Terraforming Venus

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gravityTug

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crazyeddie":c1pof0tu said:
gravityTug":c1pof0tu said:
ZenGalacticore":c1pof0tu said:
Venus' day is 243 Earth-days. And its year is 225 Earth-days!
Yeah, that fact has always struck me with regards to Venus's plight. Does anyone have an idea as to how earth would be effected if it had a similar day/year cycle?


On the other hand, if you mean, "how would Earth have been effected if it always rotated as slowly as Venus", then the answer would be different. Life may never have developed, because with such slow rotation the Earth probably would not have developed a protective magnetic field or plate tectonics, both of which are vital to our biosphere.

It was this scenario I was thinking of :) . Its pretty obvious that conditions would be more extreme on earth I just had no idea how extreme. I'm inclined to think that life would not develop beyond single celled organisms or perhaps the oceans would still provide harbour for more complex life?
 
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neilsox

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The sunshades can dim (in 12 hour spurts) the light at selected locations on Venus. Some of the sun shades can be reversible, so they deliver 12 hour spurts of light to Venus during the very long nights. That is likely less costly, even very long term than changing the rotation of Venus to a 24 hour day. More than one billion humans presently live on 1% of Earth's surface area, so we don't need a 24 hour dark light cycle for all of Venus.
I was thinking you wanted to increase the total mass of Venus by 18%, but perhaps you meant increase the present water by 18%? Likely 180 % more water than at present is not enough.
"Who knows" is part of the reason we have not began the terraforming of Venus. Investors want be reasonable certain of the outcome. The far future payback also discourages investors. Also the starting plan may be worse than useless as we improve the plan over very long term. Neil
 
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neilsox

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Assuming we invent room temperature super conductors and we cool the equator of Venus to room temperature, we can build a HVDC = high voltage direct current power grid around the equator of Venus. This may produce an adequite magneto-sphere to protect Venus from CME = solar mass ejection from our sun, at no extra cost since we need an electric grid anyway. Neil
 
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Couerl

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ZenGalacticore":1i9fzrdt said:
And yes, I think the Kuiper Belt and certainly the Oort Cloud contain more than enough water to hydrate Venus.

Actually,... I was imagining that in the distant future the richest and most easily accessible source of water would be Saturn's rings. I think there are several million (Earth's combined oceans) worth of icy chunks available there.. Set up a sort of conveyor belt (giant snow blower :lol: ) using Saturn's gravity to help slingshot the chunks in an endless stream back to Venus. The mass of the station would have to be rather large, sending hundreds of thousands of tons of ice per-hour and the targeting system would require sophisticated tracking but, what the hell.. :ugeek:

Maybe one answer to cooling Venus and making it habitable is to put it in a relatively permanent sort of snow storm.
 
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ZenGalacticore

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Courel- However we do it, I don't see how throwing a bunch of water at Venus is going to make that planet any more of a ***** than she already is! :lol:

I've always thought it was so ironically funny that our "sister" planet that was named after the Roman Goddess of Love turns out to be the most inhospitable terrestrial world in the Solar System. (Perhaps the insights of the ancients deserve our respect!) :cool:
 
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Couerl

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Well I've always thought it was rather inconvenient in an almost unfriendly sort of way the solar system formed and didn't give us at least a dozen other planets to inhabit. Venus just needs some corrective lenses and eye drops and she'll be good as new. ;)
 
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EarthlingX

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There is a hundred or so moons, in the size of a dwarf planet, at least one bigger than what we call a planet, and we are making and using tools, which will eventually enable us to inhabit them. There is no other option, it's just a matter of time, which might be running out, mostly due to our collective stupidity and short sightedness.

I can think of so many better things to do with that raw material in rings, that talk about wasting that wealth to make force to Venus hurts, not to mention that they are far away, and that there is much closer material in the asteroid belt, outside of the big planets gravity well.

Just take it as it is, do the best that can be done, adapt. Technology should enable us to do this much faster and better than doing such brutal acts, at least not at this point in our planetary history, perhaps later, when we learn not only how to move asteroids, and moons, but also stars.

Floating platforms are most likely future of Venus, and learning how to deal with them could also enable us to put them in gas giants atmospheres, where surface gravity is not such a huge problem, but a very deep gravity well is, beside the other little things, like 10 AU+ away, and other nuisance .. (Saturn)

There will be a solar plane, to start with, in not so very distant future, giving us more information about Venus atmosphere in person, and there's a couple of eyes on the way, just for that purpose - we will know more very soon.
 
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eburacum45

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The element missing on Venus is hydrogen; this has mostly boiled off, leaving oxygen behind.

Another problem with bringing water in from the outer solar system is that it also contains oxygen, so you end up with to much oxygen in the atmosphere. This excess oxygen could be combined with the crust, and so could most of the carbon dioxide (to make oxidised rock and carbonates) but this would take a long time, and would give off lots of waste heat, so the planet would heat up even more. Heating up the planet in this way would drive off a fraction of the hydrogen which has been imported at great cost.

A sunshade seems to be an indispensible toool in terraforming Venus, if only as a way of attempting to keep the temperature down while the terraforming process occurs. Bringing water in from the outer solars system could be acheived quite efficiently using Zubrin's method for terraforming Mars,
http://www.users.globalnet.co.uk/~mfogg/zubrin.htm
but it brings problems of its own with it (such as increased greenhouse effect and excess oxygen).
 
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StarRider1701

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eburacum45":883sq767 said:
The element missing on Venus is hydrogen; this has mostly boiled off, leaving oxygen behind.

Another problem with bringing water in from the outer solar system is that it also contains oxygen, so you end up with to much oxygen in the atmosphere.

A sunshade seems to be an indispensible toool in terraforming Venus, if only as a way of attempting to keep the temperature down while the terraforming process occurs.

Is there a way to just import the hydrogen and let it combine with the oxygen that is already there? But first some kind of sunshade will be necessary to reduce the awsome amount of energy that Venus receives from the Sun every moment of every day. Once the planet has cooled sufficiently, then perhaps import some frozen hydrogen from Saturn or Jupiter and make a hydrogen snowstorm, not only helping cool the place but also giving the Oxy something to combine with to make water. Dropping a little Water Ice might not hurt, too.

However, I agree with the poster that said there are too many other, better, easier to use places in this solar system for us. Terraforming (or even just reducing the level of "Hell" that is Venus) would require a considerable effort and expense for a long time with no real guarantee that humans will ever be able to live there. Or even visit for a short time to do things like mine the place... I'm not any type of Mars advocate, but compared to Venus, Mars is Heaven!
 
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MeteorWayne

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I'm not sure how much O exists in the atmosphere, but importing H to make water vapor would only exacerbate the problem, since H2O is a potent greenhouse gas; much more so than CO2.
 
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StarRider1701

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MeteorWayne":24mo58l3 said:
I'm not sure how much O exists in the atmosphere, but importing H to make water vapor would only exacerbate the problem, since H2O is a potent greenhouse gas; much more so than CO2.

Yes, water vapor is, but not liquid water on the surface. Thats the whole point of finding a way to block some of the sunlight getting to Venus, and giving it a chance to cool first before importing hydrogen. But if we're going to try to make it livable, the first step would have to be some kind of Sunshade program. A side effect of this could be a way to give "night and day" to the surface in a period resembling what we're accustomed to. Something similar to the method of night and day in the book Ringworld only on a much smaller scale and configured to give one section of the planet "night" while the next spot over has "day." This would change, of course as teh planet slowly rotates.
 
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StarRider1701

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ZenGalacticore":34bz2ssh said:
Yeah, that water will kill us.

Ho-kay? Under the right circumstances a tablespoon of water can kill a human. Not sure what your post means, Zen.
 
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eburacum45

Guest
Here's Paul Birch's recipe for terraforming Venus
from http://www.paulbirch.net/CustomPlanets.html (which contains may other, far more ambitious projects)
Venus is practically a twin of the Earth. Or it could be, once we've cooled it down to 290K from its present molten-lead heat; removed the excess CO2 (it has around 100 atmospheres at present — and practically all of it must go); provided breathable oxygen, reduced the day to something like 24 hours (because the Venusian day lasts about 120 Earthly days — and that's a bit too long to stay out of bed, and provided upwards of 100 metres of water over the whole parched planet.
We could proceed as follows.

First we cool the planet with a sunshade (Fig 5.6), quite similar to the Mars soletta. It's a little more complicated than a simple shade — sunlight is deflected sideways just enough to miss the planet — but this way we eliminate most of the light pressure, making it easier to hold the shade in place with light from the annular support mirror.
At a later stage, when we want to occupy the planet, we can orbit another soletta in a 24-hour polar orbit; the sun will then appear in the sky 90 degrees away from its true position Venus is now in shadow and starts to cool down Unfortunately, because the atmosphere is so very think, it contains an enormous amount of heat and thus takes a long time to cool down — something like 200 years. Not so long to a planetologist, but to an engineer it's ridiculous. So we look for ways of speeding things up. There are several possibilities.
One way is to construct gigantic heat pipes connecting the hot dense lower atmosphere and the cool thin atmosphere around the 1 bar level (Fig 5.7). This keeps the upper atmosphere radiating as high a temperature as possible. Such heat pipes, although tens of kilometres high, are entirely feasible with fused rock construction. The way they work is this: at the bottom of the pipe the working fluid (water, to begin with) boils, flashing into steam through an expansion nozzle; at the top, the steam jet spreads out, cools and condenses; water drains back clown to the bottom and closes the loop. As the temperature falls, water is progressively replaced by ammonia. With heat pipes the cooling period can be cut to about 90 years.
Ninety years is still rather a long time, so recently I came up with a better scheme: heatballs (Fig -5.8).
Heatballs are hollow spheres containing a small amount of water. Down at the Venusian surface, they get hot: the water inside them evaporates. Now fling them up into space from the north pole. Out in space, they cool; the water recondenses. Wandering along magnetic field lines, they find their way back to the south pole and plunge towards the surface.
Guided now through evacuated conduits deep in the atmosphere back to the north pole, they heat up once more before swinging back out into space.
The heat balls are electrically charged, and follow magnetic field lines at orbital speeds without loss of kinetic energy. The required magnetic field can be generated by a pair of solenoids, one at either pole; the field strengths are quite small, so the amount of energy stored in the magnetic field is not enormous.
Because the heatballs can spread over a considerably wider expanse than that of the planet's surface alone, they can radiate from a much greater total area, and consequently radiate a correspondingly greater amount of heat. If the heatballs swing out to, say, three planetary radii cooling rates can thus be increased by a factor ~10, bringing cooling times down to as little as a decade,
The total mass of the heatballs is surprisingly low (equivalent to only ~16 mm of water over Venus) because the water (which has a high latent heat of vaporisation) is effectively reused every orbit, say every 10,000 seconds.
As Venus cools, carbon dioxide rains out of the atmosphere, forming oceans in the low-lying regions. I don't know whether dry ice is denser or lighter than the liquid CO2, so I'm not sure whether those oceans freeze over; however, any water ice will naturally float on top of the CO2. Now because we don't really want oceans of liquid carbon dioxide we can cover them over with a floating platform of lightweight hollow blocks (Fig 5.9). The water ocean goes on top.
To get that water ocean we have to find some water. Where from? The icy moons of Saturn are the best bet — Enceladus, for example, could provide enough water to cover Venus to a depth of ~140m.
A steam-powered rocket drives the iceman out of its orbit, bouncing it off the gravity fields of other satellites, flinging it away from Saturn and into the inner Solar System. Eventually it approaches Venus, where we break it in half, one half swings round one side of Venus, the other half round the other (Fig 5.10). Now divide each half further into, say, 100 moonlets. These moonlets orbit the Sun with the same period as Venus; every half orbit then, that is, every 112 days, they return to the vicinity of Venus, where they collide, a pair at a time, just, short of the planet. Water vapour from the vaporised moonlets falls onto the planet and cools to become rain.
During icefall, it's a good idea to protect the surface from the heat and flash. We use a sky canopy, not unlike a para-terraforming roof, but a good deal thinner (we're not trying to hold in an atmosphere, just providing a sort of lightweight tent around the globe).
You can live on the surface during icefall; simply cover your colony with a transparent tent (Fig 5.1 1); the atmosphere inside is soon made breathable, but the pressure inside and outside is the same (this makes it much easier than para-terraforming on Mars). Enlarging the colony is easy; just make the tent bigger.
In the early stages of terraforming, the construction of aerial colonies (Fig 5.12), floating like enormous dirigible balloons high in Venus' atmosphere — at around the 1 bar level, where the temperature is not excessive — would enable us to move colonists in straight away providing useful economic returns early on.
After terraforming, we have a planet very like the Earth, with both land and seas, and a sun crossing the sky once every twenty-four hours. However because day and night is produced by an orbiting soletta, instead of by the planet's spin, the sun's path across the sky is peculiar Fig 5.13). This feature is likely to lead to climate patterns more even than on Earth; nowhere as persistently cold as the Arctic and Antarctic, nor as persistently hot as the equator.
 
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ZenGalacticore

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StarRider1701":3hq38tfp said:
ZenGalacticore":3hq38tfp said:
Yeah, that water will kill us.

Ho-kay? Under the right circumstances a tablespoon of water can kill a human. Not sure what your post means, Zen.


I was responding to Mr. Wayne.
 
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neilsox

Guest
eburacum45":1xrtkt9q said:
Here's Paul Birch's recipe for terraforming Venus
from http://www.paulbirch.net/CustomPlanets.html (which contains may other, far more ambitious projects)
Venus is practically a twin of the Earth. Or it could be, once we've cooled it down to 290K from its present molten-lead heat; removed the excess CO2 (it has around 100 atmospheres at present — and practically all of it must go); provided breathable oxygen, reduced the day to something like 24 hours (because the Venusian day lasts about 120 Earthly days — and that's a bit too long to stay out of bed, and provided upwards of 100 metres of water over the whole parched planet.
We could proceed as follows.

First we cool the planet with a sunshade (Fig 5.6), quite similar to the Mars soletta. It's a little more complicated than a simple shade — sunlight is deflected sideways just enough to miss the planet — but this way we eliminate most of the light pressure, making it easier to hold the shade in place with light from the annular support mirror.
At a later stage, when we want to occupy the planet, we can orbit another soletta in a 24-hour polar orbit; the sun will then appear in the sky 90 degrees away from its true position Venus is now in shadow and starts to cool down Unfortunately, because the atmosphere is so very think, it contains an enormous amount of heat and thus takes a long time to cool down — something like 200 years. Not so long to a planetologist, but to an engineer it's ridiculous. So we look for ways of speeding things up. There are several possibilities.
One way is to construct gigantic heat pipes connecting the hot dense lower atmosphere and the cool thin atmosphere around the 1 bar level (Fig 5.7). This keeps the upper atmosphere radiating as high a temperature as possible. Such heat pipes, although tens of kilometres high, are entirely feasible with fused rock construction. The way they work is this: at the bottom of the pipe the working fluid (water, to begin with) boils, flashing into steam through an expansion nozzle; at the top, the steam jet spreads out, cools and condenses; water drains back clown to the bottom and closes the loop. As the temperature falls, water is progressively replaced by ammonia. With heat pipes the cooling period can be cut to about 90 years.
Ninety years is still rather a long time, so recently I came up with a better scheme: heatballs (Fig -5.8).
Heatballs are hollow spheres containing a small amount of water. Down at the Venusian surface, they get hot: the water inside them evaporates. Now fling them up into space from the north pole. Out in space, they cool; the water re condenses. Wandering along magnetic field lines, they find their way back to the south pole and plunge towards the surface.
Guided now through evacuated conduits deep in the atmosphere back to the north pole, they heat up once more before swinging back out into space.
The heat balls are electrically charged, and follow magnetic field lines at orbital speeds without loss of kinetic energy. The required magnetic field can be generated by a pair of solenoids, one at either pole; the field strengths are quite small, so the amount of energy stored in the magnetic field is not enormous.
Because the heatballs can spread over a considerably wider expanse than that of the planet's surface alone, they can radiate from a much greater total area, and consequently radiate a correspondingly greater amount of heat. If the heatballs swing out to, say, three planetary radii cooling rates can thus be increased by a factor ~10, bringing cooling times down to as little as a decade,
The total mass of the heatballs is surprisingly low (equivalent to only ~16 mm of water over Venus) because the water (which has a high latent heat of vaporisation) is effectively reused every orbit, say every 10,000 seconds.
As Venus cools, carbon dioxide rains out of the atmosphere, forming oceans in the low-lying regions. I don't know whether dry ice is denser or lighter than the liquid CO2, so I'm not sure whether those oceans freeze over; however, any water ice will naturally float on top of the CO2. Now because we don't really want oceans of liquid carbon dioxide we can cover them over with a floating platform of lightweight hollow blocks (Fig 5.9). The water ocean goes on top.
To get that water ocean we have to find some water. Where from? The icy moons of Saturn are the best bet — Enceladus, for example, could provide enough water to cover Venus to a depth of ~140m.
A steam-powered rocket drives the iceman out of its orbit, bouncing it off the gravity fields of other satellites, flinging it away from Saturn and into the inner Solar System. Eventually it approaches Venus, where we break it in half, one half swings round one side of Venus, the other half round the other (Fig 5.10). Now divide each half further into, say, 100 moonlets. These moonlets orbit the Sun with the same period as Venus; every half orbit then, that is, every 112 days, they return to the vicinity of Venus, where they collide, a pair at a time, just, short of the planet. Water vapour from the vaporised moonlets falls onto the planet and cools to become rain.
During icefall, it's a good idea to protect the surface from the heat and flash. We use a sky canopy, not unlike a para-terraforming roof, but a good deal thinner (we're not trying to hold in an atmosphere, just providing a sort of lightweight tent around the globe).
You can live on the surface during icefall; simply cover your colony with a transparent tent (Fig 5.1 1); the atmosphere inside is soon made breathable, but the pressure inside and outside is the same (this makes it much easier than para-terraforming on Mars). Enlarging the colony is easy; just make the tent bigger.
In the early stages of terraforming, the construction of aerial colonies (Fig 5.12), floating like enormous dirigible balloons high in Venus' atmosphere — at around the 1 bar level, where the temperature is not excessive — would enable us to move colonists in straight away providing useful economic returns early on.
After terraforming, we have a planet very like the Earth, with both land and seas, and a sun crossing the sky once every twenty-four hours. However because day and night is produced by an orbiting soletta, instead of by the planet's spin, the sun's path across the sky is peculiar Fig 5.13). This feature is likely to lead to climate patterns more even than on Earth; nowhere as persistently cold as the Arctic and Antarctic, nor as persistently hot as the equator.
That might work well, but there are problems such as the liquid carbon dioxide boils if it gets much warmer than 290 k. It is sitting on a surface that is presently about 900 k which will take longer to cool to 290 k than 90 years, even if we can get the air temperature down to 100 k which will freeze the liquid carbon dioxide ocean to dry ice, except where it is touching the still hot surface.
I presume the evacuated pipe is necessary as otherwise the transport energy lost as low grade heat exceeds the amount that each heat ball removes. I think the evacuated pipes need to continue vertically for more than 100 kilometers to avoid transport energy lost getting in and out of the the atmosphere. Unless someone knows a better solution, we should forget the heat balls.
Birch did not mention the volume of the carbon dioxide ocean, but together with the 140 meters of water ocean, we would likely cover about 7% of the Venus surface instead of the 70% for Earth. 7% may be enough to provide rain fall for agriculture. A significant percent of the 140 meters of water will be in the atmosphere of Venus as water vapor if the average humidity in the atmosphere is 60%. I believe we need a sea level air pressure of about 40 psi instead of 14.7 psi to keep the liquid carbon dioxide from boiling, so atmospheric water vapor will have perhaps double the mass of Earth's atmospheric water vapor. Oxygen needs to be about 8% for humans at 40 psi. Luckily there is about the correct amount of nitrogen, argon etc to dilute the oxygen to 8%. It will however take thousands of years for photo synthesis to produce 8% oxygen. Longer if the surface rocks absorb lots of oxygen.
The 100 moonlets should not be called moons as they are in solar orbit. Also I'd guess more than half of the water vapor would remain in solar orbit if the "moonlets" collide outside the atmosphere of Venus.
Yes, the water vapor would become ice, but that ice would typically melt before reaching the surface at 290 k. Hail stones should be as rare as in the tropic zone of Earth. Birch, must be getting old/ He rarely misses a detail. Neil
 
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neilsox

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Enough light weight floating blocks to cover 7% of the surface of Venus could be as big a project as the sunshades, and the 24 hour soletta. Perhaps a thin film of another liquid with a density of about 1.2 (soluble in neither liquid carbon dioxide nor water) could keep the water from mixing with the liquid carbon dioxide? The blocks likely are not reliable long term. Neil
 
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