Terraformed Venus

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Gil Hamilton
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Re: Terraformed Venus

Post by Gil Hamilton »

Ford Prefect wrote:Obviously in real life it's a fool errand, but far more unlikely things happen in science fiction all the time, and I would rather learn what a habitable Venus could be like as opposed just hearing 'the effort required is monumentally titanic'. I know that it's so difficult to be next to impossible, but let's assume for a moment that God Himself is your ecological engineer and he's got a great deal on twelve squillion tons of cometary ice.
Easy, God Almighty snaps his fingers, Venus becomes Eden, and he uses the twelve squillion tons of cometary ice to smite heathens. :D
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Re: Terraformed Venus

Post by Junghalli »

starslayer wrote:If Venus has convection, but not enough asthenosphere, and Sikon is also right that Venusian volcanism has been decreasing for the past 2 billion years, then the problem is likely not enough internal heat, and inserting more radioactive elements to provide the long-term source necessary would be almost impossible.
I heard a theory on a PBS documentary that tectonic activity on Venus happens in cycles. As I remember the idea is that the Venusian crust gets thicker over time, preventing the internal heat from escaping. The heat builds up until it finally breaks through and you get a huge explosion of volcanism, then the cycle starts over.
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Re: Terraformed Venus

Post by starslayer »

Sikon wrote:Although other parts of terraforming like getting rid of the bulk of the extra atmospheric mass are hard to do at all, the cooling the atmosphere part could occur in a timeframe of centuries if sunlight was mostly prevented from reaching it during that time, though even that is pretty long for a human project. You're apparently worrying more about timeframes of millions to billions of years.
The reason I'm doing so is that if we have seen fit to terraform Venus, of all places, then we would be expecting a very large return of investment, which implies these extreme time scales. After all, even a relatively god-like Clarke civilization probably simply wouldn't bother if it couldn't use what it had spent its effort on for a very, very long time. And if we really need the living space, the problem probably isn't one that will be going away anytime soon. Being able to use Venus for only a few millenia to a few million years wouldn't be worth it, IMO.
Junghalli wrote:I heard a theory on a PBS documentary that tectonic activity on Venus happens in cycles. As I remember the idea is that the Venusian crust gets thicker over time, preventing the internal heat from escaping. The heat builds up until it finally breaks through and you get a huge explosion of volcanism, then the cycle starts over.
That was the prevailing view held after initial analysis of the Magellan data. However, the paper Sikon linked to contradicts that view, and if true, means the Venus has had steadily decreasing volcanism for the past couple billion years. This means that we probably won't see any more significant volcanism on Venus for the rest of its life, making the problem of plate tectonics much harder to solve.
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Re: Terraformed Venus

Post by Solauren »

#1 - Hit Venus with a large asteroid to knock it so it's axis spin is in line with the other planets. This will also put it's day-night cycle on a more regular scheduele.
If it hits properly, the damage should cause plate techonics to start.

#2 - Introduce bacteria into the atmosphere to metapolize it into something closer to Earths. This will have to be done in stages. Venus has an incredible high atmospheric preasure, so material may need to be relocated all together. Fortunately, we can just toss it into space, or bottle it. Whatever.

#3 - Chuck a few large comets at it. This will introduce water, and hopefully cool the planet down some more.

#4 - Introduce simple lifeforms that can thrive in the resulting environment. Once they cover the planet, repleat with stuff that eats them. REpeat until you can grow modern plants. Introduce farm animals, and turn the place into a giant farm.
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Re: Terraformed Venus

Post by Admiral Valdemar »

For all the hassle and energy put into doing this, you could produce numerous space colonies and a lunar base that would be far more useful for additional living and industry areas for humanity without any drawbacks such a planet would have. Really, there is little reason to terraform Mars, let alone Venus, unless we get so bored and abundant in energy and resources and stop killing one another to actually allow such a pet project to come to fruition.
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Re: Terraformed Venus

Post by Sikon »

starslayer wrote:
Sikon wrote:Although other parts of terraforming like getting rid of the bulk of the extra atmospheric mass are hard to do at all, the cooling the atmosphere part could occur in a timeframe of centuries if sunlight was mostly prevented from reaching it during that time, though even that is pretty long for a human project. You're apparently worrying more about timeframes of millions to billions of years.
The reason I'm doing so is that if we have seen fit to terraform Venus, of all places, then we would be expecting a very large return of investment, which implies these extreme time scales. After all, even a relatively god-like Clarke civilization probably simply wouldn't bother if it couldn't use what it had spent its effort on for a very, very long time. And if we really need the living space, the problem probably isn't one that will be going away anytime soon. Being able to use Venus for only a few millenia to a few million years wouldn't be worth it, IMO.
The atmospheric mass loss during the first million years is rather low, like how that on Mars was substantial over billions of years but much less over an orders-of-magnitude shorter timeframe, such as this implies.

But if they wanted to set a magnetic field up even from the start, the manufacturing requirements are relatively small in this context anyway. Quick order-of-magnitude calculations indicate that the equivalent of less than a billion amps in a single loop of superconducting cable or rather such instead spread out over many cables with proportionally less current in each could cause a large fraction of a gauss over a volume around the planet. Such would be more or less comparable to earth's magnetic field strength. With the various cables carrying up to at least a significant fraction of a MA/cm^2 current density, much less than a billion tons of superconducting cable mass could suffice.

Such superconducting cables would be many orders of magnitude more efficient usage of resources than setting up a natural dynamo of molten iron convection in a planetary core, since the former involves a fraction of a billion tons of cables, instead of dealing with a substantial portion of the planet's 500 trillion billion ton mass.

However, in any case, considering astronomically long timeframes would introduce a whole new can of worms.

Over the eons, the likelihood of terraforming still focused towards creating an environment for a facsimile of current planetary human civilization could decrease. I'm not a big fan of how sci-fi will often show a species as having advanced greatly in some technological regards yet somehow be assumed to have their own bodies be the same after a million or a billion years as pre-civilization. All sorts of assumptions can be thrown into question.

As just one of many possible examples, is near 1 atm atmospheric pressure really needed? Deep sea divers even now can temporarily breathe at least tens of atmospheres pressure in the case of a limited partial pressure of O2 combined with primarily helium, and surely there would be advancement in genetic engineering of plants and animals before millions of years from now, aside from more likely progression to postbiological bodies anyway.

Meanwhile, in the bigger picture, although an interesting curiosity, terraforming is probably more of a doubtful temporary diversion if it ever occurs than the overall future. In early centuries, it is more difficult than building space habitats, but partial measures might be considered a substantial increase to living space (although with a better chance of being practical or done on Mars than Venus by far). However, over really long timeframes such as ones with self-replicating factories, there's relatively quite limited benefit. A planetary surface is small compared to disassembly of asteroids, small moons, larger moons, and so on allowing up to literally millions of times more area of artificial constructions. Having 5 billion trillion tons locked up in planetary mass seems increasingly inefficient to utilize mostly just that within tens of meters of its surface, under 1/100000th of its total mass.

In timeframes of millions to billions of years, a civilization could even colonize billions of stars throughout the 0.1-million light-year diameter galaxy. If anything, it's too easy to underestimate change over the long term, like over a timeframe orders of magnitude longer than that over which the change from living in caves to New York City occurred.
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Re: Terraformed Venus

Post by Guardsman Bass »

Keep in mind, though, that they probably won't be acting just on the basis of which provides the most net living space and raw materials if we ever get strong enough in space to attempt this (meaning that if we get to the point where we can pull this off effectively, we'll probably already have a surplus of habitation and resources in space, and it will be largely a curiousity/aesthetic choice). In Mars' case, it's one of those "well, if you can do, why not?" cases, particularly since you actually have a chance of creating a self-perpetuating biosphere and world (unlike Venus, where unless you move the planet you are probably going to be actively managing the sunlight hitting it for all time).

Now, if you could actually move the planet - perhaps you could move it out to Jupiter or Saturn and stick in orbit around one of them, and then just hammer Venus with space ice to create oxygen to combine with the CO2 while letting the sucker cool down out there.
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Re: Terraformed Venus

Post by GrandMasterTerwynn »

Ford Prefect wrote:
Xeriar wrote:In Solar Storms I throw a dwarf planet the size of Mars at it.
I do not have that luxury this time round. :D
Sure you do. The Solar System happens to be in possession of one Mars-sized planet with all the water you need. All you need is a large asteroid, a few Von Neumanns, and a lot of patience. It won't be pleasant for those poor schmucks who will have settled Mars by this time, but it won't be your fault they didn't get the memo.

Alternately, you could simply just make do with the Von Neumann self-replicators and wait for the couple millennia it would take for them to consume the entire planet. Then build habitats out of the handily pre-processed materials. You'd get far more living space that way.
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Re: Terraformed Venus

Post by Ariphaos »

Well, I took mine from the Oort cloud. Should be at least one out there. Though two might be better in order to shift its orbit up higher. Venus with two moons would be kinda cool.

The thing is, as outrageous as it may sound, it's by far the most plausible means to begin terraforming Venus. At that point you can make it look like most anything you want, as no landmass is going to survive the collision(s).
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Re: Terraformed Venus

Post by Darth Raptor »

starslayer wrote:That was the prevailing view held after initial analysis of the Magellan data. However, the paper Sikon linked to contradicts that view, and if true, means the Venus has had steadily decreasing volcanism for the past couple billion years. This means that we probably won't see any more significant volcanism on Venus for the rest of its life, making the problem of plate tectonics much harder to solve.
Wouldn't it make the problem unnecessary to solve? My assumption that plate tectonics are necessary was predicated on the threat of everything eventually going *goop*. If that's not the case, than couldn't we just let Venus die? No one worries about Mars being geologically dead.
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Re: Terraformed Venus

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GrandMasterTerwynn wrote:Alternately, you could simply just make do with the Von Neumann self-replicators and wait for the couple millennia it would take for them to consume the entire planet. Then build habitats out of the handily pre-processed materials. You'd get far more living space that way.
That's my thinking, too. Venus is such a hassle to terraform you're better off just demolishing the entire planet and using the debris for building materials.

Though I do have a short story planned where Venus is stripped of its atmosphere and given extra rotation by means of gigantic rocket engines using the atmosphere as propellant and total conversion reactors for power. I haven't yet run the numbers to see if it's feasible, though.
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Re: Terraformed Venus

Post by Solauren »

Venus's rotation is caused by it having been flipped near 180's on it's Z axis. That's alot of inertia to overcome. You'd be better off having your engines flip it back around it's Z axis, then attemping a rotational acceleration or deceleration.
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Re: Terraformed Venus

Post by starslayer »

Sikon wrote:*snip*
Points taken. It should be noted that humans are perfectly capable of breathing through water as we stand, and could breathe water using lungs if we had a way to extract the oxygen. The only reason divers need the relatively low partial pressure of oxygen is that it becomes toxic above a partial pressure of 1.5 atm, IIRC. In any case, while you are right in that a magnetic field is easy enough to set up using superconductors, I was more thinking along the lines of restarting plate tectonics so that a self-regulating system would be in place. Really, that isn't necessary, because if we can remove 90% of Venus's atmospheric mass, we can damn well add back all the carbon we need. So your way is very much better and easier.
Gaurdsman Bass wrote:Now, if you could actually move the planet - perhaps you could move it out to Jupiter or Saturn and stick in orbit around one of them, and then just hammer Venus with space ice to create oxygen to combine with the CO2 while letting the sucker cool down out there.
This is very possible over the long-term; it isn't even all that hard. Simply use the gravity tug idea for changing asteroid orbits, albeit on a much larger scale.
Darth Raptor wrote:Wouldn't it make the problem unnecessary to solve? My assumption that plate tectonics are necessary was predicated on the threat of everything eventually going *goop*. If that's not the case, than couldn't we just let Venus die? No one worries about Mars being geologically dead.
For a self-regulating biosphere, tectonics is necessary because it replenishes the carbon dioxide in the atmosphere. Without it, the oceans will dissolve all carbon in the atmosphere relatively quickly, and it will never find its way back out again. However, we really don't need it in this case, as Sikon pointed out.
Soularen wrote:Venus's rotation is caused by it having been flipped near 180's on it's Z axis. That's alot of inertia to overcome. You'd be better off having your engines flip it back around it's Z axis, then attemping a rotational acceleration or deceleration.
Why do you insist on giving Venus a prograde rotation? It doesn't need one. Just spin the damn thing up retrograde, if you care to spin it up at all.
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Re: Terraformed Venus

Post by Solauren »

I am going under the assumption that if you rotate Venus on it's Z-Axis to a pro-grade rotation, you won't need to accelerate it's current rotation to give it a Day/Night cycle closer to Earth + Mars. In otherwords, that aspect of the Terraforming would be more cost/energy effective.

After all, it would take less fuel and energy to redirect a large asteroid at Venus then it would to cool the planet down, put rockets on it (or whatever form of locamotion you're considering), and then accelerating the rotational velocity of an object that weighs 81% of what the Earth does; 4.868 5×10(24) kg

However, I can't find any data on what's Venus's rotational speed is to base an estimate of what it's Day/Night cycle would after a Z-Axial realignment.
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Re: Terraformed Venus

Post by Ariphaos »

...what are you smoking?

You are entering into 'not even wrong' territory. You ever try to flip a spinning gyroscope? And if Venus' rotation is 243 days... what makes you think flipping it over is going to somehow magically make that ~25 hours?

So, I ask again.

What are you smoking?
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Re: Terraformed Venus

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Darth Raptor wrote:You have to introduce plate tectonics, unless you want to periodically lose the entire world in violent, melty resurfacing events. The good news is that the additions of oceans should stimulate the development of plates. Also, mirrors aren't just good for shading the planet, they can bring light to the night side. All told, it's not inconceivable for Venus to be every bit as livable as Earth when you're done with it (though, as you said, it would be a fucking chore).
Actually alot of the recent research over the last few years suggest that there is tectonic activity on Venus.
The mapping and interpretion of the regional tectonic features of Venus over the past ten years or so has led to a qualitative picture of buoyant plate tectonics. Coupled with a new understanding of Earth's earliest history, a coherent general model of plate tectonics is emerging.
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He found that the 4600-km Artemis corona, located in a high-altitude equatorial region on the planet, has 4-km deep troughs with features resembling those of the Earth trenches where the sinking of crust takes place. Specifically, the trough surrounding Artemis has chasms whose edges have distinctive bulges resembling the shape that Earth trenches acquire when crust sinks into the Earth. The bulges may represent crust formed from cooled volcano lava sinking into the planet.
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the Magellan images don't suggest that plate tectonics just stopped. It may be that Venus used to have something like terrestrial-style plate tectonics which was lubricated by water, and that once the water went away, it switched to a more episodic kind of behavior
link

Other research suggests that the plate tectonics slowed or shut down due to the lack of water and the over heating of the atmosphere.
Venus is known as the Earth's twin, but a better name might be Earth's "evil twin" planet. Although Venus has a similar size and mass to Earth, it has a dramatically different surface and atmosphere. And one of the biggest differences is that fact that Earth has plate tectonics, and Venus doesn't. New research indicates that prolonged atmospheric heat might be able to shut down plate tectonics, and cause our planet's crust to be locked in place. Don't worry, this isn't something we'll have to worry about for a few hundred million years.

This research was done by scientists from the US, Canada and Australia, and published in this week's edition of the journal Earth and Planetary Science Letters. According to the researchers, large amounts of volcanic activity or increases in the Sun's luminosity could reach a tipping point, where the system of plate tectonics just shuts down.

Don't worry, this isn't an article about the dangers of global warming. The kind of temperatures we're talking about here are beyond anything scientists are expecting from human-induced climate change.

These findings help explain why Venus might have evolved differently from Earth. Although the planet has a very similar size and geological makeup, the atmosphere on Venus is rich in carbon dioxide, and almost 100 times more dense. It acts like a blanket, trapping heat from the Sun, and raising temperatures to more than 450 °C.

Plate tectonics are very important for keeping our mild temperatures here on Earth. The carbon dioxide is pulled out of the air and trapped on the floor of the ocean. This carbon gets returned to the interior of the Earth when a free-floating sections of crust called tectonic plates slide underneath one another.

Scientists think that the Earth's plate tectonics are stable and self-correcting, assuming excess heat from inside the Earth can escape through the crust. The flowing mantle keeps the tectonic plates moving.

But if the surface of the Earth is heated up for a long period of time, it could make the flowing mantle more viscous, so it stops flowing. This would shut down plate tectonics on Earth.

"We found the Earth's plate tectonics could become unstable if the surface temperature rose by 38 °C (100 °F) or more for a few million years," said lead author Adrian Lenardic, associate professor of Earth science at Rice University. "The time period and the rise in temperatures, while drastic for humans, are not unreasonable on a geologic scale, particularly compared to what scientists previously thought would be required to affect a planet's geodynamics."

One interesting discovery is that the rise in temperature doesn't need to boil away the Earth's oceans. The tectonic shut down could happen, even though there's still liquid water on the surface of Earth.
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So theres a very good possibilty that there are plate tectonics on Venus but its also a high probabilty that they are shut down or epsoidic.
If thats the case then coolong the atmosphere and adding water could stimulate the tectonics again.
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Re: Terraformed Venus

Post by Darth Yoshi »

Wait, I don't understand. Doesn't magma get more fluid as it heats up? Or is there a threshold where magma begins gaining viscosity again?
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Re: Terraformed Venus

Post by Solauren »

Xeriar wrote:...what are you smoking?

You are entering into 'not even wrong' territory. You ever try to flip a spinning gyroscope? And if Venus' rotation is 243 days... what makes you think flipping it over is going to somehow magically make that ~25 hours?

So, I ask again.

What are you smoking?
Venus's axial spin is retrograde to it's orbit. It's rotation is actually moving the surface backwards in regards to it's orbital direction. (As opposed to the Earth, which is moving it's face in the same direction).

As a result, it's 'face' is moving slowly in regard to the sun. For every meter it's rotation spins its face 'left', it's orbit also moves that face 0.95 meters to the 'right'.
(Please note, I'm giving numbers and direction as an example to try to illustrate my point.)

That's why I want to know it's effective axial rotation without regards to the sun. How fast is it actually spinning, regardless of direction, compared to the Earth.

i.e if the Earth rotated at an effective speed of say, 100 miles per second, how fast is venus's speed by comparison? Would it need to be accelerated, decelerated, left alone?
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Re: Terraformed Venus

Post by GrandMasterTerwynn »

Solauren wrote:
Xeriar wrote:...what are you smoking?

You are entering into 'not even wrong' territory. You ever try to flip a spinning gyroscope? And if Venus' rotation is 243 days... what makes you think flipping it over is going to somehow magically make that ~25 hours?

So, I ask again.

What are you smoking?
Venus's axial spin is retrograde to it's orbit. It's rotation is actually moving the surface backwards in regards to it's orbital direction. (As opposed to the Earth, which is moving it's face in the same direction).
So. What. Why does this matter? The planets aren't billiard balls on a pool table. There isn't any magical coupling that would magically make Venus act like a tightly wound spring, waiting for just the right trigger to go sproiiinng! The direction of rotation has fuck-all to do with the direction the planet happens to be moving in its orbit.
As a result, it's 'face' is moving slowly in regard to the sun. For every meter it's rotation spins its face 'left', it's orbit also moves that face 0.95 meters to the 'right'.
(Please note, I'm giving numbers and direction as an example to try to illustrate my point.)
And what's your point? That you have the physics knowledge of a third grader? Allow me to reiterate, there is no association between the direction of planetary rotation and the direction it orbits the Sun. None whatsoever. The only effect the Sun has on the rotation of a planet is to slow it down via tidal interaction. And at the distance Venus orbits the Sun, this is negligible.
That's why I want to know it's effective axial rotation without regards to the sun. How fast is it actually spinning, regardless of direction, compared to the Earth.
Simple, it is rotating approximately 1/243rd as fast as Earth does. This is described in any astronomy textbook. It wouldn't matter what direction Venus' axes were aligned. For that matter, take Uranus, whose axial tilt is 98 degrees with respect to its orbital plane. It's sitting on its side and manages a rotational period of over 17 hours.
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Re: Terraformed Venus

Post by Ariphaos »

Solauren wrote:Venus's axial spin is retrograde to it's orbit. It's rotation is actually moving the surface backwards in regards to it's orbital direction. (As opposed to the Earth, which is moving it's face in the same direction).

As a result, it's 'face' is moving slowly in regard to the sun. For every meter it's rotation spins its face 'left', it's orbit also moves that face 0.95 meters to the 'right'.
(Please note, I'm giving numbers and direction as an example to try to illustrate my point.)

That's why I want to know it's effective axial rotation without regards to the sun. How fast is it actually spinning, regardless of direction, compared to the Earth.

i.e if the Earth rotated at an effective speed of say, 100 miles per second, how fast is venus's speed by comparison? Would it need to be accelerated, decelerated, left alone?
No... no...

Earth's prograde rotation actually fights against its orbit. So it has a sidereal day of 23 hours and 56 minutes or so, but it turns into a solar day of 24 hours because of Earth's orbit.

Since Venus is retrograde, its orbit increases the speed of its solar day - 243 day sidereal day becomes a ~116 day solar day. Flipping it is actually counterproductive, as you're wasting an immense amount of energy just to give it a prograde rotation, though that's trivial in comparison to the total amount of energy you need to expend.
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Re: Terraformed Venus

Post by CaptainChewbacca »

A lot of Venus' problems can be resolved by reducing its atmosphere. Either blocking the sun to 'freeze' it, or fixing it with large oceans into carbonate rock would suffice. Once you get rid of that runaway greenhouse effect, Venus can start to cool off. Once that can happen, tectonics SHOULD begin to start on their own as you get a more solidified lithosphere.

At the same time, because Venus can now cool down, the core will begin to differentiate and you'll get a magnetic field. To increase its rotational speed (and eliminate the need for day/night mirrors), get a good-sized asteroid and drive it on a series of close orbital passes around Venus. Once you get a rotational day up to about 35 hours, you're good. Any longer and you get weird weather and difficulties adapting earth organisms to that cycle.

Terraforming this way is very low-impact (you're not doing a whole lot except waiting and fixing carbon) and it would take about 10,000-20,000 years.
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Re: Terraformed Venus

Post by Solauren »

Xeriar wrote:
Solauren wrote:
* snip *
Ah, I had the problem backwards then. I understand.
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Re: Terraformed Venus

Post by Solauren »

CaptainChewbacca wrote:A lot of Venus' problems can be resolved by reducing its atmosphere. Either blocking the sun to 'freeze' it, or fixing it with large oceans into carbonate rock would suffice. Once you get rid of that runaway greenhouse effect, Venus can start to cool off. Once that can happen, tectonics SHOULD begin to start on their own as you get a more solidified lithosphere.

At the same time, because Venus can now cool down, the core will begin to differentiate and you'll get a magnetic field. To increase its rotational speed (and eliminate the need for day/night mirrors), get a good-sized asteroid and drive it on a series of close orbital passes around Venus. Once you get a rotational day up to about 35 hours, you're good. Any longer and you get weird weather and difficulties adapting earth organisms to that cycle.

Terraforming this way is very low-impact (you're not doing a whole lot except waiting and fixing carbon) and it would take about 10,000-20,000 years.
That's an incredibly long time-scale (at least for humans).

Wouldn't putting an asteroid in orbit, and just say, parking something like Megamaid over it speed the entire thing up? Literally suck the atmosphere off, and reprocess it for use elsewhere.
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CaptainChewbacca
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Re: Terraformed Venus

Post by CaptainChewbacca »

Solauren wrote:That's an incredibly long time-scale (at least for humans).

Wouldn't putting an asteroid in orbit, and just say, parking something like Megamaid over it speed the entire thing up? Literally suck the atmosphere off, and reprocess it for use elsewhere.
For an asteroid to 'suck' away the atmosphere of Venus, it would have to have a mass greater than that of Venus, which would be... problematic.

You could skip asteroids off the atmosphere to 'blast' chunks of it away, but you'd be replacing CO2 with volatilized rock. Besides, if a job is worth doing, its worth taking your time and doing it right.
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Re: Terraformed Venus

Post by Ariphaos »

Solauren wrote:That's an incredibly long time-scale (at least for humans).

Wouldn't putting an asteroid in orbit, and just say, parking something like Megamaid over it speed the entire thing up? Literally suck the atmosphere off, and reprocess it for use elsewhere.
Just build a filter for that. No need to build some ridiculous contraption, Chewie's method is going to take tens of thousands of years, anyway.

I still think the dual KBO collision is best. Venus can get its mass upped, shifted to a higher orbit, and be given one or two moons in the process, along with clearing the atmosphere, setting off plate tectonics, hydration, etc. You just need to give it time to cool, but a sunblock will help that.
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Set him on fire, and he will be warm for life.
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