Mars' Colorado

Elon Musk likes to warn people that most people who go to Mars won't be coming back. Robert Zubrin for his part has warned that radiation be one risk for colonists - which he probably got from Total Recall. Tonight we'll nuance this.

Robotbeat compares Mars with, er, South Dakota-Minnesota. For our part in Colorado, especially in summer, we spend some of our time in cooler basements and the rest of our time in cooler mountains. Our basements have radon. Even with mitigation Robotbeat considers 10 mSv per summer ingested right into the lungs. And then there's sunburn. On Mars a basin (like Hellas) or that vast northern depression might be getting 100 mSv per year. I'm assuming this is an Earth year to be amortised over Mars' longer cycle and eccentricity.

This is not to ignore Martian radiation. On a Martian-globe scale, the radiation is a menace to terraforming. Various schemes exist to block it longterm. I have mine own notions, involving an orbital magnet. But none of that's any concern to Musk.

I was careful to say the basin would be getting those mSv's. The Martians down there won't. They will be burying their habs under rock (we'll get to muh lava-tubes), just to keep from, er, exploding in the light atmosphere. [UPDATE 5/27: - so let's don't panic.] When Martians do drive around the surface they'll be under space-suits at least. Mars' basins, further, do not have much uranium as compared to the basalt-heavy volcanoes. This takes their own radon out of the equation.

The lava-tubes, being from lava, will be more basaltic. These tubes will serve the copper-mines. Here I'd be more concerned with rads... mostly from, sigh, radon. Total Recall wins again.

Everything I just said applies also to Ganymede: 50-80 mSv/day, but surface in nonradioactive ice. (Callisto is fine.) Gany's colonies might not need that protective magnet after all. Longterm, I dunno.