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#251 2004-07-18 13:10:46

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

Re: Terraforming Venus - methods anyone?

My question was about how close to the Sun could be slowly rotating planet as Venus -- assuming the atmosphere cycle quite evenly distribites the heat -- to have average air temperature at the surface lower than the discussed 80-90 C. Lets say we deal with 0.3 to several bars in tems of brethablity of N2/O2 mixture. If you go to the "terraforming Mercury" thread you will see the figures for Semloh`s Mercury equatorial temperatures at 0.3 bars.

If we move the Anatolii`s terraformed Venus - 2-3 bars N2/02 air to Mercury orbit -- what would be the average temperarture? How close we should move it toward the Sun the result of 15-25 C to become 80-90 C...

An environment nearly to the boiling point of the water will be not so hospitasble for naked unaided human bodies -- again suboptimal as the discussed titan-formed hyper-arctic environments, but with little airconditioning of the living areas+ the vehicles, down to ~300 K , really big civilization could be hosted. Industrial cooling of the houses would be as essencial as the sentral heating during the winter in the polar countries on Earth. Of course this could be transitional state of terraforming a planet in other solar system, but it suffices the incrementality requirements of the economics, and doesn`t needs global spinning or sunscreening...

BTW, a polar orbit soleta for such bodies gives again milder climate than the rotating earthlike planets -- lacks Coriolis force for banding the atmosphere and has 24-hour diurnal cycle for the whole surface, except narrow spots on the equator for times depending on the orbital period of the planet.

I`m also fan of the diurnal = seasonal non-sunshielded Venus as Anatolii describes it. This is the closest to the dream for non-constantly industrially aided 'geological' terraforming. Such Venus resembles most to naturally evolved living planet. A place, not structure.

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#252 2004-07-18 17:40:32

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

Re: Terraforming Venus - methods anyone?

atitarev,

Your post about the evaporation rate at Venus got me thinking about what happens at 3 bars on earth.

I believe at 3 bars water boils at 90c or so not the conventional 100c, at 62 bars Venus must boil water at 60c or something like that?

I've never given the pressure at Venus much thought until i read your post.
This much lower boiling point of water at Venus decreases the safe temperature to avoid a steam cycle.

Maybe 40c as the max with 15c fluctuations is all the planet has to work with before it becomes a runaway greenhouse.
I bet this is the reason the sister planet is the way it is.
Early in the solar systems life, Earth with a thinner atmosphere had the ability to have water in liquid state up to 100c, Venus to 80c.
As soon as the water was 80c at Venus with a say 2-5 bar atmosphere it created steam, and steam created more heat in the atmosphere, and a thicker atmosphere.
All the hydrogen from the oceans is lost over billions of years, and we end up with Venus with 62 bars of mainly co2.

That 60c/70c/80c boiling point of water at Venus is going to squash a lot of Teraforming ideas for it.
We might have to get the atmosphere to 5 bars or less, before any attempt to add water or hydrogen.
Adding water or Hydrogen to Venus in its current state will simply thicken the atmosphere with more co2 and steam and more heat.

I think 2 bars of earthlike atmosphere at Venus, with 1.8 x sunlight and no sunshade, is right at the brink of the steam cycle.
We can get a lot of assistance with a 25% or 50% sunblock in keeping it cooler for the machines and bacteria , but if we cant get the pressure below 5 bars before the sunlight returns to its normal, it will revert back to what it was.

Locking away 55-60 bars of atmosphere in even 100 years seems like a mighty big task,even for engineered bacteria and machines
And iron asteroid collisions in orbit, all working full out to fix the atmosphere.


karov

Not 100% sure about this, and about the boiling point of water at 2 bars,but...
I believe we are looking at a max of 2 bars for Venus with no sunshade
And at 2 bars its very close to the boiling point of water 96c.
Not much room for error at Venus when teraforming.

Even with Venus at the orbit of Mars it would still be a very hot hostile place.


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

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#253 2004-07-18 22:21:41

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

Re: Terraforming Venus - methods anyone?

atitarev,

Your post about the evaporation rate at Venus got me thinking about what happens at 3 bars on earth.

I believe at 3 bars water boils at 90c or so not the conventional 100c, at 62 bars Venus must boil water at 60c or something like that?

I've never given the pressure at Venus much thought until i read your post.
This much lower boiling point of water at Venus decreases the safe temperature to avoid a steam cycle.

Maybe 40c as the max with 15c fluctuations is all the planet has to work with before it becomes a runaway greenhouse.
I bet this is the reason the sister planet is the way it is.
Early in the solar systems life, Earth with a thinner atmosphere had the ability to have water in liquid state up to 100c, Venus to 80c.
As soon as the water was 80c at Venus with a say 2-5 bar atmosphere it created steam, and steam created more heat in the atmosphere, and a thicker atmosphere.
All the hydrogen from the oceans is lost over billions of years, and we end up with Venus with 62 bars of mainly co2.

That 60c/70c/80c boiling point of water at Venus is going to squash a lot of Teraforming ideas for it.
We might have to get the atmosphere to 5 bars or less, before any attempt to add water or hydrogen.
Adding water or Hydrogen to Venus in its current state will simply thicken the atmosphere with more co2 and steam and more heat.

I think 2 bars of earthlike atmosphere at Venus, with 1.8 x sunlight and no sunshade, is right at the brink of the steam cycle.
We can get a lot of assistance with a 25% or 50% sunblock in keeping it cooler for the machines and bacteria , but if we cant get the pressure below 5 bars before the sunlight returns to its normal, it will revert back to what it was.

Locking away 55-60 bars of atmosphere in even 100 years seems like a mighty big task,even for engineered bacteria and machines
And iron asteroid collisions in orbit, all working full out to fix the atmosphere.


karov

Not 100% sure about this, and about the boiling point of water at 2 bars,but...
I believe we are looking at a max of 2 bars for Venus with no sunshade
And at 2 bars its very close to the boiling point of water 96c.
Not much room for error at Venus when teraforming.

Even with Venus at the orbit of Mars it would still be a very hot hostile place.

You got me wrong, Chat. With the pressure increasing the temperatures, at which water starts to evaporate INCREASES, NOT DECREASES and vice versa. On Earth, at high elevation, where pressure is low, water could boil with 60-80 C.


Anatoli Titarev

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#254 2004-07-18 22:34:47

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

Re: Terraforming Venus - methods anyone?

Cooling by floating balloon cities and populated sunshades. Lot of hydrogen, imported from Jupiter, to make water from the CO2.
The plants could use the excess hydrogen to make hydrocarbons.
-
It would take a while, but the colonists could start after manufacturing from Moon bases becomes established.

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#255 2004-07-19 07:20:00

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

Re: Terraforming Venus - methods anyone?

karov

Not 100% sure about this, and about the boiling point of water at 2 bars,but...
I believe we are looking at a max of 2 bars for Venus with no sunshade
And at 2 bars its very close to the boiling point of water 96c.
Not much room for error at Venus when teraforming.

Even with Venus at the orbit of Mars it would still be a very hot hostile place.

You got me wrong, Chat. With the pressure increasing the temperatures, at which water starts to evaporate INCREASES, NOT DECREASES and vice versa. On Earth, at high elevation, where pressure is low, water could boil with 60-80 C.
Yes!

Chat, see: http://www.lsbu.ac.uk/water/phase.html
http://www.lsbu.ac.uk/water/phase.html , and other materials about the 'triple point' of the H2O. As the presure increases the respective boiling point is higher.

Look also about the different solid phases of water (the more than 10 kinds of ice). In the outer solar system every small solid body -- planet, planetoid or moon is made by 'cometary' material -- the primordial solar nebula mixture minus H+He: water ices, rocky dust and carbonous tar-like stuff (+ of course methan, ethan and all other possible carbohydrates). Some of the moons around Saturn, Uranus and Neptune and , also the biggest Kuipert belt and Oort cloud objects are big and massive enough to be selfgravitated to ROUND form and to have surface gravity above 1% G. That means that the dirty ices of their composition are in other phases than the 'plain' earth`s 1 bar ice and that even on their surface the ice is different in the vacuum under 80 K. That have lots of implications about the igloo-domes or mars- or titan-forming of them, but I just wanted to notice that this phase differences within the bodies, could represent 'geotermal' energy equivalent in very usefull for extraction form... Remember that using exactly phase shifts is the most familiar way for mankind to transform energy...

But, back to Venus:
Using the shown diagram we could find the combinations of temperature and presure which fit into permanent human habitability partameters:
-Assuming the temperature limits between say +/- 80 degrees Celsius for constant habitation with cloths + airconditioning & specially designed biospheres for the extremes. WE could discuss even temperatures between 80 K -- about the liquifying point of N2/O2 and 380 K -- water steam environments under 1 Bar, with extremes sub- or superoptimal for open air habitation , but needing only heating/cooling of the already right mixture under the already right presure within the habitats...
- The right air pressure as already many times pointed out is between 0.3 and 3.0 bars FOR N2/O2 brethable mixture. The partial presure of oxigen should not exseed the scuba diving top limit, the presurized nitrogen also is harmfull over several bars, so earth-composition atmosphere is not breathable over 2-3 Bars. 0.3 Bars for the lower limit is imposed by the lower boiling point of the body tissue water ( 0.07 Bars? at 37 C). For other breathable mixtures, already examined by the deep diving equipments, the N2 should be replaced with lighter gas -- the noble gasses act like anaesthetics, so only 'gas giant' atmosphere remains applicable: H or He + trace amounts of O2 (but within the boundaries of sufficient absolute presure of the 'trace' O2 gas!). Such hydrogen mixtures (non-flamable or explosive with so less O2) are brethable over 100 BARS!!!
If we replace the Venusian atmosphere with 96 Bars of H2/O2 mixture ( in ratio 99.8 : 0.2 ) it will be brethable and the humans only should live in refrigerated to 300 K volumes, without presurizing necessary. Other strange implication is that under big presures, 'liquid breathing' could be implemented -- with human lungs in water from the dissolved bigger percentage of O2 at the necessary partial presure level... But, of course breathing liquid or superpresurized air should occur to be dangerous and harmfull for long stay, so we go back to 0.3-3.0 limit of N2/O2.

I can`t find now the boiling points for water under these presures but they should be +/- 50 K accirding to 1 bar level. This causes just broeader environmental problems. Humans could cook with presure/depresure pots, aircondition the living rooms and the vehicles ( as now on Earth everywhere, BTW ), etc. The point is the open environment to be livable for adapted biota, and the temperature to be in the boundaries of the human body termal control... technically aided off course.

The optimum is ~1 bar of N2/O2 in ~300K, but you see that indeed big deviations from this ideal, non present even here on Earth, can be tolerable.

As in the thread about the low G tolerability, we assume that within the boundaries of the human body tolerable parameters of the environment we don`t need to make irreversible changes in the original body design, and only physiological & psychological readaptation is necessary in case of traveling between different parameter`s environments.

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#256 2004-07-19 08:08:57

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

Re: Terraforming Venus - methods anyone?

Another 'water phase diagram' with more accessible explanations: http://wine1.sb.fsu.edu/chm1045/notes/F … rces06.htm
===========================================
See, especially:

"The frozen state of water (ice) is actually less dense than the liquid state, thus, the liquid state is more compact than the solid state
Increasing pressure, which will favor compactness of the molecules, will thus favor the liquid state
Increasing pressure will thus lower the temperature at which the solid will melt

The melting curve slopes to the left, unlike most compounds
At 100 °C the vapor pressure of water is 760 torr or 1 atm, thus at this temperature water will boil if it is at 1 atm of pressure
At pressures below 4.58 torr, water will be present as either a gas or solid, there can be no liquid phase"
==============================================
I.e. Increasing presure will thus lower the temperature at which ice melts and make higher the boiling point!

For 3 bars if we accept that as the highest human tolerable presure for N2/O2 air mixture: the ice should melt around -5 C and boil around 150 C (?), but under the critical point!

So, we don`t have problems with the hydrosphere within the assumed -/+ 80 C average temperature, for habitation under more than 1 bar air presure up to the brethable upper limit of accepted 3 bars. People born and living in more than 1 bar will need a little decompresion allong with gravity adaptation if necessary to go to environment with lesser air presure and different gravity, say from ~1 G/3 bars/15 C of atitarev`s design terraformed venus-like planet to ~0.4 G/0.3 bars/40 C of semloh`s design of terraformed mercury-like one. Or vice-versa... Or from ~0.12 G/1.5 bars/-70 C (low gravity/high presure/super-arctic environment) of the atitarev`s terraformed Titan to 1 G/1 bar/4 C Earth...

For the bottom limit of 0.3 bars we should have ice melting at slightly higher than 0 C and water boiling at 50-60 C (?). Quite narrow liquid phase imposing different inhabitant`s habits, dressing, cream treatment for preventing the skin drying..., etc.

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#257 2004-07-19 12:01:49

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

Re: Terraforming Venus - methods anyone?

More:

1.The lower presures

~0.3 bars is the air presure on Everest. It is barely brethable in earth partial presure of 21% O2. If the persentage of O2 is higher, such ambient presure is enough for long habitation. Or higher temperature.

We need no less than 0.15 bars partial presure of O2 and not more than 0.4 bars -- for durable healthy stay of humans... Over 0.4 bars the oxigen is toxic in long run. Pure 0.15 bars O2 atmosphere makes quick water loss from the body and is more fire hazardous than the balasted with more inert gases one. Because of that these 0.3 bars of ambient presure are pointed often as the practical lower limit.

2. The higher presures:

~2-3 bars (20-30 meters under the water) is the practical limit caused by the nitrogen narcosis for use of earth comon air.

http://www.techdiver.ws/exotic_gases.sh … ases.shtml

The only practical fillers of an atmosphere with higher presure than 1 bar are: N2, neon, hellium, hydrogen. All other noble gases are more narcotic than nitrogen, and have numerous other disadvantages. With H or He we could have brethable mixtures with higher than 100 bars ambient presures, but these gases are easily lost by planets with under 1 G surface gravity. So we have N2 and Ne as practical balast gasses for higher presures.

http://www.healthatoz.com/healthatoz/At … cosis.html

3-4, even up to 10 Bars of ambient healthy presure are feasible and practical with N2 or/and Ne filling the rest of the partial presure up from ~0.2 bars of oxigen.

Venus has already present 3 bars of N2 within the thick 96% CO2 atmosphere. If we decide to leave it in place because of some global climatological reasons it would cause controlable narcosis... although that if exported this quantity of N2 will be enough to terraform several times the earth surface area.

The only thinkable source of Ne in amounts for terraforming tasks is the Sun itself -- it contains thousands of earth`s masses of neon, which could be gravitationally swapped for cheaper stuff --, say, H + He from the gas giants or the outer system...

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#258 2004-07-19 18:27:15

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

Re: Terraforming Venus - methods anyone?

atitarev,

Thanks for clearing up the pressure and boiling point of water on Venus.

I was working under the assumption that Venus had a very limited temperature set for liquid water.

This higher temperature for the boiling point of water at Venus makes teraforming a much easier task.

If we guess at the surface temperature average at Venus, we either need to block 75% of the sunlight or fix 75% of the atmosphere, or a combination of both for it to rain.

Though Venus is a pretty dry place it still has enough water to rain and form pools and ponds.
Once you can make it rain at Venus it will go a long way to scrubbing the atmosphere and cooling things more.

karov,

Looks like the 2-3 bars of pressure at Venus is what would be needed for a final teraform.

2-3 bars seems to work well with life needs and for temperature needs.

At 2-3 bars the equator and around it will be intolerable for most of life, but the bacteria should love it.

I guess we are stuck with semi permanent sun block scheme until we can fix about 50-55 bars of pressure.
Then the rain should fix the last 4-5 bars, leaving us 2-3.

Marsdog,

I still love the idea of the giant chimney at Venus.

Send the atmosphere into orbit and make a gas moon from it.
Leave about 10 bars for hydrogen import, or hydrogen mining below the surface of Venus.
Smash a few iron asteroids together in orbit for the sunshade and iron dust re-entry, and a few smog producing satellites belching smog in orbit.
Then get the machines and bacteria working at hyper speed before the sunblock starts to wear out.


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

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#259 2004-07-20 04:43:41

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

Re: Terraforming Venus - methods anyone?

Chat, just sunblocking would take thousands of years for the venusian atmosphere to cool down to earth temperatures. We`ll need Burch`s style of 'chimneys' in order to cool it down by force. But this sunscreening is not for making the temperatures of already terraformed venus lower to the earth limits. The last is not at all necessary. Once terraformed under 1 or 2-3 bars of N2/O2 atmosphere, Venus would not need screening from the sun light, or other way of reducing the natural level of insolation. It will thermosate itslef in 15-25 C average surface temperature without parasol with the depicted type of atmosphere.

We need parasol in L1 (or even orbital smoging, but I have to notice that smart swarm or microscopic smart and interacting solar sails would do the job better than plain dust particles) and chimneys in order to get rid of the bulk of the giant excessive CO2 atmosphere. These tools are one of the possible which in combination could do the job in mere decades or couple of centuries. Allong the puting asside the excessive CO2 goes the cooling to tolerable limits ( for the remaining CO2, N2 +, imported water and the first several dozens of metters of rock) of the atmosphere and surface.

The excessive CO2 could be sequestered in  frozen form beneath imported water oceans or as carbonatites rocks, but assuming that CO2 is THE necessary thing for building rotating space colonies, one way or another we should export it.

The total mass of the Venusian atmosphere is 4.8x10 E 20 kg. If we need 40-50 tonnes per square meter of areal density for rotating space habitat construction ( the carbon nanofibres base, the air, water and furnishing, humans, biosphere, all ), than the total mass of CO2 only on Venus allowes us to built 10 BILLIONS of sq.km. habitable area = 20 EARTHS!!! In mutiple colonies` bodies or more preferably incrementaly to make a rotating tube 1000 km. in diameter and  3 000 000 km. long - centered at L4 or L5 point of the Venus-Sun system in order to not spend delta V to leave the planet`s orbit and with curve following the planet`s orbit -- kept in place by M2P2 or other zero-fuel consuming drive. Such way we`ll utilize the mass of the atmosphere in real estates for sale to physical persons and governments and companies, and the terraformation itself of Venus would be just a byproduct of this enormous mega-construction, giving as bonus the 21th earth area in the finish. The most attractive advantage of such combined scheme of simultaneous terraforming + tubeworld construction is that it provides instantly habitable area, i.e. investment returns. We know that a investment return period longer than 30-40 years makes pointless every enterprise. The combination scheme has intrinsic bootstaping in it, and the modest in size private money poured in in small doses of billions of dollars per year could be sufficient. 

A combination of sunblock 'solar sail' and chimneys is very usefull - the sunblock could serve as solar power station and to provide all the energy necessary for refrigerating the atmosphere and to puting it in orbit for several centuries + mass industrial processing of it in brethable form, without to wait long the slowly and ineffective plants to fulfill such task. CO2 moon is than no necessary. The gas lifted by 'lighning' plasma canons, or accelerated by 'chimneys', or dig out with orbital momentum exchange rotavators or orbital rings on low venusian orbit, could be processed in nanofibers or else, and cheaply shipped to the mentioned Lagrange points with solar sails for construction material and components. Using solar power for lifting the CO2 doesn`t include in the account the enormous quantity of H2 which should be imported from the outer system. This H2 has great gravitational potential energy, expressed naturally in dozens of km/s cometary velocity in the inner system, so orbital rings system could be used all this H2 descended on venusian surface to be swapped/traded for ascending CO2... Such planet-lifter could graze all the CO2 and other useless onground stuff -- from 50-60 km altitude doun to the bottom in mere decades, import the H2, and even to spin the planet to week-long or day-long sol if we decide to spend energy for such silly things; and to toss the lifted material to L4 or/and L5 for the tube-world building. In the last almost purely mechanical momentum exchange planetary+colony engineering model all the solar energy in other case provided by parasol, could be redirected for the tubeworld construction, mass interplanetary transport, terraforming and any other kind of energyconsuming astroengeneering works which the mankind could decide to accomplish... If we choose 1 bar terraformed venusian atmosphere parameters, than it is pointless to say that on that planet only we have all the nitrogen to terraform the bodies within the Inner system - especially the utterly airless Moon and Mercury... + replenishing of Mars if necessary, or providing with N2+CO2 the Jovian Gallileans swaping it for H2 if this opperation appears to be more economical. Matter of purpose, money, design...

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#260 2004-07-20 07:45:56

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

Re: Terraforming Venus - methods anyone?

Great, Georgi. I also think that terraforming projects should be carried out simultanesously, then they will boost trade in volatiles (gases, water), techno- and bio-engineering products (spacecrafts, habitats, terraforming tools, genetically engineered bacteria, plants and animals).

Would be good to get some proof of what we have discussed so far by finding simulations, references to all the major points and if we could also get some approval of other members or scientists on what has been dicussed. This topic has become too long and many people won't even read it in full. Probably we need to outline how we view it and create a vote? I, personally don't have too much time at the moment, it's just a thought.

I'm not sure a lot of people will be convinced that VENUS CAN BE TERRAFORMED WITHOUT SUNSHADES AND WITHOUT CHANGING ITS ROTATION RATE (all the explanations for that were in the previous posts and what you, and Georgi Karov, also posted in Mercury, Moon and other terraforming topics, all scattered - this is a quick summary). I had difficulty finding again the simulation links (they did exist) and materials I read on this matter. When I find something I'll post here. A few people have agreed to that but I'd like somehow to get a proof. I hope the combination of coriolis effect, increased albedo with a 2-3 bars nitrogen/oxygen (90%/10%) atmosphere, hydrological cycles, winds will make terraforming Venus a possibility (after stripping its CO2 and cooling it down) as we discussed it. I'd like to sum it up and send to a couple of scientists I know, or better- prepare a comprehensive document and publish it. What do you guys think? I won't be able to contribute to it straight away but I will. We could start with Venus terraformation - for me there's almost no issues with Mars - it's been discussed many times and I consider it's proved that Mars can be terraformed. Terrafoming Venus is a much more complex matter, besides, the above method is not traditional and the final outcome may not sound as the best - a high pressure, 2 months' long days/nights, temperatures 10-20 degrees higher than average on Earth but my point is this terraforming result is realistic can be done in historically short time - 50 to 300 years, is sustainable and safe (no PERMANENT mirrors or sunshades) and doesn't involve Sci-Fi methods of shifting and spinning up planets (let's not discuss this possibility right now).

BTW, Paul Birch's name is spelled with 'I', not 'U'


Anatoli Titarev

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#261 2004-07-20 10:16:59

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

Re: Terraforming Venus - methods anyone?

I agree with you absolutely.

Thank you for the reminder about 'Birch'.

I`m waiting impatiently you to post here your links to simulations, other materials, or to post bigger elaborated article of yours on the theme. I`ll be very glad to have comprehensive document on Venus terraformation in the manner you propose.

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#262 2004-07-20 18:44:31

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

Re: Terraforming Venus - methods anyone?

karov,

I agree that the chimney in combination with all the other techniques is the way to go.

Realistically i think its a 50/100 year project to teraform Venus with chimneys in place,  so humans in protected suits could walk the surface.

The same old problem arises with the chimney though.
How do you place any machine on a surface that is above the melting point of lead?

Even the Russian landers lasted just over an hour, and they resembled tanks more than landers.

I think before the birk chimneys can be put in place we need a sunshade of sorts.

I always thought of the idea of using a small % of the atmosphere at Venus to block sunlight, might be the way to go.

A robot ship arrives at Venus, bounces gently of the atmosphere and scoops and compresses a measure of mostly co2 atmosphere.

This atmosphere is used to create a black smog, then the same maneuver is repeated.

It shouldn't take more than a few of these craft to make a very thick black smog around the planet.

At about 50% sun block the planet will be cool enough for the chimneys to be sent to the surface.

The smog machines in orbit continue until the chimney has removed 55 or so bars.

Also iron asteroid collisions in orbit are overlooked as an easy way to fix co2 directly, and a bonus is even more blocking of the sun in the short term.
As the iron dust rains down in re-entry, it directly reacts with co2.

Iron, water and hydrogen mined from Venus might also go a long way to reducing the bar pressure at Venus.
We might discover that all 3 are in abundance below the surface, and no need to import anything exists.

Magnet ram scoops of the waste hydrogen the sun throws away in the solar wind might also help Venus.

If we could collect 5x or 10x the H number that naturally falls on Venus we might have a simple system for co2 to h20 conversion.

Even a fully teraformed Venus still has some issues with radiation, so a final teraform item should include very large magnets at each pole to be used as a man made magnetic field.

Another idea i toyed with was..
How hot does Venus have to be before we reach escape velocity for co2?

Maybe heating Venus another 100c will do that?
Seems crazy to heat a planet that you want cooler, but this might be a simple technique no one has thought about.


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

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#263 2004-07-21 02:20:16

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

Re: Terraforming Venus - methods anyone?

Venus will be an enormous project.
Numerous orbiting settlements, and balloon cities will block some of the sunlight. 
-
Add hydrogen, possibly by a Paul Birch method, to get rid of the CO2 by making water.
-
Earth cools down quickly at night. Black body radiation is proportional to fourth power of temperature.  The cooling of Venus might be faster than expected.

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#264 2004-07-21 04:41:47

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

Re: Terraforming Venus - methods anyone?

MarsDog,

I agree that Venus will be an enormous project.
I do think your right about the cooling at Venus, it might be much quicker than expected.

I don't think Mars will be any easier to teraform either.
On the surface Mars seems easier, but i bet it will be just as hard to teraform.

The big difference between mars and Venus is that when Venus is teraformed it is done, but mars will always need fine tuning.

I also agree that the waste from Venus is the perfect need for mars.
It makes some sense to send from Venus to mars.
But that also makes for a much more complex project for both worlds.


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

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#265 2004-07-21 21:48:51

mbastion
Banned
From: Sydney
Registered: 2004-05-30
Posts: 19

Re: Terraforming Venus - methods anyone?

Hi,

I've created a Yahoo group to supplement my Geocities page. It's a mailing list to keep up-to-date on the latest improvements to my website as well as a discussion list for realistic Terraforming, Caeliforming and Ecopoiesis. Before and after Terraforming pictures are also welcome.

The Yahoo group is:
http://groups.yahoo.com/group/TerraAuct … erraAuctor

My Geocities page is:
http://www.geocities.com/alt_cosmos/ind … index.html

I hope you find them useful
Michael Bastion

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#266 2004-07-22 12:28:51

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

Re: Terraforming Venus - methods anyone?

Over the longer term, all the solid material in the solar system will be terraformed.
All the planets will have to be renovated, including Earth.
We could even use another sun as a nearby, conveniet backup.
By a Paul Bich method, transfer some of the Sun's material to an artificially created sun made out of the gas from the gas giants.
That would cool Venus down.

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#267 2004-07-22 14:50:56

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

Re: Terraforming Venus - methods anyone?

Over the longer term, all the solid material in the solar system will be terraformed.
All the planets will have to be renovated, including Earth.
We could even use another sun as a nearby, conveniet backup.
By a Paul Bich method, transfer some of the Sun's material to an artificially created sun made out of the gas from the gas giants.
That would cool Venus down.

tongue  tongue  tongue

Did you find the black matter to terraform your soccer ball?


Anatoli Titarev

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#268 2004-07-23 15:50:49

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

Re: Terraforming Venus - methods anyone?

atitarev,

IMHO Dark matter doesn't exist, but that is another story smile
Gravity does exist, and in a larger extent from the outside than from the inside.

Just think of a balloon being blown up with mostly nothing, then think where the bulk of the mass is in the balloon.

Now think of the universe as a balloon.
This explains the speedup quite well, or simply a speedup towards the edge where the gravity is the greatest.
All perspective.(pet theory)(paper to be) smile

Dark matter i believe will be stars that don't ignite, failed stars not quite large enough.
For ever 1 star that shines, how many don't?
1, 3, 10  etc.

Back to the Venus teraform.
I guess a grand scheme of machines that cool themselves is also an option for that hostile surface.

A bit of a tech challenge to do that though.


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

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#269 2004-07-24 10:42:26

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

Re: Terraforming Venus - methods anyone?

Sun shading Venus could involve several methods;

Colony at Sun Venus L1 point.
Near Venus Solar Arrays.
Balloon cities inside Venus atmosphere.

If each method blocked 20%, then similar to Earth intensity.
--------------------------------------------------------
Importing Hydrogen to eliminate the CO2 would produce a Water World planet.
Then the water could be used to supply other colonies.

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#270 2004-07-24 20:03:59

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

Re: Terraforming Venus - methods anyone?

Sun shading Venus could involve several methods;

Colony at Sun Venus L1 point.
Near Venus Solar Arrays.
Balloon cities inside Venus atmosphere.

If each method blocked 20%, then similar to Earth intensity.
--------------------------------------------------------
Importing Hydrogen to eliminate the CO2 would produce a Water World planet.
Then the water could be used to supply other colonies.

Sun screening of entire planet out of the on-planet methods for increasing the overall albedo can be made in many ways. Total parasoling is indeed necessary only for planets much closer to the central star than Venus or even Mercury in the Solar system are. Orbital radii as small as several solar radii are discussed as suitable for terraforming by using of sunshielding soleta mirror in sun-planet L1. For Venus we simply don`t need parasol, or we need it only in the first stages of the terraformation effort in order to capture all the power necessary for the atmosphere cooling, processing and export and , second to seize the light influx for faster cooling.

Assuming that the solar EM radiation consists of only 40% visible light, 50% IR, 9% UV and 1% others for a planet much closer than Venus to the Sun, depending on the exact desing and approach chosen for terraformation and earth-like environment preservation, indeed just FILTERING of the incoming EM radiation should be enough in many cases.

Positioned in forced (light- or mag-sailing) or free ( ~L1 with constant adjustment) orbit in the line between the star and the planet a nano-gap ( 'nano' in the range of the visible light wavelenght ) semi-transperant 'web' could reflect the infrared and ultraviolet and to let only the visible light to pass. Thus, say, Venus would recieve only 40% of its normal insolation - only in visible part of the spectrum, without the photodissociating water-depleting UVs and only with the re-radiated by the warmed surface IRs in the atmosphere. Leting so many 'gaps' as necessary could let as much light as needed to be the reduction ratio. The excessive in wavelenght or amount light can be photo- or termoelectrically industrially used.

The soleta could also redirect the light away from the planetary disc, so in such way not to gain too much momentum as in case of total reflection back or total absorbtion of the falling light.

But, again we don`t need sunscreening soleta infront Venus or even Mercury. We`ll need polar orbiting soleta if we decide to provide such slowly rotating planets with ~24 hours duirnal cycle... The clouds here on Earth reflect back into space about 35% of the sunlight. The clouds in the atmospheres of terraformed planets as close to the central star as Venus/Mercury or closer -- can be promoted to reflect even bigger percentages of the sunlight. In the most extreme and drastic cases of proximity to the star - when the candidate for terraforming world has literally semimolten by the solar heat surface - imagine an envelope/ a 'foam' of countless nano-aerostats in the upper stratosphere, which to reflect almost 100% of the total illumination keeping earth-like conditions of light and heat bellow...

Venus is in the classical ecosphere of the Sun. In normal atmosphere the temperatures on its surface are in the livable range of the liquid water.

The future explorations will show what exact scheme should be chosen for terraformation in order the best sourses of gases and the best ways of multigigatonne interplanetary transportation to be implemented in economical sence.

My honest oppinion is that terraformers will use innitially short-cut, brutaly industrial methods for cooling, chemical transformation and getting rid of the thick atmosphere in mere several decades, rather than some 'gentle', soft, slow and utterly ineffective rellying upon the photosynthesizing plant-life cycles. The other thing about I`m 'sure' that it is - if water or else should be imported from the Outer system , and other things should be exported from Venus - than it is unaviodable the use of some momentum exchange mechanism which to utilize the great orbital gravity gradient. Theorethically quick terraforming schemes non-depending on solar power or artificial fusion, but only on such mechanical power supply are feasible, and perhubs proffitable.

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#271 2004-07-26 04:26:30

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

Re: Terraforming Venus - methods anyone?

Magnet ram scoops of the waste hydrogen the sun throws away in the solar wind might also help Venus.

If we could collect 5x or 10x the H number that naturally falls on Venus we might have a simple system for co2 to h20 conversion.

Another idea i toyed with was..
How hot does Venus have to be before we reach escape velocity for co2?

Maybe heating Venus another 100c will do that?
Seems crazy to heat a planet that you want cooler, but this might be a simple technique no one has thought about.

In http://www.wikipedia.com]www.wikipedia.com in 'solar wind' search you may find that:
-----------------------------------------------------------
"A solar wind is a stream of particles (mostly high-energy protons ~ 500 keV) which are ejected from the upper atmosphere of a star.

In the solar system, the composition of this plasma is identical to the Sun's corona, 73% hydrogen and 25% helium with the remainder as trace impurities, and is ionized. Near Earth, the velocity of the solar wind varies from 200km/s-889km/s. The average is 450 km/s. Approximately 800 kg/s of material is lost by the Sun as ejected solar wind."
----------------------------------------------------------
You have to capture big solar eruption, i.e. mine the Sun at its photosphere in order to have all the trillions of trillions of tonnes necessary H2 in order to water Venus. The common solar wind is too thin. The underground reserves are quite attractive, as the Earth, Venus should hold an amount of at least 10 to 15 earth`s surface hydrospheres in the mantle. But, the most perspective sourse is the hydrogen from the minor bodies in the Outer system, due to the discussed already orbital-gravitational gradient advantages.
--------------
The cooling/accelerator`s chimney walls could be made from many common materials which survive even much higher temperatures: fire-proof bricks, blocks of basalt in the base - foamed solids upper-stage... See, http://www.paulbirch.net]www.paulbirch.net for the chimneys in "How to terraform Venus quickly".
----------------------
The thick atmosphere of Venus could be excavated/orbited in many ways - one and the most construction-consuming is to accelerate plasmed CO2 through the 'chimneys'. Other more economical momentum-exchange ways were pointed out.

But, really increasing the exobase temperature up to termal velocities several times higher than the escape velocity in the exobase hight, should evaporate the venusian atmosphere in mere centuries. That could be done by, say combination of solar powered huge x-ray lasers boiling and ionising the atmosphere + solar powered huge particle (proton?)  accelerator which on certain spot on the venusian overheated exobase to emilate the effect of thousandsfold amplified solar wind which to drag the gases toward ram-scoop traps for further use in space colonies construction. Such system can be designed quite effective with almost every bit of energy going to do CO2 lifting work, and depending on its shear power - may complete the necessary de-atmosphering of Venus in decades, and simultaneously to import from the Sun the amount of H2 for watering the planet. The decelerated from, say, several thousand km/s protons, could serve for acceleration of thousands of carbon atoms to escape velocity towards the ram-scoop. Wasteless tech!

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#272 2004-07-27 05:28:34

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

Re: Terraforming Venus - methods anyone?

karov,

The birk chimney will work if you can create it on Venus.
But what machine can survive long enough to build the chimney?
If any large structure is to be built on Venus, then it will have to be made of materials at Venus, from machines on the surface.

Maybe the complexity and technical challenges to build the chimney, will make building it such a gigantic technical effort, that building it isn't realistic.

A tunneling particle beam from space might have the same effect as the chimney, without building a chimney on the surface.

Heating up Venus at first glance seems self defeating, but i think its an overlooked tool.

If heating the planet can reduce 20 or 30 bars, then enough pressure and heat would be lost from Venus to have machines survive on the surface.

Heating Venus could see all 50-55 or so bars needed removed.

Removing 50-55 bars and leaving 12-7 bars for co2 to h20 conversion and remaining atmosphere seems about the right numbers.

I agree that mining Venus for hydrogen will yield a lot of potential water and atmosphere reduction.
Also iron will help reduce the atmosphere.

Venus will be more  a question of..
Does enough hydrogen exist below the surface to make abundant water flow on the surface, and avoid the need to harvest hydrogen elsewhere.
And how much water does Venus really need?
Could Venus do ok with 1/10 of what we have on earth since the hydro cycle will be 4x or 5x what it is on earth.

Earth would probably functions pretty well with 1/10 the water it has.


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

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#273 2004-07-31 11:48:47

Athanasius
Member
From: Kennesaw, GA
Registered: 2004-07-31
Posts: 1

Re: Terraforming Venus - methods anyone?

How about transforming the atmosphere of venus by seeding it with genetically engineered, photosynthetic, airborne bacteria? Perhaps they could survive in the upper, cooler regions of the atmosphere. As they convert carbon dioxide into oxygen and other byproducts, the atmosphere might cool as the greenhouse effect lessens. The bacteria would have to be tiny enough, or have a structure that enables them to capture tiny windcurrents enough, to be kept aloft.

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#274 2004-07-31 18:52:09

Gennaro
Member
From: Eta Cassiopeiae (no, Sweden re
Registered: 2003-03-25
Posts: 591

Re: Terraforming Venus - methods anyone?

Won't work. Photosynthesis relies on combining carbon dioxide with water and there's regrettably no water left on Venus.

If you could do it however, you'd simply use up what little H2O there is to make oxygen and hydrocarbons. The latter would be immedeately photodissociated and lost to space and you'd be left with no water and very few oxygen molecules.

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#275 2004-07-31 18:55:10

Aetius
Member
From: New England USA
Registered: 2002-01-20
Posts: 173

Re: Terraforming Venus - methods anyone?

Carl Sagan had mulled a similar idea decades ago. However, I believe I read in one of his books ("Pale Blue Dot"?) that the Venusian atmospheric circulation patterns would drag such organisms down to the scorchingly lethal near-surface environment. Also, water is virtually non-existent anywhere on Venus, making it extraordinarily difficult for the terraforming organisms to reproduce in any quantity.

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