Surviving on Mars, with Andy Weir

What does it really take to survive on Mars? Neil Tyson interviews Andy Weir, author of “The Martian,” NASA/JPL engineer Adam Steltzner, NASA Planetary Science Director Dr. Jim Green, Sheyna Gifford, co-host Matt Kirshen, Chuck Nice, and Bill Nye. NOTE: StarTalk All-Access subscribers can listen to this entire episode commercial-free. Find out more at https://www.startalkradio.net/startalk-all-access/

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.

• 0:23Neil deGrasse Tyson?

  Welcome to the Hall of the Universe of the American Museum of Natural History. I'm your host Neil deGrasse Tyson for StarTalk. Tonight, we're talking about surviving on Mars, featuring my interview with bestselling novelist Andy Weir, who wrote the story "The Martian." So, let's do this.

• 0:47Neil deGrasse Tyson?

  So, I've got with me as my brand-new co-host...

• 0:50Matt Kirshen?

  I'm honored.

• 0:51Neil deGrasse Tyson?

  Matt Kirshen. Welcome.

• 0:52Matt Kirshen?

  Thank you.

• 0:53Neil deGrasse Tyson?

  The first time?

• 0:54Matt Kirshen?

  Yeah, okay. Pleasure.

• 0:55Neil deGrasse Tyson?

  Excellent. You're a comedian from the UK?

• 0:57Matt Kirshen?

  I am, yes.

• 0:58Neil deGrasse Tyson?

  And you also have a popular podcast called "Probably Science."

• 1:01Matt Kirshen?

  Thank you, yes.

• 1:02Neil deGrasse Tyson?

  I love comedians who think about science, so...

• 1:04Matt Kirshen?

  We do. We think about it... The "probably" is in the title because we are idiots.

• 1:10Matt Kirshen?

  We cover our backs.

• 1:11Neil deGrasse Tyson?

  But eventually, when you're no longer idiots, it'll be definitely science.

• 1:14Matt Kirshen?

  That's never gonna happen, but I appreciate the optimism there.

• 1:18Neil deGrasse Tyson?

  I'm an optimistic guy. So, we also have someone who actually knows something about Mars, an engineer who's actually landed there. Not by himself, not of himself. He's put stuff on Mars. Adam Steltzner.

• 1:34Neil deGrasse Tyson?

  You led the entry, descent, and landing team for the Mars Curiosity rover.

• 1:39Speaker 02

  That's correct.

• 1:40Neil deGrasse Tyson?

  The biggest hunk of metal, unmanned metal, that we've ever put anywhere.

• 1:43Speaker 02

  I was very, very lucky to be able to lead a fantastic team of people developing that landing system.

• 1:51Neil deGrasse Tyson?

  This is the size of a car.

• 1:53Speaker 02

  Size of a car, bigger than anything we've ever put down, and it was really hard.

• 1:58Neil deGrasse Tyson?

  Okay, but you don't have to bring the rover back. In the movie The Martian, they wanted to bring Mark Watney back.

• 2:04Speaker 02

  That's correct. That is, that's a tough job.

• 2:07Neil deGrasse Tyson?

  And so that-

• 2:08Speaker 02

  So your job's easy. Yeah, my job's cake. Total cake.

• 2:11Neil deGrasse Tyson?

  You're, you're-

• 2:12Speaker 02

  Walk in the pod. Anyone could do that.

• 2:13Neil deGrasse Tyson?

  Anybody could do that.

• 2:14Speaker 02

  Seriously, any of you guys, come on, bring it on.

• 2:17Neil deGrasse Tyson?

  So, in fact, bringing somebody back from Mars who has to survive there is the topic of this evening's show.

• 2:23Speaker 02

  Yes.

• 2:24Neil deGrasse Tyson?

  Yes. And so, before we jump in, I just want to give the rundown on the story from the trailer of the movie The Martian starring Matt Damon. Let's check it out.

• 2:36Speaker 03

  This is Mark Watney, and I'm still alive, obviously.

• 2:43Speaker 03

  I have no way to contact NASA or my crewmates, but even if I could, it would take four years for another manned mission to reach me, and I'm in a hab designed to last 31 days. So, in the face of overwhelming odds, I'm left with only one option: I'm gonna have to science the [BLEEP] out of this.

• 3:03Speaker 03

  Okay, let's do the math. I gotta figure out how to grow four years' worth of food here, on a planet where nothing grows. But if I can't figure out a way to make contact with NASA, none of this matters, anyway.

• 3:21Neil deGrasse Tyson?

  Ooh. So that had seven Academy Award nominations, two Golden Globes, and how did, how did he survive? Not on, as the usual wit, prayer, and hope. He survived on, what's the quote? Sciencing the [BLEEP] out of everything. So, I recently had the, the privilege to sit down with the author of The Martian, Andy Weir, and he's a certified geek himself, not just a storyteller, novelist, who just, he's got some street cred. So let's get some backstory on Andy and the book. Let's check it out.

• 3:59Speaker 04

  I'd always wanted to be a writer, even when I was in high school. But I also like eating regular meals. And so when the time came to choose a career, I went with software engineering. And that's what I went to college for. And I'm a proud four-year college veteran, yet dropout because I ran out of money. I went right into the software engineering field. I was one of the programmers on Warcraft II.

• 4:20Neil deGrasse Tyson?

  You were a geek credential from beginning to end.

• 4:22Speaker 04

  I know, I'm just like, I'm just pure geek. Maybe not quite so much as the other people in this room here, though. I mean, I don't have a PhD in anything.

• 4:30Neil deGrasse Tyson?

  No, that's fine. That's not what makes you geek. Geek is, what do you do in your spare time?

• 4:36Speaker 04

  That's true. That's true.

• 4:37Neil deGrasse Tyson?

  If I paraphrase a comment, a geek is someone who has found something more interesting than sex.

• 4:46Neil deGrasse Tyson?

  Think about it, right?

• 4:48Speaker 04

  Geeks often don't have the option.

• 4:49Neil deGrasse Tyson?

  No! Sex is the problem.

• 4:52Speaker 04

  That's a problem.

• 4:54Neil deGrasse Tyson?

  So the nine consecutive hours on World of Warcraft, whatever.

• 5:00Neil deGrasse Tyson?

  Okay, thank you. That's an important corollary.

• 5:03Speaker 04

  Sad, but true. Yeah, that's one thing that drives me crazy is when I was a teenager, like, geeks were just like reviled, beaten up, and everybody. Now, all of a sudden, now all of a sudden, we're cool.

• 5:12Neil deGrasse Tyson?

  I think everybody has a secret geek underbelly that is not always, they don't always have the occasion to manifest. And you, I think you found their geek tickle bone.

• 5:22Speaker 04

  While I was writing the book, anytime I was tempted to take a shortcut and have unrealistic science or unrealistic physics, I'd say, "What if Neil deGrasse Tyson reads this?" No, I'm serious. Like, literally, that was my thought process. I'm like, "He will notice this, and he will point it out."

• 5:40Neil deGrasse Tyson?

  I got novelist on notice.

• 5:44Neil deGrasse Tyson?

  So, he doesn't fit your stereotype of a novelist. And maybe, in this particular case, of course, that was a good thing. Because he then infused his storytelling with a level of science and engineering that I think is without equal. Now, you don't have a typical background, do you?

• 6:00Speaker 02

  Maybe not. I mean, it takes all sorts of paths to get here, but...

• 6:04Neil deGrasse Tyson?

  Well, your path was what?

• 6:06Speaker 02

  I started in music.

• 6:07Neil deGrasse Tyson?

  In music?

• 6:07Speaker 02

  I was an artist and a musician, and into theater. And then, one night, coming home from a show, I noticed one of the... Three constellations that I know the names of. Orion was in a different spot in the night sky than it had been when I had gone to play the show. Now, I'd been a very poor student in high school.

• 6:26Neil deGrasse Tyson?

  So that's when you learned that Earth rotates.

• 6:28Speaker 02

  No, no, not yet, not yet. I actually had missed that whole thing in high school. I knew something was moving with respect to something else. And I went to take a astronomy course to teach me why the stars were moving. The joke was on me, I had a physics prereq. And that physics course blew my mind and changed my life.

• 6:51Neil deGrasse Tyson?

  Wow. So, you know, in The Martian, it's, the story is simple.

• 6:56Speaker 02

  Yeah.

• 6:57Neil deGrasse Tyson?

  Don't die. That's what it is, okay? Because living on Mars is not easy. So I, I asked Andy, just tell me more about the obstacles that humans face on Mars. I knew some of them, but he thought deeply about them. And I just wanted to hear what a storytelling novelist thought about what can kill you on Mars. Let's check it out.

• 7:20Speaker 04

  If I were going to rank the problems of Mars, the number one problem, of course, is just the sheer remoteness of it. And the complete hopelessness of immediate help or rescue. I mean, you are literally years away from anybody being able to do even so much as an unmanned probe to help you.

• 7:36Neil deGrasse Tyson?

  And most of the things that'll kill you will kill you in much less than a year.

• 7:38Speaker 04

  Yes.

• 7:40Neil deGrasse Tyson?

  You'll die of no water in eight days and no food in a month or no...

• 7:43Speaker 04

  Yeah.

• 7:44Neil deGrasse Tyson?

  Yeah.

• 7:44Speaker 04

  Or you'll, you'll, you'll die of no air pressure.

• 7:47Neil deGrasse Tyson?

  Air, so excuse me. In minutes, yes. Excuse me. If I were to rank it, I put air at top of that list.

• 7:53Speaker 04

  I put pressure is number one, and then comes oxygen.

• 7:57Neil deGrasse Tyson?

  Yes.

• 7:57Speaker 04

  And CO2, uh, actually CO2 cleansing, then oxygen. Then you start getting, okay, now we can talk about water and food.

• 8:06Neil deGrasse Tyson?

  Okay.

• 8:09Neil deGrasse Tyson?

  Yeah, so air pressure, that will kill you.

• 8:11Speaker 02

  Yeah.

• 8:12Neil deGrasse Tyson?

  No oxygen will kill you.

• 8:13Speaker 02

  Yeah.

• 8:13Neil deGrasse Tyson?

  Too much CO2 will kill you.

• 8:14Speaker 02

  Yeah.

• 8:15Neil deGrasse Tyson?

  And so Mark Watney, the character, had to figure out ways to make oxygen for himself. And since the author is an engineer, as are you, you've got ways to figure this out.

• 8:28Speaker 02

  Yes.

• 8:28Neil deGrasse Tyson?

  So could you have been as, as successful as Mark Watney?

• 8:31Speaker 02

  I would have freaked out.

• 8:35Matt Kirshen?

  Well, at what pressure do you die? And how do they calculate that? Like, whose job is it at NASA to kind of work out when you explode?

• 8:44Neil deGrasse Tyson?

  Your eyes don't explode out of your head, first of all.

• 8:47Speaker 02

  But very rapidly you lose consciousness.

• 8:49Neil deGrasse Tyson?

  Yeah, well, depending if it's absence of oxygen. If you hold your breath, you can hold your breath for a little while.

• 8:53Matt Kirshen?

  So the eyes exploding is a myth?

• 8:55Neil deGrasse Tyson?

  Yes, it's a myth. If we had, if we were sacks of gas and then the pressure rapidly dropped, then the gas would want to equilibrate and you'd pop your eyes out like one of those squeeze dolls.

• 9:04Speaker 02

  But it's not a total recall.

• 9:06Matt Kirshen?

  Oh, okay.

• 9:07Neil deGrasse Tyson?

  That's what I'm saying, right?

• 9:07Speaker 02

  If they don't pop out and then Mars gets in our atmosphere and then you pop back in, you're fine. You're like, whoa, that was close. I almost died.

• 9:17Matt Kirshen?

  But given that it's a sack of, so you're saying you, your eyes wouldn't explode?

• 9:20Neil deGrasse Tyson?

  We're fluids.

• 9:21Matt Kirshen?

  But if I had like a party balloon?

• 9:22Speaker 02

  Incompressible fluids.

• 9:23Neil deGrasse Tyson?

  If you had a party balloon?

• 9:24Matt Kirshen?

  That would die?

• 9:25Neil deGrasse Tyson?

  Yeah, a party balloon would expand and explode. And in fact, weather balloons that go up to very high altitudes where there's very low air pressure are underfilled at the ground. And then just enough to start rising. And as they get higher and higher, they grow larger and larger simply because the pressure drops. Because they have gas inside of them. Right? But we have liquid inside of us. And as the pressure drops, there are dissolved gases in our blood that will try to get out and will get out, and that's how you get the bends. Right? That takes a few minutes, you know? But generally, pressure among gases tries to equilibrate immediately. And like I said, if you just were a sack, a balloon of gas, eyeballs will pop out like that. Why are you smiling at this? What?

• 10:11Matt Kirshen?

  I don't know, it's just your voice.

• 10:12Neil deGrasse Tyson?

  Okay, okay.

• 10:13Matt Kirshen?

  You're compelling, Neil.

• 10:14Speaker 02

  The dulcet tones.

• 10:15Neil deGrasse Tyson?

  The dulcet tones.

• 10:17Speaker 02

  Say, say more about the, about your eyes exploding.

• 10:19Neil deGrasse Tyson?

  Yes, so your eyes, as they...

• 10:21Matt Kirshen?

  We should do a series where Neil just explains horrific events in a really compelling manner.

• 10:30Neil deGrasse Tyson?

  So, um, so what, uh, so in the movie they had an oxygenator.

• 10:34Speaker 02

  Yep.

• 10:34Neil deGrasse Tyson?

  Where they would heat the CO2, which is most of the Martian, as thin as the Martian atmosphere is, it's mostly CO2. And you can't breathe CO2 for, and stay alive. So, you heat it to like 900 degrees, 900 degrees Celsius. And then you can, if you, you can perform electrolysis at that temperature, yanking the carbon off the CO2, leaving O2. And then you could breathe that. So, so that's good. And then he figured that out, he knew how to do that. And that's why he didn't die for that reason. And it's also, you also have to be able to remove CO2, because it's toxic to you if there's too much. And so they talk about CO2 scrubbing, something that's a very, by the way, if you figure out how to scrub CO2 out of smokestacks.

• 11:17Speaker 02

  Yeah.

• 11:17Neil deGrasse Tyson?

  Oh my gosh. You know, that's, that's the end of global warming. You take CO2 right out of the air, bury it whence it came, then that's-

• 11:26Speaker 02

  Trees do a great job with that, by the way.

• 11:27Neil deGrasse Tyson?

  Trees do it too, yeah, yeah, yeah, yeah. You plant more trees.

• 11:30Speaker 02

  Yeah, lots of trees. Algae.

• 11:33Neil deGrasse Tyson?

  Tons of trees.

• 11:34Speaker 02

  Yeah.

• 11:34Neil deGrasse Tyson?

  Yes, okay.

• 11:34Matt Kirshen?

  So would algae maybe be a solution if you're trying to colonize Mars?

• 11:38Speaker 02

  Uh, there are, many of the notions about, about making Mars like Earth, which I, by the way, I'm not a big fan of, um, uh, involve some microbiological, uh, rapidly growing thing to help, uh-

• 11:56Neil deGrasse Tyson?

  A terraform.

• 11:57Speaker 02

  It's a terraform.

• 11:58Neil deGrasse Tyson?

  Terraform Mars.

• 11:58Speaker 02

  Yes.

• 11:59Neil deGrasse Tyson?

  Right, right. And, and so, the, so, so if you do that, you can't only just remove the CO2, you need a way to put oxygen back in. And on Earth we get our oxygen from plants, from your trees and other-

• 12:09Speaker 02

  Photosynthesis.

• 12:09Neil deGrasse Tyson?

  And other life forms, photosynthesis, exactly. So, so, so we know Mars is not an easy place to survive. And so, we might wonder, what about just other places in the solar system? Whether they're any better?

• 12:22Matt Kirshen?

  Yeah, we found a few little online reviews of some, uh, places other people have been. So this is one, uh, someone went to Venus.

• 12:27Neil deGrasse Tyson?

  Oh, online travel reviews of some-

• 12:30Matt Kirshen?

  Yeah, I, I was as surprised as you. I was as surprised as you.

• 12:33Speaker 02

  Only two stars.

• 12:35Matt Kirshen?

  Only two, yeah, it says, uh, "Book for one night, uh, a thousand hours later, night still hadn't happened."

• 12:41Neil deGrasse Tyson?

  Oh, Venus rotates, it takes longer for Venus to rotate once than it does to go around the sun.

• 12:48Speaker 02

  Yeah.

• 12:48Neil deGrasse Tyson?

  So a day lasts longer than a year.

• 12:49Matt Kirshen?

  Apparently so. Uh, "The gravity was fine, but the atmosphere was gross and the heat made me literally die."

• 12:59Neil deGrasse Tyson?

  Yeah, because, yeah, it's 900 degrees Fahrenheit there. And, yeah, so you would vaporize.

• 13:06Matt Kirshen?

  Apparently.

• 13:07Neil deGrasse Tyson?

  So you wouldn't really complain about anything else.

• 13:10Matt Kirshen?

  Well, they managed to survive just long enough to write that up.

• 13:14Neil deGrasse Tyson?

  Plus Venus, you said the gravity was fine, because Venus is generally considered our twin, our sister planet, because it has the same, it's about the same size as Earth.

• 13:23Matt Kirshen?

  I didn't know that, so more so than Mars, it's the similar.

• 13:25Neil deGrasse Tyson?

  Oh, by far, oh, by far. Yeah, you go there, you weigh a few pounds within your weight here. Yeah, that's why it's called the sister planet. It's the only thing that resembles Earth, is the surface gravity. Nothing else. All the rest will kill you.

• 13:38Matt Kirshen?

  Alright.

• 13:40Neil deGrasse Tyson?

  Where else have people been on the internet?

• 13:41Matt Kirshen?

  We've got Pluto, Pluto, yeah. The website promised a planet. We wanted a planet. This was not a planet.

• 13:53Matt Kirshen?

  And then the sun.

• 13:54Neil deGrasse Tyson?

  Oh, really?

• 13:55Matt Kirshen?

  Yeah.

• 13:55Neil deGrasse Tyson?

  People visited the sun.

• 13:56Matt Kirshen?

  People visited the sun, yeah, and this is what they wrote. They went, "Uh, ugh, one star." Oh, sorry, "A star."

• 14:09Neil deGrasse Tyson?

  I get, I see what he was doing there. Well, up next, we're gonna assess the scientific accuracy of the novel The Martian, when StarTalk returns.

• 14:31Neil deGrasse Tyson?

  We're back, featuring my interview with The Martian author Andy Weir. Let's check it out. The movie takes place in 2035. That's not a random time in the future, presumably.

• 14:45Matt Kirshen?

  Uh, no, it's not. I calculated all the orbital trajectories that Hermes has to take to get from Earth to Mars and back and all that stuff like that.

• 14:52Speaker 04

  Based on an ion propulsion drive that can provide a constant 2 millimeters per second per second acceleration. Which, as I'm sure you know, is way the hell more than we can do right now. But, whatever. Um, for a ship that size. So I needed to find launch windows for, you know, because the, or the positions of Earth and Mars now mattered, so that they could do that in the most effective time.

• 15:11Neil deGrasse Tyson?

  So these are real launch windows if we were actually to do this?

• 15:14Speaker 04

  If you had a ship with that ability, this is the time when you would want to launch it. Now NASA usually does Hohmann transfers, which are point acceler- point thrust, point thrust. Now this is a continually accelerating ship, so that, I mean, when I was about 12 intervals deep, I decided I'd just make a noose and hang myself before I worked it out with pure math. So I, I did everything with, um, with simulation.

• 15:35Neil deGrasse Tyson?

  So you have way more accurate information in this story than most people will ever know?

• 15:42Speaker 04

  Yes.

• 15:43Neil deGrasse Tyson?

  Yeah, so I think this movie's one of the most scientifically accurate movies ever made, and it was a Hollywood success. So this is encouraging. Use real orbital dynamics. And apparently, I didn't know this, that orbital dynamicists are called slingers? As in like, like slingshot?

• 16:00Speaker 04

  Yeah.

• 16:01Neil deGrasse Tyson?

  People?

• 16:02Matt Kirshen?

  That sounds like a nickname they gave themselves.

• 16:04Speaker 02

  Could've happened that way.

• 16:08Neil deGrasse Tyson?

  Yeah, I'm a slinger. Yeah, yeah, okay. And apparently, they checked his launch calculations, and they found that he was within 2% of the values that were actually required. So, so, so that, that, that's good, right?

• 16:21Speaker 02

  Pretty good. 2% still misses Mars, but...

• 16:25Neil deGrasse Tyson?

  So that's bad. It's not just pretty good, it's bad.

• 16:32Speaker 02

  For a science fiction author, it's fantastic.

• 16:34Neil deGrasse Tyson?

  Okay, so when you landed Curiosity on Mars, where would Curiosity have been if you were 2% off?

• 16:42Speaker 02

  2% of the distance from here, from Earth to Mars, we would've missed the planet.

• 16:46Neil deGrasse Tyson?

  You would've just missed the planet?

• 16:47Speaker 02

  Yes.

• 16:48Neil deGrasse Tyson?

  Okay, so how precise do you have to be?

• 16:49Speaker 02

  Um, it's like, uh, hitting a golf ball from, let's say, here in New York City to where I live in Pasadena, California, in a hole-in-one.

• 16:58Matt Kirshen?

  Didn't, uh, Kim Jong-il do that?

• 17:03Neil deGrasse Tyson?

  So we were told, yes, yes. Okay, so you're hitting a hole-in-one across the United States.

• 17:07Speaker 02

  Yeah, it's very, yes. It's challenging. We consider it a challenge.

• 17:13Speaker 04

  How many things, when you were waiting for it to land, how many different things could have gone wrong?

• 17:18Speaker 02

  Oh, countless, thousands of errors could have killed us on the way down. And I was kind of terrified, and we were watching the data, and I was kind of dumbfounded that nothing had gone wrong, yet.

• 17:35Neil deGrasse Tyson?

  So, translation, I'm so impressed with how brilliant I was. So, Andy Weir, as we've made it clear, was meticulous in bringing scientific accuracy to his story, but there's one thing he got, like, really wrong, and I had to bring it up in the interview, so let's check it out. You have a spaceship that wants to take off, and there's a dust storm, very common on Mars, that whose pressure is so great that it's tipping the spaceship, and the Martian atmosphere is so thin, and the mass of dust that it carries is so low, that it is not tipping over spaceships.

• 18:13Speaker 04

  It cannot possibly, it could barely tip over.

• 18:14Neil deGrasse Tyson?

  It's like me blowing on you now, like this.

• 18:17Speaker 04

  That's about it.

• 18:17Neil deGrasse Tyson?

  That's about it, okay?

• 18:18Speaker 04

  Yeah.

• 18:19Neil deGrasse Tyson?

  So, so you went there, and I've defended you, by the way.

• 18:21Speaker 04

  Yes, you have, thank you.

• 18:22Neil deGrasse Tyson?

  I've said, "Look, he's earned it, and he needs it to tell the story." At least, he got the fact that Mars has dust storms. And I'm the fan of Mark Twain's edict, "First, get your facts straight, then distort them at your leisure."

• 18:37Speaker 04

  Yeah, that's good.

• 18:38Neil deGrasse Tyson?

  Okay?

• 18:39Speaker 04

  I have since learned that Mars has lightning. I did not know that, at the time. So, Mars has lightning, I could have had a lightning strike ultimately be the cause of all these problems, like a lightning could have struck something critical that had fuel and oxygen mixture, and that would have been good, without violating physics, but, oh, well.

• 18:56Neil deGrasse Tyson?

  So, I did a calculation, I'm not certain it's completely correct, but if anything, it's approximately correct. Since the Martian atmospheric pressure is 1% that of Earth's, that would mean, that should mean, that...

• 19:11Neil deGrasse Tyson?

  A hundred mile an hour wind on Mars would feel like a one mile an hour wind on Earth.

• 19:18Speaker 02

  Uh, it would feel about like a ten mile an hour wind because there's a square.

• 19:22Neil deGrasse Tyson?

  Oh, so the energy, it's an energy thing.

• 19:24Speaker 02

  It's a rho v squared thing.

• 19:25Neil deGrasse Tyson?

  Okay.

• 19:25Speaker 02

  But nonetheless.

• 19:26Neil deGrasse Tyson?

  Still not gonna, in the way that a hundred mile an hour one would.

• 19:29Speaker 02

  Absolutely not.

• 19:30Neil deGrasse Tyson?

  Okay.

• 19:31Speaker 02

  And, but you know, I'm with you Neil. To tell a good story, you need a good villain. A little whoo is not a good enough villain.

• 19:39Neil deGrasse Tyson?

  It's not a good villain, but at least his villain had roots in reality.

• 19:42Speaker 02

  Yes.

• 19:42Neil deGrasse Tyson?

  Where Mars has dust storms.

• 19:44Speaker 02

  Yes.

• 19:45Neil deGrasse Tyson?

  And just to be clear, high winds on Mars with such low pressure is not gonna lift heavy dust.

• 19:52Speaker 02

  No.

• 19:53Neil deGrasse Tyson?

  It's gonna lift very light dust. In fact, that's why we call them dust storms.

• 19:55Speaker 02

  Yes.

• 19:56Neil deGrasse Tyson?

  It'll be like talc or something.

• 19:57Speaker 02

  Yeah, very small particles.

• 19:58Neil deGrasse Tyson?

  Very small particles, very light.

• 20:00Speaker 02

  But it, but it's also something that threatens our spacecraft when they're operating on the surface of Mars today. So it connects to the fact, science fact of our expeditions to Mars right now.

• 20:12Neil deGrasse Tyson?

  So that works.

• 20:12Speaker 02

  It works. It works for me.

• 20:14Neil deGrasse Tyson?

  Now, for me, the most fictionalized part of the, of the film, the one that made it so unbelievable, were several facts. One, the United States and China cooperated in space.

• 20:29Neil deGrasse Tyson?

  Not, and, and, but this one above all, above all, everybody who made an important decision in that film was scientifically literate.

• 20:40Neil deGrasse Tyson?

  That is not the world we currently live in.

• 20:42Speaker 02

  That's true.

• 20:43Neil deGrasse Tyson?

  And so, in fact, realizing that that's not the world we currently live in scares the hell out of me. I, I'm just, just, I'm just saying, okay?

• 20:54Speaker 02

  That's not a recent realization.

• 20:55Neil deGrasse Tyson?

  No, no, no, it's, it's the movie.

• 20:59Speaker 02

  Understood.

• 20:59Neil deGrasse Tyson?

  Crystallized it for me.

• 21:00Speaker 02

  Yeah.

• 21:01Neil deGrasse Tyson?

  And every important decision at all ranks, no matter their title, the people were making important decisions. They were scientifically literate. And no matter the title, if someone who reports to you had better information than you did, you listened to them.

• 21:15Speaker 02

  Yeah.

• 21:16Neil deGrasse Tyson?

  Because the.

• 21:16Speaker 02

  That actually is the most important, most laudable feature of the film for me.

• 21:23Speaker 02

  The idea of listening to all the ideas and valuing them on their merits.

• 21:27Neil deGrasse Tyson?

  No matter the power structure in which you are embedded.

• 21:30Speaker 02

  Regardless of the human being who brings them into play.

• 21:33Neil deGrasse Tyson?

  Beautiful.

• 21:33Matt Kirshen?

  Yeah, I think if this film happened like in reality and there was someone stranded on Mars, there'd be people claiming that it's all happening on a Hollywood soundstage. Like, man never landed on Mars. It's a myth. Why is the flag blowing?

• 21:49Matt Kirshen?

  It's one mile an hour.

• 21:51Neil deGrasse Tyson?

  Well, up next, our very own Mars rover expert is going to help us separate fact from fiction for what it is to drive on Mars when StarTalk returns.

• 22:14Neil deGrasse Tyson?

  Welcome back to StarTalk. We are here under the Hayden Sphere of the American Museum of Natural History, and we're talking about astronaut Mark Watney's attempt to not die. His survival on Mars from the bestselling science fiction story, The Martian, written by Andy Weir, and it's my interviews with him for StarTalk. Let's check it out.

• 22:37Neil deGrasse Tyson?

  Part of Mark Watney's survival was knowing where past sources of energy and rocket ships and because we'd been to Mars before.

• 22:44Speaker 04

  Right.

• 22:45Neil deGrasse Tyson?

  And so then he, so he's got to get around, and so he's got a rover.

• 22:50Speaker 04

  Yeah, he goes to the Ares IV eventual landing site where they have sent...

• 22:55Neil deGrasse Tyson?

  Because this was Ares III.

• 22:56Speaker 04

  He was on Ares III.

• 22:57Neil deGrasse Tyson?

  Yeah.

• 22:57Speaker 04

  Ares IV, they had already sent the Mars ascent vehicle, and it was sitting there making its fuel, and, and all the pre-supplies hadn't come yet, but they had sent the M A V. And so Mark...

• 23:08Neil deGrasse Tyson?

  By the way, which is a completely sensible way to do future space exploration.

• 23:12Speaker 04

  Yes.

• 23:12Neil deGrasse Tyson?

  You just send supplies separately, no reason to risk lives doing that. And then you send astronauts later and they can...

• 23:19Speaker 04

  Once you've confirmed that the supplies made it okay.

• 23:21Neil deGrasse Tyson?

  Yes, and then they can, then they can pitch tent and set up and play house.

• 23:25Speaker 04

  Mm-hmm, yeah. And so he realized that there's a spaceship capable of getting him into low Mars orbit, right there on Mars. He just needs to get to it. The bad news was it was 3,200 kilometers away.

• 23:35Neil deGrasse Tyson?

  Right.

• 23:36Speaker 04

  So he had to take these rovers, which were really designed for a 20-kilometer range before being recharged, and drive 3,200 kilometers. So it's quite a challenge.

• 23:46Neil deGrasse Tyson?

  Well, Adam, you led a team, Curiosity, a car-sized rover, to move on the surface of Mars.

• 23:53Speaker 02

  Yep.

• 23:53Neil deGrasse Tyson?

  What would it take to drive that 3,200 kilometers?

• 23:57Speaker 02

  A very, very long time.

• 24:00Neil deGrasse Tyson?

  Actually...

• 24:01Speaker 02

  So, it's true. She's only gone 13,992 meters in four years.

• 24:11Neil deGrasse Tyson?

  See, he used meters, now the number sounds bigger, right? You got that?

• 24:14Speaker 02

  A whopping 13,000...

• 24:16Neil deGrasse Tyson?

  Every guy knows that trick. Yeah, yeah, it's a trick. It's a trick. It's 13 kilometers. If you do it in miles, it's even less. It's like eight miles, okay?

• 24:24Speaker 02

  But we're not, unlike Mark Watney, we're not hitting the gas and trying to get somewhere. We are actually, well frankly, scienceing the [BLEEP] out of Mars along the way.

• 24:33Neil deGrasse Tyson?

  Okay, because you're not in a hurry.

• 24:35Speaker 02

  We're not in a hurry. We're exploring. We're looking at the surface of Mars. We're learning about its history. We're learning about its ancient environment. We're searching for the possibility that it could have supported life.

• 24:47Neil deGrasse Tyson?

  Okay.

• 24:47Speaker 02

  But, as evidence of how slow and how methodical and interested our science team is, we went to the Gale Crater for some clay minerals that we saw from orbit, signatures of clay minerals.

• 25:01Neil deGrasse Tyson?

  So, clay is where there was water and deposits that settle, and then you just...

• 25:06Speaker 02

  Yeah, like the bottom of a lake bed kind of feel. We still haven't got to that deposit that we saw in the entire time that we've been on Mars. And yet, we've done a whole...

• 25:15Neil deGrasse Tyson?

  Because you've been busy.

• 25:16Speaker 02

  Because we've been busy.

• 25:17Neil deGrasse Tyson?

  Because it's been stopping for pee breaks.

• 25:21Neil deGrasse Tyson?

  Alright, so, let's back up for a minute, because your specialty was getting the thing there safely.

• 25:26Speaker 02

  Yes, sir.

• 25:27Neil deGrasse Tyson?

  So that the scientists could do their job. And so, what I remember from Spirit and Opportunity, the previous round of this, they had like airbags.

• 25:37Speaker 02

  Yep.

• 25:38Neil deGrasse Tyson?

  So, the thing comes down and airbags deploy, and it bounces until it stops. Now, you have Curiosity, because those were the size of like microwave ovens, let's say.

• 25:47Speaker 02

  Yes.

• 25:47Neil deGrasse Tyson?

  Okay, so Curiosity is the size of a car.

• 25:49Speaker 02

  Yeah.

• 25:50Neil deGrasse Tyson?

  And why not use airbags again?

• 25:51Speaker 02

  So, there are no fibers known to humankind from which we can make a fabric, from which you can make a bag that could handle the loads of that car-like rover hitting the surface of Mars.

• 26:01Neil deGrasse Tyson?

  Okay, so now, actually, you used what I told is called a sky crane.

• 26:04Speaker 02

  Yes.

• 26:05Neil deGrasse Tyson?

  This sounds complicated. What is that? It's like a jetpack?

• 26:08Speaker 02

  It's like a jetpack. The rover was sort of wearing a jetpack, and then about...

• 26:14Speaker 02

  25 meters from the surface of Mars, the jetpack lowers the rover below it and the two descend until the rovers.

• 26:22Neil deGrasse Tyson?

  Okay, I think we have a video of this. Can you be the narrator voice of this?

• 26:26Speaker 02

  Yes.

• 26:27Neil deGrasse Tyson?

  Drew, you got the video? Let's check it out. Okay, talk us through it.

• 26:30Speaker 02

  Alright, so we hit the atmosphere going quite quickly, about 13,000 miles an hour. That's fast enough to burn up or melt the whole spacecraft. That would be uncool. So we wrap it in a special shell. We actually steer our way through the atmosphere. This was the first for this expedition. And that's where you see those rockets going off. We're actually maneuvering in the atmosphere. And then when we've slowed down to about, oh, a little less than 1,000 miles an hour, we open up a parachute. In our case, the world's largest supersonic parachute. We open it up at Mach 2. We get rid of the heat shield that protected us from atmospheric entry. And then we let go and we go on to rockets.

• 27:14Speaker 02

  Now you can see a rover with its wheels. There's six wheels. They're all sort of tucked up. And it's got this jet backpack on top of it. It's slowly descending into the Gale Crater.

• 27:31Speaker 02

  We're looking at the ground with a radar. And then here we do the sky crate maneuver. We lower the rover below us, drop the wheels down. Both vehicles continue to descend until Mars takes up the weight of the rover. We sense that, cut ourselves free, and fly off to a safe distance.

• 27:59Speaker 02

  Easy peasy, right?

• 28:02Neil deGrasse Tyson?

  What were you guys smoking? You could picture this, right? I'd have to say, "Okay, what's next? Let's have a supersonic parachute. Yeah, yeah, that's good." "Let's get like jetpacks. I always wanted a jetpack."

• 28:16Matt Kirshen?

  And then the thing flies away and the car's just there all sad by itself.

• 28:21Neil deGrasse Tyson?

  Yeah, no, but when the thing is holding it, how do you get rid of that? "Oh, let's use the jackpacks and fling it to nowhere. Yeah." You know that's what happened in your room. You know that.

• 28:31Speaker 02

  Well, I could, no, absolutely not. But it is absolutely true. It is absolutely true that the entire team... Recognized that if it didn't work, we were gonna get no sympathy from anybody.

• 28:47Neil deGrasse Tyson?

  No, it's not a matter of no sympathy, there would be like, you know.

• 28:51Speaker 02

  Oh, a prosecution?

• 28:55Matt Kirshen?

  I'm beginning to see why you were so happy when it landed.

• 28:58Speaker 02

  Yeah.

• 28:59Neil deGrasse Tyson?

  Yeah, so congratulations, and it's all about dropping speed to zero in a way that does not destroy the craft.

• 29:05Speaker 02

  Yes.

• 29:06Neil deGrasse Tyson?

  Now, I gotta call this out, in that video which you guys produced at JPO, the craft made noise before it started feeling the heat of the atmosphere.

• 29:16Speaker 02

  Right, yes.

• 29:17Neil deGrasse Tyson?

  I just, you know.

• 29:18Speaker 02

  Yes.

• 29:19Neil deGrasse Tyson?

  It whizzed by in the vacuum of space.

• 29:22Speaker 02

  It, I just, I think it was its rocket, its, its, uh, its reaction thrusters were making sound.

• 29:28Neil deGrasse Tyson?

  And the sound came through the vacuum to my ear.

• 29:31Speaker 02

  No, it was the transducer that was present, actually. It's just a recording.

• 29:35Neil deGrasse Tyson?

  He's making, he's making.

• 29:36Speaker 02

  Yeah, I am actually making.

• 29:37Neil deGrasse Tyson?

  Oh, yeah. So it was a recording device in the craft that you were bringing outside? So we could, it's as though our ear is on the metal of the craft?

• 29:45Speaker 02

  Yes.

• 29:46Neil deGrasse Tyson?

  Okay.

• 29:46Matt Kirshen?

  At what age, Neil, did your teacher start to hate you?

• 29:55Neil deGrasse Tyson?

  Okay, the earliest, I've never gone public on this, the earliest incident was I was in kindergarten. And I drew with my crayons the night sky. And, but it was not necessarily from Earth, it was just space. And I drew it completely black, but with some dots of white crayon. And the teacher said, "No, the sky is dark blue. The night sky is dark blue." And that didn't make any sense to me at all. And she later the next day checked on it, came back and apologized.

• 30:27Speaker 02

  Wow, great kindergarten.

• 30:29Neil deGrasse Tyson?

  Yeah, it's a good, good teacher.

• 30:30Matt Kirshen?

  That's the Neil deGrasse Tyson origin story, right?

• 30:38Neil deGrasse Tyson?

  We'll tell Marvel Comics, okay? I'll get my own movie for all of that. So, the rover cost how much?

• 30:46Speaker 02

  Hey, you know, two and a half billion dollars.

• 30:48Neil deGrasse Tyson?

  Two and a half billion dollars?

• 30:49Speaker 02

  Yes.

• 30:50Matt Kirshen?

  So two and a half billion dollars is probably the other reason you were relatively happy when it landed.

• 30:54Speaker 02

  Yeah, well, and a decade of my life.

• 30:58Neil deGrasse Tyson?

  So, listen, we've got an uncrewed rover there.

• 31:02Speaker 02

  Yeah.

• 31:03Neil deGrasse Tyson?

  Moving around slowly, but if you send people, we're gonna wanna move faster than that, presumably. And Mark Watney in The Martian had like a human-sized rover, like the kind of rover they used on the moon.

• 31:16Speaker 02

  Yeah.

• 31:16Neil deGrasse Tyson?

  I mean, big, that can, you can drive.

• 31:18Speaker 02

  Yeah, really big.

• 31:18Neil deGrasse Tyson?

  Yeah, yeah. So, how, presumably they're gonna find you when that time comes to land one of those suckers?

• 31:26Speaker 02

  Uh, perhaps. Yeah, certainly, we work together with the folks who are doing the human exploration.

• 31:31Neil deGrasse Tyson?

  Oh, at Johnson Space Center?

• 31:32Speaker 02

  At Johnson, absolutely, and we...

• 31:34Neil deGrasse Tyson?

  'Cause you guys have this sort of, well, every, all the engineers have good mechanical background on this, right?

• 31:38Speaker 02

  Yes, and we're all working together at the same purpose.

• 31:41Neil deGrasse Tyson?

  And so, so you, if I imagine humans on Mars, I would want a rover that moves faster?

• 31:47Speaker 02

  Yes.

• 31:48Neil deGrasse Tyson?

  Than your Curiosity rover?

• 31:51Speaker 02

  Yes.

• 31:51Neil deGrasse Tyson?

  Okay, and when is the next time we're gonna send another rover?

• 31:55Speaker 02

  We'll be sending a rover in 2020.

• 31:57Neil deGrasse Tyson?

  2020, so another one of these Mars windows?

• 31:59Speaker 02

  Yep, it's gonna be a rover very much the size of Curiosity, it's actually a little tiny bit bigger, but even more profoundly, I think, it's going to select samples to be corred from the Martian surface, placed in specially sealed containers for possible return to Earth.

• 32:20Neil deGrasse Tyson?

  In some other planned mission?

• 32:21Speaker 02

  In another mission that would yet to be funded, that would follow it on.

• 32:25Neil deGrasse Tyson?

  But the incremental nature of this is not unfamiliar to NASA. When we went to the moon, every next mission was an increment on the previous one before we landed there with astronauts, so...

• 32:36Speaker 02

  Yes, almost all the big stuff we've ever done as human beings has been incremental, whether it's castles, bridges, or spacecraft.

• 32:43Neil deGrasse Tyson?

  We gotta wrap up this segment. Adam, thanks for being on StarTalk.

• 32:46Speaker 02

  Oh, my pleasure. Thank you.

• 32:49Neil deGrasse Tyson?

  Breaking down the Martian and the rovers. Coming up next, can you actually grow food on Mars? That's next on StarTalk.

• 33:08Neil deGrasse Tyson?

  Welcome back to StarTalk, the American Museum of Natural History, the Hall of the Universe. We're talking about what it takes to survive on Mars, featuring my interview with Andy Weir, author of "The Martian." And we've been exploring not only what it takes to land on Mars in this show, but now we want to know what it takes to live there. And we've got just the guy to help us out, so let's do this. Joining us on StarTalk, special guest Jim Green. Jim, welcome.

• 33:41Speaker 05

  Thank you very much.

• 33:44Neil deGrasse Tyson?

  Jim is a friend and colleague, and he's up from NASA headquarters in Washington DC. So you oversee solar system exploration for NASA.

• 33:54Speaker 05

  That's right.

• 33:56Neil deGrasse Tyson?

  That's a big job.

• 33:57Speaker 05

  Cassini, Dawn, Pluto, New Horizons, Mercury.

• 34:01Neil deGrasse Tyson?

  So Cassini went to Saturn.

• 34:04Speaker 05

  Yep.

• 34:05Neil deGrasse Tyson?

  Dawn went to an asteroid.

• 34:06Speaker 05

  Two.

• 34:07Neil deGrasse Tyson?

  Two asteroids.

• 34:08Speaker 05

  Yeah, that's the series.

• 34:09Neil deGrasse Tyson?

  Okay, Messenger to Mercury. New Horizons to Pluto.

• 34:12Speaker 05

  Right, they can't hide out there.

• 34:14Neil deGrasse Tyson?

  They can't hide.

• 34:15Speaker 05

  I'm on it.

• 34:16Neil deGrasse Tyson?

  And so if I land on Mars, and I want to come back as early as possible after that, what is the launch windowing for me?

• 34:23Speaker 05

  Okay, so we can go in 180 days, get down on the surface for about 30.

• 34:29Neil deGrasse Tyson?

  Just to be clear, it can take six months to get there.

• 34:33Speaker 05

  On that order, a little more, depends on the opportunity.

• 34:35Neil deGrasse Tyson?

  Then you spend 30 days.

• 34:36Speaker 05

  Right, and then you've got to get your can back, so to speak, get in the can and get it back.

• 34:41Matt Kirshen?

  So 30 days keeps you in that same window?

• 34:43Speaker 05

  Pretty much so.

• 34:44Neil deGrasse Tyson?

  But in "The Martian," Mark Watney is stuck on Mars for way longer than that, and he grows his own food. So I had to ask the Martian author, Andy Weir, how do you do this?

• 34:57Speaker 05

  Yeah.

• 34:58Neil deGrasse Tyson?

  How do you survive 500 days? Let's check it out.

• 35:01Neil deGrasse Tyson?

  The surface of Mars is not soil in the way we think of soil on Earth. Soil on Earth has microbes and organic molecules. Not so much on Mars. So, what does it mean to farm on Mars?

• 35:16Speaker 04

  So, the first thing you need to do is breed dirt. So, you start with Martian soil, well Martian regolith, really. It's just...

• 35:23Neil deGrasse Tyson?

  So, regolith would be a surface of basically powdered rock?

• 35:27Speaker 04

  Right, and it's devoid of life. It has literally nothing, we're assuming, at the moment. And then you inundate it with water. You inundate it with biological material.

• 35:40Neil deGrasse Tyson?

  Poop.

• 35:41Speaker 04

  Poop, yes. And then you inundate it with the bacteria that is found in Earth soil. And that will make it a suitable environment for roots to germinate.

• 35:50Neil deGrasse Tyson?

  So, there's not really Mars farming, it's Earth farming on Mars?

• 35:53Speaker 04

  Yes.

• 35:55Neil deGrasse Tyson?

  Earth farming on Mars, do you agree with that?

• 35:56Speaker 05

  Yeah, that's true. But Mars is gonna help us a lot. So, what Curiosity has done is it is drilled below the surface. And, you know, we know Mars is really red. And the scientists got incredibly excited when, our first drill, we drilled up gray material. So, we scooped that into our instruments, tasted it, okay? And it had carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur nitrates, okay? And the soil was moist.

• 36:26Speaker 04

  So, that's basically fertilizer, right?

• 36:28Speaker 05

  Yeah, well, the nitrates are, yeah. But you're still gonna have to add a lot to it. And the soils also were Curiosity...

• 36:34Neil deGrasse Tyson?

  Whoa, whoa, whoa, whoa, stop! You got through the top surface of Mars, which basically has no organic anything. You get to a lower level that's not rusty red. And you get a full portfolio of atoms that make organic molecules.

• 36:52Speaker 05

  Correct.

• 36:52Neil deGrasse Tyson?

  As well as fertilizer.

• 36:54Speaker 05

  Correct.

• 36:56Neil deGrasse Tyson?

  So, would this mean that at one time in Mars's past, it was an oasis?

• 37:01Speaker 05

  It could have been. We do know that in Mars's past, that it had a significant amount of water. And about 3 billion years ago, 30% of the northern hemisphere was covered with water. And in some places, over a mile deep.

• 37:16Neil deGrasse Tyson?

  So, let me get back to Mark Watanabe's potatoes and poop. His potatoes and poop, how realistic is that?

• 37:23Speaker 05

  Ah, that's a good question. It's reasonably realistic. Uh, curiosity tells us-

• 37:28Neil deGrasse Tyson?

  Just in case you missed it, uh, he needed fertilizer and went to the toilet-

• 37:34Speaker 05

  Dispenser.

• 37:34Neil deGrasse Tyson?

  Dispenser place where all the human waste is like wrapped in packets because it does-

• 37:39Speaker 05

  Oh, it took the water out.

• 37:40Neil deGrasse Tyson?

  It do- oh, it dehydrated-

• 37:41Speaker 05

  Oh, I'm sure you had to, well, you had to recirculate that. You're not throwing water away on Mars.

• 37:45Neil deGrasse Tyson?

  Especially not out of your poop. Yeah.

• 37:47Speaker 05

  Right.

• 37:47Neil deGrasse Tyson?

  Okay, so it's dehydrated poop that he then uses as fertilizer for the plants.

• 37:52Speaker 05

  Yep.

• 37:52Neil deGrasse Tyson?

  So, that's clever-

• 37:54Speaker 05

  Very.

• 37:54Neil deGrasse Tyson?

  And it's realistic.

• 37:55Speaker 05

  Yeah, I believe so. But some of that still needs to be researched.

• 38:00Neil deGrasse Tyson?

  So, one way to imagine you're on Mars is to pretend you're there here on Earth, right? And so, there are researchers at the High Seas Research Station in Hawaii. And a crew member, that's what they're called, Shayna Gifford, sent us a video dispatch from this simulated Mars habitat. I didn't even know this thing existed. Let's check it out.

• 38:25Speaker 06

  Hi Neil, welcome to High Seas, the Hawaii Space Exploration Analog and Simulation. And I'm really excited to give you guys a tour. So, come on, let's go. This is the biology lab, and this is our astrobiologist, Cyprian Verso.

• 38:39Speaker 07

  Most of the experiments we're doing here in this lab are designed to figure out how we can live on Mars from what is already there using biology. So, one of the alternatives I'm working on is based on cyanobacteria, which are basically green microbes, you can see them here, which do photosynthesis like plants. And they're very interesting in this context because we could use nutrients from the ground, gases from the atmosphere, and water, which we can find in different forms on Mars. And once we have grown them, we can use them to produce basically everything you need.

• 39:14Speaker 06

  Fantastic. Alright, so remember to bring the green bacteria. Cyprian is doing amazing work here, and so are some of the other crew members that you'll meet soon. All of our work is powered quite literally by the sun, so let's look outside so you can see the solar panel system. That's where we get almost all of our power. So, when we have to go outside to go cave exploring or collect rocks, we put on these suits.

• 39:38Speaker 06

  We do our science, we do our exploring.

• 39:42Speaker 06

  We come back, we recompress for five minutes, and then we can enter the habitat again. Around the corner is maybe the second most important feature to the hab after the power system.

• 39:52Speaker 08

  Our toilet, it works without water, no flushing. And then, one thing you didn't see through the window is we have a solar still outside that is used to distill

• 40:06Speaker 08

  the stuff that is contained in these little buckets.

• 40:09Speaker 06

  Ha ha! So question, if we really needed to, could we use what we collect in these toilets to grow food? The way we're going to eat it?

• 40:16Speaker 08

  I wouldn't really want to do it inside the hab. I'm pretty sure the smell is not very nice.

• 40:21Speaker 06

  No, we haven't had to go there, but we could. Okay, well, that's almost your entire tour of simulated Mars. Last thing before we go, Neil. I just want everyone at home to know, we Martians heard your podcast about what you would do with trash on Mars. Our answer is: What trash? Everything continues to have a use. It's a cycle, it's a loop. And that's how we're gonna survive in space. We look forward to seeing you as soon as we get back to Earth, or maybe you'll join us here on Mars. Thanks, guys!

• 40:52Neil deGrasse Tyson?

  Alright.

• 40:58Neil deGrasse Tyson?

  Well, up next, we're gonna answer your questions about surviving on Mars on Startalk.

• 41:13Neil deGrasse Tyson?

  Welcome back to Startalk, right here at the Hayden Planetarium at the American Museum of Natural History. We're talking about Mars, surviving on Mars. And right now, it's time for Cosmic Queries, a fan favorite. And these are questions we solicit from our fanbase, and you got ahold of them somehow.

• 41:32Matt Kirshen?

  I got the questions.

• 41:33Neil deGrasse Tyson?

  Somehow you got ahold of them.

• 41:34Matt Kirshen?

  I got them.

• 41:34Neil deGrasse Tyson?

  And whatever I can't answer, I'm handing over to Jim, and it might be all of them. So, bring it on. This is called from the internet and other sources of our social media. Go for it.

• 41:45Matt Kirshen?

  Alright, Neil and/or Jim. Seth Kane from North Hollywood, California, asks: "Would underground settlements be more feasible for long-term colonies on Mars for protection from solar radiation?"

• 41:55Neil deGrasse Tyson?

  Ooh, Jim!

• 41:56Speaker 05

  Absolutely!

• 41:57Neil deGrasse Tyson?

  Good answer!

• 41:58Speaker 05

  Yeah, so... In fact, you know, what we are looking-

• 42:02Neil deGrasse Tyson?

  How bad is the solar radiation?

• 42:04Speaker 05

  Well, you know, we have two major sources that we have to worry about. One is called galactic cosmic rays. That comes from within the galaxy, bombards our solar system in every direction.

• 42:14Neil deGrasse Tyson?

  High-energy particles?

• 42:15Speaker 05

  High-energy particles. Those are the one that probably gets you more than anything else. Gets you cancer.

• 42:20Neil deGrasse Tyson?

  And then the solar-

• 42:21Speaker 05

  Solar flares and solar coronal mass ejections. Those accelerate particles to very high velocities and sprays them all over the place. But we have ways that we can see how the sun is behaving and provide alerts.

• 42:37Neil deGrasse Tyson?

  I like the way you say, "We have ways."

• 42:39Speaker 05

  We have ways. We have-

• 42:41Matt Kirshen?

  Sorry, sinister.

• 42:42Neil deGrasse Tyson?

  Yeah, I know. So this is basically space weather.

• 42:44Speaker 05

  Space weather.

• 42:45Neil deGrasse Tyson?

  Is where we monitor the conditions of space.

• 42:47Speaker 05

  Correct.

• 42:47Neil deGrasse Tyson?

  And in the future where we might have colonies or any other activity, we would just alert people, get behind the shield for the next 20 minutes.

• 42:54Speaker 05

  Right.

• 42:54Neil deGrasse Tyson?

  No different from a storm is coming, get inside. Next question, go.

• 42:58Matt Kirshen?

  All right.

• 42:58Neil deGrasse Tyson?

  Great answer. Thanks, Jim, for helping out on that.

• 43:00Matt Kirshen?

  Nick Hernandez from Fukuoka, Japan, I probably mispronounced that, says, "What sort of vehicle and power is needed to get a lander off Mars for a return trip home? And how would this vehicle compare to the Apollo lunar lander?"

• 43:14Neil deGrasse Tyson?

  Ooh, nice. Jim?

• 43:15Speaker 05

  Oh, all right, so it's gonna be-

• 43:17Neil deGrasse Tyson?

  I'll start you off.

• 43:18Speaker 05

  All right.

• 43:18Neil deGrasse Tyson?

  Okay, so the pop on the moon, it's 1/6 of Earth's gravity. So you can sort of run some numbers from that. Mars is like 40% of Earth's gravity. So whatever it is, it's gonna have to be a little more. That's all I can say. Now you take-

• 43:31Speaker 05

  Well, and a little-

• 43:32Neil deGrasse Tyson?

  Take it from here.

• 43:33Speaker 05

  And a little more than that because of the atmosphere. Because it has to plow through that. Now, even though that's, you know, a percent of our atmosphere, it's still something you have to take into account.

• 43:42Neil deGrasse Tyson?

  The air resistance of the movement through-

• 43:43Speaker 05

  The air resistance, right.

• 43:44Neil deGrasse Tyson?

  Okay.

• 43:45Speaker 05

  So these have to be pretty hefty vehicles.

• 43:46Neil deGrasse Tyson?

  There you go. Thank you. Next question.

• 43:49Matt Kirshen?

  All right. Next and final question from Mikey Baumann on Twitter. And I think this is the most important and serious question of them all. Says, "If left unprotected in the Martian atmosphere, how long would a Mars bar survive on Mars?"

• 44:07Neil deGrasse Tyson?

  In the Martian atmosphere. You know Mars bars last decades here on Earth.

• 44:14Matt Kirshen?

  Well, they get that sort of white stuff on the chocolate if you leave it for too long, right?

• 44:17Neil deGrasse Tyson?

  Right, but if you close your eyes, you don't even notice it. Yeah, that, you know what the white stuff is? It's just chocolate. It's cocoa butter. It's the ch- it's the fat of the chocolate, rising to the top. So, it's just, it's becoming unmixed.

• 44:28Matt Kirshen?

  There was a guy in the audience right there who had the face of like, "How does he know everything?"

• 44:32Neil deGrasse Tyson?

  No! Well, I think a lot about chocolate. My wife and I, my wife makes a lot of desserts. So, I, I know more about chocolate than I should.

• 44:40Matt Kirshen?

  See, when people describe you as their favorite chocolate scientist, I always...

• 44:50Neil deGrasse Tyson?

  Now, Sidewalk Science correspondent Chuck Nice, he took to the streets of New York to find out more about our collective love for Mars. Let's check it out.

• 45:01Speaker 09

  We're at a train station. Yeah. Would you take a one-way ticket to Mars?

• 45:04Speaker 10

  I don't think so, because I feel like there's other people in the field that are a lot more, you know, out there that can actually, you know, make Mars successful.

• 45:11Speaker 09

  Yeah, I'd do it. Really? You're a brave man. I'm a history teacher, so if I can make my mark in history, I would do it.

• 45:17Speaker 06

  Sure, yeah.

• 45:18Speaker 09

  Okay, now you're forever living on Mars. Well, that's fine. How about a one-way ticket to Jersey? Would you take that?

• 45:24Speaker 06

  No.

• 45:25Speaker 09

  Nah.

• 45:27Speaker 09

  Wanna go to Mars? All right. Like Matt Damon did, he put his, uh, [BLEEP] and he fertilized his, and made potatoes, you know? Basically. Well, I don't think you can say "fertilized" on TV.

• 45:45Neil deGrasse Tyson?

  Up next, Bill Nye the Science Guy imagines soaring over the surface of Mars. So, let's see what he has to tell us, tonight.

• 46:00Speaker 11

  Hey Neil! How's it going, man? Bill Knight here, we're flying over you, I don't know if you can hear me. Hey Neil! The Rose Center looks beautiful from here.

• 46:17Speaker 11

  Soaring above the city gives you a new perspective on the world below. From up here, it's easy to imagine streaking through the skies of Mars, searching for a place to land or even set up a colony. The first Americans who lived here lived in small villages. There were only about 400 people on the whole island. Today, there are 4,000 people on every city block.

• 46:46Speaker 11

  But just look at all these shapes. Everything here came out of someone's head and that person or those people understood science. Now, through the tradition of our innovations in technology, we've been able to construct these skyscraping buildings and the tendrils of trains and tunnels that connect the 8 million people bustling about below. When I look from up here, I realize how important stories like the Martian are. They're inspiring. They help us realize how much we can accomplish when we work together as we reach for the next frontier. Back to you, Neil!

• 47:37Neil deGrasse Tyson?

  So, I'm actually on record for my skepticism regarding the first settlers on Mars. Because when we think of the pilgrims as an analog...

• 47:54Neil deGrasse Tyson?

  The difference between the pilgrims landing in the New World and the first team of humans landing on Mars is that in the New World, when they got off the ship, they could breathe the air. Trees were made of wood like the trees back at home. They could rebuild damage to their ships.

• 48:18Neil deGrasse Tyson?

  Food was growing on the branches. I thought of the first colony of Mars as being way more hazardous than what the colonists experienced crossing the ocean. But then I saw the movie The Martian, and I realized that that's the wrong analogy. I wasn't thinking about it the right way. Because

• 48:39Neil deGrasse Tyson?

  the difference is that today we have the advances in engineering, science, and technology. That empowers us to take on frontiers that without it would kill us in an instant. And this is a cosmic perspective.

• 49:00Neil deGrasse Tyson?

  You've been watching StarTalk. And I've been your host, Neil deGrasse Tyson. And as always, I bid you to keep looking up.