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PostPosted: Sat Jul 21, 2007 4:37 pm 
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I have to make a correction. I keep running into people who claim terraforming can't be done, it's too difficult. Within the Mars Society many people claim terraforming Venus can't be done, or at best is very difficult. Both statements are untrue. Terraforming is a big job, but can be done. Venus does have water, not as much as we would like but its cloud layer is entirely water. Terraforming Venus is the reverse of terraforming Mars in several key areas: Mars requires mechanical/chemical means, Venus requires biological technology. Mars is cold with low pressure, Venus is hot with high pressure. Mars has low gravity but its length of day is the same as Earth and axial tilt which produces seasons is the same. Venus has the same gravity as Earth but it's length of day is longer than its year and has no axial tilt.

Carl Segan first proposed seeding the clouds of Venus with algae to sequester CO2. That was when we thought the pressure was 6 bars; now that we know it's 92 bars the problem is more difficult. We can engineer a bacterium or archaea to thrive in the clouds of Venus and convert CO2 gas into polyanhydride. That is a polymer with forumla (C2O4)n. You also have to engineer cloud layers to control insolation to manage surface temperature. Dramatic things will never work; things like importing elements to combine with CO2, or impacting Venus to blow off atmosphere, or planet size sun shades. Terraforming Venus requires knowledge of meteorology, atmospheric physics, and the ability to genetically engineer a microorganism. I've met biology students who can't think in terms of engineering a microorganism, they think that's too hard. They obviously will never be genetic engineers. If we can find people willing to work in this field we can terraform Venus. A properly engineered terraforming microbe will multiply exponentially, rapidly filling the planetary could layer and quickly converting CO2 into polyanhydride. The only limitation will be energy from sunlight. It also requires going through the entire proteome to eliminate any elements not found in the clouds of Venus. For example, using retinal as the photodye instead of chlorophyll because chlorophyll requires one atom of magnesium per molecule; the clouds don't have any magnesium. Again, genetic engineering will require work, but that's just research.


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PostPosted: Sat Jul 21, 2007 8:32 pm 
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RobertDyck,

Interesting approach to Venus.

I'm in the same camp as you with Venus, nothing i have seen so far gets Venus moving the right way.

Well other than building a carbon moon from the co2, that one falls into the very long term and very expensive category.

On your same theme though... why not engineer radiation reflecting bacteria in those same clouds?

We might loose the light doing that, but might lower surface temperatures enough to do something productive.

The 92 bars in my opinion is not the biggest problem on Venus, its the surface temperature that is tougher to overcome.


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 Post subject: Venus has plenty of water???
PostPosted: Sun Jul 29, 2007 4:04 am 
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RobertDyck wrote:
I have to make a correction. I keep running into people who claim terraforming can't be done, it's too difficult. Within the Mars Society many people claim terraforming Venus can't be done, or at best is very difficult. Both statements are untrue. Terraforming is a big job, but can be done. Venus does have water, not as much as we would like but its cloud layer is entirely water. Terraforming Venus is the reverse of terraforming Mars in several key areas: Mars requires mechanical/chemical means, Venus requires biological technology.
...


Hi Robert.
Venus' atmosphere has:

CO2...........96.3 %
N2.............03.5 %

SO2...........~150 ppm (parts per million)
H2O...........~100 ppm
Ar..............~100 ppm
COS...........<40 ppm
H2S............<40 ppm
O2..............<30 ppm
H2..............<25 ppm
CO..............~30 ppm
Ne..............~14 ppm
He..............~12 ppm
Kr...............~1.5 ppm
HCl.............~0.4 ppm
HF...............~5 parts per billion

There are strong indications that there were massive volcanic resurfacing of Venus 500 million years ago with much vulcanism since then. Given this, the tiny amount of water remaining now is disturbing. (On Earth volcanic gasses are typcially 75% water.) If all the water on Venus were to condence on the surface the water would only be ~5cm giving it even less water than Mars.

The clouds are made up of aerosol particles <10 micrometers in diameter of sulfuric acid 85% pure by weight.


Fogg (page 339) wrote:
"Sulfuric acid is generated photo-chemically, starting with the action of ultraviolet radiation on sulfur dioxide above the clouds (a simular proces converts SO2 to H2SO4 on Earth - See equations 4.11). It then becomes incorported in aerosol droplets which, after about a year, sink to the base of the cloud layer where they evoporate. Ultimately the heat of the lower atmosphere dissociates H2SO4 to SO3, which then undergoes thermochemical reduction by reacting witht eh CO back to SO2. The Venusian clouds are maintined in a dynamic, sulfur - cycling steady state and have little in common with terrestrial clouds, being more akin to photochemical smog in mode of formation and composition."



As for seeding the atmosphere with algea, there are many problems with this.

-- First, we know of no cyanobacteria that can live in sulfuric acid.

-- Second we know of no cyanobacteria that can live in the upper atmosphere (or indeed have positive boyancy).

-- Third, the upper atmosphere is totally lacking in Sodium, Magnesium, Potassium, Calcium, Phosphorus, Selenium, Iron, Copper, Zinc, Iodine and many other trace elements needed to form cells. (This is the same reason why it is unlikely we will find life floating in Jupiter's atmosphere.)

-- Fourth, all known life requires liquid water. None (I know of) grows in micrometer (which are smaller than bacteria) sized droplets of water (let alone concentrated sulfuric acid).


If you postulate engineering magical nano-tech you can do anything. If you postulate engineering magical blue green algae you can also do anything.

In my judgment, creating a new species that have the properties that I've listed above can't be done or (at a VERY generous best) is very difficult. Note that the engineering techniques discussed for terraforming Mars do not require the wholesale creation of wildly unique species. Or if that you postulate the ability to gene-engineer your Venus bacteria why not say that Mars is trivial to terraform by creating psychrophilic, hypobaric bacteria that produce PFC's? THAT is an easier species to create and Mars already has water.

My data comes from:
- "Terraforming: Engineering Planetary Environments" by Martyn J. Fogg and "Moons and Planets" by William K. Hartmann.

- "Extremophiles for Ecopoiesis: Desirable Traits for and Survivability of Pioneer Martian Organisms" by David J Thomas, et all (7 authors).

I feel that the very brief summary that I gave in the FAQ was fair. If you wish to argue these points further, the posts should likely be moved into the Venus thread.

Warm regards, Rick.


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PostPosted: Sun Jul 29, 2007 8:00 pm 
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See also ...

Frequently Asked Questions - Mars Terraforming
http://newmars.com/forums/viewtopic.php?t=5481

Terrform Venus
viewtopic.php?t=4741

Floating Venusian cities or Venus vs Mars vs Titan revisited
viewtopic.php?t=5322

Venus vs Mars vs Titan
viewtopic.php?t=5007

Terraforming Venus - methods anyone?
viewtopic.php?t=442

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PostPosted: Sun Jul 29, 2007 9:33 pm 
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Look up the term aeroplankton. Wikipedia often has a lot of information, their definition:
Quote:
Aeroplankton (or aerial plankton) is the term used to describe the tiny lifeforms which float and drift in the air, carried by the current of the wind; it is the atmospheric analogue to oceanic plankton.

The aeroplankton comprises numerous microbes, including viruses, about 1000 different species of bacteria, around 40,000 varieties of fungi, and hundreds of species of protists, algae, mosses and liverworts that live some part of their life cycle as aeroplankton, often as spores, pollen, and wind-scattered seeds.

The more interesting organisms are living bacteria. There are cyanobacteria that exibit nonflagellar swimming motility. They swim with a flap of cell membrane that they undulate or flap like wings. Some aerial microbes flap cell membranes to direct their motion through the air; a taxis (single cell version of instinct) directs them to updrafts to keep them in the air. It's like a glider riding the thermals.

Note: genetic engineer usually involves taking genes from unrelated organisms and splicing it into the host organism you are trying to create. There will never have been a single organism that has all the traits you want, you deliberately bring all the traits together. So halobacteria use retinal for their photodye instead of chlorophyll, but chlorophyll requires magnesium which you won't find in the clouds of Venus. Fine, take the gene for retinal. Halobacteria is not carbon fixing, but cyanobacteria is. Fine, don't use halobacteria as the host or the basis of your new organism, just take the genes for retinal. Some bacteria species of aeroplacton use nonflagellar swimming motility to maintain their position within the clouds; fine, take that gene. Cyanobacteria is both carbon fixing and nitrogen fixing; great, that sounds like a good basis to start with. Some anaerobic bacteria love sulphuric acid, often much stronger than the clouds of Venus; great, you identify the structures vulnerable to sulphuric acid and replace them with ones from sulphur-loving anaerobic bacteria. Will the result be "Frankenstein's Monster"? This is how all genetic engineering works; all products of genetic engineering could be called that.

The really interesting part is re-engineering the dark reaction of photosynthesis. The ideal is to store energy in some form within the cell, green multicellular plants use carbohydrate. The mechanism to consume that stored energy must be different. Plants on Earth with 2 photosystems produce oxygen as by-product of producing carbohydrate, cells with a single photosystem do not. That stored energy is consumed in a process called cellular respiration, plants that consume stored energy at the same time as they produce it are said to exhibit photorespiration. However, respiration in multicellular plants is practically identical to that in animals, they consume O2 with carbohydrate producing CO2 and H2O. Venus will not have any significant levels of O2 in its atmosphere for a very long time, so cellular respiration cannot rely on O2. Furthermore, we want the cell to produce polyanhydride as a primary product of its metabolism. The ideal is a waste product of consuming its stored energy. You have go engineer a new form of cellular respiration that doesn't require O2, and produces (C2O4)n as waste. That waste can be excreted via exocytosis. Once you come up with a system of photosynthesis and cellular respiration, you have to engineer the organelles to use it. Then engineer genes to produce those organelles. Now this is REAL genetic engineering!


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PostPosted: Tue Jul 31, 2007 1:35 pm 
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Here is my solution:

1) Fill the atmosphere with trillions of tiny, nitrogen filled aluminium balloons, which will reflect 80%+ of the incoming sunlight.

2) Keep replenishing the balloons and wait several centuries until the surface temperature drops to less than 50C.

3) Set up automated factories of the surface that compress the CO2 and inject it into sealed stainless steel bottles, constructed from local surface materials.

4) Bury the bottles in low-lying depressions and cover them in Venusian dirt.

5) After god knows how many centuries, the atmospheric pressure will have declined towards 5-6 bars, 2/3rds of which is N2. Large amounts of hydrogen will be present in the form of sulfuric acid, which will start to rain out and fill the seas. It is then a matter of converting the sulfuric acid into water and SO2 (which can be bottled and buried) and converting the remaining CO2 into oxygen and organic carbon.

6) The buried sulphur and CO2 would gradually leak out of its bottles and return to the atmosphere over millenia. The biosphere would gradually sequester the CO2 as carbonate and sulphate rich rock.

An awful lot of effort for what is sure to be a boiling hot and desperately arid planet, even after terraforming. But there is nothing to say that it cannot work in principle.


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PostPosted: Wed Aug 01, 2007 2:50 am 
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RD, I'm always glad to see your posts on this topic. I think there is some support here for terraforming the second planet, but a lot of misinformation generally abounds when people talk about it.

The lack of water is simple enough to fix. Redirect comets from the outer solar system to Venus.

Adding a significant proportion of earth's ocean water to Venus would have a huge impact on the planet without life. Think about it for a bit.
-The atmosphere becomes hundreds of times thicker.
-Sunlight never reaches the surface. It is completely dark. The slow process of cooling can begin.
-Water can condense at higher pressures and temperatures.
-CO2 dissolves readily in water, because it is polar.

Quote:
As for seeding the atmosphere with algea, there are many problems with this.

-- First, we know of no cyanobacteria that can live in sulfuric acid.

-- Second we know of no cyanobacteria that can live in the upper atmosphere (or indeed have positive boyancy).

-- Third, the upper atmosphere is totally lacking in Sodium, Magnesium, Potassium, Calcium, Phosphorus, Selenium, Iron, Copper, Zinc, Iodine and many other trace elements needed to form cells. (This is the same reason why it is unlikely we will find life floating in Jupiter's atmosphere.)

-- Fourth, all known life requires liquid water. None (I know of) grows in micrometer (which are smaller than bacteria) sized droplets of water (let alone concentrated sulfuric acid).


Not problems.
-Acidophiles, read up on them.
-Venus's atmosphere is a lot thicker than 1g/mL, and quite a few things can live above that on Earth.
-With an active water-cycle, materials on the surface would dissolve and get picked up in trace amounts in the atmosphere. Not much, but enough.
-Microorganisms, especially spores, migrate around the planet in airborne water droplets. Helps them propagate.


Last edited by Spatula on Mon Aug 06, 2007 3:14 pm, edited 1 time in total.

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 Post subject: Rick is still doubtful.
PostPosted: Sun Aug 05, 2007 7:40 am 
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RobertDyck wrote:
Look up the term aeroplankton. Wikipedia often has a lot of information, their definition:...


Hi RobertDyck, everyone.

Wow, I had never heard of aeroplankton, thanks for the tip. The universe is just so strange. Wikipedia actually has very little on them, how often are they found at the top of the stratosphere? Do you know any books that talk about their life cycle & ecology in detail?


However, despite being proven uneducated on this element of my argument, I remain unconvinced that it is simple to terraform Venus. You talk about gene-engineering terrestrial bacteria; all DNA requires phosphorous. This is not found in Venus' upper atmosphere in any quantity. (I've never seen anything that says it has been detected there at all.) That is saying nothing about the other trace elements that you need to make cells.


Spatula, the temperature on Venus' surface is ~465C which will melt lead. This is above the critical temperature of water (374C), where no matter what the pressure it is at it does not form a liquid. So there will be no water to dissolve CO2 and do the other things you mention. The water in the atmosphere, will photo-disassociate and the hydrogen will be lost. I believe I've read that NASA space probes have detected hydrogen being lost from Venus. Anyone have a link?

Spatula, what do you mean 1g/L?


Antius, when the sun was only 70% as hot as it is now, Venus was thought to have a hot wet greenhouse. The temperature then was enough to evaporate the seas. The carbonates were baked out of rocks releasing CO2 and Venus has turned into the dry greenhouse it now is as the hydrogen was lost.

Now if we add water (which is a VERY powerful greenhouse gas) we make the temperature problems worse. If we could somehow turn the CO2 atmosphere into oxygen then Venus will then radiate a lot of its heat and we might be able to get it to a stable state. But for that to happen, you have to have liquid water at the same place as the phosphorus, iodine, iron & other trace elements. I don't see this happening unless the planet is made much cooler, presumably with some sort of space mirror or the like.


In the book, "The Life and Death of the Planet Earth: How the New Science of Astrobiology Charts the Ultimate Fate of Our World" by Peter D. Ward and Donald Brownlee, they argue that the increasing temperature of the sun has brought Earth close to the edge of long term habitability. They argue that within 800 million years our planet will be sterile.

Venus is a lot hotter than Earth (1.913 times the Earth's insolation), so its oceans will always be in danger of ending up in the run away wet greenhouse that it suffered when Venus was getting 1.33 times Earth's current insolation. This suggests to me that we will ALWAYS want to have a mirror reducing the amount of heat it gets from the sun, or be adding more floating mirrors, manually sequestering CO2, moving Venus farther from the sun, etc. It just sounds like more work than for Mars.

In other threads, people have spoken of magical nano-tech to harvest CO2. Of dropping giant comets to add water to Venus. Of spinning up the planet's rotation to give a usable day/night cycle. Or of moving Venus and Mercury around the solar system, etc. These are obviously very, very difficult to do. I do not argue that it is physically impossible to terraform Venus, just that it is harder than to do so than for Mars.


Anyway, I usually ignore the terraforming Venus / Titan / Europa / etc. threads. They are (I think) very far in the future, where as Mars could be terraformed with current technology, assuming we had a population on the planet. Mars is where my interest lies.

Warm regards, Rick.


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 Post subject: Re: Rick is still doubtful.
PostPosted: Sun Aug 05, 2007 5:00 pm 
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RickSmith wrote:
You talk about gene-engineering terrestrial bacteria; all DNA requires phosphorous. This is not found in Venus' upper atmosphere in any quantity. (I've never seen anything that says it has been detected there at all.) That is saying nothing about the other trace elements that you need to make cells.

Good point, here's my answer. The following paper talks about particulates in the lower clouds.
http://wwwrsphysse.anu.edu.au/~fpm121/v ... r19all.pdf
Quoting from page 9, CLOUDS AND HAZES
Quote:
Very interesting, but puzzling, results were obtained by elemental X-ray analysis of the thin layers collected by the IPF experiment [Andreichikov et al., 1987], which was an aerosol analyzer on VEGA. Three elements were identified: sulfur, chlorine and phosphorus. Sulfur and chlorine in cloud particles had been detected previously by similar measurements, but not phosphorus. It is clear that some P-bearing substance can be important as a particulate in lower clouds. Phosphoric acid H3PO4 is a likely candidate for this substance and phosphorous anhydride P4O6 may be the gas responsible for its production [Andreichikov, 1987]. A critical review of these data was given by Krasnopolsky [1989]. The key conclusion in the paper is that the lower subcloud boundary at the level about 33 km registered on VENERA 8 and later on some other missions can be explained by phosphoric acid particles dominating in the subclouds.

So phosphorus has been detected in the lower clouds. That means our engineered terraforming microbe will have to dip into the lower atmosphere, where temperatures can get near boiling. Even lower clouds have temperature beneath boiling; after all, water droplets can't form above boiling. On Earth, sulphur loving bacteria often live in sulphuric acid pools such hot springs where the temperature is close to boiling. Sometimes the water is boiling, and with enough solutes can even be a couple degrees above +100°C. Sulphur loving bacteria thrive through all of it.

Ps. The paper is new, published April 2007.


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PostPosted: Mon Aug 06, 2007 4:31 am 
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Spatula, the temperature on Venus' surface is ~465C which will melt lead. This is above the critical temperature of water (374C), where no matter what the pressure it is at it does not form a liquid. So there will be no water to dissolve CO2 and do the other things you mention. The water in the atmosphere, will photo-disassociate and the hydrogen will be lost. I believe I've read that NASA space probes have detected hydrogen being lost from Venus. Anyone have a link?


Something to consider is that when most of the atmosphere becomes water by composition, how heat will be distributed in such an atmosphere.


Quote:
Antius, when the sun was only 70% as hot as it is now, Venus was thought to have a hot wet greenhouse. The temperature then was enough to evaporate the seas. The carbonates were baked out of rocks releasing CO2 and Venus has turned into the dry greenhouse it now is as the hydrogen was lost.


I think I made a good case for the probability that Venus never had appreciable amounts of water. Stellar evolution models and the lack of atmospheric oxygen would preclude significant water in Venus's past. It was always a furnace.

Quote:
Now if we add water (which is a VERY powerful greenhouse gas) we make the temperature problems worse. If we could somehow turn the CO2 atmosphere into oxygen then Venus will then radiate a lot of its heat and we might be able to get it to a stable state. But for that to happen, you have to have liquid water at the same place as the phosphorus, iodine, iron & other trace elements. I don't see this happening unless the planet is made much cooler, presumably with some sort of space mirror or the like.


Water is a very strong greenhouse gas, but unlike CO2 it undergoes phases. Hot water vapor is not as dense as CO2, and rises quickly to the top of the atmosphere, taking heat away from the surface. Upon radiating this heat into space, it precipitates to the surface as liquid or solid depending on the atmospheric temperatures.

The water itself traps a lot of infrared radiation due to its polar hydrogen bonds, but because of its phases it tends to be more of an anti-greenhouse gas in planetary settings.

For more anti-greenhouse effects, see Mars. Mars is so cold that CO2 experiences phases on its surface, and because CO2 can freeze and sublimate, it decreases the planet's temperature further. Or perhaps Titan, where Methane, another greenhouse gas, experiences phases and cools the moon off. Or perhaps Pluto, where the cryogenic temperatures are low enough for Nitrogen to have phases and act in a similar fashion.

Quote:
Venus is a lot hotter than Earth (1.913 times the Earth's insolation), so its oceans will always be in danger of ending up in the run away wet greenhouse that it suffered when Venus was getting 1.33 times Earth's current insolation. This suggests to me that we will ALWAYS want to have a mirror reducing the amount of heat it gets from the sun, or be adding more floating mirrors, manually sequestering CO2, moving Venus farther from the sun, etc. It just sounds like more work than for Mars.


A good concern. With increasing levels of light comes increasing reflectivity. As a material gains heat energy, its specific heat increases, causing it to have trouble gaining further energy. Instead it becomes reflective. A lot of this ties into black-body radiation - as it gets brighter, an object will act more and more like a white body. Venus's natural temperature without the greenhouse effect should not be twice as high as Earth's. Closer to the edge of livability, but well within it.

Floating mirrors are the objects of sci-fi, and will probably remain that way, concerning terraforming. If we screw up, and the planet is still a bit too hot, supplementing the atmosphere with reflective particles and anti-greenhouse gases would push it into safe territory.


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PostPosted: Wed Aug 08, 2007 12:29 pm 
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Spatula wrote:
Quote:
Spatula, the temperature on Venus' surface is ~465C which will melt lead. This is above the critical temperature of water (374C), where no matter what the pressure it is at it does not form a liquid. So there will be no water to dissolve CO2 and do the other things you mention. The water in the atmosphere, will photo-disassociate and the hydrogen will be lost. I believe I've read that NASA space probes have detected hydrogen being lost from Venus. Anyone have a link?


Something to consider is that when most of the atmosphere becomes water by composition, how heat will be distributed in such an atmosphere.


Quote:
Antius, when the sun was only 70% as hot as it is now, Venus was thought to have a hot wet greenhouse. The temperature then was enough to evaporate the seas. The carbonates were baked out of rocks releasing CO2 and Venus has turned into the dry greenhouse it now is as the hydrogen was lost.


I think I made a good case for the probability that Venus never had appreciable amounts of water. Stellar evolution models and the lack of atmospheric oxygen would preclude significant water in Venus's past. It was always a furnace.

Quote:
Now if we add water (which is a VERY powerful greenhouse gas) we make the temperature problems worse. If we could somehow turn the CO2 atmosphere into oxygen then Venus will then radiate a lot of its heat and we might be able to get it to a stable state. But for that to happen, you have to have liquid water at the same place as the phosphorus, iodine, iron & other trace elements. I don't see this happening unless the planet is made much cooler, presumably with some sort of space mirror or the like.


Water is a very strong greenhouse gas, but unlike CO2 it undergoes phases. Hot water vapor is not as dense as CO2, and rises quickly to the top of the atmosphere, taking heat away from the surface. Upon radiating this heat into space, it precipitates to the surface as liquid or solid depending on the atmospheric temperatures.

The water itself traps a lot of infrared radiation due to its polar hydrogen bonds, but because of its phases it tends to be more of an anti-greenhouse gas in planetary settings.

For more anti-greenhouse effects, see Mars. Mars is so cold that CO2 experiences phases on its surface, and because CO2 can freeze and sublimate, it decreases the planet's temperature further. Or perhaps Titan, where Methane, another greenhouse gas, experiences phases and cools the moon off. Or perhaps Pluto, where the cryogenic temperatures are low enough for Nitrogen to have phases and act in a similar fashion.

Quote:
Venus is a lot hotter than Earth (1.913 times the Earth's insolation), so its oceans will always be in danger of ending up in the run away wet greenhouse that it suffered when Venus was getting 1.33 times Earth's current insolation. This suggests to me that we will ALWAYS want to have a mirror reducing the amount of heat it gets from the sun, or be adding more floating mirrors, manually sequestering CO2, moving Venus farther from the sun, etc. It just sounds like more work than for Mars.


A good concern. With increasing levels of light comes increasing reflectivity. As a material gains heat energy, its specific heat increases, causing it to have trouble gaining further energy. Instead it becomes reflective. A lot of this ties into black-body radiation - as it gets brighter, an object will act more and more like a white body. Venus's natural temperature without the greenhouse effect should not be twice as high as Earth's. Closer to the edge of livability, but well within it.

Floating mirrors are the objects of sci-fi, and will probably remain that way, concerning terraforming. If we screw up, and the planet is still a bit too hot, supplementing the atmosphere with reflective particles and anti-greenhouse gases would push it into safe territory.


You are wrong.
Oxygen oxidised the rocks and it never remains in the atmosphere for more than million years without replenishing and there is no reason why Venus was formed with little water.

Wikipedia; http://en.wikipedia.org/wiki/Venus :
"Classified as a terrestrial planet, it is sometimes called Earth's "sister planet", for the two are similar in size, gravity, and bulk composition. Venus is covered with an opaque layer of highly reflective clouds of sulfuric acid, preventing its surface from being seen from space in visible light; this was a subject of great speculation until some of its secrets were revealed by planetary science in the twentieth century. Venus has the densest atmosphere of all the terrestrial planets, consisting mostly of carbon dioxide as it has no carbon cycle operating to lock carbon back into rocks and surface features, nor organic life to absorb it in biomass. It has become so hot that the earth-like oceans the young Venus is believed to have possessed have totally evaporated, leaving a dusty dry desertscape with many slab-like rocks. The evaporated water vapor has dissociated and hydrogen has escaped into interplanetary space. The atmospheric pressure at the planet's surface is 92 times that of the Earth, the great majority of it carbon-dioxide and other greenhouse gases. (By comparison, a few hundreds of parts per million of carbon dioxide on Earth are believed to cause significant warming.)"

For us oxygen is an essential gas but it a strong oxidant that never remains in the atmosphere of a planet without plantlife.
And there are forms of life on Earth for what it is extremely toxic and oxidise them in a while;

http://en.wikipedia.org/wiki/Oxygen

"Diatomic oxygen (O2) is one of the two major components of air (20.95%). It is produced by plants during photosynthesis, and is necessary for aerobic respiration in animals. It is toxic to obligate anaerobic organisms and was a poisonous waste product for early life on Earth."

And the UV radiation converted a bit of oxygen on Venus in the higher atmosphere to ozone that protect us from deadly UVC here on Earth but on Venus it accelerated the oxidation of volcanic sulfur and SO2 to SO3
that combined with escaping hydrogen to form H2SO4 that is sulfuric acid.
And WHY BOTHER GATHERING ICE WHEN YOU COULD CONVERT ACID TO WATER!?H2SO4>REMOVE SULFUR>H2O+S8.USE HEAD NOT "ASSUMING".
And that thing that you said about stellar evolution is a nonsense.


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PostPosted: Thu Aug 16, 2007 3:20 am 
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Quote:
You are wrong.
Oxygen oxidised the rocks and it never remains in the atmosphere for more than million years without replenishing and there is no reason why Venus was formed with little water.


Venus does not have the big layer of rust Mars has, though even if it did that wouldn't be nearly enough oxygen for a significant ocean.

Oxygen has nothing to react with on Venus... all of the surface rocks and atmospheric compounds are oxygen-rich igneous formations, just as they are on Earth. Earth and Venus started out with a very large percent of oxygen in their mass. The planets are ready-made with every oxidation reaction completed, and atmospheric oxygen is only derived from water or organic processes, after which it has nowhere to go.

Maybe I'm wrong and we've been breathing leprechauns.... maybe.

If we were to assume that all of the oxygen in the atmosphere used to be from water, at best we'd get 10% the hydrosphere of Earth, but this is unlikely, because it would only result from a very oxygen-poor planet. Venus has about as much CO2 on its surface as Earth, just in a different chemical form. If we say it started with none... that's getting into dangerously ridiculous territory.

Quote:
For us oxygen is an essential gas but it a strong oxidant that never remains in the atmosphere of a planet without plantlife.
And there are forms of life on Earth for what it is extremely toxic and oxidise them in a while;


This I just...aah... it's not even true in sort of a 'well I can kind of see what you mean' sort of way. Ganymede and Europa have tenuous oxygen atmospheres. These formed from the same processes you're claiming removed Earthloads of water from Venus. This is not a fast thing. It happens over billions of years, and that's how long much of the oxygen in these atmospheres has been floating around for.

Quote:
And WHY BOTHER GATHERING ICE WHEN YOU COULD CONVERT ACID TO WATER!?H2SO4>REMOVE SULFUR>H2O+S8.USE HEAD NOT "ASSUMING".
And that thing that you said about stellar evolution is a nonsense.


If we converted all of the H2SO4 to water, we'd have a few lakes worth. If we want a sizable fraction of Earth's hydrosphere, it would have to be several times the volume of Venus's current atmosphere. That's the main reason.


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PostPosted: Sat Sep 08, 2007 11:52 am 
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Would it be possible to drive off some CO2 by adding more heat?

This may seem counterintuitive, but I'd be interested to know what effects heating Venus' atmosphere may have.

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PostPosted: Sat Sep 08, 2007 8:54 pm 
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Michael Bloxham,

I had that same thought about a year ago that ended in a long long discussion.

To make a long story short..
Yes it is possible.

Using a plasma gun in orbit localized on one spot can heat c02 up enough to escape velocity.
You can also focus the sunlight to do the same as a plasma cannon.

Down side was the 85ish bars needed to be removed.
Even with a grand scheme it was very very long term.

co2 is a relatively heavy gas so all other lighter gas elements will be expelled at a much higher rate than co2.
Most of what we would like to keep will be expelled quickly.

All other ideas such as adding super greenhouse gas simply raise the temperature with little extra degradation of the atmosphere.


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PostPosted: Sat Sep 08, 2007 10:15 pm 
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You can bury the whole atmosphere underneath an artificially constructed false planetary surface, then spin such surface to give it a 24 hour rotational period, tilt it on its axis to give it seasons, bury some superconducting cables within the shell to give it a magnetic field, shade it from the sun, and add an Earthlike atmosphere on top. You can even contour the artificial surface to make it look like Earth with continents and oceans etc, keeping all that nasty carbon dioxide underneath and out of sight.


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PostPosted: Sat Sep 08, 2007 10:27 pm 
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Mmm, sounds delectably crunchy.

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PostPosted: Sat Sep 08, 2007 10:33 pm 
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What about a nuclear based solution, where thousands of atom bombs are exploded on the surface: both driving the CO2 away, and at the same time, stirring up a thick layer of cooling dust?

I'm sure this has been proposed before though...

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PostPosted: Sat Sep 08, 2007 11:53 pm 
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Tom Kalbfus wrote:
You can bury the whole atmosphere underneath an artificially constructed false planetary surface, then spin such surface to give it a 24 hour rotational period, tilt it on its axis to give it seasons, bury some superconducting cables within the shell to give it a magnetic field, shade it from the sun, and add an Earthlike atmosphere on top. You can even contour the artificial surface to make it look like Earth with continents and oceans etc, keeping all that nasty carbon dioxide underneath and out of sight.

This is how we might go about it.

Step 1: build a Sunshade at the Venus-Sun L1 point
This cools down the surface and atmosphere a bit so machinery can operate more effectively on the surface of Venus.

Step 2: Dig into Venus's crust to obtain material to build the artificial shell.
Autonomous robots dig into Venus's crust under 90 atmospheres of crushing carbon dioxide cooled by the sunshade blocking the Sun's light.

Step 3: Build a series of giant hexogonal plates out of the materials obtained from mining Venus's crust, build scafolding over Venus's natural topography and then stack the plates on top of the scafolding, each plate has air compressors built into it. There are two sorts of plates, top plates and bottom plates. The top plates are wider at the top than at the bottom with smooth slanted edges in the sides, and the bottom plates are wider at the bottom then at the top with smooth slanted edges at the bottom. The hexogonal plates fit tightly together with each top plate surrounded by 6 bottom plates. The bottom edges of the top plates fit tightly next to the top edges of the bottom plates forming an air tight seal, resting heavily onto the scafolding.

Step 4: Pump atmosphere through the hexagonal plates sucking in atmosphere from the top and pumping it underneath. Eventually the pressure builds up underneath the plates causing them to rise up off the scaffolding, supported by the atmospheric pressure underneath. As the Hex plates rise up in the atmosphere the sphere they form around the planet expands causing the plates to move further apart, as they do so the top plates slide downwards as their sloped edges slide down against the smooth sloped edges of the bottom plates, when the prearranged altitude is reached the top and bottom plates interlock perfectly forming a flat smooth sphere held up by the internal pressure of Venus's compressed atmosphere. Using this carbon dioxide fluid as a lubricant, the sphere moves independently of the surface of Venus, rotating faster and at a tilt to Venus' orbital planet to generate seasons.

Step 5: add scafolding to the smooth hexagonal sphere then on top of that scafolding build the artificial surface of Venus with continents and shallow oceans. A layer of artificial rock and soil is placed on top of that. Nitrogen is seperated out of Venus' atmosphere underneath and pumped on top of the outer artificial surface, and also free oxygen seperated out of the carbon dioxide, and then some carbon dioxide for plant life. The oceans are deep enough to allow for 100 meters of ocean on top, some water is obtained from Venus's original atmosphere, while the rest is made from imported hydrogen from the Outer Solar System. Oceans settle in their flat basins, Venus does not need as much as Earth to get the same water coverage since the bottoms of Venus's oceans are flat. The continents rise up above the ocean level are are built into the outer surface, and plant and animal life is introduced from Earth.

What do you think?


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PostPosted: Sun Sep 09, 2007 12:14 pm 
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Tom Kalbfus,

Interesting :)

How about a little change on that theme.

1.We bring in two asteroids and crash them into each other just beyond the la grange point of Venus as our sunshade.
Although adding a temporary L1 shade sounds like a big helper to dropping surface temperatures, so both together might offer great results.

2.When things are cool enough for machines on the surface we make all the elements for heavy lift vehicles from separated c02.
We use the separated oxygen as rocket fuel, then simply launch vehicles full of carbon to the la grange point to contribute to the sun shield.
We mine for goodies that can gobble up co2 or help in the process of creating carbon based items.

This can be an exponential process with machines building machines, so the process can be semi quick.

The initial startup process can be very small.
It creates a decreasing atmosphere and uses up both problem elements Oxygen and Carbon.

We get to pick and choose what we expel, and we end up creating a moon for Venus.

The leftovers on the surface from the process become the power stations and settlement startups.

Still the problem is the number of bars we would need launch to the la grange point, probably 30 - 50 bars of carbon.
Then the secondary problem of the increasing atmospheric Oxygen content as we remove carbon.
The second problem might not be a factor, if we use enough oxygen as propellant as we just get more c02 to separate and launch.

We can also alter this idea by simple making giant piles of carbon on the surface, but then what to do with all that free oxygen becomes a problem.
And we get no real moon to talk about.

How does that sound?


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PostPosted: Sun Sep 09, 2007 12:21 pm 
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Michael Bloxham,

No theoretical limitation exists on the size of a nuclear bomb.
You probably could make one big enough to blast away most of the atmosphere of venus.
Then again one that big might blast away most of venus.

The nuclear fallout on what was left would endure for many thousands of years, not limited to Venus.


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