With all the talk in the thread about terraforming mars it makes me wonder if we could do something with venus along the lines of blasting away most of it’s atmosphere with nukes. Is it at all theoretically possible to terraform venus?
Given all the fantastic technologies we’d need to make terraforming Mars or Venus possible (and also to take advantage of the terraforming by moving appreciable numbers of people there) you’d probably be better off just waiting for some kinda faster-than-light drive.
“Blasting away most of its atmosphere with nukes?” Damn, that would be difficult. How much energy would we need to accellerate that mass of gas to escape velocity? I don’t see that that would be a likely scenario.
Now, if we rig up a big sun-shade, so the place can cool down enough to form oceans, then we may have something. Once we get it cool enough for liquid water, we can seed it with extremophile bacteria (I think we may be able to find a couple of critters from the geothermal vents which could handle the temperatures anad which could scrub out some of the more noxious chemicals).
While we are waiting for the real estate to become viable, photoelectric cells on the parasol would add some financial incentive to the project.
DrFidelius, you’ve got to do something about all that pesky atmosphere. Without a moon to suck the atmosphere off over time, it’s got way too much. What we need to do is pull Venus back to one of the Earth’s LaGrange points (1/3 of an orbit ahead or behind the earth) so it can cool off, then pull Mercury back to be Venus’s moon. That’d give us an airless planet to put our base on while we’re waiting for Venus to become habitable. Also, we should pull Mars in to the other 1/3 ahead-or-behind spot so it warms up some.
And we’re talking what here, using kajillions of dollars just to make the place habitable in a few hundred (and I’m being generous there) years?
The most likely scenarios for extra-planetary colonization have always been:
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Just live underground somewhere like Mars or the Moon. Yeah, it’d be expensive to set up, but “expensive” not “ha-ha there isn’t enough money in the world.” The big catch here is moving the people, equipment, materials, etc from here to there. Also, convincing people to go live underground on a rock far from home. Overpopulartion isn’t nearly to the point you’ll make an easy sell of that.
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Terraform using some future miracle-technology. All your “with known methods and such” theories are ludicrous. Theorhetical in the extreme. I seriously doubt any civilization capable of lobbing enough nukes into Venus, or building a sunshade or whatever, and willing to wait out the time would have any need to do so. If they had enough resources to do something like that, they’d surely have better methods/technologies that for our purposes and understanding would simply be miraculous. Magic.
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Don’t bother terraforming or setting up anything special. Locate a planet capable of supporting earth-like life already and zip over there. The same miracle future technology that does the latter could easily do the former. Yeah, ok, you’re rolling your eyes at me and saying that faster-than-light travel, particularly of the relative simplicity I’m talking about just isn’t possible. Look in your history books, stuff that simply isn’t possible becomes ordinary all the time. Transatlantic crossings? Ordinary. Circling the globe? Ordinary. Flying faster than sound? Ordinary. Launching probes to Mars? Ordinary. So yeah, give it a hundred years or two (which, I might add, if we did your terraformings NOW, would be the earliest we could expect the planet to be useful anyway) and we’ll no doubt have made zipping about and violating physics at FTL-speeds ordinary.
Just a nitpick, chairface56. None of those things you suggested were ever thought to be physically impossible, merely logistically “impossible.” I.e., no one ever said it would violate the laws of physics to fly across the Atlantic, just that it would be damn difficult and impracticle with then-current aeronautic technology. The light limit is fundamentally different in this respect, as it is an actual barrier built into the laws of physics. Our current understanding of physics says that it is really, physically impossible to go faster than light. Not that we may not some day correct or circumvent this law, but it is fundamentally different than just being a problem of engineering.
There’s no water on Venus. None in the atmosphere, none in the surface rocks. It is thought that all the hydrogen was split off from water molecules and dispersed into space a long long time ago (cite).
So, to “terraform” the planet you’ll have to bring massive quantities of water with you. Not likely.
A sunshade would be a must.
Instead of nukes, couldn’t you just hammer it with comets or asteroids? If the comet/asteroid is big enough, it will outgas and lose atmosphere. Plus comets may add water and organics.
Even if you terraform Venus, it would still try to become unihabitable I think. Does Venus have a magnetic field? Can a carbon cycle be set up or will we have to artifically do it costing much over along time? Would land just erode away into the sea or can venus form new land?
I think that even if we ever get thriving, large, self sustaining populations off this rock (and on my more cynical days think we will be tied to the Earth forever), it will be in form of large, space colonies somewhat like the aliens in the movie Independence Day
yeh, coz no self respecting planet would want to have humans on it:p
I never figured FTL travel would actually be faster-than-light as opposed to warping space or teleporting outright or something similar. Besides, don’t tachyons and some other random crap sub-particles go faster than light in the traditional sense?
And just to nitpick back, they did say it was impossible to fly with heavier-than-air mechanical craft. Not because a specific law forbade it, but because there was no way (at the time) to make something that was heavier-than-air not fall.
The hydrogen thing is the killer where Venus is concerned. Not much you can do without it.
On the other hand there was discussion of a low tech, low cost way to thin out the atmosphere. Engineer some extremeophile bacteria that would move a lot of the gasious material in the atmophere into solid precipitate. Much like the critters who died to give us limestone took the CO2 out of earth atmosphere way back and tied it up as a solid. All you would need to do is brew something up that could live in Venus’ upper atmosphere, fill up a container with it and shoot it at the planet. Set a pressure gauge to open the packeage at a certain hight. Then just sit back and let the critters thin out the atmosphere. If they breed fast enough they could be all over the planet in a few years.
blink What?
Venus’ atmosphere is so thick because it was too hot for liquid water oceans. Carbon dioxide from the atmosphere will dissolve in the ocean and precipitate out as limestone, removing it from the atmosphere more or less permanently.
I’m not buying the sunshade idea, either. The clouds of Venus already reflects about 75% of the sunlight that hits it. It’s the greenhouse effect that’s the big killer.
Large scale nukes to blow off the atmosphere . . . I dunno. Not within the scope of our current technology. That’s also leave behind lots of nasty radioactive compounds. Sub-optimal. Also doesn’t solve the lack-of-water problem, which I concur is the major hurdle.
To take a stab at a few of the other questions:
Spacecraft measurements have shown that Venus does not have a magnetic field. Its rotation is too slow for there to be a dynamo effect in the core. (Of course, that’s what we thought about Mercury, which does have a magnetic field, so take the explanation with a grain of salt.) The slow rotation is another problem you’d have to think about while terrarforming. Right now the atmosphere is so thick that the heat from the Sun is quite well distributed around the planet, and it’s pretty much the same tempeture everywhere. Thin down the atmosphere, and decrease the cloud cover (which will increase the heating on the dayside) and you might have problems.
Would Venus create new land? Unlike Earth, Venus does not have plate tectonics. However, it may have volcanism. It’s hard to tell because dating the surface is difficult due to the lack of impact cratering. (Most smaller impactors are burned up in the upper atmosphere.) No volcanic activity has been observed in the present epoch, but we don’t have enough data to rule it out.
Let’s all blame the “The Core” for this continuing series of threads suggesting that we use nukes to change things of planet size.
Our entire supply of nuclear bombs are mere fireworks against something the size of a planet. You can’t terraform Venus (or Mars in a previous thread) with nukes. Even besides the notion that blasting huge holes into something makes for positive change, our bombs are too tiny to make any difference.
They wouldn’t restart the Earth’s core either.
Pod, how long is a Venus day?
The big bugbear with terraforming Venus is the rotation- it rotates once every 243 days
(longer than it’s orbital period)
so once you have erected your sunshade in the L1 lagrange point,
removed the atmosphere to acceptable levels
using lofstrom loops (a continous belt type space elevator)
and sent it to Mars and other parts of the solar system,
you still have to speed the planet up till it rotates sensibly.
(of course you could just leave the sunshade in place and illuminate the world with orbiting mirrors thirty thousand miles out…)
to change the rotation of a world you would need a dyson engine, an equatorial circuit of magnetic material firmly fixed into the planetary crust, and another one in orbit which you apply acceleration to.
A lot of acceleration.
I think it would be easier to build an interstellar vessel and try somewhere else altogether.
SF worldbuilding at
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eburacum,
Could you strike Venus with a series of large body glancing blows?
Yes-s… any particular body you dont like?
this method is a bit messy, mind you- you are likely to create massive impact craters and restart volcanism on a huge scale…
is that what you want?
SF worldbuilding at
http://www.orionsarm.com/main.html
Its not worth it. To speed Venus up to Earth day/night cycles would reuire 5x10^33 Js. That’s seems high. Even if you throw average comets (40 Billion kg) at the planet at 90 km/s it would take ~10^10 commets. Then you’re done. What do you use to rebuild/cool the atmosphere? Callisto?
That is a lot of energy.
Even using a dyson engine you would need to use the same amount of energy.
That represents ~500 days worth of the entire sun’s output…
you can see why it was necessary to dismantle Mercury to build solar power collectors, eh?
SF worldbuilding at
http://www.orionsarm.com/main.html