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I agree about the trains -- they could also be used on Moon or on other bodies, could be deployed vast rail-way nets, for havy weight mass surface transportation. Indeed the solar power coulds be the major source for train energy supply. Every rail-line could be paralleled with solar power panels -- between and out of the rails. If we have a net with total lenght of the rails, enough, than even on the Mars solar distance this grid vcould capture and supply all the necessary electricity, for the whole economy, not just the rail-way transport.

About the internal combustion engines with solid outcomes -- think about the vacuum cleaners. Or CO2+Al fuel cells.

The David Semloh`s proposal (copy-paste). This letter contains the major part in short of his idea for open-sky-Mercury terraforming. I think it is competitive to the paraterraforming design in economical sence -- money, time...
Here:
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Mars: The Red Planet DVD • A guided tour of Mars. Spacecraft video and stills. Free 3-D Glasses • http://www.plasmaartdvds.com]www.plasmaartdvds.com ??????? ?????????

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???????:Mercury Terraforming Prospectus
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View: Original Format
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Living on a terraformed Mercury? Impossible !?!

<b> The Basic Mercury Terraforming Idea Has That  transporting volatiles to
the world is the only "inexpensive", large-scale method. While my thinking
on how and why it would (should/could) be relatively "cheap" is  glossed
over here</b>, considerable work has been done on just about the only
practical way (a periodic comet or asteroid imitator re-directed by gravity
assist(s) to become a long-period comet streaming out toward the Ort cloud
in a ever so slightly broken apart form from the last gravity assist, for
maximum control and correctional ability, to intercept a Plutino in a
glancing blow to maximize the dV, with 0.5/sec probably necessary for the
100km sized preferrable object in a reasonable time frame for us impatient
humans ). And finding via remote sensing probes and instruments an almost
purely water/ammonia plutino  [amongst the 20,000 or so in a trojan like
orbit near Pluto/Charon large enough to do the job ] is surely not the in
the cards for the near future. <b>

Nor is it confirmed that the dissociation </b>of the atmosphere would be as
easy as it appears, though the tables look favorable towards this end (low
enough gravity, high enough solar/atmospheric entry temperatures for
extremely rapid H2 loss -- before more than 30% has recombined -- to ensure
about a 0.3 bar atmosphere with the remainder becoming water in large, polar
hugging crater lakes).
<b>
But these "trivalities" aside, </b> enormous rewards potentially greet a
properly done construction project. The planets (if Uranus is used for a
gravity asist) will be in place at earliest in about 50 years and require
about 40 years after that to move towards the inner system. But once that is
accomplished, hypothetically, a fresh planet would be transformed rather
rapidly. At the first weeks, though this might be stretched out over a
longer term as is useful by gradual introduction of the volatiles if
possible, the temperatures would be extremely hot, partly by design and
partly by necessity.  Over the next few years weather patterns would
probably stablize much as below indicates, or that is increasingly what
models seem to show, possibly allowing the poles to be shirt-sleave
environments, especially at 87 degree + latitudes, and certainly encouraging
harvestable life as much as a thousand kms outside these boundries. Millions
of people could be very comfortably supported and housed with comparably
little expense beyond the interplanetary trip and the initial celestial
engineering  job.  And as population grows, building those oft mentioned
solar parasols would be a natural next step, albeit an expensive one.

<b>And _that_ is what all my enthusiasm is about. </b>The reader has
certainly picked out far too many what ifs for comfortable conjecture. But
the fact remains that there exist few if any other alternatives. Mars
icecaps and regolith will certainly leak out fatally poisonous C02 levels
for millennia to come and other terraformed worlds will lack the insolation
to dissociate the water and ammonia to provide a breathable atmosphere, and
have a much harder time holding on to the atmosphere with the possible
exception of our Moon.  Going against intuition, Mercury seems to be an
unlikely winner in the worthwhile prospects of space settlement, and it
certainly bears further looking into than I am presently individually am
doing. In a number of respects, this proposal is no more than at a "back of
the envelope" level in a number of places at present.

The reader is also excused if images of this writer seeing one too many Star
Trek movies (no offense to Trekies, but actually I almost hated those movies
and long ago out grew most of the TV plots) come to mind.  Yes, the level of
thinking  here goes far beyond that kind of fantasy. I <i>do</i> suggest
that my idea is one of the only plausible ones in the next 150 years for a
breathable atmosphere.  But Taylorian World Houses on a smaller polar crater
scale is another option for Mercury, though the scale of dissociation alone
will be enormous as it must be then done by human manufacturing processes --
if attempted anytime in the next two centuries. If my orientation, mostly
not discussed, reviewed,  or posted yet, of the viability of transportating
the volatiles on a mass scale relatively cheaply and efficiently eventually
prove technologically and feasibly correct, then just remember ... <b> you
saw it here first </b>.

<Picture: REMARQ><Picture: Open or Check Free Email><Picture: Frequently
Asked Questions>Home > Science > Space > Space Policy (sci.space.policy)
<b>
This previous posting on RemarQ leaves out a key aspect which might cool the
planet, the effect of dust which would be very prevelent due to the great
winds and the already present talcum powder like cm or so on the surface and
greater amount near the surface which would soon be uncovered by the winds.
</b>

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Message:1 of 4From:semloh <semloh@ficnet.net>Topic:Mercury Terraforming Post
BSent:Mon, 01 Feb 1999 12:30:30 -0800This is a re-written and easier to read
version

HEADER _ A Terraforming Project_ HEADER

A TERRAFORMING PROPOSAL

Relating to human settlement on the planet Mercury, there are many seemingly
impossible conditions.* Surprisingly, it still may well be the best initial
terraforming candidate if acquiring an atmosphere through the commonly
suggested gravity assisted iceteroids approach proves viable.

Consider these reasons:

1) Providing that any choice iceteroids are available at favorable orbit
periods and only needing a reasonable amount of dV, it is much better to
have a totally airless planet because iceteroids offer numerous choices of
what elements can be placed on the world. Also, the elements have the
potential to be modified partially through solar dissociation processing in
a low or highly eliptical orbit -- soon to decay -- in which Mercury beats
all other terraforming candidates by a sizable advantage.

2) It has a relatively strong gravity, enough it seems to hold on to an
atmosphere of 02 and N2/Ar (.3 bar suggested for greenhousing and
respiratory limititions) for enough centuries like a sort of celestial lay
away plan until an expensive parasol is slowly (or quickly as technology
progresses) built to decrease heat and reduce the loss of volatiles. Though
it has a strong gravity for its size (from its massive iron core), it is
also physically small++, a fact very helpful for shortening latitudinal air
current distance and to moderate the day and night differences in
temperature.

3) Weatherwise it is clear that sacrificing the equator is best for the sake
of economy, both in start up capital and of quite possibly scarce
suitable/timely/and massive iceteroids, and on Mercury it is the only viable
option at first.

With dissociation of much of the water and ammonia ice of the iceteroid, a
50%/50% allocation of the mass to air (02/N2) and liquid surface water is
possible with little more than a 100 km sized object. (More likely, with the
dissociation being not possible or cost effective,  is a  > 30% rate of
water transformed into 02. The extra water should make little difference as
it is impossible for it to migrate far down towards the equator due to
regolith heat and wind patterns. In any planet or planetoid with a
significant fraction of equatorial regions filled with water, easily 30
times that mass is required. In the case of an un-parasoled Mercury, the
greenhouse humidity would destroy

Economy, only allowing for the poles to be habitable, does wonders for
budgets as poles only compose about a twentieth of the surface of a planet
and yet have a millions of square kilometers of living space, with the
permanent water/snowpack area perhaps set to be 4% of Mercury.++ (Water body
depth lessening towards lower latitudes because of evaporation.) Every other
terrestial planet or moon would have to have far more water, have a dry
world with a very dense atmosphere, --

excepting the extremely difficult case of Venus. Equally important for
Mercury, H20 is a much stronger greenhouse gas than C02, so the absense of
saturated air is well worth the cost of fewer clouds and lower albedo.

Iceteroid Suitability, Availability, and Selection

Going into some detail, suitable plutinos -- David Jewitt extrapolates about
25,000 being 100 km in diameter
http://www.ifa.hawaii.edu/users/jewitt/ … tt/kb.html -- and kuperoids fulfilling
all minimum requirements having well rounded characteristics and no more
than traces of unwanted gasses like methane are better expected to be very
unusual, say a single body or two with present knowledge of the frozen
objects.

(Remote sensing of interior compositions will of course have to be advanced
greatly and several objects might be dragged into the gravity assist system
with the most suitable picked after interior compositions are well know by
way of a strategic fly-by Roche limit breakup. The rejects could then be
sent to Mars, the Trojans, etc. for alternative use.)

Such slow objects (~40 AU) must have a close trajectory pass in that orbit
sub-segment approach (almost all would be in stable resonance and outside
the bounds or demand very high dV) for a gravity assist, not have more than
trace amounts of C0, C02, or more harmful gasses not easily broken down,
have a composition almost wholly of water and ammonia, and be of sufficient
size. The time factor of altering the orbit, the longest period in this
terraforming project before settlement, would be a critical consideration.

I guess, rashly, that the only practical answer is to search for a Plutino
in the group (they act like Trojans) capable of being deflected by gravity
assisted now long very long period comet or asteroid of at least (in a
retrograde orbit or modified to; broken into a number of pieces from its
last pass by for maximum amount of control in a very difficult collision
operation, one with fairly limited vector force compared to the overall
kinetic energy ), with a dV slowing of .4 km/sec in order to be altered into
a orbital period like Saturn's (rotation every 30 years), or much more
desirably a .6 km/sec to ensure quicker intercept time for impatient
Earthlings on a timetable.

From there, it would be gravity assisted by Uranus (or, improbably, Neptune
or Saturn) to the rest of the solar system. Further information on the
subject, as I am familiar with it, is available upon request, but confessed
ignorance of what actually possible in this field of celestial mechanics is
readily given. A comet life projecting astronomer or celestial would be able
to say how viable this is with few passes of the gas giants and exactly how
long it would take. A comet like orbit is by far preferrable (the
Pioneer/Voyager type of fly-by is faster but goes on a curved path so takes
longer to intercept). A retrograde orbit is also considered to be a plus
even if a glancing impact of very low degree angle proves to be unworkable.

And what about Mars?

Mars almost certainly has enough volatiles, but heating up significant
amounts would be a problem involving hundreds of well guided asteroid
strikes or extremely costly subterranean thermonuclear blasts and the
atmosphere would not be breathable for a very long time, the eons long C02
outgassing then being in far too high concentrations for plants as well. A
lesser condition, initially, exists with an iceteroid atmosphere delivered,
but only somewhat. The great icecaps could then be sealed with a layer of
ice. Still, the iceteroid requirements would be at least 30 times that of
Mercury, with only a few viable areas and a steady loss to the caps. And no
easy way exists to create an 02 atmosphere.These considerations are enough
to turn to Mercury for a second look, as Mercury could become breathable and
have outdoor crops (at least under UV inhibiting plastic) and fisheries
within a mere decade if my outline of H20 dissociation contain any merit.

The Poles Revisited

Would the water really collect only at the poles?

In an iceteroid scenario, quickly almost all water would naturally be
deposited at or near the poles in a few years time, with "day" temperatures
being so fierce at the lower latitudes. It is logical. At the poles the
insolation is low and for dozens of kilometers below it shows -- average
crater bottom temperatures presently are less than

should have areas which never rise above about 102 K (4) and that even flat
surfaces at the poles would not exceed about 167 K (5).**

Slade, M. A., Butler, B. J., and Muhleman, D. O. ``Mercury Radar Imaging:
Evidence For Polar Ice.'' Science 258, 635-640, 1992.

in accepted models of an airless environment with almost nil axis tilt at
that AU, albedo, etc. Now, much of the regolithic temperature could be
overrun by creeping heat when atmosphere is introduced, but the combined
effects of a highly likely dominant east-west wind systems more like that on
the gas giants would insulate the poles from most of the worst extremes.

And the heat from the equator? Models exist involving very slowly rotating
worlds without appreciable coriolis effect (one apparently done in MIT)
suggesting latitudinal winds would be so strong that the temperature
differential between day and night be greatly lessened.

Moreover, it seems the amount of longitudinal heat transfer gets inhibited.
This is very important to keeping the poles cool. In conjunction, the
circumpolar winds only have 1200 kms to travel from midnight to noon.

David Semloh

*3 month long winters with no sun, some twilight; extreme solar storm
exposure with a weak magnetic field; hard to get to location in the solar
system, especially by gravity assists when slinging a huge iceteroid; a 184
Celsius average present regolith temperature; the probable rapid oxidation
of the regolith; greenhousing dangers, and the list goes on. But none are
insurmountable, nor is the idea of
economy.

++ Mercury is a pretty small object with corresponding sq. km. ; It has
about twice the surface area of the moon but only an eighth of the Earth's
surface area and half that of Mars. This would miminize iceteroid
requirements further, about to a ratio of 1:150 for an economical Mercury to
an oceanic (and very unlikely any time soon) Venus terraforming project.

** Temperatures quickly rise in decreasing lattitudes as soon as the
sunlight penetrates even briefly into the bottoms, except with smaller
craters (which have
relatively higher inclination depths for being shaded continuously, but
receive more wall IR). Within small craters regolith bottoms are ~ 0 Celsius
down to the 50th latitude presently.

This is useful for settlements as it easily allows sizable, permanent bodies
of water (a few km across) to collect down in the 50 to 60 degree range,
helping
moderate peak temperatures with the reservoir heat aspects and ground effect
of cold sinking (so the body does not dry up easily, not lasting to peak
periods). While not suitable for humans in most senses of the word and lakes
would be but a few percent of the land, these latitudes could provide an
additional buffer
from equatorial heat transfers.

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Message:2 of 4From:Nicholas Landau <nlandau@eden.rutgers.edu>Topic:Re:
Mercury Terraforming Post BSent:15 Feb 1999 19:46:35 -0500semloh@ficnet.net
(semloh) writes:

Key:
<        (my earlier post)
<b>    Bold</b> Nicholas Landau
nothing   D. Semloh's reply

>Moreover, it seems the amount of longitudinal heat transfer gets inhibited.
This is very important to keeping the >poles cool. In conjunction, the
circumpolar winds only have 1200 kms to travel from midnight to noon.

<b>
Let me get this straight: with no coriolis effect, the winds will *not* blow
from equator to pole? Are you sure that you don't have this backwards?
</b>

Winds here are driven by the temperature gradient between the equator and
the poles (a gradient which will be *much much* more powerful on Mercury).
The coriolis effect is the cause of circulation cells and the resulting E/W
winds all over the world. The introductory lecture of Atmosphere and Weather
included the professor's assertion that, without the coriolis effect, the
world would have only two circulation cells: the Northern Hemisphere and the
Southern hemisphere.

<b>
The gas giants mentioned in the post have extremely powerful coriolis
effects, and so have powerful circulation along lines of latitude.

The whole notion that the circulation along longitutidal lines would be weak
seems contrary to intuition and it is also very central to your assertions
that Mercury would make a nice place to live. Based on intuition and a
little knowledge, I would assume that a powerful convection cell would have
its center at the Mercurial equator, at which point the atmosphere would
rise causing an atmospheric convergence.

Circulation would thus run from pole to equator. Actually, that is good news
in terms of temperature balance, because that means that (relatively) cold
air from the upper atmosphere would be sinking at the poles. However, its
bad news for moisture balance because the moisture at the poles (where I
assume 100% of the liquid water will be found) will be transported to the
equator. It will not re-precipitate along the way.

Hmmm...actually, that depends. As the air rises at the equator, it will
cool. For all I know, it will cool enough to form clouds at high altitude.
This would be good albedo medicine.

</b>

Well, in any case, the process by which high-altitude air is dried here on
Earth (the precipitation of the moisture as the air rises in convergence
zones) will not be present...if the water precipitates from the clouds, it
will evaporate again as it falls to Mercury's searing equator.

Well, getting back to my original point, how in creation do you explain no
cross-latitudinal winds in world without a Coriolis effect? You haven't
explained this at all so far as I have read, only cited others. It sounds
awfully wrong, and it is very important.

------------------------------------------------------------------------
Message:3 of 4From:semloh <semloh@ficnet.net>Topic:Re: Mercury Terraforming
Post BSent:Mon, 05 Apr 1999 14:58:13 -0800Should I sent you the complete
message I wrote up (and already posted ... finally ... on March 30th, 1999
Space Policy)? Let it first be said that the dominant force by far on a
slowly rotating world will be the day to night energy imbalance, even more
of an overall calorie or kinetic imbalance overall than an extremely great
discrepency of pole and equator temperature, a good deal greater than the
day to night ambient temperature difference, excepting the crucial
cumulative effect [of weight and resultant force]. This is due to the 10:1
ratio or so of land surface area, more so in the case of the extreme poles
where the polar vortex should be operating.

D. Semloh

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™ ****

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First, there is some hints that the upper parts of the venusian atmosphere are inhabited by locals -- microbiota using the UV part of the sun light. Producing even some Gaia-effects there. A little bit higher than the "human level". Could it be estimated the total biomass output of this biosphere. Could it be harvested and used (if exists) for human support in these "cloud cities".
=======================================

Second, if we get rid off big part of the atmosphere but not the entire one. Than now the highhest mountains (Maxuel ~45 Barrs, not the full 90) could be under 1 bar. These islands could be partially terraformed -- say, isolated by gassbags walls from the original CO2 atmosphere. Like earth-like land masses in an ocean of poisonous CO2 hot soup. The original biota survives in lower but again easily harvestable atmosphere level. But SURVIVES. We could terraform in the presence of native life, without to kill it. We could include it in our own ecological cycle through "filters" -- reseaving billions of tones of biomass, if we commence some measures of "agriculture" and "cultivation" over the local ecospheres...
It reminds to Larry Niven`s suboptimal worlds colonisation: single canyon, single flats...on generally inhospitable planet.
=========================================

Third, the Water issue. Puting asside the possibility for life on Venus, and concentrating on the lack of hydrogen there. Many sources were discussed for H-supply -- mostly cometary ices, hydrogen scooped from the sollar wind, etc.
But regarding the earth water reserve: we have 1.5 billions of cubic km. in the hydrosphere, another 1.5 billions of cubic km. in the crust and deeper in the depts of the earth mantle another 15 (!!!) billion cubic km. of water. Venus has lost it`s surface water. It crust smashed and roasted by the thick hot atmosphere may be is dryed totally, too. But what about the planet`s mantle water content. It should be comparable to earth`s. Hence, beneath the heated basalt of the crust we have water for several planetary oceans. The only way to release it is to strip enough part of the crust. Big asteroid strike, makes obsolete venusian water mining, cause is equal in cost of mere importing it, having in mind the necsarry size of the body and the anti-terraform global effects. The imaginable nuclear bombs are weak and ineffective. We are far away from kinda magmatic "weather control" ...
-------------
So, let burn through the litosphere by solar powered laser. The Burch`s method for regolith evaporation by soleta is inapplicable here. Stanisla Lem in 'Fiasco' points out that several dozens of terrajoules laser making spot with diameter of several hundred meters and increasing the temperature to several thousands of degrees in the spot, could penetrate the globe to one forth of the planet`s diameter. From such puncture should erupt enormous amount of totally liquified lava quicjkly degassing all of it`s water content. Burn as long as necessary. Use the beam to parallely sculpture the litosphere or to propel interstellar ships and super-distant outposts....

Don`t point it towards the Earth!!!!!!! AAAAAAAGGHHHH!

http://www.paulbirch.net/TerraformingVenusQuickly.zip

Excuse me for the crossposting, but in this link content you could see the "chimney" scheme for very fast venusian atmosphere cooling, in better way, than I could explain it.
------------------------------------------------------
Such "chimneys" could be used for C ( eventually +O) plasma channels, for lifting in orbit of  almost the entire atmosphere of Venus. Carbon is the best biulding material for space colonies. With the amount containing in the original venusian atmosphere dozens of thousands of times the earth total area could be replicated in , let say, 1000 of miles wide tube-world. Such way the fast cooling in megascale manner becomes obsolete. From the planet could be pumped out even more -- because after the planet`s crust is liberated from the enormous ~90 Bars presure, it will expand and hence further outgassing could occur. This is very convenient from economical point of view, cause if the terraforming of Venus is considered as just a byproduct of incomparably bigger "domestication" problem, and if the outgassing occurs to be unsolvable in millennias to come task... the money expenditures will be justified... Energy -- from the solar pannels in the sun-shade or from solaser if it is decided that total L1-parasol shading is not necessary.
Some processes in the plasma (+ laser trap cooling?) and other quantum-thermodinamical means could be used, either, as MarsDog`s thoughts points to. Without "lighning guns" export of the gasses.

I agree -- the lowest possible level of the "terraformed" planet atmosphere`s temperature is the point of it`s phase change in liquid form. The last even could be allowed for smaller or significant part of the planet`s surface -- tolarable varying air presure in diurnal or seasonal fashion. Even on planets where the air is so cold that humans can`t breathe it without termo-masks, there could be implanted and thriving modified/adapted genetically engeneered biota: warm-blooded plants ( see Freeman Dyson), icy Gaia-system shifting the cold desert in ecology, animals biulding igloos by instinct like the beavers making dams by woods, etc., etc.
There is enormous combinatorical space of solutions of human-supporting ecologies consisting of non-existent on earth species. The important thing is the biota complex to provide the right environmental parameters, not the actual members of the chain... even + some purelly technological shortcuts...

I`m sure that the terraforming is in NO way kinda priviledged colonisation method of the future mankind. The many times posted objections about "space colonies" or "altered human body design" vs. "terraforming" are equaly probable. Even unavoidable. The tech will give us evolutionary means and factors trillions of times faster and more capacitous than the natural "evolutionary radiation" of a single species. We shall be Dyson`s "Millions of human species". There are notions that even some will colonize in some software forms,  pulsars turned into computronium capable of emulating environments more complex than the "natural" universe. The space of posthumanitarian possibilia is infinity. But even if infinitesimal fraction of this infinity remain in it`s original modern human form it will keep on colonizing, hence producing or modifying human-friendly environments. The most effective way are the space colonies -- rotating tube worlds, undoubtedly. They could have really huge sizes -- providing billions of times bigger and optimised than original earth-like habitable surface (spagetti-habitat with thousands of km diamater). Under 1 G and using lesser matterial than natural planet per sq.m.
But hardly ever the naturaly evolved after non-repeatable long istory, with distinct features, worlds would be sacrifised for building materials, when so much is in less complex and available form -- star`s plasma, interstellar gas/dust and little bodies - asteroids and comets... The preserving of the initial state of these unique worlds lies in the field of culture. The "Reds" will keep their homes close to their innitial condition, the "Greens" will ruthlessly transform them -- matter of money, aesthetics, intentions, needs, property rights, whatever.
--------------------------------------------
If in such little disscuision group there are so many oppinions, than imagine what would happen if we could actually do the job. The humans shall do everything that occured to us (and much more) simultaneously - one will terraform planets, other roof/ dome or cavitate/bubbleform asteroids, built little or huge tube worlds, shell gas giants or stars, redesign their bodies, merge with variety of technological bases...

Lets (as you noticed, may be, I always insist) give for our colonisation practical purposes the property of WORLD of every gravitationally round body except the Sun itself in the Solar system. (BTW, according to Paul Birch through suprastellar shells the stars could be terraformed, too, but this is another theme). The actual number of all major (classical) and minor planets in the system is unknown. More and more round frozen planetoids are found in the outer space of the Solar sphere of gravitational domination -- in the Kuipert belt and further out, so our inventorization should be limited on the named objects.
Instead to list those worlds one by one - a really boring task, we could group them by size, with featuring their destance from the Sun, and directly describing the absolutelly necesarry terraformation measures for each one. We could try to establish at least an outline of general formalisation (See "Terraforming Sedna" theme)-- this is necesarry because of the distinctions in the initial conditions of these celestial spheroids makind explanation of terraforming of only one more complex than the general view, but I think enough are several major points:
1. We can not tickle with gravity -- the surface acceleration remains on the natural level. We could increase it localy to 1 G with conical centrofuges or decrease it to 1 G with "mere"
lifting of the terraformable surface higher where the natural level is arround the earth one through supramundane habitats or complete shells.
2. We can modify the illumination - increase it with soletas (up to interstellar distances) or decrease it with soletas (down to just several solar radii).
3. We can introduce/reduce the atmosphere and process it to obtain the necesarry composition and presure and temperature...

Another pre-terraformed-titan`s items:
-------------------------------------------------
1. Superconductors -- under minus 180 degrees centigrade in the Titan`s wilderness/outback mass produced in the frame of the nowadays tech comperativelly cheap superconductors could be used for as many applications as could be imagined. For example biult-in the "icecrete" highways/powersupply grid for superfast maglev cars transport. The maglev supercoductive lines could be easily continued up to the proposed L1 & L2-surface beanstalks hence integrating the land and space transport. Combined with the trans-world&space power grid supllying Titan`s economy with space-solar electricity, hence O2, hence "petrol-equivalent" industry.
------------------------------------------------------
2. Ice biuldings -- As I mentioned several post before the water ice "alloys" could have almost steel like propertiers in this hellishly cold climate -- so really huge "pocket"  volumes could be terraformed/airconditioned -- may be single wall-uninterupted sight distance over dozens of km.s? -- huge igloo systems, with all the necesarry structural insulation/fridging, aircondition, and sealing-hanging lamps illumination. If the overall living sq.m.s + farming sq.m.s per human unit is calculated over most developed societies luxurous basis, and conserned the low-gravity+materials strenght, than it should occur that Titan ice-supercities could house the population of realy huge country without this to disturb/overheat the splendid natural cryo-environment or to take over more than several thousandth part of the surface. Comfort + vast wilderness! Big environmental in broader sence advantage of the surfice-partial "pocket" terraformation, i.e. arcology construction.
Plastics and other organic materials, wood, moisture containing aerogels, jellies would solid-freeze in the pre-terraformed Titan`s atmosphere in way giving lots of interesting and on-earth unexpected structural applications...
Titan makes the perfect presurized cryo-lab and cryo-home in the Solar system...
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3. Cryonic graveyard -- if the one-way trip cost to Titan from Earth (say advanced light sailing from earth orbit + aerobraking in Saturn and Titan) is less than, say $50 000 per kg in Y2K prices, than it is economical to send there the heads of literally as many as wished "neurosuspension patients" of the cryo-sepulture bussiness. At arrival -- simply burry them in certain geologically very stabile ground. They`ll stay freezed untill physical way of reincarnation is elaborated. Having in mind the lower 1/7th gravity Titan could become the Solar system`s super-cold Florida: low gee place for retired persons, enjoing a big deal of entertainments... hand-wing flying in or out of terraformed biuldings/igloos, methan/ethan lake "water"-sports, parachute jumps from orbit... waiting to die calmly or not so calmly and to be neurosuspended in natural geologically sure crionic facility -- beautifull graveyeards made from coloured ices, not ugly tincans with liquid N2.
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4. Solar illumination -- the distance to Saturn makes the solar power flux about 100 times lower than earth`s. But this means about 15 Watts per sq.m. average insolation!!! Comparable with the standart indoor artificial illumination. During the day time on Titan it is cold but light enough for the humans to be able to read, or to percept the landscape -- a little bit dim but with colours. Even without additional global illumination with redirected/produced light the Titan environment would be eyes-friendly for the superwinter-dressed+O2backpacked Titan-outback roamers. This off course depicts an atmosphere devoted of the orange organic smog, i.e. transperant enough -- achievable by local resourses and climate tickling?
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5................. You contineau!!!
I think that the advantages of such presurized cryo-nature are big enough for the titanians not to decide in long run to totaly terraform the open planetary surface. The tech-sphere could replace with equivalent or better the open type biosphere where we`ve used to be nested human technological civilization. Bubbles of TERRA amidst super-winter!

Let`s talk about the value and advantages of the pre-terraformed Titan.
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No doubt Titan, as it is now, is the most hospitable world in the solar system. That means that minimum of the natural human phenotype extention via attaching artefacts to the body is necessary. I mean all portable and stationary life support equipment which a human being needs to survive on other celestial body. On Titan, it seems, that we`ll need the lightest and most unsophisticated tools to ensure ability and standart of living. I think -- even on the 50-es technological level. There could be posted quite volumous essay, but I have no time to arrange all the stuff and ideas, so:
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1. The surface presure is 1.5 Bars. That is equal to 5 meters under water on Earth. An atmospheric  presure under which human could live a whole life without harm. So, Titan is the only place off-earth where non-presurized biuldings could be made.The air out is very cold, >90% N2 + carbohydrates. The air in (under the SAME presure) is warmed, O2 added up to the physiological partial presure, minus the carbohydrates. This resembles more to airconditioning than to sealed-presurised completely isolated life-support on Mars, Moon or wherever... The same is the situation conserning the personal siuts (covering the whole body termo-clothes, with mask, gloves... + bottles with O2 -- a system simpler than the earth`s deep-dive equipment), the ground, air, and liquid-going vehicles and vessels passenger compartments life support. NO space-siuts. NO radiation protection.
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2. Mentioning the transport: The old fashioned internal combustion, jet engines and other chemical motors could be used almost unchanged here. With the only difference that they`ll have to bear the Oxidizer (O2) in their board tanks, and the fuel comes from the outside (in the air - the several percents of methan content, or for the ships - oceans of fuel, if oceans exist). With this quite low escape velocity of Titan, mere jet-planes burning the atmosphere`s metan with onboard oxigen, could serve as surface-to-orbit reusable shuttles. Smaller wings, and easier vertical take off with this weak gravity + high air dencity.
The production and supply of O2 should be as important as the petrol industry, nowadays, here on earth. O2 could be prodused, say, by water electric dissociation. The electricity ( in order the Titan economics not to relly upon import of fissible material (uranium, plutonium, thorium), the undiscovered local sources of them or non-achieved techs like fusion, or on deep-deep "geo"thermal sources...) could be imported from space via Titan-Saturn system`s L1&L2 beanstalk`s cables, produced by photovoltaics from little soleta concentrated light. (The soleta starts as small as to hardly cover the minimal innitial requirements for started colony, and gradually is grown until it could begin to implement terraforming functions...)
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3. Water ice under this cold, makes perfect mass biulding material for cities (properly isolated from the internal heat), roads, ports, etc.
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Pleace, proceed... and comment!

Could a significan degree of cooling of only the exosphere be done?
What tech could be used for such job?

Here is an article by Paul Birch, where is in-short outlined the topic about constructing terraformed supramundane shells and terraformed rotating tube worlds, together with the necesarry for the "plain" terraforming of terrestrial planets:

http://www.paulbirch.net/CustomPlanets. … anets.html

Described is also the Pat Gunkel "topopils" rotating space habitats` concept.

Namely in this text is depicted the "three-level" habitat engeneering taxonomy, about what I was talking about in the begining of the "supramundane" thread: tubes where we have not natural gravitational anchors, natural terrestrial planets terraforming and supramundane shells. May be very reallistic the autor tends to describe (except with Mars case) almost only about 1 Gee habitats. Such way the terraforming efforts are entirelly focused on worlds with equal or bigger surface gravirty than earth`s.

Legitimately arises the question: "what to do with the smaller terrestrial worlds?". Excluded from the terraformation options` list I think that we should pay them little more attention in regard of their numerousity. Like in every mass-numerousity distribution in this universe, as smaller are certain entities as bigger is their number. My notion is that we must not exclude them from the terraform-list, and in the way the biggest natiral masses could be made earthlike, a "Supramundane oceans" or other world-envelope techs could be used to be human-livably converted their surfaces.

In the Solar system there are more than 30 astronomical bodies discovered,which have solid surfaces and are shaped round by the balance of their self-gravity & internal structural force (i.e. passed the Wild bound). Being unique and more valuable as distinct places/planets-with-names  than mere materials` sources, the opportunities for their colonisation has to be seriously took under attention. Such way the gap in the gravitational "Main sequence" in the cathalogizing of the terraformable objects would be closed.

These "strange" and "funny" ideas to get the sun - or every other supra-planetary mass astronomical body within that universe - terraformed, belong to Paul Birch.
See: http://www.paulbirch.net]www.paulbirch.net; more exactly -- http://www.paulbirch.net/OrbitalRings-I … gs-III.zip; pgs.237 and 238, "3.4.1.Super-Jovian planets" and "3.4.2.Super-stellar planets" , also: http://www.paulbirch.net/SupramundanePl … lanets.zip
Separate thread on this is already started. Notice the topic "Supramundane habitats+" and please, lets discuss there.

About Sedna and the other outer mini-planets, I`ll start another thread, too, with more or less detailed description and "proof" for the theoretical plausibility of the concept.