Mars Terraforming is only possible with new technology but mass colonization of Mars capability provides it

72 thoughts on “Mars Terraforming is only possible with new technology but mass colonization of Mars capability provides it”

1. I believe no need to wrap the superconducting coil around the Martian equator. Just need suitable valley for beginning and coil between peeks. On each peak magnetic tower. For sure all the buildings in valley should have conductive net for protection

2. I believe no need to wrap the superconducting coil around the Martian equator. Just need suitable valley for beginning and coil between peeks. On each peak magnetic tower. For sure all the buildings in valley should have conductive net for protection

3. I believe no need to wrap the superconducting coil around the Martian equator. Just need suitable valley for beginning and coil between peeks. On each peak magnetic tower. For sure all the buildings in valley should have conductive net for protection

4. True, maybe ‘liberating’ subsurface stores of Carbon on Mars could suffice, not related to the polar casp. This question cannot be answered with current data on the subsurface of Mars.

   On the other hand, a future Venus-Mars-Earth-Triad, could see as much traffic as we have big-wheel-transport-rigs on the international roads. Because of our limited foresight in multi-variable networks that grow exponentially, it could be less of a challenge than we imagine.

5. Actually, no, they won’t have a different orbital period.

   The orbital period is based on the speed you need to be going at a particular distance from the primary to balance forces. L1 is closer to the Sun than Mars, but has the same orbital period, because the gravity from Mars does some of the balancing, reducing the needed velocity.

   Likewise, *if the solar wind were constant*, you could find a point even closer to the Sun, where the thrust from deflecting the solar wind plus the gravity from Mars balanced part of the increasing Solar gravity, still permitting you to have the same orbital period.

   That point might, however, be a LOT closer to the Sun than L1, giving you problems keeping the protected zone large enough at that great distance to encompass Mars.

   The problem is, the solar wind isn’t remotely constant, so there isn’t actually any one position that balances the forces. And the L1 point *isn’t dynamically stable*: You get pushed one way, you fall towards Mars, you get pushed the other way, you fall towards the Sun. So even a regular station would need station keeping thrusters to stay there.

   A station intended to deflect enough of the solar wind to protect Mars would be subject to simply enormous thrust from the wind, and very variable thrust, so it would need incredibly powerful station keeping thrusters.

   Or you just wrap the superconducting coil around the Martian equator, and forget about thrusters. Which is what you’d actually do.

6. Buoyancy is free, but limited. This really depends on your firing rate. You fire too much too fast, and your balloon gets pushed down more than buoyancy can recover. The platforms may be large, but at 1+ teratons/year, the firing rate and recoil are also large.

   By “equivalent” I just meant anything that can balance the force such as jets, railguns, etc. I doubt buoyancy will be enough.

   The solar wind effect can probably be accounted for, except during major sudden spikes. But AFAIK such spikes aren’t uniform in all directions, so they still need to hit the beam to have an effect. The wind itself is generally quite weak, so I’m not sure it’ll have much of an effect to begin with. The bigger problems with the beam proposition are aiming and focusing. If we can’t focus the beam sufficiently, or can’t aim it accurately enough, most of that material will miss the target.

   Honestly though, the more I think about it, the less appealing the whole terraforming idea sounds. If we’re going to spend that much time, effort, and resources moving that much mass etc, even if it’s all automated, there are probably far better uses for all of that.

   Time-wise, this is going to take at least 200 years (if not a few thousand), starting from at least 50 years in the future or so (since the scale of this pretty much requires self-replicating tech). So there’s at least ~250 years for competing technologies to develop in the mean time. Between orbital construction, genetic and other enhancements, and who knows what else we’ll develop, I rather doubt we’ll still need terraforming by the time this is done.

7. What am I missing? Why would you need to combat recoil with beams? Buoyancy is free. If we are assuming rail-guns on top of balloons, then the recoil would result in the balloon being compressed or descending a bit before buoyancy pushes the platform back up again. If Venus is really being colonized or used for terraforming Mars, these platforms will be so large and stable, that they will hardly budge or not at all. Mars also will not have problems absorbing the impact force…. but you added ‘or equivalent’, that’s sneaky.

   A complication and argument for not using plasma is the variable solar wind. Given that and the long time of flight, your beam of ice particles will scatter into difficult to manage patches and trajectories (I wonder if the light reflected of it could result in a rainbow stretching in a winding path across the night sky). In the scheme with the straws you do need to use the pressure drop because you are making humongous icicles, which needs to happen in a localized manner, at the exit, preferably inside of a container; a jet of sparse cold molecules doesn’t help in that scheme.

   The heat pump will work, it has to, but the time scales become a problem. 92Bar. Also, after Mars is terraformed, you might not have a reason to continue to shoot the gas into space and even desire to hold on to that resource. Maybe you can use and waste some of the available heat on Venus to power a C02 fountain only on the night side. You shoot it upwards but not beyond escape velocity and after radiating some of its heat away, it would drop down again. Of course, cooling must exceed the illumination on the day side, so you are fighting opposing forces. You indeed need extra to solve for the irradiance on the dayside. e.g. a swarm of mirrors in orbit or L1.

   In other schemes the C02, together with the H (and N) is used to make plastics and cover the entire lower venusian atmosphere with a plastic reflective layer kept in the air with trapped O bladders beneath it. Bubblewrap planet?The change in reflectance would allow the CO2 to eventually cool and even freeze out. Afterwards you cover the C02 layer over with dirt or gravel for it to never ever again see the light of day.

   The problem with that scheme is that according to some scientific papers radar indicates that Venus radiates more heat than it receives from the sun. In those papers, the temp of Venus cannotentirely be explained as being the result of only the pressure and greenhouse effect but must also result from internal heat (e.g. a Venus that is still cooling, or a Venus who’s core (a giant dynamo) is heated by the solar electric field). If that is indeed the case, you wouldn’t be able to cool the C02 or it would take another engineering idea (e.g. the great thermos-flask) to overcome the radiated internal heat.

   The last idea I have is to harvest heat to turn C into diamond.That would ‘compact’ the problem for C, but you still have the O and the N. Does Venus terrain require oxidation?

8. I understand. The underlying assumption seems to be there was and must be an immediate short term ROI. Fact is that it became a national policy. Wind mills were built on a large scale to do the pumping, to drain marshes, swamps a.o. Later came the dike building initiatives, the great disaster of the fifties and the latter part of the 20th century is famous for the delta-works which were national construction works on a beyond pharaonic scale.
   With regards to Mars, if you want to argue gradualism, you can. For instance: there is only so much C02 to compress into habitable domes, before you run out (para-terraforming), and after that you’ll need imports and the urgency, or business case to do so becomes stronger. But forward looking entrepreneurs could first set up import of N from Venus, to aid with agriculture and food production in the existing domes on Mars. First you would ship only the urgently needed gases (and noble buffer gases), and after a while you would/could reinvest to expand operations. But humanity often works with much vaguer business plans. What was the Business Case for Carbon Credits? (the derived Business Cases (afforestation, capture, reduction) were there result of installing a legal regime that created artificial scarcity where there was none). They led to large afforestation projects in e.g. Australia. What is the Business Plan for combating climate change or for the Paris Agreement? These measures could be explained in terms of being business cases to buy future agricultural productivity. To have any meaningful effect, they need to be in place for decades. You can argue they need to be in place for centuries, since for all our current received wisdom, natural warming processes we do not yet understand could still be going on and if after 200 years of further research C02 turns out not to be the main culprit, efforts to create an ‘ideal’ world climate will probably continue. In any case, combating climate change, or the quest to dial in some ‘preferential stable climate’, is a form of geoengineering, even terraforming, that we have decided to engage in.

   Recognizing in explicit terms that we are doing terraforming with Earth, makes it easier for the public to understand and see that it could be done for Mars, maybe even with some form of novel legal regime, e.g. making the import of gases mandatory whenever a colony wants to expand. The argument could be that in that manner, these C02 compressing habitats don’t damage or scavange the preexisting Martian atmosphere which has benefits for extant martian life (e.g. some rad protection) and for spaceships (propellant needs + the air resistance does help somewhat in slowing them down which increases their payload fraction compared to pure retropropulsion). As you argued for the Dutch, cumulatively, it might set in motion a nationwide respectively a planet-wide result, even if the initial ambition was more limited.

9. Actually, volatiles are the vast majority of the inner solar system. You forgot to count the Sun.

   l’wik: Most of this gas is hydrogen (about 70%) and helium (about 28%). Carbon, nitrogen and oxygen make up 1.5% and the other 0.5% is made up of small amounts of many other elements such as neon, iron, silicon, magnesium and sulfur.

10. The phrase “business plan” points to one weakness in the plan. The business case for each justifiable chunk of the effort isn’t there.
    AFAIK, the Dutch didn’t set out to make an entire country. The Dutch weren’t embarking on a 200 year project with a country at the end of it. One family was embarking on a years long project to drain this particular swamp here and turn it into a field. Another family was enlarging their farm over there, with a real, valuable return available for the people doing the work now. A village here, an estate there. It added up over time. It’s much easier to do something if there is a payoff at each step in the plan. And even easier if there is a personal payoff for each subsection of each step.

    Not to say that it can’t be done. Just that I think the politics of setting up a giant project with a payoff centuries in the future is probably more difficult than the technology and engineering.

    Of course, if we DO get radical life extension then the calculations are different.

11. Perhaps crashing a C-type (carbonaceous) asteroid of a few kilometers diameter into Mars would do the trick? about 40% of asteroids are C-type around 2AU out, mars is around 1.5 AU. Would also need an oxygen source to burn the carbon. Ironic to go to so much trouble to CAUSE rather than prevent rampant pollution.

12. You’d still need the opposing beams (or equivalent), since the railguns have recoil. Newton’s 3rd law and all that. The extra sails complicate things somewhat, but with self-replicating tech, it might be doable. But the solar wind is pretty weak, so you’d need really enormous sails to move that much mass. And lots of them.

    In another comment I suggested putting all the carbon in the sails, and having them haul oxygen instead. Then use the oxygen to convert the sails back to CO2. But if you have self-replicating tech, you may as well build out as much solar and orbital mirrors as you need, and go with the simpler plan. Technically, you can make do with simple jets, as long as you can get the needed velocity and flow rate – no need to ionize to a plasma. And btw, it will condense into ice anyway, once it’s in space.

    While we’re speculating on future tech, I wonder if the outgoing beams could be set up as a heat pump. So they would carry a bunch of heat away from the Venus atmosphere at high temperature, while the balance beams would be at a lower temperature than the atmosphere. Then if we do this at the 5-20 teratons/year level, we get to cool down Venus as a side-effect. If we cool it down enough, the CO2 will condense, the greenhouse effect will shut down, and we’d be half way to terraforming Venus as well.

13. Yep. 10^18. So…. Going through your numbers for 1 Teraton/yr.. I am not sure plasma gun is optimal. Current Railgun barrels today aren’t up to spec, but I was inclined to playing with shooting frozen icecubes in graphene shells. When you use shells, you only need to go to orbital speed at 7.5km/s (and Venus is 90% Earth G, so that’ll help). The rest of the energy can be provided by the solar wind, which both photonic or magnetic sails can harvest and steer with. You don’t need an opposing beam or laser driven schemes. Also, due to the lower acceleration requirements, the power requirements drop about sevenfold to ~43 times current terrestrial production. That’s not that bad, given that e.g. electricity production in 2014 is 3.9 times what it was in 1973 (just wikipedia figures, nothing fancy). There is room for exponential growth of energy use on Earth, so lets say that in 20 years Africa makes a growth spurt and what we produce actually doubles. In that case the Venus scheme only needs about 20 times Earth production.

    Now, there is a technique that is supposed to hardly require even that amount of energy: Space fountains. Basically large straws with the bottom end in the atmosphere and top end beyond Venustationary orbit. Centrifugal force, or whatever you are inclined to call it, will do the sucking for you, courtesy of the Venusian rotational energy. I’d still create a pressure drop at the end, converting the gases into icecubes and shipping interplanetary using solar energy.

    Length, diameter, number of ‘straws’, counterweights would have to be dialed in, and you still need to manufacture the infrastructure etc., but suddenly the energy requirements could come into the realm of what we have experience with.

14. try to inflate a balloon, he that requires some lungs right, next try to inflate a planet width CO2.
    How much would you need .. its gonna take forever.. wont see that happen in the next 1000 years.

15. > I have a concern about O’Neil colonies, over the long run, though: They’re going to *leak*, and volatiles are a tiny, tiny fraction of the mass of the inner solar system.

    Depending on the specific design, that may be a non-issue. They don’t have to be open. Of course, no seal is perfect, so there’s still going to be some leaking, but by the time we can build these, we won’t be limited to the inner solar system for supplies. And the supplies don’t have to be in volatile form either. Oxygen is pretty plentiful, as it tends to react with everything. Hydrogen is plentiful in various ices, in the gas giants’ atmospheres, etc. Sometimes they’re found together as water or various hydroxides in carbonaceous asteroids, various ice deposits and hydrated minerals, and subsurface oceans. For nitrogen there’s Venus’ and Titan’s atmospheres, and various ices further out.

    Carbon is plentiful too, but for our uses, most of the carbon won’t be in volatile forms, so it won’t leak as much. But food carbon can leak as CO2, so if we do need to restock, there’s Venus’ atmosphere, carbonaceous asteroids, Titan, etc.

16. To answer my own question, Venus’ atmosphere is 4.8e20 kg, so even 20 teratons/year (10 in the outward beams and 10 in the balancing beams), which is 2e16 kg, is only 0.004%. Probably negligible in terms of mass movement. Though to save energy, we’d want to push a much larger mass at a lower velocity for the balancing beams.

    Energy-wise, it’s 96.5% or 4.6e20 kg of CO2, with 44 g/mol molar mass and 37 J/K*mol heat capacity. So:

    4.6e23 g / 44 g/mol = ~1e22 mol. Times 37 J/K*mol = 3.7e23 J/K total atmospheric heat capacity.
    5.6e16 W (=56 PW) * 365 days/year * 24 hours/day * 3600 s/hour = ~1.8e24 J/year
    1.8e24 J/year / 3.7e23 J/K = ~5 K/year of heating.

    Times 400 years that’s 2000 degrees, minus radiative cooling. Could be an issue. At least we’d need to slow this down enough for radiative cooling to keep up, to keep the temperature manageable. At an export rate of 1 teraton/year, it’s 1/10th the heating, which should be ok. But then it takes 4000 years to reach full atmospheric pressure at Mars (200 year for minimal presuure). Meanwhile, our spacefaring abilities keep advancing, including construction of large space habitats. So I’m really not sure this is worth the effort.

17. Continuing my previous reply, the plasma needs enough delta-v to escape Venus orbit and reach Mars. Venus’ gravity is similar to Earth, so I’ll ballbark the escape velocity at 10 km/s, assuming ~1 bar atmospheric pressure at the cannon altitude. Mars injection is maybe another 5 km/s or so. It will vary depending on the planets’ orbital positions, since we’re not always firing during a least-energy launch window. Some extra relative velocity at Mars is fine (helps with the heating effort), so let’s round that up to 20 km/s total.

    E = 0.5*m*v^2 = 0.5 * 1000 kg/ton * (20000 m/s)^2 = 2e11 J/ton.
    1000 tons/hour = ~0.28 tons/s, so that’s ~5.6e10 W or 56 GW per cannon, continuously.
    For 1 teraton/year, we need ~100000 cannons, so 5600 TW or 5.6 PW (petawatt) total. That’s ~300 times our current global energy production here on Earth. Probably double that, since you need to shoot a matching beam in the opposite direction to balance the thrust. Plus inefficiencies.

    For 10 teraton/year, it would take 56 PW, or ~3000 times our current energy production. That’s about 1/3 of Kardashev I level. With the above-mentioned overheads, it’d probably be close to full Kardashev I. Which is fitting, since we’re talking about terraforming a whole planet.

    I wonder what kind of effect all those rear balancing beams and waste heat will have on Venus though. That’s a lot of extra heating and churning.

18. First, 1000 teratons is 1e18 kg (1 with 18 zeros) – your starting point was off by 3 orders of magnitude.

    Second, railgun barrels are a problem because railguns use a solid sliding armature to launch the projectile. The armature is in direct electrical contact with the barrel, which creates a lot of friction and heat that ablates the barrel. But with CO2 you don’t have that problem, since it’s a gas. You basically need a continuous stream plasma cannon, not a railgun. The plasma isn’t in direct contact with the barrel, so there’s a lot less ablation (though there may be other wear and tear mechanisms going on).

    To simplify the calculation, we can ballpark the required flow rate as 1 teraton/year for minimum atmospheric pressure on Mars in 200 years (Earth years). 10 teratons/year if you want to get full atmospheric pressure in 400 years (your figure of 1000 teratons in 200 years is 5 teratons/year). We actually want a mix of CO2, O2, and N2 similar to Earth, with just enough CO2 to get enough greenhouse effect for Earth-like temperatures. There’s enough nitrogen in Venus’ atmosphere to do that. Oxygen can be split from CO2. But we’d want to start with mostly CO2, to get the greenhouse effect going as early as possible.

    So, 1 teraton/year is 1e12 tons/year (1e15 kg/year). A year is ~10000 hours, so this is ~100 million tons/hour (1e8 tons/hour). Using your firing rate figure as a 2nd ballbark, 1 ton/shot * 10 shots/min = 10 tons/min = 600 tons/hour. Let’s scale that up a bit to ~1000 tons/hour per cannon. Then for 1 teraton/year, we’d need ~100000 such cannons. ~1 million cannons for 10 teratons/year.

19. You can’t do a hundred levels. Well, mechanically you probably could, but the waste heat dissipation would be impossible if anybody was actually living in them; No matter how high you stack them, you’ve only got one surface from which to reject the heat. Even if you run a biosphere using only highly efficient lighting at the frequencies chlorophyll uses most efficiently, you might get two layers.

    If your goal was actually maxing out livable space, you’d move that material into orbit and build O’Neil colonies.

    I have a concern about O’Neil colonies, over the long run, though: They’re going to *leak*, and volatiles are a tiny, tiny fraction of the mass of the inner solar system.

20. Not necessarily: One of the terraforming proposals is to manufacture “super-greenhouse gases” on Mars, and release them. They could be much more effective than mere CO2 at retaining heat. Search for ”
    Keeping Mars warm with new super greenhouse gases”

21. Actually, as far as colonizing Venus goes, the winds are a feature, not a bug: Venus has a *very* long day, but the winds are moving fast enough to considerably shorten it. It’s not wind a floating colony would have to be concerned about, but instead turbulence. Doesn’t seem to be a lot of that 30-40 miles up, near the equator.

    As for the polar temperatures, search for “Death Plunge Of Venus Spacecraft Reveals Surprisingly Cold Temperatures On The Hottest Planet”; This relates to temperatures in the upper atmosphere, of course, but I’m not suggesting that the polar surfaces are livably cold, just that they might be more hospitable to automated mining equipment.

22. No need to go as far as orbital scoops. Air is buoyant in Venus’ atmosphere, so there were suggestions of blimp habitats. Combine that with Brett’s suggestion of a particle beam, and you get a fairly simple solution:

    Put industrial blimps near the top of the atmosphere with either solar or nuclear power. Probably better solar, since it’s not limited by fuel, and this will take a LOT of energy. Then you can pump the atmosphere in directly, process it, turn it to a particle stream, accelerate it out a mass driver (aka make a beam), and point it at Mars (give or take orbital mechanics corrections). You can place mirrors in orbit to get more solar power.

    You’d need to point a similar beam downward to balance the impulse and stay on top of the atmosphere, so once the beams get going, the buoyancy becomes insignificant. But you’d have the same problem with an orbital platform. Also you might need to point the outward beam in different directions over time to keep Venus’ orbit stable (not sure if the thrust would be large enough to alter the orbit – maybe not). But you should get that naturally from Venus’ and Mars’ relative motion.

    You’d need self-replicating tech for this scale anyway, so you can start from seed machines that naturally float in Venus’ atmosphere. From there, the CO2 gives you carbon for structural materials (graphene, CNTs, polymers, etc) and oxygen for the air. The 3.5% of nitrogen in Venus’ atmosphere completes the air composition. Various hydrogen compounds give hydrogen to complete the picture.

23. And you loose Ceres. What is so great about that? I just explained that you can get 4 times the surface area of Mars as a virtually perfect human climate without transforming. And support trillions of people. And that is probably a gross understatement. We may be able to dig a hundred or more levels. So why terraform? Ceres can provide space and resources for billions more people living in Ceres.

    What is so great about terraforming? It just diminishes resources better spent elsewhere.

    Now if we happen to find a planet that is almost the same, and we just need a few little tweaks…fine.

    Why be so locked into living on surfaces of planets people?

24. There is a lot going on. For one, if they are just adding more CO2, that stuff holds energy pretty well. It is a greenhouse gas after all. So it could even speed up. On Earth water affects the speed in many ways, overall slowing it by taking the energy in the process of vaporizing. Without that moderator, I suspect the wind speeds on Earth would be far faster. Mars would have no moderator. So even though it is further from the sun, who can really say without a good bit of computer modeling?

    The energy of Earth winds is not spent hitting the surface, for the most part, it is spent mixing. In fact, it gets much of its energy from the surface, convectively and from re-radiation at lower frequencies the sun’s energy.

25. ‘The total mass of the asteroid belt is estimated to be between2.8×1021 and3.2×1021 kilograms, which is just 4% of the mass of the Moon.’ So bombarding Mars with the entire asteroid belt would not make any discernible difference to the gravity there.

26. ‘.. there is some reason to believe that the ground temperatures around the Venusian poles are not nearly as outrageous as elsewhere..’
    If the whole planet is blanketed in supercritical CO2, the idea that the poles might have a human-tolerable temperature is about as plausible as finding parts of the Marianas Trench bottom where you could go diving in a wetsuit. It snows lead sulfide on parts of the highlands. That melts at 1,118 C, so do you think it could be okay for a ski resort ?
    The winds at cloud top level on Venus average 220 miles an hour. They scoot round the sunlit hemisphere and then downwell on the shady side. It doesn’t sound like a secure environment for building a colony.

27. First, there is plenty of oxygen on Mars, and it can be released by heating up the soil. The main concern in heating a planet is not some greenhouse gas, but pressure. There is no need to limit yourself to CO2. Then again, 1000 Teratonnes pf CO2 shot from Venus with railguns is conceivable. Today BAE Naval railguns are at 2.6km/s and 32Megajoule, but in a couple of decades we could conceivably shoot car sized shells out of a barrel (Barrel tech is the showstopper in these technologies, but mass drivers can trade strength for length and a vacuum housing). But let’s assume 2.6 km/s and be lenient on the masses we will be able to fire without shortening the lifespan of the barrel.

    The back of the envelope calculation miracle

    1000 teratonnes of CO2 in kg, is 1 with 15 zeros. Thus: 1Tton / 1000 kg payload projectiles, 365 days, 24 hours, 60 minutes is only 1,902,588 now… instead of once a minute, let us fire 10 times a minute, as in modern tanks: 190,259. Number of rail guns: 1000…. We get 190 years. That is the amount of time the Dutch needed to rid their country from water. Now,  a 1000 guns isn’t that many, compared to the number in the world inventory, or compared to the amount of over sized windmills China or Europe currently installs every year. So… is it impossible? No, it sounds like a business plan. You can also increase the number of guns to use smaller shells within the range of fielded barrel technology. The world has about 100.000 towed artillery pieces, so the numbers involved, in a coordinated commercial effort, are not excessive.

    Want more pressure? Repeat or expand the operation.

    In any case, if there is a business plan for Dutch people creating a tiny piece of land, than there is a business plan to reclaim a planet sized piece of land for…green people.

28. Unless you WERE adding more energy to the system, such as by having big mirrors to focus sunlight on the planet. Or dropping comets on the surface to add volatiles, water, and geothermal hot spots.

29. Added bonus: Some nice deep craters would have more atmospheric pressure at the bottom compared to the planetary average.
    If your craters are km deep you could have habitable regions long before the average surface was survivable.

30. Tuning the magnetic field strength would let you keep a constant level of thrust. But only at the expense of greatly reducing the protection exactly when a big burst of radiation comes through.
    This will stop the radiation. Except when the radiation is particularly bad. Which doesn’t help much at all.

31. Mars orbit is 1.524 AUs. That means it get only 28.25% of the solar radiation. To get enough solar energy to bring it up to Earth temperatures, it would need a mirror 10,800 kilometers in diameter.

32. Yes, a promenade with water, plants and animals would do wonders for the people’s morale. The bigger, the better. And look very nice in the promotional videos.

    Even if in practice, many of these exposed domes would prove to be bad for the living critters in them just by being outside at the mercy of the random bursts of solar activity. But for aesthetic and recreational purposes, it would be fine I guess, including their periodic re-populations.

    But for crops, meat and critical recycling purposes, you need to have those well guarded, most likely covered by a thick layer of rocks and dirt. And they would probably look a lot less pretty, including a lot of intensive crops stacked in small rooms, meat growth tanks (either cloned cells or full animals, mostly fish) and bacterial vats.

33. You wouldn’t move it by rocket if you were going to do it. You’d deliver it in the form of a neutral particle beam, all “payload”. But, yes, it would take centuries even with the necessary technology being developed.

34. If you raised the air pressure, the wind speeds would drop proportionately. There wouldn’t, after all, be any more energy to drive the wind, it would just be distributed across a much larger, slower moving mass of air.

    The winds get going very fast on Mars because the atmosphere is very thin, and thus doesn’t effectively dissipate energy against the surface.

35. As I related in a comment thread since lost, surface domes require extremely strong and thus expensive construction. Buried domes, on the other hand… A fabric bag weighted down by sandbags sufficient to counter the internal air pressure would require only a few pounds of fabric per square foot, and the overburden of dirt would be good shielding against radiation and meteors.

    With internal cable stays to suppress instabilities, there’s no real reason such domes couldn’t be arbitrarily large. Unlike surface domes, that get harder to build as they get bigger.

36. Measurably increasing Mars’ mass would require astronomical numbers of asteroids. OTOH, a long term program of cometary diversions might well be in order, to increase the available volatiles. Particularly if this were done well away from the Sun, the required delta V to accomplish it would be relatively minor.

    Dropping Ceres on Mars would be a shame: The impact would probably be sufficient to render Mars too hot for a long while, and Ceres itself is a good candidate for colonization.

37. OTOH, there is an altitude in the Venusian atmosphere where both temperature and pressure are suitable for human life, and in an atmosphere composed almost entirely of CO2, breathable air is an excellent lifting gas.

    Thus, it would be feasible to colonize Venus prior to terraforming, using floating colonies with people living inside the flotation bags. Materials could be raised from the surface by means of dredges hung from the colonies.

    Also, there is some reason to believe that the ground temperatures around the Venusian poles are not nearly as outrageous as elsewhere; If that proves out, at the poles only pressure and a toxic atmosphere would be problems.

38. A quick and dirty way to get CO2 into the Martian atmosphere would be underground H-bomb detonations in the Nili Fossae deposits.

39. Average? In bad year when colony will especially need this device to work in full power it will end up on Mars unless it’s weight measured in million of tons

40. Is there any reason you couldn’t adjust the current in the loop &/or tilt the shield to keep the shield between Mars & the sun?
    I doubt the viability of this scheme, but I don’t see that keeping the shield between Mars & the sun would be a show stopper.

41. We have to account for 100 years of tech progress as well. I haven’t seen any shorter estimates for the beginning of actual terraforming.

42. The most important thing about Venus is its gravity which is approximately the same as earth. I am thinking large domed cities power by energy beamed from the solar shades.

    As for the excess CO2 take could be converted into some sort of mineral. The biggest problem will be the lack of water. Bagging some comets and redirecting their orbits so they hit Venus could be a solution.

43. Matter of how much energy. Moving mass from Venus to Mars requires a lot more energy than moving mass from Ceres to Mars. On top of that you can move mass using mass drivers from Ceres. Also Ceres has a lot more available water and CO2 than Venus. Most of the mass of Ceres would be available which is not the case for Venus.

44. So what?

45. And?

46. It only needs to average known level, and it does.

47. The technology which can make Mars habitable on the surface outside of a hab module with for example, only an oxygen mask–this is anticipatable. designable technology now, not hard to do.

    No currently anticipated technology can make Venus habitable with only a similar measure of intervention.

48. And how you can somebody rely on thrust from solar wind? It is so unpredictable

49. In that case your device and planet will have different orbiting time. Device will always go faster. If you try to use thrust to correct it device will fall toward the sun: so you will need additional thrust to correct going ahead + falling 🙂

50. And Venus is much closer to Earth

51. Agreed. Comparing to Mars it only need large orbital mirrors to create twilight on Venus by regulating solar radiation

52. You put the shield a bit sunward of the L1 point so the thrust from the solar wind is balanced by the gravity of the sun being larger & the gravity of Mars being less.

53. If we are going to posit future advanced terraforming technology–which is a reasonable thing to do–then there is a case to be made that Venus is a more suitable planet for human colonization. It already has an atmosphere, and has gravity nearly the same as Earth, which is a big deal. If we assume exponential progress in various technologies such as AI, nanotechnology, etc, then it should soon be possible to figure out a solution, possibly involving self-replicating nano-robots that could transform Venus’ sulfuric acid and carbon dioxide into oxygen and nitrogen. Other aspects of Venus would have to be engineered around, such as the lack of magnetic field, atmospheric pressure, etc.

54. For a long time, buried cities and some domes will be the reality.

    At high latitudes, solar wind and CMEs could be blocked with a thick hill of dirt, allowing a dome with a view of the sky and even the ground outside on the pole-ward side. Add mirrors to reflect in sunlight and it could be a much like being outdoors. This might be a reasonable approach for agriculture and parks without heavy power consumption, if plants can tolerate the cosmic radiation. With cosmic radiation cut in half relative to open space, humans could enjoy limited time visits.

55. But combined with the L1 magnetic shield, maybe domes would be safe enough against radiation? Still have cosmic rays, but occasional short term exposure wouldn’t be bad – half as much (per hour) as you’d get coming from Earth.

    If so, domes with Earth-like atmosphere (not pressurized CO2) could be made for recreational/psychological purposes. You wouldn’t try to build Earth-like cities under domes, but parks on top of buried cities – sure, once the colony is well established.

    And if you’re only doing parks, you probably just use localized magnetic shielding, unless for some reason an L1 shield is really cheap.

56. Venus also has 3 times as much nitrogen as Earth, which would be useful if we want to make a breathable atmosphere. But hauling trillions of tons of material is truly daunting. For the minimum 200 trillion tons in 200 years, we want a trillion tons per year. That gives the full 4000 trillion tons in 4000 years.

    Our entire mining operation here on Earth is in the billions of tons per year, and that’s with fully developed infrastructure. Still hundreds of times less than what this would take. And then you have the rocket equation for getting all of that mass from Venus to Mars. You’d probably need fusion rockets just to get the Isp to keep the fuel mass manageable. And that still may not be good enough.

    Maybe transform the CO2 into graphene solar sails, and have them haul the oxygen to turn the sails back into CO2… Anyway, short of self-replicating tech, it’s difficult to see how we can even get close to that scale.

57. I don’t see a magnetic shield at L1 as feasible.

    The magnet part? Sure. But what happens when it deflects the solar wind? What happens, especially, if it’s hit by a coronal mass ejection? *Thrust*.

    And, what opposes that thrust? Bupkis. Unless you build in truly massive propulsion capabilities.

    No, you build it on Mars, where the material and people are going to be anyway, and there’s the mass of an entire planet to anchor it to.

58. My tweet to Elon: What about towing (carefully) asteroids from the asteroid belt to crash into Mars to A) increase its mass B) generate heat to melt existing, and new, locked up water (Ceres alone could more than double Mars’ water). Decide before establishing colonies in harm’s way!

59. ‘How much does the average person spend outside and not counting their own yard?’ A lot more than you think, hopefully, and in your yard you can still feel sun on your face, watch the changing clouds, hear the birds and the insects. I think most people would rather be in jail, where at least they can spend an hour outside a day, and get visits from family, than live their entire lives in a hole on a dead world. If you’re claiming that humanity needs Mars as an insurance policy, it would be easier to survive in a mine on a post-apocalyptic Earth than on Mars, and you don’t have to spend your life there on the off chance it becomes necessary.

60. You need to get rid of the excess atmosphere and heat. Shading has the nice property of taking care of both: with a 100% shade the planet would cool off quickly in geological terms, I’ve read somewhere that in a few centuries it would froze over completely and then condense and fall as CO2 ice.

    You can bury that ice or transform it in something useful, and then you return the solar light to the levels you want.

    It would still be a very slowly rotating ball, though. Fixing rotation would be a really monumental endeavor, requiring hundreds of thousands of years at least, with very large engineering. But the planet itself could be inhabitable in a millenium or so with solar shades, a few water rich comets and some self replication trickery for making an O2 rich atmosphere.

    If we get really good at curing aging, those starting the effort could live on the planet and see it terraformed.

61. That depends how far you want to go with your terraforming.

    There is nothing stopping us from deploying huge space mirrors to raise the ground temperatures to any level we want.

    Gee, you probably need to do that to get started with terraforming.

62. Unpractical and too much radiation hazards from solar activity and cosmic rays.

    Underground buildings are better.

63. Shades would make Venus livable. Large solar shades.

64. Moving water from Ceres to Mars would be easier. Large number of large mass drivers flinging water to Mars is the way to go.

65. What happened to domed cities? No reason to terraform.

66. Google orbital air scoops for how to get the CO2 out of the Venus gravity well in the first place.

    As Mindbreaker points out, Venus has LOTS of CO2. Or to put it another way, enough to terraform Mars, and a dozen Jovian and Saturnian moons.

    Maybe even Mercury? (NO, the sunward side of Mercury will never be OK. But with the right atmosphere the shaded and polar regions might approach acceptable. Maybe.

    And maybe Luna?? The gravity isn’t enough to hold the atmosphere long term, but if you have a stream of CO2 being exported from Venus maybe you could reach an equilibrium?

67. No need for ships doing trips. One way, home made comets or lumps of carbon should suffice. Energy is free if provided by our star. Maybe graphene solar sails blowing outwards in the solar system. Biggest issue is how to mine the Venus atmosphere and bring stuff out of the gravity well. When Mars has had enough CO2, the rest can be dumped elsewhere or stored as purified carbon on Venus. Or use it to build structures in space.

    25 years is nothing. Not even Star-Trek did terraforming in such short time periods. Centuries or millenia are more realistic. When robots and AI systems are doing the work and energy and raw materials are harvested for free, the economy is disrupted and all our usual market economy conceptions of how things are done become irrelevant. Just bootstrap the process and eventually, it gets done.

    There are even schemes how to move entire planets in their orbits to compensate for the slowly changing Sol activity. Earth may have to move outwards not to get fried in the future. This can be done with simple asteroids and mass drivers and time. The process takes many millions of years but that is exactly what is needed to sync with Sol.

68. It is the wind in Antarctica and the dark that are the biggest issues…but for the most part I agree with you. There is no short sleeve weather on Mars, even if the pressure issue was fixed. With the current low pressure high speed winds don’t bother a thing other than paint (still can get sand moving very quickly). But if they raised the air pressure…nasty…very nasty.

    One way or another you are going to have to have a lot of protection. You would want to be in a building/shelter or vehicle of some kind, not trudging for miles in a wimpy suit.

    It reminds me of an episode of Top Gear (Polar Special) where they had a 4×4 vs dogsled race to the north pole. I’d take the 4×4 any day.

69. There is vastly more CO2 on Venus than you could ever use on Mars. You defiantly will not make Venus livable. And they are not exactly close. Try doing the calculation for how many trips you would need to bring Mars up to 1/2 Earth air pressure. 2,000 trillion tons is a lot to move. If you did 1 million tons per run I get 2 million runs. It probably will take at least 18 months per run (there and back). So if you want it in place in 25 years, you need 120,000 of these ships making runs.

    Compare that to just making caverns to accommodate everyone. Much cheaper. Not remotely close. You could probably have an average of 4 levels of caves over the entire planet. 200 million square miles of caves. That is roughly the equivalent of the surface area of Earth including the oceans.

    Cavern technology can be used all over the Solar System. Make it good and trillions of people can have a very high quality of life.

    We need to develop robotic systems that can make these things everywhere. Get plenty of supplies created by growing and synthesizing from mined resources, everything built, beds made, then bring the people, or grow them.

70. I see no real advantage to pressurization. Likely every jet you have ever been in has been pressurized without incident. It is not like we can’t deal with it as is.

    How much does the average person spend outside and not counting their own yard? They are in their cars, other transportation or in buildings or between a vehicle(s) and buildings most of the time. Very easy to close that gap. Much, much, much easier than providing an atmosphere for Mars. On Mars, likely the habitats will be underground and have built-in efficient transport. No reason you can’t have large parks and such in vast caverns. And certainly there is no reason it has to look grungy or dark. No reason it has to be humid, and cold, with no air movement.

    And I think the space suits that will be used, for the most part, will be very baggy, allowing one to bring in all their limbs and head into a central area, where one can eat, do hygiene and such. No place for a campfire, but you can’t have everything. Not necessarily industrial strength for crazy lifting and such. More of a transportation devise than a raincoat. Most likely, it will have assisted motion. Though there may be rather limited call for it. I suspect that telepresence and AI robots will be the goto technology for much of the non-pressurized environment activities.

    People are not going to Mars to see some distorted environment, they want the real thing. Especially scientists. They don’t want the whole place different than it was. They want to do science in unaltered conditions.

71. Even if you terraform Mars it’s going to be about as livable as Antartica at best simply because of its orbit.

72. The trick is to move the CO2 from Venus to Mars and get 2 planets for the price of one.
    Once you get to solar powered, self replicating machinery, almost anything is possible.

Comments are closed.