For a few chapters you are following an engineer, and it talks about the alloys and techniques she's using to build housing. A little while later you follow a geologist and the topic shifts a bit as this geologist goes out exploring.
You follow biologists, psychologists, economists, and each time it dives into the challenges they have in how they perceive Mars and what to do with it.
Inevitably, there's a conflict between the "Reds" and the "Greens". Given the series titles (Red Mars, Green Mars, Blue Mars), I'm sure you can figure out who wins. However, it seems to suggest a result that I find fairly likely -- it doesn't matter what you say we should do with Mars, people are going to do what they want. We already don't care about externalities here on Earth, there's no way we can police them on Mars.
That said, while I used to be a huge fan of the idea of colonizing Mars, I've swung around to the idea that colonizing asteroids is far more interesting. Mars is relatively resource poor, and asteroids are incredibly resource rich. There are some kilometers wide balls of iron, nickel, and platinum group metals out there. Not to mention water and carbon. All the materials you'd need to undertake construction in space and none of the challenges of having to lift it into orbit.
The “let’s just build cylinders” (which I think we should eventually do!!) often strikes me as a knee jerk contrarian position, an attempt to avoid hard questions about environment, and a “grass is always greener in fields further in the future and with less solid understanding.”
Planetary bodies with water cycles (or a history of them) are rich. Airless bodies have massive difficulties that are often handwaved away.
And now we have powered flight (without needing propellant) demonstrated. Mars really is a much better place to establish a permanent human presence.
Furthermore, in future wars planets would also be far easier, bigger and immovable targets compared to asteroids and space-stations. Just look up what happens when you drop a 10ton tungsten rod from outer-space. Thanks to gravity, when it hits the ground it has the same impact of a small nuclear device.
When humanity starts to create colonies outside of earth, I expect most planets will only become fully automated mining colonies. Colonizing planets is a Star Trek fantasy that, most likely, will not be worth it.
Is that actually true? I mean, you could hoist two and a half of those tungsten rods into LEO with a single Falcon 9 expendable launch, and if we're just looking at kinetic energy, you can't get more out than you put in. So, the tungsten rod's re-entry wouldn't create any more energy than it took to lift it into orbit in the first place (assuming tungsten doesn't do anything weird like combust), and there'd be a lot of energy lost in the process. I wouldn't consider a Falcon 9 launch to be "equivalent to a small nuclear device" in terms of energy.
Another way to look at is is that a 10,000 kg mass at a height of 1,000 km above a planet with gravity of 9.8 m/s^2, is 10,000 * 9.8 * 1,000,000 = 9.8 * 10^10 joules. 1 kilowatt hour is 3.6 megajoules, so that comes out to 27,222 kilowatt hours of energy. A kiloton is (according to a google search) equal to 1,162,200 kilowatt hours, so that comes out to about 0.023 kiloton TNT equivalent. With some of that energy lost as atmospheric heating.
That isn't to say that dropping tungsten rods from orbit isn't a serious threat, or that you couldn't impart a lot more energy by flinging them at the Earth with much greater velocity. I just don't think the comparison to nukes is quite right.
They also evaded the 1967 Outer Space Treaty, which forbade "objects carrying nuclear weapons or any other kinds of weapons of mass destruction".
I'm not sure they actually reach the yield of a nuclear device, but "bunker-buster" nukes are relying on overkill in yield since they can't achieve that kind of ground penetration in delivery.
"Dropping a tungsten rod on earth" is not picking it up and dropping it. It's firing it at the earth. Depending on what body you're firing it from, that's a lot of additional delta v.
Something coming at the earth from the Moon, for instance, is moving at least 2.3 kps, plus another kps if you fire it forward. This calculator is telling me that's 55.2 gigajoules, about 15 thousand times higher.
Assuming your math is right, and then my math is right, .35 megatons is still an exceedingly bad day.
If we add in 1/2 * 10,000 kg * (7500 m/s)^2, to account for sideways LEO-equivalent momentum, I have it coming out as about 0.0906 kilotons: about 4 times more energy. Which isn't too surprising, since the hardest part about getting into orbit isn't the going up part, it's the going sideways fast enough enough part.
My whole formula is this: (((10000 * 9.8 * 1000000) + (0.5 * 10000 * (7500 * 7500))) / 3600000) / 1162200
Basically, (mgh + 1/2 mv^2) converted from joules to kilowatt hours to get it into a larger unit I can sort of relate to, and then converting that in turn to kilotons equivalent TNT in order to compare with nuclear yields.
That's assuming I didn't leave off some zeroes somewhere or apply a formula incorrectly.
What do you mean "fire it forward"? If you fire it forward, it will never fall on Earth. To get from Moon to Earth, you need to fire it backward in Moon orbit, to slow it down. Essentially, you need to slow it down a lot if you want it to get to Earth surface, as opposed to orbiting it alongside Moon.
Thus speaks the lord thy over-lord:
I. You shall not erect asteroid defences.
II. You shall not send others to space to rule beside me.
III. Once every aeon i shall send a rock to test your faith. You shall fight one another, to proof your worthiness.
IV. Be nice to one another.
V. Game-theory applies, but in a similar way for everyone living in system, to everyone else out-system.
That’s... not as good as a nuclear device? Susceptibility to 10 ton tungsten rods is pretty lame to worry about when a 10 ton actual nuclear bomb would be so much worse.
A heavy object picks up some kinetic energy as it falls into a gravity well, but realistically a tungsten rod moving at orbital velocities could destroy a space station or asteroid habitat just as effectively as it could destroy an Earth target. And there'd be somewhat of a difference: with Earth, we have an atmosphere to slow fast-moving objects down and provide an early warning that something is coming at us. (Probably not enough early warning to do usefully react, but still. A couple seconds is more than 0 seconds, and maybe there's some way to use that to a tactical advantage.) In space you'd have no warning at all, unless you can track it on radar or telescope, in which case Earth could do the same.
Earth's big advantage is that everything we do is so geographically distributed that any damage done is a temporary setback. It would be a sad day, but the human race will go on. Unless it was a really big rock, in which case it would be hard to redirect one into Earth's orbit without anyone noticing.
I suppose if you really want to be protected from flying rocks, the best bet may be to find some moon or minor planet with weak gravity, and tunnel deep into the surface and set up shop there. You could do something similar on Earth, though there's a limit to how deep you can go before it gets too hot. (In Consider Phlebas by Iain M Banks, there is planet whose original inhabitants had built a deep underground subway system where train cars house the military command structure, and in time of war the trains would always be moving around so that a nuclear-armed adversary wouldn't know where to strike. That approach could work too.)
Realistically, though, I think if humanity develops the technology to start moving large heavy objects around the solar system, then almost everyone is going to be very vulnerable. The best defense is to be on friendly terms with all your neighbors, and have very good visibility into where everyone is and what they're doing.
See also The Moon is a Harsh Mistress
If you literally drop something in orbit then it stays in orbit. In order to make it fall to the ground you first need to de-orbit it.
It surely could be done, but the amount of trial and error required and the potential for high stakes failures is a daunting challenge.
What do you think about Kim Stanley Robinson's hollowed out asteroids? Less efficient use of materials and angular momentum, but possibly a more stable arrangement.
Worth what? Some people may be willing to pay a high price in order not to be submitted to Earthly governments anymore. We do not know yet how our home planet and its politics will look like in 2050 or 2100. There is a chance that it may be a cruel dystopia.
Do we have any idea, based on our experiences with space stations & lunar landings? Genuine question, I'd really like to know.
IIRC, largely no - it's a very open research question.
> I'd really like to know
I fuzzily recall seeing an applicable NASA space medicine slide deck last year, but I'm not quickly finding it - sorry.
> depend on whether Mars has enough gravity
While it's common to oversimplify and exaggerate minimum-size constraints on rotational gravity, even if greater than Mars gravity is needed almost continuously, it might perhaps turn out easier engineering to maintain that on Mars (with mounted spinning things, or maybe pods in curving tunnels) than in space (spinning habitats). You still have vacuum at hand, but also support and workspace - things are more easily stopped, stood next to, and kicked.
Is the physiologic response between the two extremes linear? My intuition says no, but I don't have real data to check.
And to make matters more complex, that dose could be spectrum, rather than a constant value. Eg, spend X hours doing Y in the compact ~2 meter centrifuge at Z g, plus ... and ... .
The water cycle concentrates diffuse elements into usable mineral deposits, yes. But those elements are only diffuse in the first place because of the planetary environment. The base abundance of industrially useful elements in asteroids can be tens, hundreds, or thousands of times higher than Earth (or Mars) precisely because these materials sank to the core or mantle of planets, or get chemically locked up in expensive to refine oxides. Indeed many of the rare metals we prize are actually of asteroidal origin, because they have been completely depleted in the Earth's crust in geologic antiquity.
What's more, chondritic or M-class asteroids typically have extremely accessible minerals, such as pure metals already in reduced form, or mixtures of loosely compacted minerals that can be sorted with a crusher and a centrifuge.
There's zero evidence for this at all. We have no experimental data on living in partial gravity, only microgravity(zero-G). It may be perfectly fine, it may be just as bad as no gravity, we truly don't know.
There was a module for the ISS that was designed to test this but it got scrapped, a massive waste IMO, as it seems to be one of the most outstanding questions we have right now for space biology. Other big issues like radiation exposure is well understood.
You don't have to colonize them, but mining asteroids makes tons of sense.
I found it incredibly naive and unrealistic. Clearly many others disagree :)
I originally encountered the Mars Trilogy as a teen and it is fair to say that it changed my life. I feel in love with the romantic portrayal of Mars colonization, and eventually ended up working at NASA. Recently I decided to go back and re-read the trilogy and found myself unwilling to finish even the first book. I just couldn't stand it. So you're not alone.
You might like Icehenge though. It works more as a stand-alone novel (or 3 novellas, really) set in the same universe, but with a focused plot and the politics mostly relegated to the background. It's a very under-rated book, being overshadowed by the more well-known RGB Mars trilogy that followed.
That depends very much on how the putative Martian society is set up.
There used to be an idea in cultural anthropology that a society becoming heavily dependent on technology and coordinated labour (specifically, sophisticated irrigation systems) went hand in hand with the evolution of a centralized authoritarian state to manage that.
The idea has fallen out of favour, but you can see how something similar might apply in spades on Mars. Life there is going to be marginal at the best of times; living off-grid would be a truly daunting prospect.
One thing I liked about Red Mars is how it brought up independence. Astronauts are well known to rebel against their respective commands (US, Russian, etc). It'll be interesting when command cannot do anything about it on a longer timeframe than your stay on the ISS (or skylab).
You practically get an undergrad in areology reading it. Super curious to see how our reality lines up with the timelines in the book.
Metal asteroids can, with some luck, provide us with boundless supplies of pretty much all metals, as I understand it. This will be one of the great milestones in human civilization.
But I think it's a place you go to work. Mars is far more interesting as a place to live and build a society.
Mars has a lot of the same disadvantages that earth does. Its got a lot of gravity, and you can't communicate through the planet from one side to the other
That out of the way, McKay comes off as overly aggressive at times, and wishy-washy in others. It seems contradictory to call Jakosky's model ridiculous and absurd while also claiming we don't have enough data to know for sure. Jakosky is a well-known and respected Mars researcher, and I would much rather trust his 2018 paper over a paper or two written in the early '90s before we had detailed observations of the Martian atmosphere or surface.
At the very least, I appreciate Jakosky planting an empirical stake in the ground for his position.
However, I struggle to see a reason to oppose the concept of terraforming Mars. I don't study the planet for a living so I'd love to hear your thoughts on it.
The exploitation argument doesn’t make any sense because Mars doesn’t have any resources that would really make sense to ever bring back to Earth, except as a side product. It’s a new home like an island in the Pacific for the Polynesians. I don’t consider Polynesians settling uninhabited new islands to be objectionable at all, but instead an expression of what makes humanity wonderful. Preservation of a dead rock for preservation’s sake makes no sense. It’s treating stasis as better than life, and I just can’t get behind that.
I'm sure you wouldn't object to national parks or wilderness areas, it's just that in the case of Mars there is no (known) life. How much each of us values the presence of life will differ, but in my view it's worth preserving Mars.
I'm surprised that a researcher wouldn't be enthusiastic about being able to do science directly on the planet's surface. Sure, an extended human presence there will require a lot of supporting infrastructure, and sure, that will all have a direct effect on whatever might already be there -- or might not be, and in either case, changing that environment might not be desirable.
But even at the current faster speed of remote exploration of the planet, you can expect, what, like 3 more robotic missions to Mars before you retire? And each one will be an iterative improvement over the last.
There must be so many questions you have about the planet that just won't be answered in your lifetime unless we go there and have a look around. What's your position on that?
I am not opposed to scientific exploration at all, (I work with several people who run Ops on MSL and Percy), but putting people on the surface requires much more infrastructure and expense. A sample return mission is already extremely complex and costly, and would be orders of magnitude more so if the mission also had to support human life.
Further, terraforming Mars so that people could go explore it seems completely backwards, since you would be altering the conditions you would be studying.
To your question:
>There must be so many questions you have about the planet that just won't be answered in your lifetime unless we go there and have a look around.
I'm not even sure what those would be. Almost any question we could want answered could be solved with a probe or a rover. Obviously there are questions we can't answer right now, but those are largely because we send rovers that are specialized in some areas, and totally ignorant of others. To answer those questions, it would be simpler, cheaper, and better for Mars to send more robots than to send people in my view.
There are millions of Mars-like planets out there in the galaxy. I'd be more than happy to preserve, say, 10% of them. But there's only one that's in the right place to be the next step for humanity.
Turning choice, large asteroids into liveable habitats seems an infinitely more productive task.
Proxima Centauri will outlive the vast majority of stars in the galaxy.
The Alpha Centauri system will be just 3 light years away in 30,000 years. In 1.4 million years, Gliese 710 will pass within 0.2 light years of Earth. That’s close enough to be reached in a human healthspan with some beefed up (but still fairly sane) nuclear-electric propulsion that we could probably start building today if we had a reason to go out to 0.2 light years.
But other interstellar propulsion systems with higher performance are feasible, such as pellet stream beamed propulsion combined with a magsail. Really good fusion might work, too. Laser propulsion is feasible especially for probes but isn’t terribly efficient (pellet stream uses like a hundredth the energy for the same payload). Antimatter would be nice, but I’m not convinced feasible storage could be developed to beat the usable energy storage density of fission or fusion... or rather we’re probably much more than 100 years away from sufficiently efficient antimatter storage.
Seems like the winning move is to go double or nothing and try and make life more sufferable (containing less suffering) on both planets.
Why not make it more sufferable here on Earth first, build all sorts of guardrails on existence, e.g. modify biology such that we all have a certain maximum to which the pain knob can be turned. And only then terraform other planets? Why be premature?
If we sit on our hands and do nothing then life on earth is doomed to extinction and we will be directly responsible. Our duty as rational beings is to preserve and spread life. If you really want to be anti suffering then figure out a way to improve things so nothing needs to suffer. We’re already on a trajectory for doing that for humans so there’s no reason to think we couldn’t do it for all life.
Even if the odds are slim it’s cowardly to not even try.
This is the most astounding perspective on the value of life that I can imagine. Like the argument of a genocidal supervillain.
Death is death whether caused by direct action or neglect.
As for me, I'm bowing out, thanks for the perspectives so far. Downvotes drain my energy.
But on the other side, what is really the point to this?
In a couple of million years, none of this really matters.
It must be very different to you, having studied it. Like how a biologist may have a fondness for a particular nemotode worm which means nothing to most of us. It makes me feel shortsighted thinking of it in this way. Reminds me of pro-colonial/imperialist rhetoric like this.
Will our descendents see us the same way? Is there a good reason we want to extend our empire into the stars other than... seeing it a lot in sci-fi media?
The ingenious people across the world are the original colonialist. Should we condemn them for what they did?
As a Polish person who inherited an extremely difficult history, I feel fine with my Slavic ancestors.
What I know is that The Sun will destroy the Solar System. The time will most likely destroy everything else with the heat death.
So, I would want to explore to learn the answer to The Last Question - does everything has to die in ever increasing entropy?
You can read the short hard science-fiction story "The Last Question" here: https://www.multivax.com/last_question.html
We could turn mars into a sweet art project.
This is assuming that worst case scenarios are possible on Earth as on any planet… I think that’s a reasonable assumption.
I don't care about Mars' surface processes. If I had a button to blast its outer layer off and replace it with a habitable one I would press it without hesitating - yet I imagine if I spent years studying the planet academically I would act differently, based on an amalgam of my concepts of "studying" and "Mars" I came up with on the spot and am ignoring anyway. Empathy is a poor substitute for understanding.
There's a philosophical difference here too. I don't see a problem with pulling resources from as much of the galaxy as we can reach if it prolongs Earth life, assuming we don't find other lifeforms. The galaxy only has mystique when we assign it, which we can't do if we're dead.
We got to the moon, Mars, and several other solar system bodies in the past half century without any mimicry.
Maybe you don't, but I have very strong optimism for technological advancement, and also for modifying our life form to rid ourselves of our tendency to destroy things before heading to other stars. When I say "we" will go to other stars, it won't be Homo sapiens, but another species that we will create as our successor.
We may get humans to Mars. It's technically possible. But I don't think we will ever live there.
>We got to the moon, Mars, and several other solar system bodies
You're conflating humans and probes, which are vastly different.
I disagree. Robots can build infrastructure far ahead of human settlement, such that everything already exists when we are ready to travel.
We can also potentially re-engineer our own life form, or create an entirely new inorganic lifeform, to withstand various conditions, including radiation and a wider range of temperatures. That will be our successor.
We are only beginning to understand genetics in the past decade. We have a long, long way to go, and a lot to understand. Science is still at its infancy.
Also, this is something I could never say in an academic context, but deep down I don't believe in conservation of energy, partly because the big bang itself violates it. Yes, I would be ridiculed for saying this in a scientific context, but so would someone in the 1500s for saying that the Earth goes around the sun. I think at some point in the distant future we will not be reliant on stars as our energy source.
If you truly do not believe in the conservation of energy, I think we're done here since none of my arguments will be good enough for such wild speculation.
Human bodies suck because they need to eat, need to poop, complain if what they eat isn't tasty, fight with each other, and get cancer, but our legacy as intelligent life doesn't need to continue in our current carbon-based meat bag form.
This reads like an ungrad astronomy major fever dream.
I do think it’s possible that our best hope for navigating the transition beyond the singularity involves transplanting our humanness to another kind of life form. I’m not necessarily talking about uploading… more about a staggered intergenerational transition mixed in with life as we know it. I realize that to some people, this will continue to sound like crazy talk, until one day it isn’t. It’s ok if you are one of those people :-).
Yes, it reads like a dream. Technological breakthroughs of the past were created by people with dreams, not by skeptics.
Let's say it takes ~8 minutes to get to LEO vs 4,380 minutes to get to the Moon. That's a factor of ~550x longer flight time for a distance 2000x further.
Alpha Centauri is 1500x further away than Mars. It currently takes ~7 months to go from Earth to Mars (at 25,000 mph), assuming similar scaling that comes out to only 400x the flight time, or just about 230 years.
Reaching 10% would be enough to visit nearby stars within a lifetime.
And once we can extend human life spans to many hundreds of years these journeys become even more achievable.
As I said elsewhere, I think the disconnect here is between potential and probable. Homo sapiens have twice come to the edge of nuclear oblivion already (being saved only by luck essentially), and I would wager we are are speeding much faster towards nuking each other than reaching the stars.
Submarines work well because we didn’t bother making them anything like fish.
There is, but extrasolar objects don't have engines and do very low energy transits.
We'd need a large habitat, a power source that can last for a couple thousand years and a lot - and I mean a LOT - of reaction mass to accelerate it and to brake it when it arrives at its destination. Ideally, it'd be preceded by numerous robotic probes that'd chart the worlds ahead for possible refueling stops (that could add a couple thousand years to the mission) and have a number of possible targets lined up on a reasonable trajectory so that if the next system is not really that hospitable or doesn't have anything worth doing a very large delta-v for, it can just press ahead to the next destination.
Another thing it'd need is a lot of determination to build it, to seal it with a population, test it for generations to make sure the ecosystem works and is stable, and then send it out into the unknown without any possibility of returning to Earth. It's very long term engineering we rarely do.
For some reason there are a lot of people around today that believe life is suffering and that the universe would be a better place with fewer humans in it.
It's a hard position to argue with because it's just so full of holes and lunacy you don't know where to start.
I think you can’t argue with it because it’s like an unexpected emotional vacuum. You can’t really convince someone who doesn’t like food that the carnival is an enjoyable place. They’re operating on a fundamentally separate plane.
Why not? It would seem that's something we're going to have to master in order to populate the galaxy. Seems like it would make sense to figure it out somewhere close to home so we can have all the appropriate gear onboard a flight out into the cosmos.
We will figure it out.
You are extremely optimistic about having several hundred million years left on Earth, when the longest living hominid existed for only ~2 million years.
I firmly believe that homo sapiens will self-destruct long before that point, as we have greatly overstressed the planet in only 200,000 years, mostly in the last 200.
My view is that learning to master inhabitation of Mars and other places in space will enable us to revert Earth from a bunch of agricultural land and farms and suburban sprawl back into a garden (dotted with dense, luxurious cities) which we camp out in during the weekend.
Space development shows how to thrive WITHOUT fossil fuels. It’s so strange to me that folks seem to have this backwards.
>Space development shows how to thrive WITHOUT fossil fuels.
Not sure how that's the case given the staggering emissions of Falcon 9 for example.
> However, even if slower, terraforming Mars remains a great long-term goal; but long-term meaning like ten thousand years. Which means we have to get our relationship to our own planet in order for anything interesting to happen on Mars…
> The main project for civilization now is creating a sustainable way of life here on Earth. That’s the necessary first step; anything beyond would rely on that succeeding, so exploring space is less important now. That said, space science is an earth science. What we learn around the solar system can often illuminate the project we have here of keeping this planet’s biosphere healthy. So I like the space program, and feel it is not funded out of proportion to its importance. Robotic missions are already doing a lot of what we need done, but humans are better at many things than robots, and it’s more exciting to see humans on the other planets than it is to see robots. So, on balance, I’d like to see more investment in space science and less in areas like weaponry. Our taxpayer bailout of the banker gamblers who lost their bets in 2008 cost us about ten thousand times the entirety of what we’ve spent on NASA.
This interview in particular is worth reading for this whole topic being discussed here.
Hydrogen is one of the most common rocket fuels, and Starship will need to used synthesized methane (which we actually make on board ISS using direct cabin air carbon capture and the Sabatier process using hydrogen made from water split with solar electricity) on Mars to return to be reused, and Musk said SpaceX would eventually use synthesized methane for Earth-side refueling of Starship as well.
How does that work, exactly?
This hand waves away all the accomplishments in seafaring prior to the 19th century.
There were loads of innovations around the shape and profiling of ship hulls depending on conditions in which they operated. Same for sails and stuff, not to mention doing away with rowers. This improved speed quite a lot on top of range.
Not simply, but mostly: progress started before the steam engine. But yeah, pop sci is hyping a lot of things that are very, very unlikely in the near future, and it looks like we won’t have much beyond that.
There's so many engineering and scientific advancements needed to make space-based sustainable colonies using materials sourced solely from Earth that your position would delay any colonization of space past a few great filters.
I was enjoying your takes on preserving Mars, but saying that humanity should only be allowed to change Earth is nihilistic in the extreme.
It would take those nukes three days to reach earth, which is a huge amount of time for countermeasures to target and destroy them. And a handful of responding nukes could easily wipe out all lunar military sites and personnel, while lunar weapons could barely nick Earths military capabilities.
I think the unstated premise here is that populating the galaxy is something we should do. Looking around at what we're doing here on Earth, I think humanity populating the galaxy would be a net negative for the galaxy.
You know how the aliens from Independence Day are portrayed as a race that goes from planet to planet draining its resources until there's a husk left? That's exactly what humanity would do. There's no question about that.
"The Harvesters are a race of highly intelligent and incredibly technologically advanced hive-mind extraterrestrial beings. They are a threat of universal proportions that seeks to harvest and destroy planets to refuel their ships, to grow, and to perfect their technology at the expense of driving indigenous races to extinction."
We are the Harvesters in this story.
200 years ago nobody would even think of flying on Earth, and yet here we are, taking it for granted that you can get almost anywhere on this planet within 24 hours for a couple thousand dollars, and within a century of inventing the car we landed a robot on freaking Mars.
Now I do think that we will take charge of evolution and invent a form of life that will be our successor to withstand a much harsher range of conditions and absent from the "bugs" of current life such as cancer and heart disease, rather than our current unreliable meat bags, but we'll make it happen nonetheless.
All that said -- I do want to see more attention toward terraforming Earth as well. Even with zero global warming, the sun's brightness will increase such that our oceans will boil away within 1 billion years, even though it won't actually engulf the Earth for another 4 billion. I would think it's realistic to extend the habitable period of life on Earth from ~300 million years to maybe 2 billion years with some terraforming tricks. That will buy us more time to terraform Mars or Saturn's moons in preparation for the red giant phase of the sun.
Also, learning to terraform the Earth can reverse global warming, because, you know, politicians don't give a fuck about stopping it, so we should attempt to learn to reverse it as a backup plan while the political environmental efforts continue in parallel.
And if we can cure cancer in the next 50 years (I think realistic), we'll have even better odds of surviving an event, as a species.
While we have the theoretical capability to destroy all plant life, I think realistically we'd end up obliterating a few cities before war would cease, and a full-on nuclear winter is unlikely.
I mean it's not really about what you think. See the top two links here about the devastating effects of small-scale conflicts
This sounds wildly optimistic, considering our chronic inability to fix our behaviour before it results in excessive damage. Never mind the occasional asteroid.
> 200 years ago nobody would even think of flying on Earth, and yet here we are, taking it for granted that you can get almost anywhere on this planet within 24 hours for a couple thousand dollars, and within a century of inventing the car we landed a robot on freaking Mars.
The myth of Icarus is a bit older than 200 years. So are Leonardo da Vinci’s drawings. Plenty of people did in fact think of flying, most probably before they had any way of writing it down for us to read.
What does Mars need? An atmosphere. Doesn't really matter what it's made of, we need more pressure on the surface. But no one lives on Mars! It's not "oh how much work would this be" it's "redirect a comet and let it crash into the planet".
Most of the big early stage terraforming problems offer disproportionate returns on investment - you can do extinction-level event damage with no consequences and amazingly reasonable delta-V investments.
Personally, I've been hoping we'll get lucky and a suitably large comet would just hit Mars. A couple years back a retrograde comet looked like it would, but missed. It wouldn't have taken much effort at the right part of it's orbit to guarantee that hit.
This is what does make me wonder about the "oh it's too hard" people. We know there are bodies in the asteroid belt with more water then all of Earth's oceans. The gases and liquids we need are already in orbit and once we know where they are, getting them to Mars is comparatively very simple.
What does the terraforming argument look like once you change some of those initial assumptions people start with? Once CO2 in the atmosphere is warming it up, and surface pressure is 0.3 atmospheres? And once liquid water has filled all the low land areas?
These aren't insurmountable hurdles for us with todays technology - but they are catastrophic sort of changes which you can only do in the early phase. But once we're looking at a planet which is still "uninhabitable" but with sunlight, water and CO2...well that's an environment where Earth's greenery is going to go crazy colonizing.
Can you say more about the technology to redirect that much mass to make it collide with Mars?
(I understand that shifting an orbit is much different from escaping from a gravity well, but I don't have a good intuition for how different, maybe because I haven't played Kerbal Space Program or something.)
So either gravity-tug with ion thrusters do a minor correction, or more likely a solar reflector to turn part of the bodies mass into it's own propellant. Or a nuclear charge on the right side of it.
I suspect if we were committed to this as a thing we were doing, then once you turned more resources to it the actual calculus would get more complicated: you'd want to map out and characterize everything in orbit, and then start looking for second or even third order redirect candidates - i.e. use a smaller body on a more useful orbit to collide into a larger one for a redirect.
The technological criteria are much more reasonable for all of this though: we need to be able to get to what we're going to redirect reasonably quickly, several times so we can characterize and put the gear in place to do the mission. At this point you'd hopefully be using a bunch of Starships running on autopilot.
If you take some near-future tech into account, then if end up building the laser array for the Breakthrough Starshot project, a decent use of that most of the time would be lasing the surface of redirect candidates from Earth.
EDIT: Just realized I didn't answer your question very well - changing an orbit is much cheaper then escaping a gravity well. To go to the Moon from Low Earth Orbit takes maybe 1000ms-1 of delta-V (weak-boundary transfer and such - I'm probably a little off on that) under the right conditions.
To get into Low Earth Orbit through you need to blow through at 8km/s of Delta-V and then a lot more to overcome atmospheric drag.
But to return form a Near-Earth Object (say an asteroid) back into the Earth's atmosphere can be done with as little as 60 ms-1 of delta-V in some cases (a little more if you're aiming to hit the ground and not just plough through the atmosphere).
Basically with the right timing, orbital adjustments can be incredibly cheap.
EDIT 2: Basically it's quite likely there's more then a few comets out there which are going to make close passes to Mars already, where for the cost of an impactor, we could ensure they hit Mars instead if we found them early enough.
Aren't there only a handful of asteroids over a 100,000 cubic kilometers? Even if they were entirely ice - aren't there 1,350,000 cubic kilometers of water in the oceans?
Even if the largest asteroid was completely ice - it still couldn't have as much water as the ocean, right??
But deorbiting more amenable bodies into Mars from the numerous comets that impinge on our solar system is achievable. And of course if there's water somewhere, then there's water almost everywhere (which there is - if nothing else there's a huge amount of it in Saturn's rings).
The point is, what you can do terraforming Mars, is quite different to anything you could do to Earth, because you can't just freely cause some cataclysmic events here.
EDIT: The other key point is all this work is largely fire-and-forget once you know how. An automated solar reflector probe can be launched and happily continue causing some body to outgas for years, with no human intervention at all.
Even if it's entirely ice - pi*500km^2 = ~785,000 cubic kilometers of water, right?
Isn't that half of what's in the oceans? What am I doing wrong??
> In answer to this challenge, Dr. Jim Green – the Director of NASA's Planetary Science Division – and a panel of researchers presented an ambitious idea. In essence, they suggested that by positioning a magnetic dipole shield at the Mars L1 Lagrange Point, an artificial magnetosphere could be formed that would encompass the entire planet, thus shielding it from solar wind and radiation.
Everything is temporary in the long run.
>"MAVEN has observed the Martian upper atmosphere for a full Martian year, and has determined the rate of loss of gas to space and the driving processes; 1–2 kg/s of gas are being lost."
If that's 10k years it's less appealing, but 1m years might be worth it.
No need to worry about atmosphere loss & you can start incrementally and get usable land almost at only, not only after long years of terraformation.
With "terraforming" you'd have the problem that dozens of generations would have to work their proverbial asses off without ever experiencing the fruits of their labour. Not exactly a strong suit of the human race.
Another advantage of the world-house approach is the possibility to leave sites of interest as-is by not including them. With terraforming it's impossible to preserve select areas for scientific or cultural reasons.
So to rebuild it, might want to quickly get to a sustainable value before its blown away again? I favor crashing Saturn's icy asteroids into Mars to release gigatons of water vapor.
Does this mean that mars is losing atmosphere faster today than it did 500million years ago? That's really fascinating!
Here's a sunday-supplement summary I did find:
The critical component for the magnetic field (the molten iron ball) is hard to replicate.
Terraforming will in part be a permanent process. The atmosphere lost will have to be continually replaced. And that's fine.
We need to learn the ins and outs of how to terraform, at first, at home, on Earth.
We have several current problems on Earth that are good candidates for terraforming:
How to reduce CO2 in the atmosphere.
How to produce drinkable water in places there aren't any.
How to grow plenty of food on land that is sub-optimal.
If we can do those things here on Earth, then we might possibly have some chance of success in terraforming alien places like Mars.
We should be living in spinning space stations in warm-and-toasty solar orbits
There is no evidence that 1/3 Gee won’t be fine for humans to live in. NASA has already figured out how to have humans life in zero fee for long periods (low rep, high force exercises).
Mars had enough sunlight to power solar panels and grow plants.
Spinning space stations have their use as well, but have to import 100% of resources. Mars is lousy with water, CO2, and easily accessible elements such as Iron.
It's likely that you feed yourself with hydroponics, and use the waste materials and imported inoculate to start a composting operation, where, like earth gardeners, you feed a little bit of dirt into each batch. If you can tune that to break down perchlorates, then soon you'll have compost you can grow more food in, at which point you start getting compound interest. Assuming, that is, that you send actual soil scientists and not industrial ag people, who think soil is something you wear out and then buy at a store.
On a planetary scale? How?
Just the soil colonists will be using is all you need.
Until then, just rinse off your suit and boots when you enter the dome.
This is such a weird statement. It's less than five times three very large areas combined... It leaves me with no idea how large it is. For those curious, it's about the same land surface area as earth has (removing oceans).
They've got the same challenges but are easier
Mars has 0 people living on it, and is already uninhabitable. We literally cannot make it worse for anybody, and are in no danger of wrecking anything we need to survive by trying.
I would much larger we try planet-scale geo-engineering on Mars, then try planet scale geoengineering on Earth (and we're already flirting with that because of climate change).
There is a wealth of information to be gained from attempting dramatic changes to a planet's condition, and establishing a biosphere, which would be extremely important for any attempt at large scale Earth biosphere repair.
How does it work?
* Do scientific research and exploration
* Win fame and prestige
* Enjoy having no existing property claims or cultural heritage to disturb
* No laws. Make your own laws. Escape persecution.
* Build a low light-and-RF-pollution observatory
* Create the ultimate off-site backup
Mars might not have regions that are better suited than these inhospitable parts of Earth but it has the feature of "not being Earth".
Consider it a backup/fallback for the "single point of failure" that Earth currently is not just for humanity but for all of life in the universe that we know of.
Now that we are developing the technical abilities to be able to remove this possible failure point and to finally add some redundancy for life, I think we are almost morally obligated to do so.
Mars also has fewer natural protections than Earth: a thinner atmosphere, no magnetic field to speak of, and no giant moon that deflects or absorbs at least some percentage of objects that would otherwise impact Earth. So Mars is more susceptible to dangerous radiation and object impacts than Earth.
For the same cost outlay (or way less) as trying to make Mars an effective backup for Earth Earth could be made more robust and dedicated purpose-built backups could be created.
Mars as a backup of Earth is like a cheap eBay thumbdrive hanging from a wind chime on your patio is a backup for your data.
What could happen to the Earth that would make it even close to as inhospitable as Mars?
It hardly matters that the apocalyptic Earth is more hospitable to human life than Mars currently is if we don't have any humans left to resettle Earth.
Even if a huge asteroid hit, we could almost certainly build shelters where more people could survive the initial impact than we can settle on Mars in the foreseeable future.
An analogy: a bunch of important files become corrupt (cataclysmic event) and the domain expert is no longer with the company (loss of knowledge and industry). It is much easier to move forward if one has a way of contacting a subject matter expert (Mars colony) to restore or rebuild what has been lost.
I believe we also need a colony to hold on to seeds of civilization in the very sense of the word.
It's like making a backup of your computer but never testing restore. The chances of that backup not being complete or recoverable are fairly high.
The backup of human civilization on Mars will probably be theoretically worse than one that can be made on Earth. But it will be supporting life, making it fully tested and thus practically better.
We might not colonize a neighbouring star system in the near or medium term future but I am convinced that if we do not start moving out into the solar system, we never will go anywhere else either.
Mars has no fossil fuels, so that can't be it. Minerals cant really be destroyed or exhausted. Technological knowledge is much easier to preserve from cataclysmic events on Earth than it is on Mars (if we fall under some kind of technophobic super empire that seeks to destroy this type of technology, that will as easily spread to Mars as to the rest of the Earth).
If our low earth orbit space gets too full of debris, we become stuck until we can find ways to clear it out.
But no doubt they will say: use broadcast power.
I'd like to see a system that, allowed to order any stock catalog item on Amazon or Digi-Key, could self-replicate.
Sure, temperatures would go down (but nowhere near as cold as Mars) and it would be hard to harvest plants, but we would still have fossil fuels to generate electricity for grow rooms, and we would still have earth soils that are ultra-rich in nutrients. The surface would be nowhere near as radioactive, so people could still work outside, allowing mines and so on to keep operating as today.
Overall, while it would be a huge tragedy, kill billions, and destroy our civilization as we know it, it would still leave the Earth as an absolute paradise compared to Mars.
If we were talking about another planet in another solar system, you could have some arguments about long term survival, but otherwise the earth will at worse become as inhospitable as Mars, until the sun burns them both to a crisp at about the same time in a distant future.
Similarly, any asteroid impact of a size that the Earth has seen since life appeared would neither wipe out ALL of humanity nor leave the Earth in a shape as horrible as Mars is in right now.
Edit: we know this for sure, because even after the asteroid that wiped out the non-avian dinosaurs, human sized and larger animals survived and thrived through the impact and fallback, despite having no access to any kind of technology or preparation. If the cold-blooded crocodiles could do it, I'm not worried about our chances.
Solar flares do not count as earth-ending events, at worst they could destroy our current electric networks and kill and strand maybe millions, but they are not in any way civilization-ending, nevermind life-on-earth ending as far as I know.
You also have a deep gravity well.
Land on Mars is free, there are zero taxes, no political system or unwanted populations.
There is no waiting for regulatory approval on a new building, no requirements to hire x % of your workforce as y demographic subset of the population. There is no national Government to negotiate with. Your population is completely comprised of high-IQ, motivated and skilled people, making for the best human gene pool of any place in the galaxy.
When SpaceX gets to Mars, it can simply... build, without limits. This is something not seen on Earth since the colonisation of the new world (which even then had native populations to contend with).
Until SpaceY gets to Mars. Then the absence of governments and regulation stops being an unmitigated benefit for SpaceX.