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There were some posts on this on the Terraforming Venus topic.
It's got a magnetic field, metals and Mars-like gravity so those are some pluses. Lots of incoming sunlight too. Not much in the way of atmosphere and just a bit of water that we know of. No fair posting about building rails around the globe and running a city along it in permanent sunset. KSR already took that idea. A sun shade of some kind is probably going to be a must.
Thoughts?
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Mercury's best use might be as a place to manufacture for other projects in the solar system.
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To average out the temperature extremes, habitation will likely be in caves, near the poles, where ice was detected. .
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The problem with a sunscreen at that distance from the sun is the enormous thrust you'll generate. You have to find some way to keep ot from becoming a high-speed interstellar probe. A reflective shield that blocks ~85% of the incoming light to Mercury recieves about 2 GIGAnewtons of thrust. For solar shields further out from the sun, you can probably have them held by the sun's gravity but I seriously doubt that this will be practical in this case.
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Is there a modified L1 point;
taking the thrust from the Sun into account ?
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If there is; what effect would solar wind variations have ?
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I imagine there's a modified L1 point just as there's a modified L2 point for a mars mirror. Solar wind isn't a factor if it's a mylar sheet, it's solar pressure. If it's a magnetic field with shiny dust suspended in it, both solar wind and light pressure are going to be pushing it. I guess there's still a balance to be struck but I don't know how wild things get that close to the sun.
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With lot of metals and 9 times the sunshine intensity,
I can see Mercury as the manufacturing and raw material supply center for space colonies.
Mercury inhabitants could live in large shopping mall type environments, inside the craters with ice nearby.
The momentum from the propelled parts could, over time, make one side of Mercury continuously face the Sun, while the other side, being cold, collects solar wind particles - It might be cold enough to form an atmosphere on the cold side ?
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The answer for the solar shade is 'very wild'. My calculations account for the light pressure. The solar wind is about 1/10,000th the force (still significant) but this is a highly damaging force. You're looking at a solar wind flux 9 times higher than here at earth. Your Mylar will quickly degrade under a constant stream of 500 km/s ions. The only way to get around this is to make the shield very thick and massive. That helps a bit since it allows the shade to keeps its shape and to weigh it down to counteract the light force.
At this point, you're looking at a shade massing at 1.9 trillion metric tons. (assuming 100 grams/square meter of mass - a fairly reasonable number) Furthemore, being inside the L1, you no longer have orbit stabilization - your shade will start to pull ahead of Mercury because of the smaller orbit. That's OK since you can just tack the shade to provide lateral thrust. However, the situation is VERY delicate, any perturbation in light levels, etc will result in a runaway shade. Furthermore, meteor impact and terrorist actions would be devastating to the shade.
What happens to your terraformed Mercury when 15 kW/m^2 suddenly hit it?
FOOMP!
15 kW/m^2 is about what you'd expect to see inside a toaster when its running.
Even IF you can build this crazy shade - which is doubtful - it's got to have a diameter > than Mercury's and be thick - and you can get an atmosphere there (which will have to be imported, if you can avoid catastrophic loss of the terrafoming from shade failure, even if you can impart a spin to Mercury - even if you can do all this....
You have a tiny, rather miseable planet.
Much better to just burrow underground or sit on that train track and mine metals and set up solar collectors than it is to try and terraform.
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Maybe in a billion years, if the humanity still lives, someone will consider seriously shifting planets further from the Sun to protect the planets and lives from the expanding Sun. By that time, they should be able not only to that but also spin up planets.
I read articles about shifting and spinning up planets. Don't kaugh! It may sound crazy but it's one of the ways to go. I remember someone argued that planets are good where they are and they should be spread apart. Mercury is just too close to the Sun. If it were possible to shift Mercury to the distance of 85-90 mln km from the Sun (Venus is at 108 mln km, Earth at 150) (sorry I am used to km, not miles) and spin it up, Mercury might get a hot but tolerable climate to support life. The method for shifting planets was not too clear to me, something to do with solar winds.
Another method would paraterraforming - living in domes or underground using the cheap energy source
Anatoli Titarev
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What can we do on Mercury´s surface, except looking and research? Inteerplanatary supplying is rather hard, Ithink, because a body so near the sun requires high delta-v to put stuff to outer solar body´s.
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About the only reason to set down on Mercury, IMO, would be to set up huge power transmission plants. You could use bug microwave emitter arrays to beam needed power across the solar system. The plentiful metal rewources don't make much sense, as you pointed out, because of the huge gravity well that needs to be climbed out of. The asteroids present a much more practical source for resources.
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Move mercury to become a moon of venus or mars, or move it out to jupitor add ice from its moons. Much better than an entire water worlds that you get from jupitor moons. Moving a planet is hard, put if you ever had a way to create a fleid that alter mercury mass to a few grams than it would be easy, just turn its mass back on when you got it where you want it. They do this things in star trek I think.
I love plants!
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Ummm, I hate to point out the obvious but Star Trek is not a good source for technical information.
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Before colonization of Mars we could crash Mercury into it and add a little mass and then use the ejecta to for a moon in proportion to Mars as luna is to terra. It could happen couldn't it?
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Yeah, you could probaly get away with hitting it with Ceres - Mercury would probably just result in Mars turning into debris.
The only problem is that most of the surface of MArs would be gone and turned into magma. You'd have to wait thousands or millions of years for it to cool off and settle down. Kinda obviates the whole point of terraforming, IMO.
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The large scale, long term plans remind me of the Dyson Sphere. To get the most surface area and collect the most energy, the solar system has to be disassembled. Some bodies, like Mercury are easier to take apart. Providing the material for millions of space colonies, Mercury would be no more.
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Regarding some very probable in long run meta-environmentalist notions (like the "reds" ideology in K.S.R. martian trilogy) may be moving and dismantling of any noticeable body in the solar system will be prohibited. I that respect even the terraformning itself could not be allowed, but if not enough spiritual spark ever ignites towards protecting the baren rocky-icy worlds, than we could see attempts to be terraformed the extremal locations within the System -- bodies way beyond the Goldilock zone. In Groups after google-search I found this about the Mercury terraforming. Notice: no parasols initially, partial territorially habitable zone AND the autor David Semloh states that this is the easiest, cheapest, fastest planet to be terraformed(B). In his wrightings I didn`t saw a method for preventing the athmosphere dissipation or the hydrogen spill after the first wished photodissociation phase, but with magnethodinamical means -- modified mag-sails both the exosphere could be cooled down significantly, the escaping particles returned constantly back and the steady massive flow of the sollar wind harvested/scooped for hydrogen resupply. Here you are some of his posts in the mentioned ancient message thread:
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Type "David semloh Mercury" on Google -- Groups
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For me it seems quite serious and considered. The promissed couple of millions of sq.km. habitable area at the planet`s poles are well enough (two) big pocket-civilizations to develop. In long run their representatives could keep the terraforming untill the whole planet is climatologically moderated, with parasol off course -- there arround L1 point of the Mercury-Sun system, could be positioned anything in industrial sence, even quite more accessible, that would otherwise provide the barren Mercury. A planet with athmosphere could be very succesfully mined for metals, too.
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For now the Moon is most convenient; but once we have easy access to Mercury, it will be the choice place to manufacture due to availability of energy.
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I read speculation regarding the instability of Mercury's orbit, stating that it may be the next planet to meet a catastrophic end, such as being flung out of the Solar System.
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As I already point out, Mercury terraforming could be done incrementally; no parasol/sunscreen would be necesarry for the described Semloh`s plan for single 100km. water/amonia iceteroid volatiles supply. Only the very high latitudes above 80 degrees north and south would be habitable shirt-sleeve open air environment. Thousand km toward the equator from both poles could be colonised by harvestable biota + some temperature oasises in these regions. The lower latirtudes are realm of hot water vapour stormy clouds circumplanetary vortex -- effectivelly stoping the heat from poles and driving atmospheric hydrocicle. David Semloh thinks that this equilibrium situation of partial terraforming could be done for 150 years, together with the several decades for importing the iceteroid from the Kiupert belt.
If the mercurians later decide to occupy the lower latitudes towards the equator, than some way of reducing the solar light flux should be implemented. A pletora of things do exist which could be designed for such job:
1. L1 parasol -- the mentioned problems with the stability of its orbit due to the close proximity of the Sun and the increased light pressure could be avoided with use of active copstant control of the huge light-sail of the parasol, as a parachute, hovering over or with annular support mirror "behind" the planet, the reflercted light of which keeps the parasol in position. The excess light left after the maneuvering could be harvested in usefull forms -- beamed, stored...
2. Mercury could be supplied with a almost planet-diameter wide equatorial BAND of reflective, or micro-grid material -- rotating with slightly greater than the orbital velicity in order to remain tight; the excess light could be harvested by the same structure...
3. NOn-magnifing soleta could be positioned and activelly held as a solar-sail ship into position, the reflective strip arrangement of which to redirect the light away from the planetary disk -- either for further utilising by other instalations, or simply deflected by focusing out the incoming light flix... It is said that because such soletas indeed are hige lences and do not stop but slightly redirect the light, the light presure influnces negligibaly their orbital dinamics...
The proximity to the sun could compensate by optimality of the solar-sailing conditions such insideness in the solar gravity well, for incoming and outcoming cargos.
Really the same way as in the Moon case the asteroids are the best for metals mining, so it seems only terraforming lefts as economical use of the mercurian "land". It is just a empty biulding terain, gravity hook for atmospheres...
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The concern is catastrophic failure. When a meteor hits Earth the damage eventually corrects itself. Mercury might end up with a superheated atmosphere, ending the settlement.
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Sun shields suppose considerable capability to build other structures. People would feel safer in a large space based habitat than on the surface of a terra formed Mercury.
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There were some posts on this on the Terraforming Venus topic.
It's got a magnetic field, metals and Mars-like gravity so those are some pluses. Lots of incoming sunlight too. Not much in the way of atmosphere and just a bit of water that we know of. No fair posting about building rails around the globe and running a city along it in permanent sunset. KSR already took that idea. A sun shade of some kind is probably going to be a must.
Thoughts?
What about paraterraforming as an option?
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From RedNova site:
"paraterraforming involves the construction of a habitable enclosure on a planet which eventually grows to encompass most of the planet's useable area". The claim is that 1960's technology is sufficient.
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No doubt Mercury will be settled starting from the poles. Then various means will be used to extend habitation. Mercury
receives 8 times the Sun's intensity and it will be a challenge to prevent overheating, away from the poles.
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Paraterraforming is just other way to keep and regulate atmosphere. There are designs with equal value for Mercury without the necessity of roofing the world. Matter of money and aesthetics.
There is big difference between building flimsy parasols and soletas and huge, robust, massive rotating structures. The first thing is far easier. They are easier maintainable and replaceble.
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Paraterraforming is just other way to keep and regulate atmosphere. There are designs with equal value for Mercury without the necessity of roofing the world. Matter of money and aesthetics.
There is big difference between building flimsy parasols and soletas and huge, robust, massive rotating structures. The first thing is far easier. They are easier maintainable and replaceble.
I am excited about Mercury (I don't think many people are). To add to above listed, I had an idea:
If Mercury can hold atmosphere (at least for hundreds/thousands or millions of years), we could probably design shade and mirror sysems on the ground to allow the light to penetrate only partially onto the ground. The closer to poles - the simpler the design. Cities could be built in pretty deep valleys, protected by tall natural or artificial mountains. Almost like domes but only partially closed. Very little sunlight could keep the temperatures down. What do you think, does it make sense?
Anatoli Titarev
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Inverted cone, cable anchored, balloon building structures would reflect on the top, while deflecting surface heat radiation into space.
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The incoming radiation would be reduced by the top reflecting area, while all of the surface area would be able to radiate to space.
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Inverted cone, cable anchored, balloon building structures would reflect on the top, while deflecting surface heat radiation into space.
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The incoming radiation would be reduced by the top reflecting area, while all of the surface area would be able to radiate to space.
Yeah, something like that. Balloons are a good idea for reflecting light.
Anatoli Titarev
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