21 votes

Why not Mars

34 comments

  1. skybrian
    Link
    From the essay: [...] [...] [...] (I omitted all the footnotes; see the blog post for them.)

    From the essay:

    [...] fifty years of progress in miniaturization and software changed the balance between robots and humans in space. Between 1960 and 2020, space probes improved by something like six orders of magnitude, while the technologies of long-duration spaceflight did not. Boiling the water out of urine still looks the same in 2023 as it did in 1960, or for that matter 1060. Today’s automated spacecraft are not only strictly more capable than human astronauts, but cost about a hundred times less to send (though it’s hard to be exact, since astronauts have not gone anywhere since 1972).

    The imbalance between human and robot is so overwhelming that, despite the presence of a $250 billion International Space Station National Laboratory, every major discovery made in space this century has come from robotic spacecraft. In 2023, we simply take it for granted that if a rocket goes up carrying passengers, it’s not going to get any work done.

    [...]

    The fact that we failed to notice 99.999% of life on Earth until a few years ago is unsettling and has implications for Mars. The existence of a deep biosphere in particular narrows the habitability gap between our planets to the point where it probably doesn’t exist—there is likely at least one corner of Mars that an Earth organism could call home. It also adds support to the theory that life may have started as an interplanetary infection, a literal Venereal disease that spread across the early solar system by meteorite. If that is the case, and if our distant relatives are still alive in some deep Martian cave, then just about the worst way to go looking for them would be to land in a septic spacecraft.

    [...]

    The chief technical obstacle to a Mars landing is not propulsion, but a lack of reliable closed-loop life support. With our current capability, NASA would struggle to keep a crew alive for six months on the White House lawn, let alone for years in a Martian yurt.

    The technology program required to close this gap would be remarkably circular, with no benefits outside the field of applied zero gravity zookeeping. The web of Rube Goldberg devices that recycles floating animal waste on the space station has already cost twice its weight in gold and there is little appetite for it here on Earth, where plants do a better job for free.

    I would compare keeping primates alive in spacecraft to trying to build a jet engine out of raisins. Both are colossal engineering problems, possibly the hardest ever attempted, but it does not follow that they are problems worth solving. In both cases, the difficulty flows from a very specific design constraint, and it’s worth revisiting that constraint one or ten times before starting to perform miracles of engineering.

    [...]

    Even if you don’t care about contamination, NASA is required by treaty to care, and that has severe consequences for mission design. It means human landing sites will intentionally be kept far from anything interesting. The phenomena of greatest scientific interest on Mars (gullies, recurrent slope lineae, intermittent methane sources, and underground water) will all be off-limits to astronauts. So will terrain features like caves or lava tubes that could conceivably shelter life. The crew will not live in a Martian pueblo, but something resembling a level 4 biocontainment facility. And even there, they’ll have to do their lab work remotely, the same way it’s done today, raising the question of what exactly the hundreds of billions of dollars we’re spending to get to Mars are buying us.

    (I omitted all the footnotes; see the blog post for them.)

    8 votes
  2. [5]
    nothis
    Link
    The only thing that makes me hesitate about the article is the dismissal of "port-a-potty chemistry engineering". It might not be exciting, but it's as real as any engineering out there, maybe...

    That’s my case against Mars in a nutshell: it comes front-loaded with expensive research, the engineering is mostly port-a-potty chemistry, and the best-case outcome is that thirty years from now, we’ll get to watch someone remotely operate a soil scoop from Mars instead of Pasadena.

    The only thing that makes me hesitate about the article is the dismissal of "port-a-potty chemistry engineering". It might not be exciting, but it's as real as any engineering out there, maybe more so than most.

    I'd agree, to a point, that a lot of arguments for making Mars our "backup planet" in case of an extinction event are just excuses to make giddy and emotional excitement about space travel sound serious and rational. But one take is that it's not the journey itself that brings the most benefits, but the many scientific/engineering advancements that it inspires and one of those is, yes, making humans able to survive in pretty much any environment. There's much ridicule for sending a "terrarium" to Mars in this article but I do think that having the technology to seal a bunch of people in a hermetic tube for years and allowing them to survive in a self-sustaining environment is a goal worth pursuing. How about having a bit of an imagination: New ways of food production, new forms of long-term food storage, chemistry for recycling and reusing waste, more convenient 3d printing innovations for producing arbitrary tools while just having to bring along the raw materials, new ways to deal with air pressure, sand storms, radiation...

    We're talking about a couple hundred billion dollars. If this was all it needed to end world hunger, kill cancer and create world peace, we'd long have achieved it. I mean, theoretically, it might, but the problem is getting people together to actually use that money in a shared effort. Taking people to Mars might actually be an effort of that scale and that alone is worth something. It requires people to be smart, work together, find solutions to problems, be innovative, be more efficient. What else do we have that is this hard where the enemy is physics and engineering (things we can actually solve) rather than politics (which tends to work best when people are distracted by a goal that does not involve hating each other).

    7 votes
    1. [3]
      skybrian
      Link Parent
      Yes. I'm fascinated by the idea of making closed ecosystems. Biosphere 2 has a controversial history and was something of a stunt, but I support more research along those lines. I think the...

      Yes. I'm fascinated by the idea of making closed ecosystems. Biosphere 2 has a controversial history and was something of a stunt, but I support more research along those lines.

      I think the research could be done much more cheaply on Earth, though? When we're successful at making closed ecosystems here, it will be time to try it in other places.

      A related idea is making small, self-sufficient economies that don't trade with anyone, like on an island somewhere. Even without being a self-contained ecosystem, I think it would be tremendously ambitious to try to do this while maintaining anything like a modern way of life.

      2 votes
      1. nothis
        Link Parent
        Yea, I guess this is what the question comes down to. I don't know how to get a precise answer to that. I just think having a larger goal feels like it might help, and IMO it is a "feely" question...

        I think the research could be done much more cheaply on Earth, though?

        Yea, I guess this is what the question comes down to. I don't know how to get a precise answer to that.

        I just think having a larger goal feels like it might help, and IMO it is a "feely" question since this has more to do with psychology than economics or engineering. How do you get people to work on things? Whatever the cost, it's in realms so absurd I don't think you can just do simple math (i.e. "one million starship-screws = 100,000 people vaccinated in Africa"). Pushing all that money onto earth-projects would dilute it since there's too many conflicting interests, too much bureaucracy, logistics problems, etc. A mission to Mars would be one project, one goal, probably confined to a handful of labs and offices.

        I mean, yea, all of this is mushy as a concept, I just don't think treating it as a cold-hard-facts kind of issue is doing it justice.

        4 votes
      2. rosco
        Link Parent
        Plus if we did get them functional we could use them to maintain ecosystems that are critically endangered.

        I think the research could be done much more cheaply on Earth, though? When we're successful at making closed ecosystems here, it will be time to try it in other places.

        Plus if we did get them functional we could use them to maintain ecosystems that are critically endangered.

        1 vote
    2. papasquat
      Link Parent
      Agreed, but there are a lot of other, more affordable, less dangerous ways to achieve this.

      I do think that having the technology to seal a bunch of people in a hermetic tube for years and allowing them to survive in a self-sustaining environment is a goal worth pursuing.

      Agreed, but there are a lot of other, more affordable, less dangerous ways to achieve this.

      1 vote
  3. [4]
    DrStone
    (edited )
    Link
    From the About section of the site: Puts a lot of the snark, dismissiveness, and confidence while speaking at length on a massive interdisciplinary endeavor completely outside their wheelhouse...

    From the About section of the site:

    My name is Maciej Cegłowski, I'm an ex-painter and computer guy. I live in San Francisco.

    This site is a collection of blog posts and short essays I've been writing since 2002. These are mainly about travel and food.

    Puts a lot of the snark, dismissiveness, and confidence while speaking at length on a massive interdisciplinary endeavor completely outside their wheelhouse [edit - added following clause] into perspective

    6 votes
    1. cfabbro
      (edited )
      Link Parent
      Maciej is being pretty humble and intentionally vague (likely for humorous effect) in that About section. He is a reasonably well known figure in the tech world, especially due to how many...

      Maciej is being pretty humble and intentionally vague (likely for humorous effect) in that About section. He is a reasonably well known figure in the tech world, especially due to how many conferences he is invited to speak at on a very wide range of subjects related to technology, computing, data collection, privacy laws, social media, etc. He has also been asked to speak before Congress several times on issues related to the above.

      But you're not wrong that he is definitely operating well outside his wheelhouse with this particular essay... which, as a result, is not one of his better or more persuasive ones, IMO.

      5 votes
    2. [2]
      skybrian
      Link Parent
      Isn't your reply also pretty dismissive? It would be interesting to hear from experts about what he got wrong, but I don't think the imagined reaction of hypothetical experts counts as a rebuttal....

      Isn't your reply also pretty dismissive? It would be interesting to hear from experts about what he got wrong, but I don't think the imagined reaction of hypothetical experts counts as a rebuttal.

      Apart from writing style, it's a good effort and there are plenty of footnotes for following up if you're interested in reading further.

      4 votes
      1. DrStone
        (edited )
        Link Parent
        Without giving too much personal away, I have a formal background in one of the related hard science/engineering fields and have worked a while in the web programming industry after a career...

        Without giving too much personal away, I have a formal background in one of the related hard science/engineering fields and have worked a while in the web programming industry after a career switch.

        While Maciej may be very knowledgeable about computers, art, and their intersections (thanks @cfabbro for the info), he comes off here fitting the stereotype of arrogant SF tech guy that I’d expect to see in the HN comment section. I’ve met plenty like that, and I’m sure I have been guilty of the same overconfidence on more than one occasion. It’s a bit different when it translates to lengthy, emphatic essays for public consumption.

        Others have already brought up some points where he’s dismissed or belittled organizations, sources of important advancements, and interesting science - and there’s plenty more in the essay.

        At this point, I don’t feel I have been overly dismissive of this essay.

        9 votes
  4. [3]
    DanBC
    Link
    Nobody ever mentions the electrostatic dust. I can't use it as a shiboleth because even NASA rarely mentions it. But I'd like to see someone tackle it.

    Nobody ever mentions the electrostatic dust. I can't use it as a shiboleth because even NASA rarely mentions it. But I'd like to see someone tackle it.

    5 votes
    1. [2]
      skybrian
      Link Parent
      Is this what you mean?

      Is this what you mean?

      The lunar surface is covered by a layer of dust particles called regolith. These dust particles can be stirred up during robotic and human exploration activities or released by natural processes such as meteorite impacts. Apollo astronauts noted that lunar dust particles readily stuck to surfaces such as spacesuits, optical lenses, and thermal blankets, causing numerous problems. Apollo mission spacesuits were damaged by abrasive lunar dust and several astronauts noted that moon dust was resistant to cleaning efforts; even vigorous brushing could not remove it.

      4 votes
      1. DanBC
        Link Parent
        Yes! It happens on Mars as well as the Moon, and it's going to make things like solar panels a bit tricky to use and maintain for a long time.

        Yes! It happens on Mars as well as the Moon, and it's going to make things like solar panels a bit tricky to use and maintain for a long time.

        2 votes
  5. [4]
    nukeman
    Link
    Meant to type this up weeks ago. I disagree with the article, although it makes some good points, and I’ve seen similar pro-probe arguments made before. With respect to life support system R&D,...

    Meant to type this up weeks ago. I disagree with the article, although it makes some good points, and I’ve seen similar pro-probe arguments made before.

    With respect to life support system R&D, it’s a catch-22. No planned manned mission to Mars discourages funding for such research, which makes a Mars mission harder, which further discourages funding. Why spend all the money when you can just lifeboat the crew if there’s an emergency on the ISS?

    To get life support systems to where they need to be, there needs to be a focused development program, along the lines of Biosphere 3 -> LEO Habitat -> Lunar Habitat -> Mars Habitat. This needs to be linked with a long-term program for a mission to Mars.

    One concern it have with the authors arguments is that they seem to think all the money we’d spend on a manned Mars mission would go to several probe missions. Some might, but the bulk of it would get divided up for other missions in NASA, or be dragged away to outside the agency. Manned missions have a political staying power that unmanned ones don’t.

    Finally, a manned mission can improve unmanned missions. A base on Mars or in Martian orbit significantly reduces latency in communicating with probes, potentially allowing for more complex missions without having to pre-program every maneuver.

    5 votes
    1. [3]
      skybrian
      Link Parent
      It seems like this assumes that the public (as represented by Congress) has its heart set on Mars and couldn't be convinced that other space missions are cool in themselves, rather than just as a...

      It seems like this assumes that the public (as represented by Congress) has its heart set on Mars and couldn't be convinced that other space missions are cool in themselves, rather than just as a stepping stone to Mars. Why is a Mars habitat cooler than a Moon habitat, for example?

      Also, space enthusiasts seem to like the Mars robots, as well as the Hubble and Webb telescopes. It's not clear to me that they won't be interested in other Mars missions, as well as other deep space missions.

      How many people even know the names of the current astronauts on ISS, or what they've been doing in the last year? What's the last thing that happened on ISS that you can name? It seems like Webb was the biggest thing to happen in space in 2022?

      2 votes
      1. [2]
        nukeman
        (edited )
        Link Parent
        Among space enthusiasts, yes most of them love unmanned missions. Among the general public, the majority only hear about it for thirty seconds on the news, if at all. I suspect part of the...

        Among space enthusiasts, yes most of them love unmanned missions. Among the general public, the majority only hear about it for thirty seconds on the news, if at all. I suspect part of the enthusiasm gap is tangibility, you can always meet the astronaut, you almost certainly won’t meet the probe. A Mars habitat isn’t inherently cooler than a lunar habitat, although the much greater distance and by extension, duration (potentially as high as 24 months) makes it more of an engineering challenge overall.

        Ironically, I think your final argument actually supports mine, in a way. The ISS is an ongoing mission, without a defined end goal. A mission to Mars has a defined end goal: get to Mars and set up a base/habitat. Most Americans don’t know many ISS folks (probably the Kellys, maybe one or two others). Virtually all of them know at least one of the men who walked on the moon, and I suspect Mars would have a similar effect. I do think this would fade as a Mars base became a permanent fixture with residents and regular missions, but by then, you’ll have firmly built your political base to support an indefinite presence. In any case, you can move onto the next mission (Jovian moons? Asteroid? Venusian orbit?) as a focal point.

        One other consideration: media. With a manned Mars mission, you can have daily vlogs from the crew, weekly long-form shows, and numerous specials once landing occurs. That would be hours of content that the networks would go crazy for. Unmanned missions have gotten what, maybe five to ten total minutes of coverage per network over a 12 month time span?

        2 votes
        1. skybrian
          Link Parent
          Even though I'm going with it a bit as a hypothetical, I'm not wild about using publicity as a justification for research. It seems backwards? NASA publicizes everything they do to get support...

          Even though I'm going with it a bit as a hypothetical, I'm not wild about using publicity as a justification for research. It seems backwards? NASA publicizes everything they do to get support from the public, but the Webb telescope (for example) was designed based on research priorities, not what the public would want.

          Making stuff the public wants makes more sense for a movie or video game than for research, and the public would be more entertained by a movie.

          I think in general, time is on the side of unmanned missions. Stuff on Mars doesn't move much, so there's no hurry. The robots are very good at waiting and last a long time, so a long round-trip latency waiting for orders is fine. When there are long stretches with nothing happening, we at home can do something else.

          There's no reason to demand attention from the public all the time and it wouldn't work anyway - people get bored with anything that's in the news for too long.

          2 votes
  6. [4]
    lou
    (edited )
    Link
    There are lots of snark on this article. I'm sure that was not the author's intentions, but comparing NASA to Amtrack only reduces its persuasiveness with me. They also depict the wish for Mars as...

    There are lots of snark on this article. I'm sure that was not the author's intentions, but comparing NASA to Amtrack only reduces its persuasiveness with me. They also depict the wish for Mars as cultish. I'm sure there are strong criticism to be made for these projects, but the contempt showed here guarantees that only those who already agree with the premises will be persuaded by the arguments.

    In any case, I believe it's important to notice that there are reasons for going to Mars that are neither engineerial nor scientific. The citizens in the public will directly impact the pace of space exploration through their votes and support (which impacts budgets). A new generation must be inspired and seduced by the perspective of learning about our surroundings.

    And I do believe there is inherent value in space exploration. Maybe the author would think I'm "cultish" too.

    4 votes
    1. [3]
      skybrian
      Link Parent
      What reasons do you find persuasive for sending people to Mars? You say "inherent value" but that's not really a reason.

      What reasons do you find persuasive for sending people to Mars? You say "inherent value" but that's not really a reason.

      5 votes
      1. lou
        Link Parent
        I can't think of anything that might persuade you, sorry.

        I can't think of anything that might persuade you, sorry.

        6 votes
      2. teaearlgraycold
        Link Parent
        I think most humans care more about exploration than preservation. And fucking up Mars comes at no (or limited) human cost.

        I think most humans care more about exploration than preservation. And fucking up Mars comes at no (or limited) human cost.

  7. [13]
    DaveJarvis
    Link
    "Some of the reasons for exploring space, when there are numerous social problems on earth, were described by Dr. Ernst Stuhlinger, Associate Director of Science at the Marshall Space Flight...

    "Some of the reasons for exploring space, when there are numerous social problems on earth, were described by Dr. Ernst Stuhlinger, Associate Director of Science at the Marshall Space Flight Center, Huntsville. His beliefs were expressed in his reply to a letter from Sister Mary Jucunda, O.P., a nun who works among starving natives of Zambia, Africa."

    "Space flight, without any doubt, is playing exactly this role. The voyage to Mars will certainly not be a direct source of food for the hungry. However, it will lead to so many new technologies and capabilities that the spinoffs from this project alone will be worth many times the cost of its implementation."

    https://www.nasa.gov/sites/default/files/atoms/files/nasa_economic_impact_study.pdf

    Compelling reasons to venture beyond this single, solitary rock include: Catastrophic volcanic eruptions. Devastating climate change. Extinction-level asteroid impact. Gravitational shifts from a rogue celestial body. Directed supernova blast. Coronal mass ejection. Unknown cosmic cataclysms. Loss of magnetosphere. All-out thermonuclear war. Unyielding plagues.

    Back up your data, back up your species.

    4 votes
    1. [4]
      skybrian
      Link Parent
      A problem with the spinoff argument is that it's very generic. It's a blank check to spend money to do anything technically challenging. But among all the possible ways to spend trillion dollars...

      A problem with the spinoff argument is that it's very generic. It's a blank check to spend money to do anything technically challenging. But among all the possible ways to spend trillion dollars on speculative R&D, some are likely more promising than others? If putting people on Mars costs the same as 100 projects on the scale of the James Webb Telescope, some of which will likely have spinoffs too, what do you choose?

      "Backing up the species" is a very long-term project. A manned mission to Mars is very far from making a sustainable off-world colony and might not be the best way of getting there. In the meantime, I think it's likely that we're going to have to get through the next century (at least) without a full backup, somehow.

      3 votes
      1. [3]
        Toric
        Link Parent
        Ok, backing up the species is a long term project, and a single mission to mars in no way accomplishes that goal. Are you saying its such a long term goal that we should never even start on it? We...

        Ok, backing up the species is a long term project, and a single mission to mars in no way accomplishes that goal. Are you saying its such a long term goal that we should never even start on it? We will never get to the point of living on multiple celestial bodies without sending a mission to at least one. Do you think there are better candidates?

        If the long-term goal is worth getting to, then surely the next step is also worth it?

        1 vote
        1. skybrian
          Link Parent
          I think very long-term goals like that are worth starting on, but there are a lot of different ways to get there and people can disagree on what the "next step" should be, or when the steps should...

          I think very long-term goals like that are worth starting on, but there are a lot of different ways to get there and people can disagree on what the "next step" should be, or when the steps should happen. There are so many things to learn and lots of ways to do research. Some steps will surely be easier later due to improvements to technology and scientific knowledge.

          As an example, research into building self-sufficient economies and ecologies on Earth would be much cheaper and probably more generally useful.

          Part of the problem with a discussion like this is that it's framed as "Mars: yes/no" rather than choosing among a variety of projects to do next. Projects not chosen now can be chosen later.

          1 vote
        2. papasquat
          Link Parent
          By the time a self sustaining, robust civilization could be established on another planet (by robust and self sustaining, I mean it could go on without a problem even if all of earth got wiped...

          By the time a self sustaining, robust civilization could be established on another planet (by robust and self sustaining, I mean it could go on without a problem even if all of earth got wiped out), there will be actual good reasons to go other planets.

          If humanity survives long term, it will get to the point where:

          1. natural resources are so rare on earth that expensive interplanetary mining and trade will become economically viable and
          2. Space travel will become cheap enough to do it.

          At some point, those two economic factors will coalesce so that mars colonies start making sense, and eventually over the very long term, those colonies will stop becoming as dependent on earth.

          Forcing that to happen with the "life boat" being the goal just doesn't make sense though. We're talking about something that will likely take half a millennium to do, quadrillions of dollars, and tens of thousands of lives lost.

          1 vote
    2. [8]
      papasquat
      Link Parent
      I can't think of a single one of those things where even a fully colonized mars would survive, and earth wouldn't. Even after hundreds of years of dedicated colonization, mars will still be...

      Compelling reasons to venture beyond this single, solitary rock include: Catastrophic volcanic eruptions. Devastating climate change. Extinction-level asteroid impact. Gravitational shifts from a rogue celestial body. Directed supernova blast. Coronal mass ejection. Unknown cosmic cataclysms. Loss of magnetosphere. All-out thermonuclear war. Unyielding plagues.

      I can't think of a single one of those things where even a fully colonized mars would survive, and earth wouldn't. Even after hundreds of years of dedicated colonization, mars will still be fragile harsh cold radioactively bathed desert, and earth will not. Even an earth hours after a direct impact with a Chicxulub asteroid sized object would be far more habitable than mars on its best day. There's actually no event I can even fathom that would wipe out human civilization on earth, but not on mars.

      There are compelling reasons to colonize other worlds at some point (mostly economic ones in the far future). The "life boat for humanity" one doesn't make much sense to me though.

      1 vote
      1. [7]
        DaveJarvis
        (edited )
        Link Parent
        Mars doesn't have plate tectonics, ergo it can't have volcanic eruptions, so I'm not sure if you're trolling. Mars doesn't have a hospitable climate and barely has an atmosphere to retain any...

        I can't think of a single one of those things where even a fully colonized mars would survive, and earth wouldn't.

        Mars doesn't have plate tectonics, ergo it can't have volcanic eruptions, so I'm not sure if you're trolling. Mars doesn't have a hospitable climate and barely has an atmosphere to retain any heat, so climate change would never be a human-ending scenario on Mars. The likelihood of asteroids hitting both Earth and Mars, wiping out humanity simultaneously is vanishingly small. A CME would hit Earth and miss Mars because Earth and Mars are rarely aligned at the same time and Mars is much, much farther away from the Sun's reach, lessening the impact. Similarly, a supernova blast could hit Earth but miss the red planet. Mars doesn't have a magnetosphere to speak of, so protection will have to be present in other ways, making loss of its paltry magnetic field moot. Mars doesn't have nuclear weapons on it, so we couldn't nuke ourselves. Mars doesn't have a biosphere, so plagues wouldn't be an issue at the same evolutionary pace as is possible on Earth.

        Or maybe my point about having a backup wasn't clear?

        Yes, Mars could get hit by an asteroid, which could wipe out any people. But then we'd still have Earth and could re-populate Mars. And vice-versa. That's what I mean by having a backup copy.

        These arguments are moot, though, because neither of us can control whether Earthlings will become Martians. Humans colonizing Mars is going to happen. And soon. My guess is we'll have a semi-permanent settlement between 2050 and 2075.

        1 vote
        1. [6]
          papasquat
          Link Parent
          Yeah, that's not why I said that though. Earth would survive all of those things. There's literally no chance a volcanic eruption could end all human life on earth. Climate change also has no...

          Mars doesn't have plate tectonics, ergo it can't have volcanic eruptions, so I'm not sure if you're trolling. Mars doesn't have a hospitable climate and barely has an atmosphere to retain any heat, so climate change would never be a human-ending scenario on Mars. The likelihood of asteroids hitting both Earth and Mars, wiping out humanity simultaneously is vanishingly small. A CME would hit Earth and miss Mars because Earth and Mars are rarely aligned at the same time and Mars is much, much farther away from the Sun's reach, lessening the impact. Similarly, a supernova blast could hit Earth but miss the red planet. Mars doesn't have a magnetosphere to speak of, so protection will have to be present in other ways, making loss of its paltry magnetic field moot. Mars doesn't have nuclear weapons on it, so we couldn't nuke ourselves. Mars doesn't have a biosphere, so plagues wouldn't be an issue at the same evolutionary pace as is possible on Earth.

          Yeah, that's not why I said that though. Earth would survive all of those things. There's literally no chance a volcanic eruption could end all human life on earth. Climate change also has no chance of ending all human life. An asteroid would have to be many, many times bigger than any one that's ever been recorded to hit earth to wipe out human life. There's no chance of a CME hitting earth with enough power to end all life. ANY electromagnetism from outside the solar system would necessarily hit both mars and earth due to the sheer distances involved. Even a very low divergence laser beam after a couple of light years will become far, far wider than our entire solar system, let alone something completely divergent like a gamma ray burst. Mars doesn't have nuclear weapons, but any nuclear war sufficient enough to wipe out all human life (already probably impossible) wouldn't also somehow forget about the self-sustaining colony on mars. Any plague with a long enough incubation time to not be detected before it could wipe out all of humanity (again, probably also impossible) would absolutely be spread to mars too.

          It would be very, very, very hard to wipe out all human life on earth. The stuff you listed would cause a massive, insane loss of human life and probably the end of modern civilization as we know it, but not the end of humanity. Humans are adaptable, and if we supposedly have the technology to live on mars, then we absolutely have the technology to survive anything but the absolute and total destruction of the earth's crust. That leaves almost no failure scenarios short of a rogue moon happening to wander into the solar system. Mars is less habitable than just about any environment that exists on earth, and if there were really a need for a "lifeboat for humanity" why haven't we just colonized antarctica, or the bottom of the ocean? It would be way easier and would protect against virtually everything that mars would. Cities and civilizations just don't exist without there being an economic incentive for them to. You can't just force it.

          1. [5]
            lou
            (edited )
            Link Parent
            I think most will agree that this is unlikely to happen, but some things should be prevented even when unlikely. In any case, our Sun has an expiration date. We'll eventually have to leave one way...

            It would be very, very, very hard to wipe out all human life on earth

            I think most will agree that this is unlikely to happen, but some things should be prevented even when unlikely.

            In any case, our Sun has an expiration date. We'll eventually have to leave one way or another. Why shouldn't we take the first steps now?

            1 vote
            1. [4]
              papasquat
              Link Parent
              because the sun's expiration date is billions of years from now, being on mars won't help us, and humanity will look nothing like it does today when that happens, if it even exists in a form we...

              because the sun's expiration date is billions of years from now, being on mars won't help us, and humanity will look nothing like it does today when that happens, if it even exists in a form we can still classify as human. There's no need to spend hundreds of trillions of dollars, trillions of man hours of effort, and put a lot of real humans at risk for something that may or may not affect us in 3 billion years.

              1. [2]
                DaveJarvis
                Link Parent
                Multicellular life on Earth has 500 to 800 million years until the Sun's expansion makes the planet inhospitable. So while the Sun will last for a long while yet, life doesn't have "billions" of...

                because the sun's expiration date is billions of years from now

                Multicellular life on Earth has 500 to 800 million years until the Sun's expansion makes the planet inhospitable. So while the Sun will last for a long while yet, life doesn't have "billions" of years left. Still, 500 million years should be enough time to get us off this rock.

                https://en.wikipedia.org/wiki/Future_of_Earth#Climate_impact

                1 vote
                1. papasquat
                  Link Parent
                  Sure, but to put that into perspective, 800 million years ago, not only did humans not exist, animals didn't exist. It took around 800 million years from life to go from sponges to human beings....

                  Sure, but to put that into perspective, 800 million years ago, not only did humans not exist, animals didn't exist. It took around 800 million years from life to go from sponges to human beings. Can you imagine how different we're going to be in 800 million more? Throw in the breakneck speed of technology and its eventual integration into the human body and the needs of "human" colonists millions of years in the future is something we haven't the faintest clue about. "Humanity" could exist purely as code running on powerful supercomputers and controlling robotic bodies in a few thousand years. Who knows what it's going to look like in a few hundred million?

                  1 vote
              2. lou
                Link Parent
                I don't know. Seems like the kind of thing that is reasonable to think about in the extremely long term. We never saw a successful multi-planet civilization, we have no idea how long it takes to...

                I don't know. Seems like the kind of thing that is reasonable to think about in the extremely long term. We never saw a successful multi-planet civilization, we have no idea how long it takes to get there. And there are other dangers besides losing the Sun, some of them man-made.

                I would err on the side of caution.