Why would a city on Mars avoid Armageddon?

<self-sustaining colony on Mars because the idea that an Earth-dependent martian city might improve odds of survival does not make much sense at all, imo.>>

Sure, that could happen but expanding to Mars would improve the odds of survival (because an extinction event on both planets simultaneously is less likely than one just on Earth). Earth is currently a so-called "single point of failure" (SPOF)[0] for humanity and all forms of life that we know of.

If we spread humanity and life to Mars and beyond (in an independent/self-sustaining way and not just as an outpost that depends on Earth), neither of the planets alone is SPOF anymore. The solar system is still SPOF but even the close galactic neighbourhood might not be of much help against events that threaten the solar system as a whole (see e.g. about the effects of a gamma-ray burst [1] in our 'proximity'. Note when reading [1] that 1 kiloparsec = 3200 light years! [2]).

[0] https://en.wikipedia.org/wiki/Single_point_of_failure

[1] https://en.wikipedia.org/wiki/Gamma-ray_burst#Effects_on_Ear...

[2] https://en.wikipedia.org/wiki/Parsec

Addressed in Ray Bradbury's novel The Martian Chronicles (1950).

In Bradbury's story, the vast majority of residents of the Martian colonies returned back to Earth when (atomic) war was imminent, leaving Mars all but deserted, and the Earth destroyed.

I found this hard to believe, but this set up a really cool ending.

Before to colonize mars there is a thing that we as species could, or should probably do (in my arrogant opinion), and is to put a copy of security of the human species in the moon, in form of a few boxes full of frozen reproductive cells. Maybe also copies from a few animals that are really essential to us as wolves, red jungle fowl or horses. If we can put it in the moon, we can put it in Mars, and that would be the cheaper way to put a significant amount of people in the planet Mars. This will be needed either to replace the people that will die in accidents in a such hostile environment, or to replace fast people killed in a massive catastrophic event in the earth, like a nuclear winter period and to alleviate the effect of bottle neck genetic periods in humans. We had some in the past.

The problem is that would grant like 30 years of safety. Maybe. Not much more, but could be enough.

This is a theme in the Mars Trilogy series. Without spoiling anything, I think the timeline can make a difference. If Armageddon happens far enough into the future on earth, Mars might have become independent. The population of Mars might also feel detached from the events, just like we in the West don't care too much about military coups in smaller countries.

I don't think "a backup copy of humanity" is the best argument for space settlement. It's not necessarily wrong, but it's not the strongest and you are correct that it's not foolproof.

The best argument is that frontiers are where innovation happens, and where outsiders can migrate as a "pressure valve" for civilization. Without a frontier there is nowhere to try new things and it's impossible to challenge existing norms without fighting. No frontier means either eternal stagnation or eternal war. (War can take the form of either overt violence or constant political turmoil.)

https://en.wikipedia.org/wiki/Frontier_thesis

I don't think it's a coincidence that sci-fi that posits a frontier (generally space but sometimes others) is usually more optimistic than sci-fi that posits a humanity confined to Earth's gravity well. Writers and artists see this.

We are rapidly approaching a state in which the entire planet is settled, surveilled, and regulated. This is unprecedented in human history, and I think it's going to be fairly dystopian. I can only see two possible outcomes: absolutely total global surveillance state or a global "failed state" resembling a dystopian cyberpunk anarchy like Stephenson's Snow Crash. They're not mutually exclusive; the first could lead to the second.

I don't think it's feasible to reverse this trend. It's a natural outcome of humanity's growth and technological advancement. Pushing out to a new frontier is really the only option.

The time to travel from Earth to Mars is about 8 month. They'll have plenty of time to launch some intercepting mission.

I feel like I've missed some context here. Currently we do not have a city on Mars, nor have we developed nuclear missiles which can deliver a payload to Mars. I'm sure that such a thing is within our grasp, but a military still has to be incentivized to build an interplanetary nuclear weapon stead of spending that defense budget elsewhere. If the martian cities cannot strike from Mars, then there is little incentive to building the capability to destroy them.

Anyhow, what are we talking about here? Why did the topic of Mars and avoiding nuclear armageddon come up?

To propose we go to Mars to protect the species is backward. People with the means want to go to Mars to show off or other personal reasons. Then they drum up some humanitarian-sounding reason for government and popular support.

If we could prove beyond shadow of a doubt that no dangerous asteroids would hit Earth for a million years and that pursuing Mars accelerated our environmental problems here, I don't doubt that the same people would come up with new justifications and keep going, even if counterproductive.

100 times worse than living on Mt. Everest. Maybe build a nuclear shelter on earth?

It's not about saving humanity or saving consciousness or all that BS.

It's about a very selfish 1st world problem:

Seeking thrill and also not to be discounted the willingness to feel special. Everyday we see and interact with so many people, we have also internalized the concept of being one unit in a 8B sample and that hurts our ego as we want to feel unique and irreplacable.

People hope to find that in a small Mars community, feeling irreplaceable both on a conceptual level as well as a practical level (meaning for the operation of the colony).

It takes ~1 months at quickest approach. This pretty much eliminates any biological pandemic level issues.

War on Mars will also be something else. Canadians understand this all too well. You're far enough from everything to make you not a target. Life on Mars will be precarious for everyone far worse than the mutually assured destruction that prevents it happening on Earth.

It doesnt eliminate all issues, but it certainly eliminates lots of issues.

For the Moon-Earth war, read "The Moon is a Harsh Mistress" by Robert Heinlein.

For the Earth, Mars, and Asteroid belt conflict, watch "The Expanse".

This question presupposes a lot and it's a deep topic so I don't want to get lost in the weeds.

Your question, I assume, is based on the idea that humans may well colonize Mars and one of reasons for doing so is to increase humanity's chance of survival an otherwise extinction-level event.

It's worth pointing out that nuclear war is just one of many potential extinction level events. Even then, nuclear war in particular is unlikely to exterminate the entire species. Another where colonizing Mars would help is, say, a massive body impacting Earth.

But stepping back, colonizing Mars is largely a romantic notion, not a logical one. People imagine themselves walking on Mars but there are severe problems with this:

1. Gravity is much lower than Earth. It's roughly similar to the Moon. It's unclear how we'd deal with living in low-gee like this on an indefinite basis;

2. Mars has an atmosphere but it's actually worse than no atmosphere in many ways. It's barely above vacuum so you can't breathe it, even if it was the right gas mix (which of course it isn't). All it really does is stir up dust to cover all your above-ground installations. Solar panels are likely to be one of these so you can't really avoid it. Dirt and dust on Earth have been eroded by eons of wind and water. Not so on Mars. Martian dust is jagged and "sticky" as a result. So it's more annoying.

3. Mars has no protection from solar radiation unlike Earth (ie the Van Allen belt / magnetosphere); and

4. Even though gravity is lower, getting into and out of the gravity well is still a considerable issue, particularly given the lower atmosphere doesn't have the same potential for aerobraking as Earth's atmosphere does.

For nuclear war in particular, a political entity may well also exist on Mars that will make a nuclear strike. You'd likely get more warning since Earth's superpowers have quick strike capability from nuclear attack submarines that can be positioned off the coast of major cities. Mars of course has no oceans so you're talking air or ground vehicles or ground installations.

Nuclear missiles could come from Earth but you'd get a lot of warning for this (weeks to months) and this wouldn't be cheap.

Personally I'm convinced the future of spacefaring humans is in orbitals not on other moons or worlds.

To some extent, this is the overarching theme of the second season of For All Mankind; you may find it interesting.

If it were a self-sustaining colony, within a couple generations basically everyone would be everyone else's cousin. That would probably reduce the impetus for major war as opposed to family drama.

Mars city is irrelevant. What matters is self sustaining spaceships.

Exactly. This is why I am pro exploration but not colonization. At least not until we can terraform. Colonizing mars now would be a huge waste of resources.

If we are on Mars likely we'll be in space habitats very shortly thereafter.

So it's more a signifier of diaspora on space than about a single Mars city

All this effort to avoid the collapse of human civilization seems misplaced. Protecting humanity from calamity is only necessary if humanity serves a purpose. Would you back up computer data that is of no use to anyone? Of course not. The fact that something exists does not justify going to extraordinary lengths to preserve it.

Uniqueness does not make something useful or worth preserving, either.

As individuals, we all expire at some point. Is there a reason to think that humanity should be any different?

Forget nuclear war. If Mars was used to test bio-weapons or nanotech weapons then it could leak onto earth by accident.

How likely is it that a life-destroying Gamma Ray Burst hitting Earth would spare Mars ?

Probably because there would be no humans.