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#226 2004-06-01 06:56:40

Cobra Commander
Member
From: The outskirts of Detroit.
Registered: 2002-04-09
Posts: 3,039

Re: Terraforming Venus - methods anyone?

Just a thought on the "cloud city" concept, since floating them is high-risk at best, they need some kind of anchor. Why not, materials allowing attach such a 'city' to a series of tethers, similar to those proposed for space elevators?


Build a man a fire and he's warm for a day. Set a man on fire and he's warm for the rest of his life.

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#227 2004-06-01 10:37:37

dicktice
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From: Nova Scotia, Canada
Registered: 2002-11-01
Posts: 1,764

Re: Terraforming Venus - methods anyone?

Mbastion: Re. Venusian cloudcities, your thoughts are very cogent. At the altitude of 50 km, where the atmospheric pressure is 1 bar, the wind appears to be 250 mph, with circulation rising along the equator and dividing north and south to sink back at the poles. The cause of the high wind velocity has not yet explained. Blimp-like atmospheric probes will answer gust-of-wind questions. To roll a cloudcity massing that of a small city on Earth could then be computer simulated for feasibility. Gravitational tethers, undoubtedly would be incorporated for miriad applications. A list could include: atmospheric volatiles and liquids, as well as surface mining, retrieval; stabilizing ballast/aerodynamic structures suspension; waste management control; etc. Normal Earth atmospheric composition at 1 bar filling the aerostatic envelope would both prevent sinking lower or rising higher. Materials for the envelope balloon layers and aeroelastic design would be sufficiently failsafe, with compartments and emergency lifting gas reserves, including resistance to sulfuric acid exposure. In the absence of Coriolis effect, jetstreams such as Earth's couldn't exist, but the 4-Earth-day circulations around Venus must be considered. With 25 km more atmosphere overhead, radiation from space shouldn't be a problem. Water and hydrogen from H2SO4, as well a sulfur, would possible, surely? Same thing for oxygen and carbon from CO2. Your question: If a cloud city will work on Venus, then why has it not already been tried on Earth, even as an experiment? Outside of aerostats using hydrogen, helium or hot air, the fact that breathable air won't support one is answer enough. Great stuff, this discussion!

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#228 2004-06-02 00:08:34

atitarev
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From: Melbourne, Australia
Registered: 2003-05-16
Posts: 203

Re: Terraforming Venus - methods anyone?

Mbastion: I'm left in awe of your webpage, having just given it a brief perusal. I'll have to refer to it often before going out on a limb in  my posts, from now on. But. regarding Venus: What do you have to say about the cloudcity concept (see Terraforming Venus) as a shorter-term alternative to surface terraformation (assuming you want live to see, and even participate, in the beginnings of space migration there)?

Don't be so easily discouraged Dicktice.

There is a hot discussion going on in the topic:
Water, not CO2, Bad for terraformers?

http://www.newmars.com/forums/viewtopic … ...4;st=45

Mbastion, sorry I didn't say welcome. You are welcome! smile
I also wait for your answer in Terraforming the Moon. It's actually a principle topic can we or can we not terraform some planets (especially Mars)- doesn't matter where you write your point I'm following your argument with others.

Regarding cities in the sky - it is interesting and a very good start of colonizing. But this is digression - the topic is about terraforming, not colonizing Venus, although one may not happen without the other but the final objective should be making Venus as comfortable as possible. I am sorry but I don't see much public/government support in the space exploration and missions if there were no plans to make the planets habitable. Scientific reasons only won't get us far enough, IMHO. smile


Anatoli Titarev

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#229 2004-06-02 07:52:33

dicktice
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From: Nova Scotia, Canada
Registered: 2002-11-01
Posts: 1,764

Re: Terraforming Venus - methods anyone?

My main concern with terraformation is that it takes such a long time, and I can't recall any human projects since medieval cathedral building, that seriously followed a plan longer that a generation. For this reason, I tend towards initial, or intermediate, building-block projects. Ultimate terraformation of Venus, with year-plus long days, is so daunting, quite aside from the surface pressure/temperature problems, that I shrink from such a long-term challenge. On the other hand, the previously posted mid-atmospheric conditions would seem too opportunistic to ignore, in the short term. In fact, I'll go out on a limb and state: To attempt to terraform planets and moons to resemble Earth would be a waste of time. We should be satisfied simply, to make them as livable as possible wherever practicable in, on, above and/or around 'em.

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#230 2004-06-05 22:49:03

MarsDog
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From: vancouver canada
Registered: 2004-03-24
Posts: 852

Re: Terraforming Venus - methods anyone?

Cloud balloon cities could reflect radiation from above while allowing radiation to escape from below.
-
Consider a reflective, teardrop shaped object, nearly flat at the top. Incoming radiation is reflected, while radiation from the ground is deflected. The result is the cooling of Venus.

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#231 2004-06-06 04:54:19

chat
Member
From: Ontario Canada
Registered: 2003-10-23
Posts: 371

Re: Terraforming Venus - methods anyone?

I wonder if cloud city could be built using the atmosphere at Venus.?

A small chemical factory/polymer factory arrives at Venus, descends to 50km, it blows up a small balloon to stop the decent, then using the atmosphere it begins creating cloud city.

Lots of chemicals floating around at that altitude that could be used.

This could make for a tiny start cost.
Any Chemical engineers have any thoughts on this?


The universe isn't being pushed apart faster.
It is being pulled faster towards the clumpy edge.

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#232 2004-06-06 11:48:57

MarsDog
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From: vancouver canada
Registered: 2004-03-24
Posts: 852

Re: Terraforming Venus - methods anyone?

The balloon could lower a cable and collect dust containing heavier elements. Maybe enough Fluorine floating around to make Teflon. Interesting that some gasses contain metal such as Uranium Haxafluoride.

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#233 2004-06-06 12:16:59

karov
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From: Bulgaria
Registered: 2004-06-03
Posts: 953

Re: Terraforming Venus - methods anyone?

The venusian thread is too long. I can`t find whether this is conserned:

http://www.paulbirch.net/TerraformingVe … uickly.zip

,parasol, CO2 sequestration, superfast forced cooling of the atmosphere, spining the planet or setting by mirror in polar orbit a diurnal cycle, cloud cities...

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#234 2004-06-14 18:39:55

karov
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From: Bulgaria
Registered: 2004-06-03
Posts: 953

Re: Terraforming Venus - methods anyone?

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!

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#235 2004-06-15 09:01:24

dicktice
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From: Nova Scotia, Canada
Registered: 2002-11-01
Posts: 1,764

Re: Terraforming Venus - methods anyone?

I don't believe in violent measures to make Venus (or any other whatever) habitable for humans. Adaptation, is my only recommendation, if only because collisions and burnings, etc. would require more than a lifetime to  recover--and who wants to wait that long?  Stands to reason!

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#236 2004-06-15 15:20:58

karov
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From: Bulgaria
Registered: 2004-06-03
Posts: 953

Re: Terraforming Venus - methods anyone?

The realistic timeframe for any planet`s terraformation always is far longer than average human lifetime.
Violent measures as huge colisions and burns if their consequences are not estimated properly, could indeed postpone the final terraformational deadline, making worse the pre-terraforming effort innitial conditions.
But, the reason about the proposed deep lasering of Venus is that this heat injection could create enormous magma chamber (in the lower mantle of this planet, devoted of plate tectonics) and to cause the most massive lava eruption in the venusian history, hence -- direct way of deep water reserves release. The point is the hydrosphere establishment to relly entirelly on local deposits. The atmosphere of Venus after the super-eruption would become even hotter and denser but WETTER. The other non-violent even gentle way of reaching and utilizing of this infra-planetary water is to use millions and millions of drilled superdeep shafts in order the deep water (or only the hydrogen) to be separated from the molten rock and used in industrial way for modifying the atmosphere and creating of water for surface oceans.

See: http://news.nationalgeographic.com/news … ...ld.html

http://physicsweb.org/article/news/7/6/ … ws/7/6/5/1

the examples are from earth, but Venus is generally believed to have the same inner structure and composition.
The estimation is about 5-10 times bigger amount of H2O in the earth, than on it. The outer water of Venus photodissociated escaped in space, may be crustal water, too. But the mantle is sealed by the crust, so it has to`ve been wet yet. Such amount is an enormous reserve, and should not to be neglected. 15 billions of cubical kilometers makes entire Sedna or Rhea or Iapetus or Titania or Oberon or 2004DW of water. I think that this in-situ wealth would be much more cheap and less energy (and time?) consuming to excavate/mine than to reorbit the equivalent mass in ice-teroids. The other option -- to harvest the solar wind hydrogen -- means spoon-feeding even if the 8 particles/cm3 are scooped magnetically from really wide area.

Both Earth and Venus and the other rocky terrestrial worlds coalesced innititally wet. We have to find way to use this natural gift of conserved undersurface water.

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#237 2004-06-23 15:19:22

kashif777
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From: kingston, canada
Registered: 2004-06-23
Posts: 3

Re: Terraforming Venus - methods anyone?

"I saw a new heavens and a new earth.  The old heavens and the old earth had passed away."

"The earth will be consumed by fire."

"To him who overcomes, I will give the morning star."

If there ever was life on Mars, and there is life on Earth now, there will surely be life on Venus in the future.

Was there a civilization on Mars?  Take a look at a map of Mars.  You will notice that Olympus Mons forms the base of a perfect cross with three other peaks.  This may be a sign from the previous civilization to us of the greatest thing they knew before they blew themselves up.  I think we should excavate Olympus Mons to search for remains.

What about us?  Is it not obvious we will wipe out all life on earth by nuclear war?  What hope is there, then?

"I saw the New Jerusalem come down from heaven like a bride adorned for her husband."

The author of Revelations gives us human dimensions for this object, much like a Borg Cube, about the size of the moon.

Will the best of our planet be beamed up (a la rapture) to this space Ark for transport to a new home?  Such a spaceship would be a great moon for Venus orbit.

Though the details are in the hands of a Higher Power, we might think of ways to make the Morning Star more habitable.

The main problems are high surface temperature and pressure due to a runaway greenhouse effect.  This is very much like what a primitive earth might have looked like.  With the introduction of cyanobacteria, the CO2 could be pulled down and temperatures and pressures would drop.  There are scientists working on bacteria in the atmosphere whose theories suggest airborne organisms might be thriving here in our skies, and possibly above Venus, too.  50 kms above the surface, temperature and pressure are similar to ours.

It may indeed take eons, but it seems are very plausible prospect given the prophecies in the Bible.

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#238 2004-06-24 12:49:32

kashif777
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From: kingston, canada
Registered: 2004-06-23
Posts: 3

Re: Terraforming Venus - methods anyone?

Carl Sagan proposed seeding Venus' atmosphere with algae to fix the CO2 back in the 1960s.  An article in Wikipedia says this is unfeasible because the CO2 would be recycled once the organisms died and fell back towards the surface.

If that is the only objection, I think we have a viable solution with Sagan's idea.  Cyanobacteria (blue-green algae) can live forever, by continually splitting in two.  Dirk Schulze-Makuch of UTexas has analyzed Russia's Venus probe data and suggests that there may in fact already be colonies of bacteria in the clouds of Venus.  This would explain the odd changes to the atmosphere which no other theory can.  The presence of certain biomolecules also confirms this theory (carbonyl sulfide, e.g.).

If water is a problem, there are bacteria which can degrade sulfuric acid with water as a byproduct.  In fact this organism already coexists with cyanobacteria in bacterial mats on earth.

It would seem mechanical solutions could be bypassed entirely in favour of the biological seeding option Sagan outlined decades ago.

In his book "Pale Blue Earth" Sagan wrote that the pressure would be too high for us to live on Venus even if the algae idea worked.  When he proposed the seeding idea, he thought the pressure was only a few bars.  I am not as well-educated as professor Sagan, but I believe the pressure problem goes away once the greenhouse gases (CO2 mainly) are fixed by the algae.  If you are worried about the O2 causing too high a pressure, think again.  The CO2 is a greenhouse gas, which raises temperature and pressure follows.  O2 is not a greenhouse gas so temperature will not rise from trapped radiation.  PV=nRT shows that if temperature is lower with our algae's crop of O2, so is pressure!

Correct me if I am wrong (kashif777@yahoo.com).

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#239 2004-06-24 12:57:34

kashif777
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From: kingston, canada
Registered: 2004-06-23
Posts: 3

Re: Terraforming Venus - methods anyone?

Regarding the New Jerusalem... if it is to go into orbit around Venus, this might set up a resonance and alter the rotation period, too.

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#240 2004-06-26 15:37:49

karov
Member
From: Bulgaria
Registered: 2004-06-03
Posts: 953

Re: Terraforming Venus - methods anyone?

Just a thought on the "cloud city" concept, since floating them is high-risk at best, they need some kind of anchor. Why not, materials allowing attach such a 'city' to a series of tethers, similar to those proposed for space elevators?

Again from "Terraforming Venus Quickly" by Paul Birch. This is the first detailed calculation of entire terraforming option version I know. Inclided is even estimation of the prices in 80`es british pounds. See the entire study on http://www.paulbirch.net]www.paulbirch.net  , for the floating cities and the artificial planetary surface see: 8.Floating colonies and 8.1. An Artificial planetary surface at pg.163 of the document entitled "Terraforming Venus Quickly".
==============================================
The Floating colonies: "Colonies of various shapes and sizes are possible. A suggested standart is a fractal hexagon ~100 km on a side. Its 26000 km2 could hold ~6 000 000 people at the population density of the United Kingdom. Sucj shapes are selfsimilar and pertiling, permiting colonies of various sizes to be linked together into larger ones... Large buoyant colonies are very different from ordinary air-ships. They behave more like rafts on water, rigid on scales smaller than 100 metters, highly flexible on scales biger than 1 km. Their areal density of ~1000 kg/sq.m., twice the wing loading of a heavy military jet, enables them to withstand extreme turbulence and differential winds faster than 140 m/sec. without hazard."  One threat for the atability of such colonies are the open water bodies on their surface. The water in lakes and rivers should not slosh too much from side to side. The lakes shoud not be wider than 7 km., and the rivers are provided with weirs at similar intervals... As the atmosphere CO2 cools and rains down, the floating colonies gradually descend... untill turn themselves in water ocean floating pieces of terra firma... Such huge sub-continental size rafts could be used here on Earth, too.
=============================================
The Artificial surface:"Since floating colonies could be aggregated into large rafts of any size, there is nothing in principle to preclude covering the whole planet with them. The artificial surface thus formed would obviate all need for further terraforming. A complete planet could be built on this foundation, including its own seas and mountains. However heavily laden, it would be supported by the atmosphere compressed beneath it, the heat and density of which would no longer matter.
This extreme form of 'terraforming' essentially entales the construction of 'supramundane planet' ... But in the case of Venus, buoyant support would seem to be more convenient.
We may argue that in terraforming Venus we wish to create and colonise a planet with a natural geosphere, solid mountains and deep oceans. A rough world, neither completely tamed nor fully landscaped. A new Earth. Not identical to the old but similar. An artificial planet would not really meet these desires. There are also many other bodies- the giant planets especially-which are not suitable for conventional terraforming, but which would be ideal locations for supramundane planets. So, having noticed the possibility of giving Venus a completely artificial floating surface, we put it in one side.'


Such colonies could be built everywhere on planets with buoyancy 'curface' at 1 G -- islands, continents, even full 'crusts' floating... On gass, water, or other liquid...

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#241 2004-06-28 11:46:49

REB
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From: Houston, Texas
Registered: 2004-04-07
Posts: 555
Website

Re: Terraforming Venus - methods anyone?

http://moon.pr.erau.edu/~holmesg/venus.html

Some good info on Venus' atmosphere (Two good graphs)


"Run for it? Running's not a plan! Running's what you do, once a plan fails!"  -Earl Bassett

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#242 2004-06-29 04:45:41

karov
Member
From: Bulgaria
Registered: 2004-06-03
Posts: 953

Re: Terraforming Venus - methods anyone?

Very interesting article, REB! Thank, you!

Notice:

1. "Venus' atmosphere is comprised of mainly carbon dioxide with a small amount of nitrogen and only some traces of various other chemicals." -- This "small amount of nitrogen" is 3+ BARS of N2, a quantity enough for another, except itself, ~3.5 earh`s surfaces air cover under 1 bar, containing the usual 70% N2. That means Venus should be the major exporter of filling N2 gass for terraforming the rest, say, ~10 terraformable planets/moons within the System or/and the massive planet-size tube worlds constructions (together with the carbon-fibers from the rest of the atmosphere)... together with the depositories in the outer system - gas giants` amonia, moons, comets, KBO... afterwards.

2. "Near the surface Venus is much hotter than Earth with an average surface temperature of 467 degrees Celsius. Interestingly the temperature at upper-levels of the atmosphere is colder than those of Earth. Thus the temperature decreases rapidly with increasing altitude(see figure below)" -- this is indeed very interesting regarding the closer proximity to the sun of this planet. Hope such effect could be achived and controled technologically around smaller bodies in order their open-sky atmosphere to last indeffinitely. See the treads for terraforming the Moon and Mercury`s one for link to splendid article by Gerald Nordley.

3. "Venus also has a slow rotation rate (243 earth days equals one day on Venus) which practically eliminates the coriolis effect. The combination of these conditions creates a near perfect Hadley cell that extends all the way from the equator to the pole in each hemisphere, where warm air at the equator rises and flow towards the pole then sinking at the pole and the flows back toward the equator as shown below." - See the picture. It is simulated that such air-cyrculation pattern occurs on every slowly rotating planet regardless of the atmosphere`s density. Such notion leads the mentioned by me in the terraforming Mercury thread David Semloh to conclude that partial (polar) habitabilty of Mercury could be achieved in first time for hundreds of times lower than Venus gass/water import requirements, i.e. cost. The two Hadley cells should redistribute the heat dayside/nightside and the equatirial to polar circum-flows must run the hydrosphere cycle properly... It is estimated as pointed out by atitarev that the average toposphere temperature on terraformed, but non-spined faster and non-sunscreened Venus naturally should be about 15-20 degrees higher than Earth. The average temp. on Earth is low enough, so indeed quite pleasant climate and weather should be on terraformed with earth equivalent atmosphere Venus -- from the equator to the poles... It may occur that the slowly rotating bodies, with solar day seazon-long would have nicer and calmer climate. At least closer to the central star. The lack of noticable Coriolis effect protects the atmosphere form banding as the gass giants (and Earth) and blocking the heat and water transfer around the planet.

Regarding these features of the Venusian atmosphere, think about Mercury, too!

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#243 2004-07-12 15:23:25

kippy
Banned
From: Chicago area
Registered: 2003-11-06
Posts: 70

Re: Terraforming Venus - methods anyone?

I think I found the perfect name for the sunsnade project if this ever happens http://en.wikipedia.org/wiki/Svalin]Svalin.  Maybe they could call an artificial moon of comet cores Cupid.

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#244 2004-07-17 05:10:01

karov
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From: Bulgaria
Registered: 2004-06-03
Posts: 953

Re: Terraforming Venus - methods anyone?

I think I found the perfect name for the sunsnade project if this ever happens http://en.wikipedia.org/wiki/Svalin]Svalin.  Maybe they could call an artificial moon of comet cores Cupid.

I agree that the practice in insolation/light deflection will impose special terms or profecional slang for distinguishment of the different techniques. A 'svalin' is good term for light deflecting morrors/soletas. Equally good word should be invented for signing of the concentrating type of soletas -- all the possible diversity.

About Cupid, I think it is plausible to think about forming an artificial moon form the watering bodies from the Outer system if ( which is the most possible scenario ) it is regarded as necessary the import of water/hydrogen on Venus, rather to scoop solar wind or dig out and pyrolise the mantle for the 10-15 world oceans beneath the crust. It should appear more economical and cheap to bring the several hundred of millions cubic kilometers of water with cometary bodies. Such approach give as access to the huge celestial mechanics reserve of usable power of the System and simultaneously gives us the usable mass of water.

See, http://www.neofuel.com]www.neofuel.com . A typical comet consists of a third water, a third of frozen mud (silica-aluminium and other mineral compounds) and a third of tar-like substance - kerogen (hydrocarbons) -- the same composition as all the noons and planetoids (+Pluto-Charon planet) further than Jupiter from the Sun -- indeed the chemical composition of the primordial solar nebula minus the H-He.
From all this we need only the water, or even only the hyrdrogen -- the rest consists of chemicals which we consider to have to rid off from Venusian atmosphere -- rock, carbon and oxigen...

An orbital ring system or other monentum exchange mechanism, could do simultaneously these jobs:
- to slow down the iceteroids to comperativelly low venusian orbit - ready for processing and extracting the hydrogen;
- to transform their gravitational potential energy in usable for terraformation purposes form - electric?
- to trade CO2 and excess N2 (ascend) for water (descended) in the atmosphere with net gain of power and without violent way of transportation - no colisions.
- to collect the remaining carbon and rock from the cometary bodies in 'Cupid' an artificial moon depository for rotating space colonies and other free space structures building.
- to spin the planet by the ORS on account of the deorbited from Kuiper Belt high solar orbit mass...

An incrementally developing and growing ORS could do the task in exponential manner -- indeed in mere decades or couple of centuries including the 40-50 years of the deorbited from KB comet`s trip time.

For all the astro- and planetary engeneering activities within the Solar system or in any galaxy we have both the energy and the materials on right positions. We need just to couple, to short-cut the vast gravitational-nuclear reservoir of energy+materials which is every system in each era of its evolution.

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#245 2004-07-17 05:54:30

chat
Member
From: Ontario Canada
Registered: 2003-10-23
Posts: 371

Re: Terraforming Venus - methods anyone?

IMHO Venus needs.

1. a cooler surface so machines can work there.
A man made sunshade of fabric seems vast on scale and impractical to place in orbit.
One solar flare and it is destroyed.

Another form of sunshade is needed.
Asteroids/comets collisions in orbit,Smog producing satellites or other.

2. co2 then o2 are the main problems at Venus.
Fix the co2, or collect it and use a giant chimney to send it to escape velocity.
This method works for both c02 and 02.
Fixing co2 or dumping co2 will both take time.

3.hydrogen and iron used as fixing agents.
Both mined from the surface or below the surface and used to fix and change the atmosphere.

4.spin speed of Venus.
Best to do nothing.
Get used to the hot days and cool nights, and the 243 day 1 day cycle of that.

5. importation of water.
comets seem the most practical.
No point in sending water to Venus until the surface temperature is below 100c.
Adding water or hydrogen above that temperature will cause steam and a steam cycle.
A steam cycle is how Venus got the way it is.

6. a novel method to stop Venus from raining 24/7, or for you non earth types 243/1.
At 1.8 solar energy and a near earth like atmosphere it will rain everywhere pretty much all the time on Venus.
Venus will probably end up with a 2x earth atmosphere weight after teraforming at best.

7.Pack hip waders, and good umbrella  big_smile


The universe isn't being pushed apart faster.
It is being pulled faster towards the clumpy edge.

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#246 2004-07-17 07:28:37

atitarev
Member
From: Melbourne, Australia
Registered: 2003-05-16
Posts: 203

Re: Terraforming Venus - methods anyone?

Chat, it sounds good to me but the solar day on Venus is not 243 but 116 Earth days - a very common error. It takes Venus 243 days to rotate around its axis but 116 days from dawn to dawn. Agree, no need to change rotation but fix the atmosphere.

The fully terraformed Venus might get pretty rainy and cloudy but it will keep the climate within the tolerant norms - the average temperature being 15-25 C. On Earth it's 4 C.


Anatoli Titarev

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#247 2004-07-17 14:55:46

karov
Member
From: Bulgaria
Registered: 2004-06-03
Posts: 953

Re: Terraforming Venus - methods anyone?

Yeah, it appears that the rotational rate is not so essential for the heat redistribution in the atmosphere. Slower or non-rotating planets with comperativelly thick atmospheres ( even in the brethable range ) should have indeed milder climate than the fast spining with all bands and multicellar meteorology of theirs dew to the Coriolis effect. The non-rotating, say tidaly loced to red or brown dwarfs will have non-photosynthesising areas on their permanent night sides, but the air currants will keep them warm and some migrational mechanisms as the salmon one could include the dark sides` stockpiles of chemicals in the biological cycle...

About the average temperatures - Earth - 4 C ( spreading to +/- 60 in different time and places), Venus - 15-25 C (distributed in almost equal local and contemporal figures)... Tolerable for conventional non-extremofile earth biota is average temperature of , say +50 C. That means a planet with earth air ( minus some of the greenhouse gases ) prety close to the Sun -- Mercury? Or closer?  Regarding the air presure, and other characteristics... we could calculate how close to the Sun could orbit a planet capable to support earth-like habitability. What is the higher constant temp= which the earth life could tolerate + the humans. Envision very hot planets - super-saharas, or steam heat jungles... bit how hot 60-70 degrees Celsius?

This without sunshades or other illumination decrease method (bigger albedo at the surface, more clouds...) gives quite wide Goldilock sphere for engineered worlds.

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#248 2004-07-17 17:05:27

chat
Member
From: Ontario Canada
Registered: 2003-10-23
Posts: 371

Re: Terraforming Venus - methods anyone?

atitarev,

You are correct it is a nearly 4 earth month solar day.
I argued that exact point about 2 months ago, and here i am saying 243 days *lol*

I think your correct also on the rain, the more it rains on Venus the more likely it is to buffer the planet temperatures.
So let it rain all it wants.  smile

I bet the rain on Venus would be cool to watch.
The ground becomes wet with a brief shower, dries out 4 times as fast as on earth, then does the same thing again.
Pools don't last for long unless it rains for a few days straight, and when it stops raining  the pools dry up before your eyes in just a few hours.

karov,

Good calculation on the goldilocks characteristics of a planet.

I think for human habitation we are talking about a max temperate of 74c on the equator, with a 25c shift due to local climate.

That puts us right on the brink of a steam cycle.
To be safe we probably need a max temp of 60c with 25c fluctuations for local climate.

If it rains on Venus 2x or 4x as often as earth, i believe the local climate shifts will be no more that 5c  10c planet wide.
So probably 80c is ok.

Seems to point to the fact that if we cool Venus enough to get machines and life working on locking away the planets atmosphere.
It should stay that way once it begins to rain, and as long as the equator never gets above 99c again.


The universe isn't being pushed apart faster.
It is being pulled faster towards the clumpy edge.

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#249 2004-07-18 06:07:00

karov
Member
From: Bulgaria
Registered: 2004-06-03
Posts: 953

Re: Terraforming Venus - methods anyone?

Water evaporating at 100 C is under ~1 bar. For Venus Atitarev pointed 2-3 bars for average 15-25 C. Average 80-99 C -- the maximum for water to be in liquid form, i.e. for habitability -- means closer orbit.

How close to the Sun -- Mecurian or lower?

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#250 2004-07-18 08:36:18

atitarev
Member
From: Melbourne, Australia
Registered: 2003-05-16
Posts: 203

Re: Terraforming Venus - methods anyone?

Water evaporating at 100 C is under ~1 bar. For Venus Atitarev pointed 2-3 bars for average 15-25 C. Average 80-99 C -- the maximum for water to be in liquid form, i.e. for habitability -- means closer orbit.

How close to the Sun -- Mecurian or lower?

The temperatures on the terraformed Venus are of course indicative. I read about simulations saying that they would be 15-20 degrees higher with the right atmosphere. With 2-3 bars the temperature, which water starts to evaporate would be higher, not sure - 140-150 C? We don't want this temperature but if we get a hot equator (over 100 C) and mild poles we still won't lose water, if the pressure is 2-3 bars.

However, I hope when it's stabilised, we should get the temperatures like Chat described.

The lack of the axial tilt on Venus will cause creation of multiple stable climatic zones - one of the zones is bound to be comfortable! There will be seasons though (much shorter than on Earth) - not due to the axial tilt but due to the long sol. We may call the night - winter, the noon - summer, the morning - spring and the evening - autumn (fall).


Anatoli Titarev

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