“John Carter,” based on Edgar Rice Burroughs’ “John Carter of Mars” stories, is an epic about a Civil War veteran who is transported to Mars and fights for freedom — mostly while shirtless, because that’s what happens when you cast Taylor Kitsch. Wardrobe choices aside, how sound is the “sci” part of this sci-fi film, which opens Friday? We asked Dr. Jim Garvin, chief scientist at NASA’s Goddard Space Flight Center, to assess John Carter’s fighting chances on “real-world” Mars.


The surface gravity on the fourth rock from the sun is about 38 percent of Earth’s, an advantage for a fighter (and a possible explanation for how a shirt might float away).

Weight: “You’ll lose about 30 percent of your body weight and be a lot stronger,” Garvin says. That is, if you can keep all your muscle mass — which Carter does, having skipped the five years it would take a spacecraft to get him to Mars.

Agility: “You’d be able to move around faster. You’d be more effective as a fighting machine.”


Carter fights monsters in the film, but in real life they would be the least of his worries. “There’s a lot of things in space that can kill you,” Garvin says.

Atmosphere: “The atmosphere [of Mars] is not breathable,” so he’d be suffocating “in a matter of minutes, depending on how out of shape [he is].”

Weather: While Mars can be pleasant, with surface temperatures in the summer hovering in the 50s or 60s, it can get really cold. “In an average place on Mars, we expect the temperature to be zero to minus 10 degrees Celsius,” Garvin says.

Water: “All the water is hidden, so it’s a really dry place,” Garvin says. “If Captain Carter is a thirsty man, he’ll have to work harder to get his water.”

Dust: There’s a lot of dust, and “we don’t know if it’s toxic,” Garvin says. “There could be places on Mars that could be poisonous.”

Sunburn: If you’re going to Mars, keep your shirt on. “The ionizing radiation of UV rays from the sun — well, there’s no ozone layer, so you’d be getting cooked really quickly.” And the radiation in space can lead to sarcoma, Garvin says.

So, Martians should probably look elsewhere for their fighting machines, as human beings may not be cut out for the Red Planet.
“We’re a bad organism in deep space,” Garvin concedes. “There’s a lot of ways you can go, let’s face it.”