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#126 2014-01-10 11:28:21

Void
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Registered: 2011-12-29
Posts: 7,817

Re: Venus

Tom seems to have said:

Whatever carbon dioxide you throw away is less oxygen for the ocean you'd want to create.

Actually it depends on what your objective is. 

It appears to me that floating habits is the only pay as you go method.  Nobody is going to invest in converting a planet to future habitation if it is not about to give near future pay out.

Once you have a Venus largely populated by a unified mesh of floating habitats, the pressure to terraform further (Assuming you got rid of the Sulphuric Acid), is greatly reduced. 

With the acid gone the temperatures should fall.  With the floating habitats reflecting light, the temperatures should fall.

At some point it should be possible to mine the surface, using presumed sophisticated machinery.

As for atmospheric mining, the objective is not to throw away CO2, but to capture it into tanks in orbit and sell it presuming there is a buyer that has use for it.  There could be no market, or some twist of the future as per technology, might make it very much in demand.  For instance rotating habitats constructed from Mercury or our Moon might be traveled to the Venus (Proximate) orbit to harvest solar energy, and maybe they would stop by in Venus orbit to be filled with CO2 and N2.  Of course H2 would have to be brought in from elsewhere.  That would provide a market that could expand wildly, and eventually draw down the atmosphere of Venus, and also provide enormous habitat for humans. 

If not then floating habits, and mining on the hot surface of Venus, but if it or something like it occured, then put domes at the poles, and contain some of the water in them.

Bring Hydrogen in?  Only if it is economical.  As for Oceans, if you have the sky mostly obscurred by floating habitats, then the thermal difference between day and night would already be moderated to a degree, and perhaps at the poles let significant light in, but other places where you still are just mining, just a little light.


Although it is great to think of schemes to terraforming, if the process involves humans, it will require a payroll, and a budget to buy goods and services to improve Venus.  Many schemes ignor that.

If it is our robot replacements doing it, then they don't require terraforming of Earth like planets, they would be likely to do well in Moon like worlds.

I don't see terraforming Venus as a process of Replicating Earth, just making Venus more useful to humans.

Last edited by Void (2014-01-10 11:30:18)


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#127 2014-01-10 14:02:05

Terraformer
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Re: Venus

I don't understand Tom's objection to using comets. The atmosphere is very thick; small comets would vaporise completely on entry, so why not keep up a steady stream of such bodies, more like snow than a fist?


Use what is abundant and build to last

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#128 2014-01-10 14:05:31

robertwalker
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Re: Venus

Yes that's a good point - and comets are fragile anyway - probably quite easy to break them up before they arrive at Venus, to make them into smaller pieces if you have a large comet. And if you make sure there are no habitats in immediate vicinity of where the comet strikes also...

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#129 2014-01-10 18:53:37

Tom Kalbfus
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Re: Venus

Terraformer wrote:

I don't understand Tom's objection to using comets. The atmosphere is very thick; small comets would vaporise completely on entry, so why not keep up a steady stream of such bodies, more like snow than a fist?

The less concentrated the gas the better, I have ideas of sending gas tanks and then exploding them prior to impact so that Venus gets hit by an expanding gas cloud, people living in the atmosphere won't notice anything other that an increase of water clouds and the heat of atmospheric entry and the presence of free oxyhen should cause hydrogen combustion making water vapor. I believe Venus has an ozone layer, that is free oxygen for instance.

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#130 2014-01-10 18:55:43

Tom Kalbfus
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Re: Venus

robertwalker wrote:

Yes that's a good point - and comets are fragile anyway - probably quite easy to break them up before they arrive at Venus, to make them into smaller pieces if you have a large comet. And if you make sure there are no habitats in immediate vicinity of where the comet strikes also...

You recall what happened in Tunguska, Siberia? That was a comet that exploded in the atmosphere, that was quite noise and multiple comet explosions are unpleasant to live around, people will complain about the noise and the damage the shock waves cause to their habitats if nothing else.

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#131 2014-01-10 19:11:36

robertwalker
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Re: Venus

Yes (at least a likely hypothesis for Tungaska) - but that would be a comet large enough to be worth breaking up before it hits Venus. If you are able to divert comets to hit Venus, would be easy presumably to break them up into tiny chunks say 1 or 2 meters across before they hit the atmosphere. Then you'd hardly notice that anything happened just a nice meteor shower.

I don't know if it is worth while to divert comets to hit Venus, whether that's the best way to deliver water, or if we can somehow make do with the water already there - and I rather think one would do it a bit differently. With advanced technology probably wouldn't be hard to just make lots of parachutes and aeroshells for the fragments of ice, maybe each a few meters across, and parachute them down to wherever they are needed. (Have semi- autonomous machines to make the parachutes, say - or whatever - with only the most minimal of supervision - I think by the time we can divert comets where we like across the solar system and need to make these decisions then will have such devices, 3D printers, etc etc).

But if you did just want to bombard Venus with comets, I think it could be done gently, as gently as you want to, by breaking all the comets into 1 or 2 meter diameter chunks in some way before impact, so it is just experienced as a meteor shower by the hab inhabitants.

Last edited by robertwalker (2014-01-10 19:14:21)

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#132 2014-01-11 13:27:08

Tom Kalbfus
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Re: Venus

I was thinking more of short period "artificial comets" that originate in the outer asteroid belt. The comet consists of s giant tank filled with liquid hydrogen or liquified methane. then place explosive charges all across the skin of the tank and blow it up into tiny fragments, then you get a blob of liquid hydrogen or methane floating in space that rapidly boils away into an expanding gas Cloud just prior to impact. We try to time it so that the gas cloud does not expand to larger than Venus before it hits the Venusian atmosphere, so a lot of hydrogen molecules hit the upper atmosphere of Venus, perhaps getting a sky glow, or perhaps not even that, but it reacts with the free oxygen in the atmosphere to produce water vapor, after that the water vapor cools into white puffy water clouds and it rains and the rain evaporates before reaching the ground and that's the water cycle. The sulfuric acid droplets get diluted by the increased amount of water vapor.

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#133 2014-01-12 22:00:23

robertwalker
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Re: Venus

Yes, that sounds good to me smile

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#134 2014-01-12 22:01:24

robertwalker
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Re: Venus

This is the article I've been working on for some time on Venus Cloud Colonies for my Science20 column

Venus Cloud Colonies - Second Home for Humanity?

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#135 2014-01-13 12:57:06

Tom Kalbfus
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Re: Venus

Also remember that the Venusian year is 224.7 days, for each day of that year there is an asteroid that is optimally positioned for a minimal energy transfer orbit from that asteroid's position to Venus. Let us suppose that the burn which allows for a transfer from the asteroid's position to Venus can be done in under 60 minutes. There are 24 hours in a day so herefore 5392.8 hours in a Venusian year. Since the asteroids are hardly moving at all in their orbits in relation to Venus, we'll treat them as fixed in their position more or less, they move a little forward with each Venusian orbit, so lets say it takes 5400 hours before the planet Venus and a particular asteroid is properly aligned for a minimum energy transfer from the asteroid to Venus. There are 5400 asteroids that have mining bases and processing plants for extracting hydrogen from the asteroid and liquifying it, and they each have 5400 hours to process enough hydrogen, build the transfer tank and rocket motors and then liquify the hydrigen and store it in the tank, and when the proper moment arrives teh tank is launched toward Venus, and there are 5399 other asteroid mining bases that are doing similar stuff getting ready to launch their hydrogen tanks while this one is launching theirs. Every hour another hydrogen tank is launched toward Venus, an at Venus the tanks arrive once per hour from different asteroids in the belt, each tank is exploded prior to impact so all that impact Venus is an expanding gas cloud of hydrogen and fragments of the tank that carried it for a meteor shower. This can go on until Venus has accumulated enough water to make an ocean and reduce its carbon dioxide atmosphere.

Now how massive is this carbon dioxide atmosphere? Venus has a surface pressure of around 90 bars of carbon dioxide plus around 3 bars of nitrogen. Now Earth has an atmosphere consisting of around 80% nitrogen and 20% Oxygen at a surface pressure of 1 bar. Since Venus has a gravity of around 90% that of Earth, it actually has around 100 times the mass of Earth's atmosphere in carbon dioxide. A mole of carbon dioxide is 44 grams. A mole of water is 18 grams. A mole of Oxygen is 16 grams, a mole of carbon is 12 grams, and a mole of hydrogen is 2 grams.

The chemical formula for carbon dioxide is CO2, that is two oxygen atoms for every carbon atom that's 12 grams of carbon + 32 grams of Oxygen Equals 72% around 72 Earth atmosphere of oxygen. The mass of the Earth's atmosphere is 5.1480×10^18 kg so 72 times that mass is 3.70656 x 10^20 kg, since the proportion of hydrogen to oxygen in water is 2 grams for every 8 of  atomic oxygen oxygen (as opposed to oxygen in its molecular fore O2 which is 16) 20% of this mass of hydrogen would have to be transfered from the asteroid belt to Venus in hydrogen this is 7.41312 x 10^19 kg that has to be transferred in total from the asteroid belt to Venus to make this ocean and reduce Venus' atmosphere. If there are 5400 asteroids then each asteroid would have to process about 1.3728 x 10^16 kg of hydrogen or 1.3728 x 10^13 metric tons of it. the asteroid Gaspra is 2.5 x 10^13 metric tons of rock, it is probably not 50% hydrogen by mass, but we can swich asteroids once an asteroid runs out of hydrogen. If we allow 10 venusian years to extract that hydrogen from each asteroid that means every 5400 hours a hydrogen tank containing  1.3728  x 10^12 metric tons of liquid hydrogen is produced. and sent on its way for collision with Venus.

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#136 2014-01-13 18:32:05

SpaceNut
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Re: Venus

SpaceNut wrote:

In the past life question have lead to flame wars so we need to tread lightly.

We do know that the essential elements are available but what are the catylists. First are protiens but then, What is the next key event that will cause a radom RNA strand to form is it as simple as a stirred pot that is left to simmer causing a slow mixing and fragment forming. At what point do we call it life?

several pages back we touched on the what we think is life but we know that it comeback to the amino acids.

Mapping Amino Acids to Understand Life's Origins

Only 20 standard amino acids are used to build proteins, but why exactly nature "chose" these particular amino acids is still a mystery. These amino acids are essentially the building blocks of life, and the same 20 standard amino acids have been used in proteins throughout the history of life on Earth, since the existence of the Last Universal Common Ancestor three to four billions years ago.

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#137 2014-01-13 23:04:13

Tom Kalbfus
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Re: Venus

robertwalker wrote:

This is the article I've been working on for some time on Venus Cloud Colonies for my Science20 column

Venus Cloud Colonies - Second Home for Humanity?

I just read your article. Very interesting. I like the Russian illustrations too, so much better than the one in Wikipedia which shows Cloud City on the imaginary gas giant of Bespin from Star Wars: The Empire Strikes Back. So these illustrations were done by the Soviets in the 1970s. Unfortunately the only political motivation for the Soviets was to beat the West and America, as they were more interested in conquering Earth than space. So the Soviets failed to follow through, even though they had better luck with Venus than they had with Mars. Putin doesn't seem much more interested on conquering an empire in space either, he is more interested in the Ukraine and Belarus. The Earth doesn't seem to be that easy to conquer, as the various inhabitants of it will violently resist being conquered, but there is no one on Venus, the challenge of conquering Venus are purely physical if done early enough. If everyone is focused on Mars, I wonder at what price we could have Venus?

I recently read a book called Mars Inc by Ben Bova, basically in the first book, a club of billionaires is established to send humans to Mars. I got to thinking, what if a private group of people, not an established government on Earth were to try to colonize Venus? I think the first colonies of Venus will likely be proximity colonies, that is O'Neill type colonies orbiting Venus instead of Earth, since we have plenty of incentive to develop the technology to colonize space and mine the asteroids. What changes to O'Neill's designs would be necessary to build Island One, Island Two, Island Three, and the Stanford Torus in orbit around Venus? I think if the long term goal is to terraform Venus, one of the first things to do would involve colonizing the space around Venus above its atmosphere. The Atmosphere of Venus would allow a means of aerocapture into Venusian orbit. Venus has nitrogen which might be skimmed from Low Venusian Orbit and collected to a Venusian O'Neill habitat. Nitrogen is a lighter gas than carbon dioxide, so there would be plenty at the upper fringes, so spaceships grazing the upper atmosphere without slowing down from orbital speed can collect some. Eventually we could have enough presence in Venusian orbit to begin constructing the orbital mirror array, which will simultaneously shade Venus from too much sunlight and redirect sunlight to produce a virtual 24-hour day light cycle for Venus, this artificial day to be adjusted for Venus' 100-hour super rotational day, for the benefits of those living in Venus Cloud Colonies, the other thing the mirrors will do is reduce sunlight to Earth normal levels, and it can alternate the sunlight levels to above Earth normal for the northern Hemisphere while below normal for the Southern Hemisphere to create northern summer/southern winter, then as we gradually decrease sunlight intensity for the northern hemisphere and increase intensity for the southern hemisphere the planet passes through northern autumn/southern spring, we continue doing this until we reach northern winter/southern summer, then we reverse this trend to pass through northern spring/southern autumn for a complete 365.24 day seasonal cycle on Venus. The artificial days on Venus will match those on Earth so both planets can use the same calendar.

While were getting ready to start colonizing Venus, there is one thing we can do that will be very helpful, that would be to simulate Venus on a computer. I have in mind two simulations of Venus, one as it is now, and the other as the way we'd like it to be. There is a lot of meteorological modeling of Earth, what would happen with we were to take such weather modeling tools and adjust the variables for Venus, assume 0.9 gravity, a planet that rotates more slowly, and artificially implemented 24-hour day, 365.24 day calendar year for Venus as I described above, assume by fiat an Earth like atmosphere surrounding Venus that consists of 80% nitrogen, 20% oxygen and trace amounts of carbon dioxide for the plants to grow, and an ocean with approximately the same coverage as Earth over Venusian topography. I would like to know under these circumstances where the various climate zones will be, where the jungles, forests, prairies, deserts, oceans, lakes, rivers, and seas will be, what the weather patterns will be, where will optimal places to live be, where they're will be glaciers and ice fields, tundra and so forth. I think Venusian oceans will on average be shallower than Earth, thus more ideal for marine life, lots of fishing and so forth. I think a virtual Venus might be just the thing to garner actual public support, make it accessible from the internet, let people put themselves virtually on the surface of Virtual Venus and give them an idea of what it would look like with Earth life on it. Venus will have a lot more large islands than Earth does, and only two major continents. With enough computing resources, we could have virtual ecologies simulated on the planet's surface, we can experiment and play around with those to decide on what we eventually would want.

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#138 2014-01-22 20:33:57

robertwalker
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Re: Venus

Hi Tom, just to say thanks, glad you enjoyed the article, and those are interesting ideas.

The extra amounts of sunlight at Venus shouldn't make much difference to the Stanford Torus as they already need a large mirror to reflect sunlight into the habitat (so that the interior is not exposed directly to solar flares and can be shielded), so I think the main difference would be that the mirror can be smaller.

I haven't come across any climate computer type models for terraforming and surely if we do get the ability to do it, will need to do lots of modeling to have any chance of success in any of these big megaproject type schemes. By the time its feasible I expect our computers will be far more powerful also, probably using qubits or maybe something we haven't thought of yet.

Yes, interesting idea that you could use space mirrors to convert the 4 day super-rotation day into something shorter. BTW someone commenting on one of my articles llnked to an interesting project to make breeder solar panels in the sahara desert. This is in 2010.

Sun and sand breed Sahara solar power

And apparently their first solar plant has now become operational, Sahara Solar Breeder programme: Technological platform operational

The idea is to use the power from solar panels to make new solar panels from the desert sands, and so have exponential growth of construction of the panels.

Relevance to Venus, that if you can do the same in space, it might be quite fast to build solar panels and indeed space mirrors also, or whatever else you want to build along with them. Then perhaps these big megaprojects may begin to be feasible - along with great responsibility to make good use of the power we have from this technology.

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#139 2014-04-18 07:22:29

RobertDyck
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Re: Venus

Found a paper dated this year. It states the Russia Venera probes used X-ray fluorescence to examine the atmosphere as they descended. They found phosphorus in the clouds.

These instruments measured elemental composition of the cloud particles and found not only sulfur, but also phosphorus, chlorine and iron – notably, as much as phosphorus as sulphur in the lower clouds below 52 km [Andreichikov et al, Sov. Astron. Lett. 1986, 1987].

This is very encouraging, because phosphorus is needed for DNA.

Last edited by RobertDyck (2014-04-18 07:23:14)

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#140 2014-04-19 01:49:29

Spatula
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From: Raleigh, NC
Registered: 2007-05-03
Posts: 68

Re: Venus

robertwalker wrote:

However one issue with this is the global resurfacing of Venus every few hundred million years (instead of steady continental drift). Perhaps you would do better to leave a fair bit of the atmosphere there which would also help to insulate your colonies from present day eruptions also as Venus is probably geologically active.

http://www.space.com/9155-hellish-venus … ffect.html

According to newer models of Venus's interior, it appears likely that the global resurfacing phenomenon on Venus is actually a result of its thick atmosphere. This also has the dual effect of explaining Venus's lack of a magnetic field.

As heat released from the interior of the planet builds up in the atmosphere, it eventually reaches a much higher temperature than it currently is at the surface, and the entire crust becomes mobilized. When this happens, the interface between the mantle and space is much more conductive as a result, with heat leaking out of the planet at a far faster rate than it does on Earth. Eventually the mantle cools and the surface solidifies again, and a steady trickle of volcanoes begin the process anew for the next few hundred million years, as the core reheats the mantle.

I find this very interesting. If you boiled off the oceans on Earth, you would literally be looking at the same exact planet in 250 million years. It would take only a couple hundred thousand years for the atmospheric oceans to lose their hydrogen to space. In that short span the planet would dry out like Venus. The surface temperatures would skyrocket, the crust would eventually mobilize, and Earth's interior would lose a large percentage of its thermal energy in a short span of time, losing its geomagnetic dynamo. After the surface cools there is no longer enough energy in the mantle to power plate tectonics, and a steady trickle of volcanoes builds up heat in the atmosphere again.

If you rewind all of that, Venus could've easily looked like Earth as recent as 1 billion years ago, before things went wrong.

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#141 2014-04-19 02:03:37

Spatula
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Re: Venus

Regarding all this talk about changing the planet's spin, I'm not sure this is necessary.

http://arxiv.org/abs/1307.0515

Assuming we could achieve some kind of global ocean on the planet, giving it some fraction of the hydrosphere on Earth, I see no reason why this cloud model for tidally locked planets wouldn't also occur on Venus, allowing it to be habitable despite its slow rotation.

I will probably post more on the subject later. Venus is a great deal of interest to me--much moreso than Mars as far as terraforming is concerned. It's a larger planet with a lot more mineral resources to reap, and the gravity would be much more ideal for humans.

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#142 2014-04-25 22:54:04

Tom Kalbfus
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Re: Venus

You have to prevent half the light from reaching Venus in the first place. The main problem with Venus and the reason it is such a high pressure oven is because it receives too much energy from the Sun. the mechanism for blocking the light can also be used to alter the length of day and night on Venus. Blocking sunlight and redirecting it is a 2-dimensional problem, physically spinning up the planet to achieve a 24-hour day night cycle is a 3-dimensional problem. If we can manipulate the light, we can have a terraformed Venus with 24-hour days, seasons, and 365.24 day years, and can use the same calendar and clocks that Earth uses. We can build a mirror array that is 3 times the radius of Venus and have it circle Venus blocking all the sunlight directly received from the Sun, and by angling the mirror arrays, we can provide indirect reflected sunlight on Venus at half the intensity. the sunlight can be reflected around the planet and then reflected on the planet from any angle around the equator, and by varying the intensity of sunlight alternately on north and south hemispheres, we can create seasons. so conserve mirror area, the Sunlight shines normal to the equator at local noon and the day length never varies, staying at a constant 12 hours of day followed by 12 hours of night, this makes climate a little different on Venus, by letting more light reach the poles, we can avoid ice caps, while preventing the equator from getting any hotter than Earth's tropics. The poles get snow in the winter and the Sun shines at a low angle, but it appears brighter than on Earth, and gets only a little dimmer for winter so it snows, but no glaciers or permanent ice caps, and since one of the continents is located near the north pole, this would be a good thing!

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#143 2014-04-26 04:17:43

RobertDyck
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Re: Venus

The planet Venus has a mass of 4.869e+24 kg, which means 4,869,000,000,000,000,000,000,000 kg! Do you realize how heavy that is? What makes you think you can change the spin of a planet? When settling another planet, one goal is to find a planet different than ours. The goal of Terraforming is to make the planet capable of supporting human life, not making it exactly the same as Earth. You can't change it's diameter, you can't change it's surface area, you can't change how close it is to the Sun, you can't change it's orbit, and you can't change it's spin. What you can change is it's atmosphere and hydrosphere.

Venus has a length of day longer than it's year. Work with that. Venus rotates retrograde, which is backward to the other planets. It rotates once every 243.0187 Earth days, so its siderial day is that long. But solar day is the time it takes from Sun rise to Sun rise; one solar day on Venus is 116.75 Earth days. It's orbit is 224.65 Earth days, so that is its length of year. Again, get over it, work with it.

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#144 2014-04-26 04:26:41

RobertDyck
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Re: Venus

I said before, terraforming Venus requires Carl Segan's idea. But details are a lot more complicated. His idea was to seed the atmosphere with single cell organisms that would convert the excess CO2 into something solid that would precipitate out. Primordia Earth had about the same atmosphere as Venus, but then a hot, high pressure, liquid water ocean formed. With a CO2 atmosphere, Earth's ocean was initially carbonic acid. That dissolved rock more quickly than weathering today. Calcium and magnesium dissolved in ocean water combined with CO2 also dissolved, creating calcite and dolomite. They precipitated out as limestone. When diatoms living in the ocean die, their skeletons become chalk. When coral living in shallow ocean water die, their skeletons accumulate to form coral rock. Coral can be compressed to form a type of limestone, but the vast limestone deposits that aren't coral were formed without life, in the oceans of primodial Earth. They're still with us today. So Earth's CO2 was precipitated as a solid, we have to do the same on Venus. But Venus doesn't have an ocean, so we have to work with what's there. The only water on Venus is its clouds, so it has to be done in the clouds. How are you going to do that?

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#145 2014-04-26 05:39:14

Terraformer
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Re: Venus

Do we know what the surface is like? If we cooled the atmosphere down to the point that it would form a CO2 ocean, would that CO2 react with the surface - and what would the effects of adding water be to it?


Use what is abundant and build to last

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#146 2014-04-26 06:58:57

JoshNH4H
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Re: Venus

In the past I've suggested that carbon dioxide could be stored as oxalic acid, which contains about 2% Hydrogen by mass.  A plus to this strategy is that we already know of many organisms that produce oxalic acid naturally.


-Josh

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#147 2014-04-26 09:20:53

RobertDyck
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Re: Venus

Terraformer wrote:

Do we know what the surface is like? If we cooled the atmosphere down to the point that it would form a CO2 ocean, would that CO2 react with the surface - and what would the effects of adding water be to it?

The surface is solid rock. The Russian Venera landers took digital images. There aren't many, but here is one of them.
venus_surface_venera13.jpg
The NASA orbiter Magellan used radar to map the surface. Optical cameras or laser range finders can't see through the clouds, but radar can. They found mountains are squashed compared to Earth. A lot of volcanoes, but all volcanic cones are squashed. The believe this means the crust is thin. And when a volcano erupts, lava stays hot a lot longer, result in liquid flow farther so volcanoes are not as high, they're squashed. This means Venus has been as it is for hundreds of millions of years, probably billions. Surface pressure is 92 bars, which is 90 times that of Earth at sea level. Surface temperature depends on exactly where, it's hotter at the equator, cooler at the poles, but mean surface temperature is 735°K (462°C; 863°F). There's no water at the surface; considering the temperature, is that surprising? Spectra measured by telescopes can see sulphuric acid in the tops of clouds, but it turns out there isn't any sulphuric acid at the surface. The pressure and temperature are sufficient that CO2 itself acts as an oxidizer, combining with sulphur in rocks to form carbonyl sulphide, (COS). Order of atoms in the molecule is OCS, but it's usually written COS. This substance is a stronger corrosive than sulphuric acid. However, it doesn't survive in the lower temperatures and pressures at higher altitudes, it breaks down into carbon monoxide and sulphur combines with oxygen from CO2 making sulphur dioxide and more carbon monoxide. When that sulphur dioxide mixes with water in upper clouds, combined with UV from sunlight that becomes sulphuric acid. That's the same process that makes acid rain on Earth. And the clouds of Venus do rain, but the rain drops boil into steam while they're still tens of miles above the surface. Or is that a hundred miles up? No rain gets anywhere near the surface.

The X-ray fluorescence instrument in Venera probes discovered phosphorus in the lower clouds. Not the upper clouds, just lower. The instrument didn't say what compound, just presence of that element. That implies carbonyl phosphide also forms on the surface, and also breaks down in the upper atmosphere. Again, this is important because living things need phosphorus to make DNA. Since it is there, that would allow since cell organisms to grow in the clouds.

The only water on Venus is its clouds. Those clouds are vast, engulfing the entire planet, but if all that water rained out the planet would still be drier than the Sahara. So whacking a comet or two into Venus is called for. Or taking an ice asteroid out by Saturn or Uranus and redirecting it toward Venus. That ice asteroid would become a comet as it approaches the Sun.

An alternative is a magnetic field designed to trap solar wind, and direct that hydrogen into the atmosphere at the poles. That would be aurora. The hydrogen would combine with oxygen, creating water. Aurora hit the atmosphere hard enough to make it glow. I think that's enough to break up any molecules. Free oxygen from CO2 has a chance to combine with hydrogen (burn) to form water. If you add enough hydrogen, would that increase carbon monoxide? Would that increase the rate of carbonyl formation at the surface? Would that increase transport of sulphide and phosphide to the clouds? How long would it take to build up significant water from solar wind?

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#148 2014-04-26 10:09:34

Terraformer
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Re: Venus

When I talk about the surface, I'm referring to its composition. If there are oxides there, they might react to form carbonates if the temperature is lowered enough, and it might be possible to transform Venus (back?) into a hot greenhouse with floating colonies that shade the surface. That could enable us to lock up most of the CO2, especially if extremophiles can be engineered to do that work for us.

Maybe we could get to a 450K surface under a dozen or so bars of pressure, dominated by a shallow ocean, with floating habitats in the habitable air above.


Use what is abundant and build to last

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#149 2014-04-26 10:41:36

Antius
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From: Cumbria, UK
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Re: Venus

Void wrote:

Tom seems to have said:

Whatever carbon dioxide you throw away is less oxygen for the ocean you'd want to create.

Actually it depends on what your objective is. 

It appears to me that floating habits is the only pay as you go method.  Nobody is going to invest in converting a planet to future habitation if it is not about to give near future pay out...

...I don't see terraforming Venus as a process of Replicating Earth, just making Venus more useful to humans.

A very valuable point, I think, one that often seems to get lost in terraforming debates.  It is easy to allow imagination to run away with itself over what might be technically possible within the bounds of physics, and to lose a sense of practical realism.

If you have a dollar to invest you are interested not just in ultimate return, but rate of return.  You want returns that you can realise within your lifetime or at most, your children's lifetime.  And the further away the dividend is, the greater it ultimately has to be - exponentially greater with time.  If it's 1000 years away, it might as well be infinite, for it will be no use to you or anyone that you know.

Build a few CFC factories on Mars and you can build non-pressurised buildings and grow crops on the surface within a century.  A massive return on a realistic timescale.  Even if the factories cost $100billion to set up, you can imagine that project being implimented, because of the rate of return that it provides.

But terraforming Venus?  A project that requires planetary engineering on a scale orders of magnitude greater and will not provide benefits for a millenia.  It won't happen unless the returns are large enough in the short term to make it worthwhile for the initial investors.  And that is the problem that sets Venus apart from Mars, no real returns are available until planetary conditions have changed dramatically, which would take millenia.

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#150 2014-04-26 11:23:02

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,932
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Re: Venus

Terraformer wrote:

When I talk about the surface, I'm referring to its composition.

It's rock. That means oxides. Exactly which minerals is still a bit of speculation. Basically it's basalt. We haven't sent a over to Venus, or a lander with an arm capable of taking samples. Russian landers chilled down to cryogenic temperature before entering the atmosphere, then used thermal momentum (it's mass) to slowly heat up. They recorded atmosphere profiles while dropping on the parachute, and took surface images. They used fixed instruments to take measurements of the surface, but that's basically fixed instruments from the lander observing the surface with X-ray and digital cameras, not any sort of sample arm.
http://en.wikipedia.org/wiki/Geology_of_Venus
Some anomalies in radar reflection from Magellan has led to speculation. One possibility is a layer of pyrite, another possibility is minerals that absorb radar such as perovskite (calcium titanium oxide) or pyrochlores (sodium calcium neobium oxide, perhaps with fluorine). But this is speculation based on strength of radar reflection. On Earth, pyrochlores forms a continuum, varying the metal between neobium and tantalum.

Pyrite is iron sulphide. Venus, sulphur? Duh! The possiblity of rare titanium or earth metals is interesting.

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