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I don't really agree with that at all. You need not only nukes on Mars but multiple advanced and adversarial colonies with nukes for MAD to be a thing. And C&C

I don't really agree with that at all. You need not only nukes on Mars but multiple advanced and adversarial colonies with nukes for MAD to be a thing. And C&C with a 40 minute round trip latency is not happening. Kind of problematic when the most probable way we get into nuclear war is a country convincing itself it can successfully execute a decapitation strike. Then you'd also need to know a lot like how nukes would even work on Mars. Dramatically lower atmospheric pressure, amongst other things, will mean nukes will function dramatically differently and be substantially less dangerous. You're looking at dramatically reduced shock/blast waves, less of a threat of fallout (since environmental exposure is already lethal), and so on. It's another great argument for expansion - each colony will have to deal with different situations, which makes various threats - less threatening. For another example, a directed gamma ray burst could be catastrophic on Earth, and is one hypothesis for the Great Ordovician Extinction, but on Mars it would almost entirely harmless.

ben_w 2y ago
There's no such thing as an unarmed spaceship. The capacity to gently land 150 tons on the surface of Mars, is also the capacity to make 150 tons land at, at least, Martian escape velocity — equivalent to an explosion of 411 tons of TNT. Doesn't matter if it's RFGs instead of nukes, the people are just as dead. And any belligerents during a nuclear war on Earth will have grounds to presume second-strike capability exists on any affiliated off-planet colony, so will be motivated to attack those colonies as part of the nuclear war on Earth. > For another example, a directed gamma ray burst could be catastrophic on Earth, and is one hypothesis for the Great Ordovician Extinction, but on Mars it would almost entirely harmless. Are you sure? I thought even exceptionally focussed GRBs were about 0.1°, and that angle corresponds to maximal Earth-Mars separation at just 0.025 light years, at which point I'd be more worried about the gravitational pull of the GRB star removing both Earth and Mars from Sol orbit.
- somenameforme 2y ago
  The biggest threat of things like gamma ray bursts, supervolcanos, asteroid impacts, etc are not the immediate effects. Those effects are dangerous but in a very localized area. The bigger threat is the indirect consequences. For gamma ray bursts, they would deplete the ozone allowing lethal levels of UV through. But on top of this chemical reactions in the atmosphere would produce nitrogen dioxide which itself is poisonous but far more dangerous is that it's basically smog - it would block out the sun driving a massive cooling and potentially impairing photosynthesis resulting in a cycle of death on up the food chain, starting at plants. On Mars its effect would be largely inconsequential.
  - defrost 2y ago
    Maybe specific Gamma Ray Bursts close by, in general we've already seen at least 16 GRB's in the lifespan of the early Vela satellites and survived those just fine. There are a few books on the subject: eg. https://books.google.com.au/books?id=6mGGX6AGBTAC https://books.google.com.au/books?id=6mGGX6AGBTAC I'd venture the biggest threat of a GRB not dampened by distance would be the explosive event that caused a sun to release as much energy in a few seconds as our Sun will in its entire 10-billion-year lifetime.
    - somenameforme 2y ago
      GRBs happen relatively frequently. GRBs that end up orientated directly towards Earth do not.
  - ben_w 2y ago
    > On Mars its effect would be largely inconsequential. No. A GRB strong enough to reduce Earth's ozone layer by half, would be about 100 kJ/m^2: https://ntrs.nasa.gov/api/citations/20050179464/downloads/20050179464.pdf https://ntrs.nasa.gov/api/citations/20050179464/downloads/20... On Mars, where there's no ozone layer in the first place, and the atmosphere is much thinner, and there's no magnetosphere, IIRC just over half the radiation from a GRB reaches the ground. Given a human cross-sectional area from above is about 0.25 m^2, that means that a human outside during such an event would get 25 kJ almost entirely absorbed by their body. A lethal dose for a 100 kg human is about 1 kJ absorbed. And when I say "lethal", 1 kJ absorbed is 99%+ lethal within 2-14 days, even with immediate treatment, and the victim suffers rapid incapacitation due to CNS failure. You'd need to bury everyone under, IIRC, 2-3 meters of regolith to protect against that. You'd also need your crops underground for the same reason. If you're going to all the trouble to have a farm functioning under several meters of soil, you can also do the same things needed for that, on Earth, far more cheaply. Furthermore, the nitrogen dioxide levels expected in such an event, would reduce Earth surface sunlight levels by 10-60%. Mars, just by being further from the Sun, gets a reduction of 48-64% (varies over the Martian year) relative to Earth — even when there's no planet-spanning dust storms, which it also gets.
JumpCrisscross 2y ago
> You need not only nukes on Mars In a world with colonies, those colonies become nuclear targets. You may not even have to expend a juke—just ram a ship into it. My point is that the same logistics that would sustain a Martian colony make striking it easier. Mars isn’t a solution to war on Earth. It’s a long-term insurance policy against planet-wrecking accidents, whether natural or human. As for viruses, it’s like someone millennia ago arguing that humans expanding to more continents reduces the risk of disease. Yes, for a bit. But the same factors that enable that expansion make global pandemics possible.
- somenameforme 2y ago
  Even on Earth colonies would be unlikely to be targeted. Nukes are limited, valuable, and going to be expended on targets in order of priority. For instance Peurto Rico would be extremely unlikely to be a target because it's just a completely worthless target in spite of having millions of Americans. Even from a morale crushing perspective, Americans do not consider Puerto Ricans Americans, in the same way that 'Martian Americans' will not be considered Americans for those living stateside. You'd achieve nothing.

ben_w 2y ago

There's no such thing as an unarmed spaceship. The capacity to gently land 150 tons on the surface of Mars, is also the capacity to make 150 tons land at, at least, Martian escape velocity — equivalent to an explosion of 411 tons of TNT. Doesn't matter if it's RFGs instead of nukes, the people are just as dead. And any belligerents during a nuclear war on Earth will have grounds to presume second-strike capability exists on any affiliated off-planet colony, so will be motivated to attack those colonies as part of the nuclear war on Earth. > For another example, a directed gamma ray burst could be catastrophic on Earth, and is one hypothesis for the Great Ordovician Extinction, but on Mars it would almost entirely harmless. Are you sure? I thought even exceptionally focussed GRBs were about 0.1°, and that angle corresponds to maximal Earth-Mars separation at just 0.025 light years, at which point I'd be more worried about the gravitational pull of the GRB star removing both Earth and Mars from Sol orbit.

somenameforme 2y ago
The biggest threat of things like gamma ray bursts, supervolcanos, asteroid impacts, etc are not the immediate effects. Those effects are dangerous but in a very localized area. The bigger threat is the indirect consequences. For gamma ray bursts, they would deplete the ozone allowing lethal levels of UV through. But on top of this chemical reactions in the atmosphere would produce nitrogen dioxide which itself is poisonous but far more dangerous is that it's basically smog - it would block out the sun driving a massive cooling and potentially impairing photosynthesis resulting in a cycle of death on up the food chain, starting at plants. On Mars its effect would be largely inconsequential.
- defrost 2y ago
  Maybe specific Gamma Ray Bursts close by, in general we've already seen at least 16 GRB's in the lifespan of the early Vela satellites and survived those just fine. There are a few books on the subject: eg. https://books.google.com.au/books?id=6mGGX6AGBTAC https://books.google.com.au/books?id=6mGGX6AGBTAC I'd venture the biggest threat of a GRB not dampened by distance would be the explosive event that caused a sun to release as much energy in a few seconds as our Sun will in its entire 10-billion-year lifetime.
  - somenameforme 2y ago
    GRBs happen relatively frequently. GRBs that end up orientated directly towards Earth do not.
- ben_w 2y ago
  > On Mars its effect would be largely inconsequential. No. A GRB strong enough to reduce Earth's ozone layer by half, would be about 100 kJ/m^2: https://ntrs.nasa.gov/api/citations/20050179464/downloads/20050179464.pdf https://ntrs.nasa.gov/api/citations/20050179464/downloads/20... On Mars, where there's no ozone layer in the first place, and the atmosphere is much thinner, and there's no magnetosphere, IIRC just over half the radiation from a GRB reaches the ground. Given a human cross-sectional area from above is about 0.25 m^2, that means that a human outside during such an event would get 25 kJ almost entirely absorbed by their body. A lethal dose for a 100 kg human is about 1 kJ absorbed. And when I say "lethal", 1 kJ absorbed is 99%+ lethal within 2-14 days, even with immediate treatment, and the victim suffers rapid incapacitation due to CNS failure. You'd need to bury everyone under, IIRC, 2-3 meters of regolith to protect against that. You'd also need your crops underground for the same reason. If you're going to all the trouble to have a farm functioning under several meters of soil, you can also do the same things needed for that, on Earth, far more cheaply. Furthermore, the nitrogen dioxide levels expected in such an event, would reduce Earth surface sunlight levels by 10-60%. Mars, just by being further from the Sun, gets a reduction of 48-64% (varies over the Martian year) relative to Earth — even when there's no planet-spanning dust storms, which it also gets.

JumpCrisscross 2y ago

> You need not only nukes on Mars In a world with colonies, those colonies become nuclear targets. You may not even have to expend a juke—just ram a ship into it. My point is that the same logistics that would sustain a Martian colony make striking it easier. Mars isn’t a solution to war on Earth. It’s a long-term insurance policy against planet-wrecking accidents, whether natural or human. As for viruses, it’s like someone millennia ago arguing that humans expanding to more continents reduces the risk of disease. Yes, for a bit. But the same factors that enable that expansion make global pandemics possible.

somenameforme 2y ago
Even on Earth colonies would be unlikely to be targeted. Nukes are limited, valuable, and going to be expended on targets in order of priority. For instance Peurto Rico would be extremely unlikely to be a target because it's just a completely worthless target in spite of having millions of Americans. Even from a morale crushing perspective, Americans do not consider Puerto Ricans Americans, in the same way that 'Martian Americans' will not be considered Americans for those living stateside. You'd achieve nothing.