The Martian: Science vs. Fiction

Houston, we have some questions: A point-by-point breakdown of the new sci-fi film with the Johnson Space Center. Spoiler alert!

The latest sci-fi epic from director Ridley Scott stars Matt Damon as a future astronaut stranded on the forbidding environs of Mars. The 3-D film is a technical marvel, providing images we've never seen -- Martian electrical storms, for instance. But how close does the film stay to real science? Pretty close, it turns out.

The filmmakers worked with NASA during production and made scientific accuracy a priority. We talk to Doug Ming, chief scientist for NASA's Astromaterials Research and Science division about specific plot points in the film.

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"Overall, I thought it was pretty well done," Ming says, speaking from Johnson Space Center in Houston, Texas. "There was nothing in there that I would cringe at, scientifically. But there were some things that most of us would think was pushing it to the max."

Let's dig in. Warning: Spoilers dead ahead!

Fiction: The alien landscape in "The Martian" is entirely convincing -- ginormous cliffs of red rock and vast expanses of rocky sand, created from a mix of digital effects and location shooting in Jordan. Does it measure up to what we know about Mars?

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Science: "Well, we actually do have cameras on Mars," Ming says. "We have two rovers that are on the surface right now. We've taken an enormous number of images. Mars is a very dynamic place -- it's got the largest volcano that we know of in the solar system. It has a valley that, if it were here in the United States, would stretch from the East Coast to the West Coast. The features are enormous, much bigger than what we'd see here on Earth. They did a pretty good job of what we would really see on Mars -- the boulders, the soil, those kinds of things."

Fiction: In the film, astronaut Mark Watney (Damon) plants and grows a potato crop on Mars, using Martian soil and an improvised irrigation system.

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Science: "I've been predicting that we could do that since I first came to work at NASA 30 years ago," says Ming, who earned his Ph.D. in Soil Science from Texas A&M University in 1985. "I do believe you could take soil materials, like Watney did in the movie, put it in a controlled environment and add water, and it would grow -- with the exception of a couple of nutrients that would need to be added. One of those is nitrogen."

Fiction: To grow his potatoes, Watney fertilizes the plants with solid human waste from himself and the other astronauts. By unpacking the freeze dried packets from the habitat's toilet system, he's able to provide particular nutrients -- including nitrogen -- to his crops.

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Science: "If I was on Mars, and I was in his predicament, I would have done exactly the same thing," Ming says. "We don't do that here on Earth because of human pathogens -- we want to make sure we get those out of the system before we start recycling. But sure -- it's absolutely feasible. Human urine has a lot of nitrogen in it, too."

Fiction: Mars is a very dry place. To provide water for his potatoes, Watney improvises a system to produce H20 directly, by burning oxygen from the life support system in his habitat with hydrogen gas from leftover spaceship tanks. His first experiment goes spectacularly wrong.

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Science: "Yeah, you know that part was interesting," Ming says. "There's no doubt -- hydrogen, you burn it, it combusts. If you have an oxygen source, you can potentially produce water. In theory, it works. But to do it in a closed habitat like that? That would be tricky."

Fiction: In the film, massive Martian dust storms -- with lightning and tornadoes -- pop up suddenly and complicate things for Watney and the other astronauts. Would Martian weather storms really work like that?

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Science: "Yeah, that's one of the areas where those of us that know about Mars thought -- oh, that's pushing it," Ming says. "There have been some major dust storms on Mars over the past 20 years. They pretty much engulf the planet. It happens fairly fast, but it does take some time to develop.

"Would it have happened like it did in the movie, with no warning? No -- our orbital assets on Mars would see them. We do have some predictive capabilities to say -- hey, there's a dust storm heading your way. That's one of the scenes where I'd say that's pushing the reality a little bit."

Fiction: Watney gets around in a six-wheeled vehicle that looks awfully familiar. Why is it that, in the movies, all lunar buggies and Martian rovers have six wheels?

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Science: "The suspension can move up and down -- it's one of our designs," Ming says. "There may be a situation when one of the wheels is off the ground, but the other five are doing the job. We have the same kind of setup on our rovers on Mars, Opportunity and Spirit. For future manned missions, there's this thing called the Multi-Mission Space Exploration Vehicle that NASA has developed. They look a lot alike -- the six-wheel vehicle in the movie and the one we've got."