10 ms·

Seems to me this article entirely misses the point. If we had sustainable industrial civilization on both Earth and Mars, then if one planet gets hit we can re

by roca 6y ago

Seems to me this article entirely misses the point. If we had sustainable industrial civilization on both Earth and Mars, then if one planet gets hit we can repopulate it from the other planet, i.e. to kill off humanity any disaster would have to hit both planets at once, and of course the probability of unguided space rocks doing this is effectively zero. I'm skeptical about the value of settling Mars myself, but the article's estimation of the probability of Mars being hit by civilization-killing rocks is pretty much irrelevant to the value of settling Mars. (And it kind of bothers me that "the director of astrobiology at Columbia University" doesn't see this. It bothers me enough to wonder whether I'm the one missing something obvious.)

pantaloony 6y ago
I can’t think of many things that make it better to be on Mars with no Earth support (even if your colony’s pretty well-developed and capable) than a survivor on Earth after a disaster other than something like a dwarf-planet-sized impactor. Climate change, nuclear war, and a dinosaur-killer asteroid combined wouldn’t do it. So-called “snowball Earth” is preferable. Earth with everywhere but the poles too hot and arid for crops is preferable. Mars is very hostile. Especially if you allow for your Earth-survivors having equipment like the Martian colonists do (far cheaper to provide, redundantly and distributed and hardened and with regular up-keep and replenishment, on Earth than on Mars). I can come up with some sci-fi scenarios, too, but as far as stuff that suddenly makes Mars better to be on than Earth and could happen today, it’s basically just super-huge impactors. Which isn’t nothing, but it’s a pretty small slice of the apocalypse pie.
- roca 6y ago
  I agree. This is why I am myself skeptical about settling Mars. Maybe there are scenarios where an Earth disaster causes breakdown of physical and intellectual supply chains and expertise/components from Mars are essential to recovering industrial civilization on Earth.
  - pantaloony 6y ago
    To be clear I think settling Mars is cool and I’m not upset if someone tries—I’d love to watch that and cheer them on. I just think the “it’s a backup for humanity” angle is, at best, pretty weak.
giantrobot 6y ago
While a K-T event might eliminate life on Earth, a Mars colony could be wiped out by a long dust storm or broken sewage system.
- pfdietz 6y ago
  The K-T event obviously didn't eliminate life on Earth.
  - giantrobot 6y ago
    For some values of life.
- rbanffy 6y ago
  Why would a long dust storm wipe out a Martian colony? I don't think plants will be grown using sunlight (which is 25% Earth's sunlight). Nuclear reactors would provide energy for years after deployment, even though sourcing local fuel would require large industrial plants. As for the broken sewage system, that's simple: build more than one. In fact, instead of one large colony, build a couple dozen smaller ones and never tax them to full capacity. It's my assumption Martians will take birth control very seriously.
  - giantrobot 6y ago
    So you're assuming a Mars colony would have a nuclear reactor(s). Setting aside for a moment what a Herculean task that would be, how would you expect a nuclear reactor work on Mars? They require massive amounts of cooling, most of a nuclear power plant is essentially the core's cooling system. There's no ready sources of water to use and the atmospheric density is a tiny fraction of Earth's. A Martian cooling tower would have to be enormous. A cooling system might have other configurations but it would still be enormous. Dust storms on Mars can last for months. While the overall wind energy isn't as high as on Earth thanks to much lower atmospheric density, Martian dust still gets everywhere. So your Martian reactors would have their cooling systems constantly covered in insulating dust. While Reactor Cooling Maintenance Technician would be an in-demand job, a long or particularly bad dust storm would doom the colony. Building a second sewage system, or any other infrastructure, isn't always practical or even possible. The problem with infrastructure on Mars is it must always work or people will die. If an infrastructure problem kills or disables enough Reactor Cooling Maintenance Technicians the colony is doomed. A broken sewer line on Earth is inconvenient to dangerous but rarely an existential problem. A broken sewer line anywhere but Earth is an existential threat at best.
kevin_thibedeau 6y ago
Earth would have to turn into a lava planet for Mars to be a better option. Antarctica is more habitable than Mars and nobody's planning to set up self-sustaining colonies there. Every technology needed to survive on Mars could be implemented far easier here no matter how bad it gets.
- Ericson2314 6y ago
  There is a treaty prohibiting antarctic colonies that expires soon. We'll see then.
  - variaga 6y ago
    The reason nations were willing to sign a treaty agreeing not to colonize the antarctic is that none of them wanted to do it anyway. Prior to the treaty, humans had already colonized every other continent, and had the means to travel to Antarctica for _thousands_ of years. If colonizing Antarctica was in any way worthwhile, someone would have done it 100s (or 1000s, or 10,000s) of years ago.
    - smegger001 6y ago
      >If colonizing Antarctica was in any way worthwhile, someone would have done it 100s (or 1000s, or 10,000s) of years ago. except technology has advanced since then.
      - Ericson2314 6y ago
        And the global warming directly cuts costs regardless of technology level.
    - xmprt 6y ago
      Maybe that's why everyone signed the treaty in the first place. They didn't have the tech but now that they do, it's worth giving it another shot.
    - dleslie 6y ago
wtetzner 6y ago
But why is preserving humanity in that case even a goal? Everyone on Earth still dies in that disaster scenario. I understand wanting to prevent people from dying in the disaster, but just letting them die and then repopulating from somewhere else just doesn't seem like a worthy goal to me.
- FabHK 6y ago
  Better that half of humanity dies than all of it.
FabHK 6y ago
I share your puzzlement. One could similarly say: "A co-pilot is, at best, no less likely to make a mistake than a captain. Why have two pilots in the cockpit then?" The author writes: > Of course, potentially halving our existential crises by doubling our presence in the solar system is not to be sniffed at [...] Having a backup planet doesn't "halve" the risk of existential crisis, just like the second pilot doesn't halve the risk of plane crash or having a backup of your main HD doesn't halve the risk of you losing all your data. It reduces it much more (assuming, as you point out, that the risks are at least somewhat independent). This is so obvious that I'm wondering whether the author just wishes to push this dream of an O’Neill cylinder habitat.
- LargoLasskhyfv 6y ago
  What's wrong with O´Neill cylinders?
titzer 6y ago
The Moon is hundreds of times closer than Mars and pretty much all the arguments for spreading our risk among two heavenly bodies still hold if we were to target the Moon instead of Mars.
- xref 6y ago
  Why does Mars get so much more press than the moon? I guess it has a bit more gravity, 37% of Earth vs 17% for the moon. We can’t survive in either atmosphere. Temperature differentials on mars are less extreme? That seems like the least of the engineering problems however.
  - roca 6y ago
    Mars has more Earth-like gravity (should be significantly better for humans). It has a lot more water. It has a 25-ish hour day instead of 4-week day. (The latter may not matter to humans since we'd have to be inside most of the time anyway, but it matters for things like solar power.) Mars temperature is much better. I'm still not saying we should settle Mars first, but it does have some real advantages.
    - titzer 6y ago
      That 9 month trip is a real killer, though. No dust storms on the moon, and solar power is way more efficient than on Mars. See, e.g. how weak rovers are overall, despite having the best engineered solar panels that money could buy. Solar energy is only about 600Wm^-2 there versus more than double that on Earth. The Moon also has no atmosphere to scatter blue and UV light. Mars is a terrible idea for a long-term colony, IMHO.
    - LargoLasskhyfv 6y ago
      Why wouldn't space based solar power work for the moon, when the concept is discussed for earth? [2] https://en.wikipedia.org/wiki/Space-based_solar_power https://en.wikipedia.org/wiki/Space-based_solar_power Only thing i can think of are decaying orbits because of irregular mass distribution. But when thinking of such concepts, why not plan for some station keeping expendables? It's not like were talking about some feeble pebbles thrown into orbit there like we have done up until now...

by roca 6y ago

pantaloony 6y ago

I can’t think of many things that make it better to be on Mars with no Earth support (even if your colony’s pretty well-developed and capable) than a survivor on Earth after a disaster other than something like a dwarf-planet-sized impactor. Climate change, nuclear war, and a dinosaur-killer asteroid combined wouldn’t do it. So-called “snowball Earth” is preferable. Earth with everywhere but the poles too hot and arid for crops is preferable. Mars is very hostile. Especially if you allow for your Earth-survivors having equipment like the Martian colonists do (far cheaper to provide, redundantly and distributed and hardened and with regular up-keep and replenishment, on Earth than on Mars). I can come up with some sci-fi scenarios, too, but as far as stuff that suddenly makes Mars better to be on than Earth and could happen today, it’s basically just super-huge impactors. Which isn’t nothing, but it’s a pretty small slice of the apocalypse pie.

roca 6y ago
I agree. This is why I am myself skeptical about settling Mars. Maybe there are scenarios where an Earth disaster causes breakdown of physical and intellectual supply chains and expertise/components from Mars are essential to recovering industrial civilization on Earth.
- pantaloony 6y ago
  To be clear I think settling Mars is cool and I’m not upset if someone tries—I’d love to watch that and cheer them on. I just think the “it’s a backup for humanity” angle is, at best, pretty weak.

giantrobot 6y ago

While a K-T event might eliminate life on Earth, a Mars colony could be wiped out by a long dust storm or broken sewage system.

pfdietz 6y ago
The K-T event obviously didn't eliminate life on Earth.
- giantrobot 6y ago
  For some values of life.
rbanffy 6y ago
Why would a long dust storm wipe out a Martian colony? I don't think plants will be grown using sunlight (which is 25% Earth's sunlight). Nuclear reactors would provide energy for years after deployment, even though sourcing local fuel would require large industrial plants. As for the broken sewage system, that's simple: build more than one. In fact, instead of one large colony, build a couple dozen smaller ones and never tax them to full capacity. It's my assumption Martians will take birth control very seriously.
- giantrobot 6y ago
  So you're assuming a Mars colony would have a nuclear reactor(s). Setting aside for a moment what a Herculean task that would be, how would you expect a nuclear reactor work on Mars? They require massive amounts of cooling, most of a nuclear power plant is essentially the core's cooling system. There's no ready sources of water to use and the atmospheric density is a tiny fraction of Earth's. A Martian cooling tower would have to be enormous. A cooling system might have other configurations but it would still be enormous. Dust storms on Mars can last for months. While the overall wind energy isn't as high as on Earth thanks to much lower atmospheric density, Martian dust still gets everywhere. So your Martian reactors would have their cooling systems constantly covered in insulating dust. While Reactor Cooling Maintenance Technician would be an in-demand job, a long or particularly bad dust storm would doom the colony. Building a second sewage system, or any other infrastructure, isn't always practical or even possible. The problem with infrastructure on Mars is it must always work or people will die. If an infrastructure problem kills or disables enough Reactor Cooling Maintenance Technicians the colony is doomed. A broken sewer line on Earth is inconvenient to dangerous but rarely an existential problem. A broken sewer line anywhere but Earth is an existential threat at best.

kevin_thibedeau 6y ago

Earth would have to turn into a lava planet for Mars to be a better option. Antarctica is more habitable than Mars and nobody's planning to set up self-sustaining colonies there. Every technology needed to survive on Mars could be implemented far easier here no matter how bad it gets.

Ericson2314 6y ago
There is a treaty prohibiting antarctic colonies that expires soon. We'll see then.
- variaga 6y ago
  The reason nations were willing to sign a treaty agreeing not to colonize the antarctic is that none of them wanted to do it anyway. Prior to the treaty, humans had already colonized every other continent, and had the means to travel to Antarctica for _thousands_ of years. If colonizing Antarctica was in any way worthwhile, someone would have done it 100s (or 1000s, or 10,000s) of years ago.
  - smegger001 6y ago
    >If colonizing Antarctica was in any way worthwhile, someone would have done it 100s (or 1000s, or 10,000s) of years ago. except technology has advanced since then.
    - Ericson2314 6y ago
      And the global warming directly cuts costs regardless of technology level.
  - xmprt 6y ago
    Maybe that's why everyone signed the treaty in the first place. They didn't have the tech but now that they do, it's worth giving it another shot.
  - dleslie 6y ago

wtetzner 6y ago

But why is preserving humanity in that case even a goal? Everyone on Earth still dies in that disaster scenario. I understand wanting to prevent people from dying in the disaster, but just letting them die and then repopulating from somewhere else just doesn't seem like a worthy goal to me.

FabHK 6y ago
Better that half of humanity dies than all of it.

FabHK 6y ago

I share your puzzlement. One could similarly say: "A co-pilot is, at best, no less likely to make a mistake than a captain. Why have two pilots in the cockpit then?" The author writes: > Of course, potentially halving our existential crises by doubling our presence in the solar system is not to be sniffed at [...] Having a backup planet doesn't "halve" the risk of existential crisis, just like the second pilot doesn't halve the risk of plane crash or having a backup of your main HD doesn't halve the risk of you losing all your data. It reduces it much more (assuming, as you point out, that the risks are at least somewhat independent). This is so obvious that I'm wondering whether the author just wishes to push this dream of an O’Neill cylinder habitat.

LargoLasskhyfv 6y ago
What's wrong with O´Neill cylinders?

titzer 6y ago

The Moon is hundreds of times closer than Mars and pretty much all the arguments for spreading our risk among two heavenly bodies still hold if we were to target the Moon instead of Mars.

xref 6y ago
Why does Mars get so much more press than the moon? I guess it has a bit more gravity, 37% of Earth vs 17% for the moon. We can’t survive in either atmosphere. Temperature differentials on mars are less extreme? That seems like the least of the engineering problems however.
- roca 6y ago
  Mars has more Earth-like gravity (should be significantly better for humans). It has a lot more water. It has a 25-ish hour day instead of 4-week day. (The latter may not matter to humans since we'd have to be inside most of the time anyway, but it matters for things like solar power.) Mars temperature is much better. I'm still not saying we should settle Mars first, but it does have some real advantages.
  - titzer 6y ago
    That 9 month trip is a real killer, though. No dust storms on the moon, and solar power is way more efficient than on Mars. See, e.g. how weak rovers are overall, despite having the best engineered solar panels that money could buy. Solar energy is only about 600Wm^-2 there versus more than double that on Earth. The Moon also has no atmosphere to scatter blue and UV light. Mars is a terrible idea for a long-term colony, IMHO.
  - LargoLasskhyfv 6y ago
    Why wouldn't space based solar power work for the moon, when the concept is discussed for earth? [2] https://en.wikipedia.org/wiki/Space-based_solar_power https://en.wikipedia.org/wiki/Space-based_solar_power Only thing i can think of are decaying orbits because of irregular mass distribution. But when thinking of such concepts, why not plan for some station keeping expendables? It's not like were talking about some feeble pebbles thrown into orbit there like we have done up until now...