Gravity Assist Podcast: Science and Science Fiction with Andy Weir, Part 1
The Gravity Assist Podcast is hosted by NASA’s Director of Planetary Science, Jim Green, who each week talks to some of the greatest planetary scientists on the planet, giving a guided tour through the Solar System and beyond in the process. This week, he’s joined by author Andy Weir to explore the fascinating intersection of science and science fiction, delving into the biggest surprises about Mars and the Moon, and how Weir’s novel, The Martian. has provided a powerful gravity assist for young readers.
Here’s a short teaser for this week’s podcast:
You can listen to the full podcast here, or read the first part of the transcript below.
Jim Green: I usually ask this question at the end of an interview, but it seems more appropriate to begin with it. What was your gravity assist, Andy? How has science inspired you to get into writing science fiction?
Andy Weir: Well, it was probably through my father – he’s a scientist himself. He’s a linear accelerator physicist. He’s retired now, but he spent his whole career shooting electrons down a tube. He’s always been a science dork and a science fiction fan, and he had an inexhaustible supply of science-fiction books in the house for me to read. So, I guess you could say I was indoctrinated from birth.
Jim Green: I see. So, you had an opportunity to read the library. Who were some of your favorite authors?
Andy Weir: Well, my “holy trinity,” so to speak, are (Robert) Heinlein, (Isaac) Asimov and (Arthur C.) Clarke. I’m 45 years old, but I grew up reading my father’s science fiction collection, reading the juvenile (novels) from the 50s and 60s and early 70s.
Jim Green: They still hold up really well.
Andy Weir: Some of them, yeah. Parts of them don’t. Parts of them didn’t age well, but other parts of them still hold up really well, especially when they decided to stick with real physics.
Jim Green: What really surprised you about Mars when you were doing the research for your first book, ‘The Martian’?
Andy Weir: I had a lot of fun doing the research, and that’s always the part of writing that I enjoy the most. I already knew a lot about it to start with because I’ve spent my life being a space dork. I feel like I’m in a building where that’s very much accepted here at NASA Headquarters in D.C. I’ve always been into it. So, I started with more than a layman’s knowledge of this stuff, but among the things that I discovered while researching Mars that I didn’t know before was how fast Phobos’ orbit really was, how ludicrously close to the planet it is. It’s well within whatever Mars’ geosynchronous orbit is called and, in fact, it’s nearing the Roche limit, and it’s probably going to be a ring in a few hundred thousand years. So, that means that even though Phobos and Deimos both go the same direction around Mars, if you’re on the surface of Mars, they appear to be going opposite directions, because Phobos is going around Mars faster than Mars can rotate. That’s one thing I found really interesting.
I was also fascinated by Olympus Mons on Mars, the tallest mountain in the Solar System, but it also has an incredibly wide base, almost the size of the state of Texas. The grade is so gradual that the curvature of the planet actually has more of an effect on the horizon than the grade. So, you could be standing on the slopes, for lack of a better word, of Olympus Mons, and you would think you’re on a flat plain.
Jim Green: Yeah, it’s really spectacular, and this is one of the features that a lot of our scientists point to that says Mars doesn’t have plate tectonics. And so, as magma just pokes through the surface, it just sits there and accumulates. But then–
Andy Weir: –Well, I’m going to interrupt you there because recently, within the past year, they [scientists] were able to prove that Mars had an active volcano that lasted on the order of over two billion years, maybe. And the way they were able to prove that is by examining a specific shergottite, a meteorite that had fallen to Earth but originated on Mars. They were able to analyze that and prove that it came from basically the same lava source that these other shergottites came from, and that proved that the same lava source had been active for two billion years. Well, that shergottite that they did the proof with? I have a shergottite at home, a Mars rock at home that was a little gift from me to me with my ‘Martian’ money. I have it at home and it is that same on, a different piece from the same fall, but it’s the same meteorite. So, it was funny when I was reading that news, because of course, I read space news. I was like, it’s from this [meteorite] NWA7635 – wait, that sounds familiar, so I go into my living room and look at the little plaque that I have, because of course, I have it in a little display case, and that’s my meteorite.
Jim Green: Hang onto it!
Andy Weir: Well, I’m not going to be giving it away. It cost a lot.
Jim Green: That’s true. It may have other secrets to behold. This is really important why we need to do that next Mars mission, the sample return mission. We’re going to core rock, and we’re going to bring that back, and that’s going to tell us how fast the climate on Mars changed.
Andy Weir: That sounds fantastic.
Jim Green: It’s called Mars 2020.
Andy Weir: I’m still catching up on some of the details. That will collect the samples and leave them behind for a future return mission?
Jim Green: Once we land it in a geologically diverse area – probably where the water has modified the minerals, where the ancient shoreline on Mars has been – we’ll start coring rock. It cores about a three-inch-long chalk-like cylindrical, a core sample, and it puts them into a metal sleeve, and after it does several of those, it lays them in a pile and moves on. Then later on, we’re going to come and pick them up, take them back to a Mars ascent vehicle. Then we’ll bring it all back [to Earth] because we really want to interrogate those [samples] in the laboratory. That’s where the gold is, in bringing back those samples and really studying them.
Andy Weir: Yeah, I mean, you guys are sending entire laboratories to Mars to look at the samples, but, boy, they’re nothing compared to what we can do on Earth with the facilities here.
Jim Green: Right now we call it Mars 2020, but next year  we’re thinking about having some sort of contest where kids from across the country can name it.
Andy Weir: Sure. That’s how you named Curiosity.
Andy Weir: You know, they’re just going to call it ‘Marsy McMarsFace’. I mean, that’s going be like the top voted one. That’s the thing now.
Jim Green: Well, we hope not! But I’m sure we’ll get that as an entry, and it’ll be from Andy Weir, at least.
Andy Weir: Oh, no, I’ll be much nicer than that.
Jim Green: What I really enjoyed in The Martian is the concept of what happens when humans first get to Mars. Why did you pick the era that’s just around the corner to write about?
Andy Weir: Well, I wanted it to take place as close to the modern day as possible, but I needed to give enough time in the fictional future to actually develop the technologies that would be necessary. The main kind of tech that’s in The Martian that we don’t have in reality yet is the strength of the ion drive that Hermes uses. Like, the technology’s all proven. It works, but we don’t have anything like the scale that would be necessary for it. So, I gave us about 20 years to work that out.
Jim Green: The art direction in the movie, the things that [Production Director] Art Max did, was really spectacular.
Andy Weir: Absolutely beautiful.
Jim Green: What was it like to see The Martian in the theater for the very first time?
Andy Weir: Oh, man, it was great. [Twentieth Century] Fox brought me onto their lot, and we watched it in one of those little, you know, test theater rooms where they watch it internally. The first cut that I saw was missing most of its special effects, so it’s just a bunch of people walking around in front of green screens, or big obvious black wires holding them up in the zero-G scenes. But still, I’ll tell you, right at the beginning, when it started that intro and it put ‘The Martian’ up on screen, I cried.
You can read the second part of the transcript here.