03

  Yeah, for this particular experiment, we used one of the, what is called a standard strain, one that is, as Annalisa described, very well characterized by thousands of laboratories on Earth for all kinds of environmental studies and developmental studies. So.

• 20:02Neil deGrasse Tyson?

  But the real question is, does it contract cancer like all species of mice do? No matter, no matter what's your feed.

• 20:10Paul Mecurio?

  Really? I've been working out, I've been exercising. I got cancer? Come on, Doc, you're in.

• 20:15Neil deGrasse Tyson?

  Right. Every mouse ever studied in the lab gets cancer.

• 20:18Paul Mecurio?

  Can I, can I just say this? The arapida sounds, actually, it sounds like on a, as on the salad or appetizer menu of a, you'd find it like in a three-star Michelin, you know, restaurant. It sounds delicious, but it's, you know, it's a veggie. Can you guys work on a plant that tastes like pizza, maybe? You know, something a little more fun, or Krispy Kreme donut?

• 20:42Neil deGrasse Tyson?

  That's top secret. That's a top secret project in the back room.

• 20:46Paul Mecurio?

  You got a glazed donut, a powdered donut.

• 20:49Neil deGrasse Tyson?

  So is this an edible plant? Is it an edible plant? I mean edible, is it, I'm following up on Paul's comment. Is this a seed and plant that we would consider eating? Or is it, you just got to get any kind of plant working at all first?

• 21:02Speaker 02

  A little bit of both. So, could you eat it? Yes. Have we eaten it? Oh, sure. Is it really tasty? Eh, you know, it just tastes like a green plant. It's a.

• 21:12Paul Mecurio?

  Tastes like chicken.

• 21:13Speaker 02

  It does.

• 21:17Speaker 02

  Only the ones that we've engineered with chicken flavor.

• 21:22Paul Mecurio?

  Now you're talking. I want to go to space right now. I want to go.

• 21:26Neil deGrasse Tyson?

  Okay, so you have to, this is, you have to crawl before you walk and walk before you run, right? You want to get any kind of, you want to get plants to do this at all? And that becomes the, the starting point. Is that fair?

• 21:36Speaker 02

  Yeah, yeah. That's why we call it a model plant.

• 21:39Neil deGrasse Tyson?

  Okay, and does it have any special, dare I call them talents, where it needs fewer nutrients relative to other plants? I mean, does it do better under stress conditions? You know, it's, I'm just wondering, because you'd want to start broadening how much you stress the system, the plant, right? So that you can enclose as much of what goes on in space as possible.

• 22:02Speaker 02

  Well, I'd say the only talent that this, that this Arabidopsis has is that it's a member of the mustard family. And the mustard family is really plastic and resilient in all sorts of environments. I mean, think about all the different vegetables that you eat, everything from broccoli to Paul's favorite kale and turnips, all these things are all in the same family.

• 22:25Neil deGrasse Tyson?

  But just to be clear, you use the word "plastic."

• 22:29Speaker 02

  Oh.

• 22:30Paul Mecurio?

  Yeah.

• 22:30Speaker 02

  I meant as in Malibu.

• 22:32Neil deGrasse Tyson?

  Thank you.

• 22:32Paul Mecurio?

  You just ruined every hot dog for me from now on. You ruined every, you ruined my baseball games, my 4th of July cookout, no.

• 22:40Neil deGrasse Tyson?

  You're using the word "plastic" in its original definition, which gave it the name to the petroleum byproduct that, that it's called "plastic," right? The word "plastic" predates "plastic." And you're using it in the original term. Okay. Okay, so it's, so that's a good fact about the plant.

• 22:58Paul Mecurio?

  And, but there are, and there is, but there are stresses within the different soil samples you use, right? Some have heavy metal and salt. Some are more sensitive to drought, right? So, so you found different results based on the three different Apollo missions, the soil that you brought back, right? And that the older the soil, the less fruitful it was, right? So it doesn't matter what plant you're putting in it, right? You've got to, you've got to first somehow control that soil in some way and eliminate some of those stresses within the soil, regardless of the plant? Is that right?

• 23:35Speaker 03

  Yeah. So you're hitting on what may well be one of the more fundamental things that, that we discovered as part of this project.

• 23:44Paul Mecurio?

  Okay, well then I think I'm done. If I did that.

• 23:45Neil deGrasse Tyson?

  Dan, Paul, yeah. Stop there, Paul. Because, yeah.

• 23:47Paul Mecurio?

  I'm gonna go have, I'm gonna go have a hot dog with ketchup and.

• 23:52Neil deGrasse Tyson?

  Stop on your head, Paul.

• 23:54Speaker 03

  Exactly. So very, very clearly, what, what, what we found with these plants, yeah, is that they in some ways act as if they are stressed. But one of the, one of the key things in terms of interpreting this, and I think, Neil, this will appeal to you, is that this is an experience beyond the evolutionary experience of these particular organisms. And so, Paul, to interpret our results directly as equivalent to a terrestrial response that we know about, might be right. It might be only partly right because, as Annalisa mentioned, they're reaching into their metabolic toolbox to deal with what they found.

• 24:38Speaker 03

  And what they found is quite literally brand new. It's out of their world. So, so we have a job ahead of us to help the world interpret what the plants are telling us. And it could be, yes, that they have, they have to deal with heavy metals and other things that are different among different soils on the moon, yes. It could be there are other general things that they're dealing with simply because they're in a strange new environment.

• 25:11Paul Mecurio?

  Does it matter what area of the moon the regolith comes from? Does it, do you get a different soil? Like, I mean, look, it's pretty obvious that Neil Armstrong got a, got bum steered into lousy territory when he was dragged, when he was walking around the moon.

• 25:25Neil deGrasse Tyson?

  Oh, just a, a little known fact, all right? They, the astronauts landed in the Maria, which is very flat areas. It's called Maria, which is Latin for seas, because at one point, people thought that wide, dark areas were, were, because they were flat, that they were bodies of water. And before anyone really knew any physics or chemistry. But the reason why they landed there is because it was flat. And they didn't want the lunar module to try to land on something that would end up tipping it over on some unfavorable terrain for a horizontal landing. So that was, it was a safety region, reason initially. And so.

• 26:05Paul Mecurio?

  And so, if the, if the soil that Armstrong brought back on 11 had been used earlier... I guess it just aged. It's not like wine. It goes the opposite. It doesn't age well, right? So if it had been, if it had been, whereas 17.

• 26:20Neil deGrasse Tyson?

  Wait, wait, wait, wait, wait. Paul, she just said this stuff has been there a billion years. So what's 60 years gonna do for anybody? What are you saying?

• 26:26Paul Mecurio?

  Yeah, I, I, you know, it's, it's, well, there's a difference between this dirt from 17 and the dirt from 11, right? In terms of its efficacy. So there must be something to that.

• 26:37Neil deGrasse Tyson?

  Okay, what is the difference? So what is the difference?

• 26:40Speaker 02

  Okay, so the difference is, is that the Apollo 11 materials were exposed to the solar wind for, and I'm not gonna get the number exact, but say a billion years longer than the samples in Apollo 12, Apollo 12 landing site. And so in that billion years, as Neil said earlier, you don't have anything to weather it per se. You just keep accumulating the deposits from the solar wind, the, the heavy metals, the, the nano phase iron, the different things that make it also sharper and, and more reactive surfaces and things. And so it just gets more and more to a plant hostile. And so is there a difference among the sites? Absolutely.

• 27:24Speaker 02

  Is it something we can mitigate? Yeah, probably.

• 27:28Neil deGrasse Tyson?

  So that's interesting. And just in case people didn't know, you know, we take this phrase "heavy metal" for granted, but there are light metals. I don't know if anyone has ever thought about what the light metals are. Such metals exist. Aluminum is a light metal, and it is light enough to have the density of rock. And we think of rocks as heavy, but aluminum having the density of rock means you'll find aluminum, at least on Earth, aluminum and rock in the same places because they settle out in the original molten earth, having the same density. And so aluminum is like one of the most abundant elements in Earth's crust. So aluminum, titanium, sodium are all light metals. That's all. And there's never a light metal band. Right?

• 28:12Paul Mecurio?

  Yeah.

• 28:16Paul Mecurio?

  It's called Barry Manilow.

• 28:18Neil deGrasse Tyson?

  Barry, that's what that is.

• 28:22Paul Mecurio?

  Why did volcanic ash? Some of these planets did a lot better in volcanic ash, right?

• 28:27Neil deGrasse Tyson?

  Well, I like that, right? The moon has a fascinating volcanic history. And we know on Earth, volcanic regions, not initially because it kills everything, but then becomes very fertile soil. So, so if we, in the future, might we target sort of volcanic plains? Which, which many of these Maria are. But is there anything we can learn from volcanic fertile places on Earth? And, and apply that to these other planets?

• 28:55Speaker 02

  Paul, were you also asking perhaps about the controls that we used? The volcanic materials that we used as a control? So we use this material JSC1A, which is a lunar simulant. That yes, is a type of volcanic ash. It's ground up basaltic material that's as similar as to the lunar materials that we can get.

• 29:14Neil deGrasse Tyson?

  JSC stands for Johnson Space Center, I bet.

• 29:17Speaker 02

  That is correct.

• 29:18Neil deGrasse Tyson?

  So it's their own, it's their own sort of off the shelf starter kit, I guess. Is that what that is?

• 29:23Paul Mecurio?

  And it's branding.

• 29:24Speaker 02

  Exactly. Yep.

• 29:28Neil deGrasse Tyson?

  And, and so, but I guess what I'm asking is the, there are places on the moon that are less volcanic than others. And given that I've tasted many a wine from volcanic soils here on Earth, and the viticulture is extolled for its virtues. Can we say that there's, in the future, we might target volcanic regions versus others?

• 29:54Speaker 03

  I think that would be, in growing food and growing wine on the moon would be one set of factors, yes, they would choose the landing site. I suspect that it wouldn't be the major driver for where we go to the moon.

• 30:08Paul Mecurio?

  Well, I think you need to change your priorities then, personally. I think it should all be about the wine.

• 30:13Neil deGrasse Tyson?

  The wine on the moon.

• 30:14Paul Mecurio?

  Right.

• 30:15Neil deGrasse Tyson?

  And the moon's already made of cheese, right? So wine and cheese.

• 30:18Paul Mecurio?

  And legalize marijuana. I mean, when that kicks in, I'm there.

• 30:24Paul Mecurio?

  So the regolith didn't do as well as the volcanic ash. That's the bottom line. But it did get a participation trophy. I just wanted to make that so we granted it well. But but can you take properties from the volcanic ash and factor it into the regolith? Maybe you can, maybe you can't, right?

• 30:37Speaker 02

  Sure. And so the terrestrial volcanic ash is, and again, both the the lute materials and the simulant are both essentially ground up salts. And so they have the fundamental characteristics of each other. But the whereas the the material from earth is more rounded. It's it's less reactive. It has less surface area. It's less sharp.

• 31:00Neil deGrasse Tyson?

  You did use that word sharp. I hadn't fully appreciated that the texture of something matters greatly in terms of the interaction of it and its surroundings, right?

• 31:11Speaker 02

  Right. I mean, think of the difference between a sea glass and something you dropped on your kitchen tile the same day.

• 31:18Neil deGrasse Tyson?

  Right, right, right, right. Yeah, you can walk on sea glass, right? It's basically smooth pebbles, right? So you could walk on your freshly broken glass, but you'll cut yourself.

• 31:29Speaker 03

  Exactly.

• 31:31Neil deGrasse Tyson?

  Let me ask a question that will surely blend into our third segment. There's not enough talked about, I mean, in in people who think about this know about it, but in the public, the fact that, you know, an ant can walk straight to a wall and then just walk up the wall, right? And we can't do that. And an ant could get trapped in a small bubble of water and because of the surface tension of the water. And all I'm saying is that for small things, gravity, as we experience it, becomes less and less and less important to their lives. And so you have plants growing in zero G on the

• 32:12Neil deGrasse Tyson?

  International Space Station, and you study its molecular changes, properties, genetic code. Why should zero G have any effect on it at all when it's at the molecular level? And why do molecules give a rat's ass about gravity?

• 32:33Speaker 02

  That's a great question.

• 32:35Speaker 03

  And it's really not whether the molecule cares, it's whether the organism cares.

• 32:40Neil deGrasse Tyson?

  Oh, the fuller organism. Oh, okay.

• 32:42Speaker 03

  Yeah.

• 32:42Neil deGrasse Tyson?

  All right.

• 32:43Speaker 03

  So do plants care whether there's gravity or not? That's a big question.

• 32:47Neil deGrasse Tyson?

  Well, they do grow up instead of down, so maybe, maybe so.

• 32:50Paul Mecurio?

  Not mine, not mine.

• 32:54Neil deGrasse Tyson?

  Yours just don't grow. That's a different problem.

• 32:57Speaker 02

  It's, it's really all about cues, right? It's all about directional cues. And so on Earth, plants had evolved to use gravity. So the roots grow down, the shoots grow up.

• 33:09Neil deGrasse Tyson?

  But wait, how do you, wait, wait, wait, how do you know the, the, the shoots grow up against gravity rather than towards sunlight?

• 33:17Speaker 02

  They do both, actually.

• 33:18Neil deGrasse Tyson?

  Okay, well, let's hold that. Let's hold that. We're gonna take a quick break and when we come back, we're gonna get into sort of the molecular physics of these plants and what forces of nature do they care about most? And what do they just not care about at all? On StarTalk, we're talking about growing plants in space, not only in orbit, but on planetary bodies when we return.

• 33:48Neil deGrasse Tyson?

  We're back. StarTalk, talking about growing plants in space, in orbit, planetary bodies. I got Paul Mecurio with me. Paul, how do we find you on social media? Plus, you've got a podcast, don't you?

• 33:59Paul Mecurio?

  Yep, it's called Inside Out with Paul Mecurio. You've been on it. You had a great

• 34:04Neil deGrasse Tyson?

  Your name is in the podcast?

• 34:05Paul Mecurio?

  My name is in the podcast, just only so I remember whose it is. Because I have

• 34:12Paul Mecurio?

  Yes, so you can get it wherever the millions and billions of podcasts are sold, as they say. And at Paul Mecurio, that's where you can add.

• 34:20Neil deGrasse Tyson?

  At Paul Mecurio, okay.

• 34:21Paul Mecurio?

  M E. M E C U R I O. If you do M E R C U R I O, there's an Australian actor who has a really, wears tight pants. That's not me.

• 34:29Neil deGrasse Tyson?

  Okay. And we have Annalisa Paul and Robert Furrell, who are on the faculty at the University of Florida, specializing in horticulture with sides of interest that help us figure out how you're going to grow plants in space, possibly to eat them one day. And how can we find you guys? How can the public find what you guys do?

• 34:49Speaker 02

  Well, we have a laboratory website called UF Space Plants. And if you were to Just Google that, you'd come up with this.

• 34:57Neil deGrasse Tyson?

  Nice. So U F S, University of Florida, space plant.

• 34:59Speaker 02

  Yes, correct.

• 35:00Neil deGrasse Tyson?

  And space plant, I just love that pairing of those two words. It just sounds great. We've heard of space aliens, but space plants, you know. By the way, I have on good authority, I don't know if you knew this. I couldn't imagine I could tell the two of you something you didn't know in advance, but I bet this is one of them, that E T, E T from the movie E T was conceived as a sentient plant.

• 35:25Speaker 02

  Cool.

• 35:25Neil deGrasse Tyson?

  That's why, that's why E T had that glowing finger and you'd come near the plants and the plants would rejuvenate. Do you remember this from the movie? Yeah, yeah. So E T was a vegetable, not an animal. Just thought I'd tell you that. I knew you would dine and learn something like that today.

• 35:41Speaker 03

  Had to know it.

• 35:42Neil deGrasse Tyson?

  Yeah.

• 35:43Paul Mecurio?

  Surprising the kid liked it if it was a vegetable. It was, that's a strange combination.

• 35:47Neil deGrasse Tyson?

  Oh, yeah.

• 35:48Paul Mecurio?

  Usually kids don't like vegetables. Can I just ask that these two great scientists, the aridoptis, which is, you know, the basis for your research, what is the best vinaigrette to go with that? Have you done that research yet? And where are we on that? Because that's a very important question for the astronauts, I think.

• 36:05Neil deGrasse Tyson?

  Actually, Johnson Space Center has a food lab where they, they combine flavors that have a good enough shelf life for a long-term space mission.

• 36:12Paul Mecurio?

  May I suggest a little avocado vinaigrette? That's just my suggestion.

• 36:17Speaker 02

  Perfect.

• 36:17Speaker 03

  The hint of sweetness will make all the difference.

• 36:20Neil deGrasse Tyson?

  You got it.

• 36:20Paul Mecurio?

  There you go.

• 36:22Neil deGrasse Tyson?

  So tell me, tell me again about, how do you know that the plant is reaching up against gravity rather than reaching up towards sunlight? Because wasn't it, for a long while, didn't we think that plants turned towards the sun because they wanted sunlight, but in fact sunlight was killing some chemical in their, in their, on the side of the, of the branch? That it ended up curling towards it and it was just a side effect that the leaves faced the sun? Isn't that what, isn't that what's actually going on inside the plant?

• 36:52Speaker 02

  This is precisely what is going on. So that's actually very well said. It's not that they're, they're, but they are doing that. They are reaching towards the sun, but they do that by, because they evolved such that when you have too much sun, what it does is it makes the other side of the cell elongate more. And so as it elongates, it causes it to curve. The same thing happens with, in, for, for gravity sensing. The plants are growing down on earth. But if you say, if you take a plant to, to an environment that has no gravity, you lose the gravity cue. And so you still have to rely on light for that cue.

• 37:28Neil deGrasse Tyson?

  Yeah, but if you have a seed.

• 37:29Speaker 02

  And still grow towards light.

• 37:29Neil deGrasse Tyson?

  If you have a seed embedded in a blob of soil and you're in zero G and then you water it, however you do that, because there's no gravity, but okay, you get water in the soil, however you do it magically, how, would, how does the seed know which way to open and then pop out of your blob of soil?

• 37:46Speaker 02

  So we've done this experiment essentially. We've done that it's that the blob becomes auger on a plate. It becomes closed in light. We've done it in the dark. The plant has an inherent mechanism on how to grow away from where it's planted. Because if it didn't, it would just grow in this little tight blob and then it would use up all the nutrients right around it and it would die.

• 38:06Neil deGrasse Tyson?

  Oh.

• 38:06Speaker 02

  And so, and so it has an inherent mechanism to elongate and make this sort of a coil kind of a growth pattern that takes it away from its planted. This, the, the roots just coil away, the shoots coil away in the other direction. And eventually you get something that looks more or less like a plant, even when you grow them in the dark. But if you grow them in the light, then plants without gravity use light as a cue. The plant's roots grow away from that light and the plant shoots grow towards that light, even without gravity.

• 38:38Neil deGrasse Tyson?

  Or at least away from which way the shoot is going, because if you're in the soil, it won't see the light at all, I presume.

• 38:43Speaker 02

  That's true.

• 38:43Neil deGrasse Tyson?

  Right, right. So how about all these people I see growing plants, I get, is it called hydroponic? Growing plants just in a pot of water. Why can't you just do that in space?

• 38:52Speaker 03

  Well, in fact, you, you can, one can. And one of the sort of major engineering thrusts of plant growth in space is try to understand how to manage water in zero gravity, because.

• 39:10Speaker 03

  In the absence of gravity, capillary action takes over and you get blobs of water attached to your roots. And so you can essentially drown your roots with very little water in space, simply because gravity is not pulling the water away. So there is, there's a lot of biology and water management that is on Earth dependent upon gravity, especially for hydroponics or things related to that. So, so yeah, water management is a big deal. And would that be a way, a non-soil way to grow plants in space for life support? Yeah, absolutely.

• 39:51Neil deGrasse Tyson?

  Okay, but then you have to still feed it nutrients, right? And they have to be nutrient-rich water. Can't be distilled water.

• 39:57Paul Mecurio?

  Yeah, and that's called Miracle Grow, Neil. Everybody knows that.

• 40:01Neil deGrasse Tyson?

  Everybody's so stupid me.

• 40:03Paul Mecurio?

  Just between the four of us, you guys cheat a little bit and throw a little Miracle Grow in when you're doing these experiments? Just to see. I look at Rob, he's on it. There you go. Yeah, absolutely. This is breaking news, everybody. We just.

• 40:16Neil deGrasse Tyson?

  Breaking news.

• 40:18Paul Mecurio?

  So what about light and the, you know, the light that these plants need and will need? I know there is going to be controlled environments in space, but right? I mean, have you experimented with different types of lighting that these different plants need?

• 40:31Neil deGrasse Tyson?

  Dude, have you never grown marijuana? You just get a grow light. What like, what kind of question is that?

• 40:38Paul Mecurio?

  I haven't, but I know somebody on this.

• 40:40Neil deGrasse Tyson?

  Of course you haven't, of course you haven't.

• 40:41Paul Mecurio?

  In this meeting that has and discovers it.

• 40:43Neil deGrasse Tyson?

  No, initially, just in all fairness to that question, when I first thought about the problem, I said, if you're going to travel to the outer solar system, the sun gets dimmer and dimmer and dimmer and dimmer. So you can't rely on sunlight. And I was imagining you couldn't grow plants, but of course you can. You just have some other grow lamp, right?

• 40:59Speaker 03

  Well, so Paul, again, potentially by pure mistake or random error, landed on a very, very.

• 41:07Paul Mecurio?

  Wait a minute, wait a minute. Wait a minute. That was a very passive aggressive compliment. Are you the vice president of passive aggressive compliments at the University of Florida? I got stopped by Ren. I wrote stuff. I don't know.

• 41:23Speaker 03

  And it's showing up.

• 41:25Paul Mecurio?

  Can you say that again? I asked a good question so I could record this and tell my wife that I asked a smart question.

• 41:30Speaker 03

  Okay. So here's the real deal. The question of how you would get lights to your plants on another planetary surface is a very fair one because you have to trade off the cost of generating the energy for lighting up the LEDs against the cost of building, for example, a light collector and a translucent tube to bring that light to your growth surface.

• 41:57Neil deGrasse Tyson?

  Which would then be a passive, would be energy passive for you.

• 42:00Paul Mecurio?

  Plus, you've got to factor in use of electricity for the disco ball every Saturday night when you're having your disco party on the moon.

• 42:06Neil deGrasse Tyson?

  All of this.

• 42:07Paul Mecurio?

  All of this has to be factored in. But continue, sir.

• 42:10Speaker 03

  No, that's basically it. The whole idea of how you manage light as you transit around the solar system, or whether you dig underground and use nuclear power with your LEDs, or whether you pipe light in from the surface. These are all, this is the stuff of science fiction. But it's becoming science, fact and reality as we think about what a habitat on the moon might look like. Do we want natural sunlight? How do we collect it? And how do you pipe it down into where you're going to live? Whether you're a person or a plant.

• 42:46Neil deGrasse Tyson?

  Okay, so here's the $900 question. Will all future astronauts have to be vegetarians? Or is there some way you're going to also sustain animal life out there that would then be edible? I guess chickens or something. I mean, is there, is there a, who's thinking about this?

• 43:05Speaker 02

  NASA's actually thinking a lot about this. The problem is, is that the best animal protein sources are not commonly utilized in Western cooking, things like mealworms.

• 43:19Neil deGrasse Tyson?

  Yum, yum, yum. And insects in general are high protein.

• 43:22Speaker 03

  Exactly.

• 43:23Paul Mecurio?

  Is there a way to make sure that any of these astronauts who are vegetarians have the gene taken out of them where they lecture you about how great being a vegetarian is? Can you guys work on that, please? I'll give you more of my light information and my brilliant lighting questions, but please, if you can all work on that.

• 43:45Neil deGrasse Tyson?

  But otherwise, there's, you know, what you haven't talked about is fungus, right? Fungus, I mean, mushrooms are occasionally described as being meaty. Maybe that would be the compromise between a pure vegetarian diet and one that would involve meat, because portobello mushrooms taste meaty.

• 44:08Speaker 03

  Do they ever?

• 44:09Speaker 02

  But it also helps with this concept of what do you do with all the biomass that you can't eat directly? So you need something to help break that down. And so, you're right, funguses could do that.

• 44:20Paul Mecurio?

  And let's not forget about psychedelic mushrooms. I'm just putting it out there.

• 44:23Neil deGrasse Tyson?

  Okay.

• 44:26Neil deGrasse Tyson?

  In case being in space is not enough for you.

• 44:28Paul Mecurio?

  No.

• 44:31Paul Mecurio?

  Yeah, this is all right, but I really like, this is a trip, but I'd really like to be tripping right now.

• 44:37Speaker 03

  In the end, we will be traveling, whether we wanted to by design or not, we'll be traveling with microbes, fungi, and probably intentionally with plants, but we will have an ecosystem of some sorts wherever it is we're living. So back to your question about fungi. And would they be part of the ecosystem that does, that does do some composting, if you will, in space as part of the life support system? Yeah, very likely.

• 45:09Neil deGrasse Tyson?

  And Paul, you can tell Rob is VP because he's, once again, he said it very tactfully. Let me tell you what he didn't say, but is what he actually said, right? There is fungus growing on our skin and all over our bodies that we're taking it to space no matter what. Okay?

• 45:27Paul Mecurio?

  Now I have to take a shower after this show.

• 45:31Neil deGrasse Tyson?

  Wait, Rob, am I correct? You left, you didn't say that, but you know that's what you meant.

• 45:35Speaker 03

  You are, of course, absolutely correct. There's no way we are sterilizing our skins and our innards when we're traveling anywhere.

• 45:43Paul Mecurio?

  I love Rob because he says really scary stuff that it doesn't sound scary at all, you know? That was kind of a good question, you dummy, like that kind of stuff. I just love this. I, uh, thank you. I'm gonna have to have an extra therapy session this week, Rob. I appreciate it. Let me ask you this real quick about Apollo 11, the regolith from that versus 12 and 17. 12 and 17, you, it gave you better plants, if you will, or whatever. So would that be like, to put it in layman's terms, so that would the food generated by the Apollo 11 regolith versus the 12 and 17? 12 and 17 would be like food sold at Whole Foods, way above what it should be costing, and then the Apollo 11 stuff would be sold at

• 46:24Paul Mecurio?

  like Costco. Is that kind of how this would work? If there were a Costco and a Whole Foods?

• 46:30Neil deGrasse Tyson?

  Please don't, please don't answer yes to that.

• 46:35Paul Mecurio?

  That just took away from my light question. That light just.

• 46:38Neil deGrasse Tyson?

  No, no, no.

• 46:40Speaker 03

  But, but in, in all fairness, one of the real questions would be, does it taste differently if it's grown in different, different?

• 46:49Paul Mecurio?

  Aha! Another good question.

• 46:51Neil deGrasse Tyson?

  Actually, that's brilliant. That's right, because wine picks up some of that flavor. Yeah, yeah. Well, let me, let me catapult this because I'm done with Apollo in this conversation. Let's, let's go straight to poop potatoes, which were famously grown on the surface of Mars during the movie The Martian. So first, question one, how good is human feces as a fertilizer relative to like cow?

• 47:17Neil deGrasse Tyson?

  poop. Second,

• 47:19Paul Mecurio?

  I can answer that.

• 47:20Neil deGrasse Tyson?

  Could he? It's how realistic is that? Because, by the way, professionally, in the, in the storyline, Matt Damon's character was a botanist. So he's supposed to be all up in how that's supposed to work. And so can you comment on the, the, the efficacy of his actions in that film?

• 47:42Speaker 03

  I'm gonna, I'm gonna start by saying, first off, there, there is almost never in the history of movie making, where the botanist is a space hero. So let's just celebrate that.

• 47:56Neil deGrasse Tyson?

  By the way,

• 47:57Speaker 03

  Exactly what it is.

• 47:58Neil deGrasse Tyson?

  I got raked over the coals in Twitter. I think I said something like, um, it seems to me it would be easier for the engineer to know as much engineering as he did, to pick up some botany on the side than for the botanist to know all the engineering that he did. So, and then the, the botanist just, just wrecked. Cause you're right. The, the, cause we have engineering heroes in science all the time. I should have backed up and given the botanist the day in the sun. So

• 48:27Paul Mecurio?

  Can you just let us have our escapism for two hours?

• 48:31Neil deGrasse Tyson?

  I, I, I did the same with the movie Arrival. The movie Arrival, we want to talk to aliens and they got a linguist and a physicist. It's like, no, get a, get a, get a, a cryptographer and an astrobiologist. And then all the linguists jumped all over me.

• 48:45Paul Mecurio?

  Well, yeah, we shouldn't go off on Mary Poppins. No one can fly with an umbrella. Like,

• 48:49Neil deGrasse Tyson?

  No, that is not true.

• 48:52Paul Mecurio?

  Really?

• 48:52Neil deGrasse Tyson?

  All right.

• 48:53Paul Mecurio?

  Let me see.

• 48:53Neil deGrasse Tyson?

  So, so I, I will concede the, we have a hero botanist. Okay. So now let's get back to the poop potatoes.

• 49:02Speaker 02

  All right. So I'm gonna, I'm gonna jump in on this one. First of all, I am happy to say neither Rob nor I are experts in poop. So.

• 49:12Neil deGrasse Tyson?

  Okay. That's a separate profession. That's a separate sub-profession of what you guys do. Okay.

• 49:17Speaker 02

  However, I will say that the, the Martian Regolith, as far as we know, from lander studies and stuff, not as far as we know, but as far as you know, like scientists know, is full of things like perchlorates, for instance, toxic stuff, plants hate it, so do humans. And if you have perchlorate type soils here on earth, what do you do? You mix it with water and you mix it with organic materials to help mitigate the toxicity of that. So just saying, Matt Damon was close.

• 49:44Neil deGrasse Tyson?

  Okay, so he had the, the, the, the hermetically sealed poop of everyone. And which meant whatever was anaerobic was still happy still in there, I presume, right? And because your lower gut is all anaerobic, right? So, so, okay, so there's some-

• 50:01Paul Mecurio?

  But his poop wasn't representative of poop in general because it was all based on just eating potatoes and, and whatever that pill he was grinding up, so you can't-

• 50:11Neil deGrasse Tyson?

  No, no, he didn't use his own poop. He used the poop in the trash left by his crew of all the days they had spent there.

• 50:18Paul Mecurio?

  Oh, so there was-

• 50:19Neil deGrasse Tyson?

  Don't you remember? And he cut open the packet and he said-

• 50:21Paul Mecurio?

  Right, so there were like Big Macs in there.

• 50:22Neil deGrasse Tyson?

  Dude, Freddy, what were you eating back there?

• 50:24Paul Mecurio?

  Yeah, right, Big Macs and Juju, you know, and like, yeah.

• 50:28Neil deGrasse Tyson?

  Right, right, right.

• 50:29Paul Mecurio?

  Snickers bars, got it, okay.

• 50:31Neil deGrasse Tyson?

  Okay, so there is some, some sci-fi authenticity to that, to that approach.

• 50:37Speaker 03

  Absolutely, and we do, we do have to answer the question. Human poop, yes, is perfectly good, fertilized.

• 50:43Neil deGrasse Tyson?

  So why don't we all just poop into our house plants?

• 50:46Paul Mecurio?

  I have.

• 50:46Neil deGrasse Tyson?

  Gotcha, gotcha.

• 50:48Paul Mecurio?

  No, I've done that experiment. I was, not intentionally, I was drunk, but you know what? Good things come from drinking, what can I tell you?

• 50:57Paul Mecurio?

  Hey, speaking of Martian, Neil, when they do the sequel, who is gonna play? Who are we gonna cast to play Annalisa? And who is gonna play Rob? We gotta decide.

• 51:05Neil deGrasse Tyson?

  Oh, meaning the sequel to the Martian?

• 51:06Paul Mecurio?

  Yes.

• 51:06Neil deGrasse Tyson?

  Oh, my gosh.

• 51:07Paul Mecurio?

  They're gonna be, they're gonna be the hero.

• 51:08Neil deGrasse Tyson?

  Okay, I'm friends with Andy Weir. I'll put him on top of this podcast.

• 51:11Paul Mecurio?

  So I think for Annalisa, we should do Sandra Bullock.

• 51:15Neil deGrasse Tyson?

  Oh, who's gonna play them, the characters?

• 51:17Paul Mecurio?

  Yes, yes. And for, and for Rob, uh, how about, because he's so passive aggressive, Christopher Walken? How about that?

• 51:27Neil deGrasse Tyson?

  Okay. Deal, done, we've, we've got it.

• 51:32Paul Mecurio?

  So that's all done, so call Andy in.

• 51:34Neil deGrasse Tyson?

  Yeah, yeah. Thank you for that.

• 51:35Paul Mecurio?

  Is he? So what if you're going to a place like Venus where it's 800 degrees? Is this at all? None of this is feasible, right?

• 51:42Neil deGrasse Tyson?

  No, that's the end of story.

• 51:44Paul Mecurio?

  Right, right.

• 51:45Neil deGrasse Tyson?

  End of story.

• 51:46Paul Mecurio?

  Well, you can grow eggplant, then put some cheese on, and you instantly have eggplant parmesan, I guess. But that's about it.

• 51:51Neil deGrasse Tyson?

  Very instantly.

• 51:52Paul Mecurio?

  Yes.

• 51:54Neil deGrasse Tyson?

  Just for context, a pizza oven is 500 degrees, and the surface of Venus is 900 degrees.

• 52:00Paul Mecurio?

  Yeah.

• 52:00Neil deGrasse Tyson?

  So, and I did the calculation. You could cook a pizza in seven seconds on the windowsill. And then I got out geeked, and someone said, "No, you left out the radiative energy from the atmosphere itself, so it'll cook in three seconds."

• 52:12Paul Mecurio?

  Uh-huh.

• 52:12Neil deGrasse Tyson?

  So, yeah. So, no, our esteemed guests today are not thinking about plants on Venus.

• 52:18Paul Mecurio?

  But Mars, right, this is all building to Mars, right? Hopefully, this could be used, this could be used on Mars. Absolutely.

• 52:26Neil deGrasse Tyson?

  Yeah.

• 52:27Paul Mecurio?

  And also, food scarce areas on Earth as well is another.

• 52:30Neil deGrasse Tyson?

  Yeah, I want to just end on the thought. Can either of, each of you just briefly comment? Surely, we're going to learn things from your work that will help us produce food here on Earth in places that either previously were not arable, or were arable, but now we can improve on what their yield is, or productivity, or nutrition? Surely, there's some overlap here. Is that not right?

• 52:58Speaker 03

  Absolutely. One of the things that this work does is it pros the edges of the adaptability of plants

• 53:05Neil deGrasse Tyson?

  There it is.

• 53:05Speaker 03

  in various difficult spots. It happens to be an extraterrestrially difficult spot, but the analogy is the same.

• 53:13Neil deGrasse Tyson?

  Yeah, there you go. And Mars is drier than the Sahara. So if you grow something on Mars, we can do it in the Sahara, I'm pretty sure. Guys, we got to end it there. This has been fun and illuminating. And I think, you know, when you guys have, when you can grow a, what, an apple tree? Give me a call. We'll bring you back on.

• 53:39Neil deGrasse Tyson?

  I think of Isaac Newton and apple trees, but you know, fruit and other things more interesting than kale are would be a must. Otherwise, I'm staying here on Earth.

• 53:49Paul Mecurio?

  I'm with you, or you know, the Krispy Kreme doughnut, I'm going to go back to that. If you really are good at what you do, you would figure that out. I'm just saying.

• 53:55Speaker 02

  We'll engineer it in.

• 53:57Neil deGrasse Tyson?

  Yeah, you can, you can live for centuries off a Krispy Kreme doughnut.

• 54:00Paul Mecurio?

  Oh, God.

• 54:01Neil deGrasse Tyson?

  The energy content is, you can power missiles.

• 54:04Paul Mecurio?

  It's like a Twinkie, you know?

• 54:08Paul Mecurio?

  Thousand year haploid. And when you guys walk to do, you know, when you do the celebrity walk for the premiere of Martian 2, I would like to be with the two of you as, you know, because they're going to be have stars playing you in the movie. So I'd like to be there for that.

• 54:25Neil deGrasse Tyson?

  All right, Annalisa Paul and Rob Furrow, delight to have you for the first time on StarTalk. And maybe it won't be the last. And Paul, this will be your last time.

• 54:34Paul Mecurio?

  What?

• 54:37Neil deGrasse Tyson?

  You were brilliant here, Paul. You would like, all in. I'd love your man. Neil deGrasse Tyson here, your personal astrophysicist, as always, looking up.