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Why We Should Build Cloud Cities on Venus

253 points by cryptoz 12y ago

imaginenore 12y ago
Would you rather be surrounded by very thin CO2 of Mars or clouds of sulfuric acid of Venus? And no possibility to live on the surface? At least we know how to transform CO2 into oxygen. Mars just seems orders of magnitude more friendly.
- Arnavion 12y ago
  I imagine Venus being closer to the Sun (and having a higher temperature in general due to the greenhouse effect of its atmosphere) makes it easier to generate usable energy there, RTGs notwithstanding.
- aetherson 12y ago
  Venus has a LOT more CO2 than Mars does. And the band that people are envisioning putting the aerosats in has, well, less sulfuric acid than does the denser lower atmosphere. Honestly, probably the realistic view is that it never makes sense to colonize, or even send long-term human presence to, any planet besides Earth. But to the extent that we want to dream of human presence on another planet, I think that the big obstacle to Venus is not the hostility of the upper atmosphere, it's the difficulty in getting any non-gaseous resources out of it. At the very least, it seems like sending a robotic balloon probe to Venus to try to tool around in the upper atmosphere for an extended period of time is at least as worthwhile as sending another lander to Mars.
  - _rpd 12y ago
    > it never makes sense to colonize, or even send long-term human presence to, any planet besides Earth I don't know, establishing a second, independent biosphere is sound from a risk management standpoint.
    - celticninja 12y ago
      I agree, I think those in the other camp are the ones that only calculate whether there would be a financial benefit and return from the project.
      - TeMPOraL 12y ago
        Economy is an engine of progress, but some people raise it to the level of a God. It's a tool, not a justification. We shouldn't limit our actions only to those that turn profit, 'lest we turn into mindless drones generating entropy without much purpose.
    - dalke 12y ago
      It would be much cheaper to establish a dozen independent biospheres here on Earth than one off Earth. Put one in the Canadian Shield, another under the Australian desert, etc. If scattered well, several should survive even a Chicxulub-class event. But I suspect you mean something different than independent biospheres. If so, what risks are you thinking of?
      - tlb 12y ago
        Most people who have ever tried living in an isolated biosphere on earth decided, after some number of months, that cities and trees and sky were pretty desirable, opened the airlock and left. Possibly it would work on another planet with no return vehicle.
        dalke 12y ago
        In any case, the first step would be to develop a long-term, viable independent biosphere. We haven't yet figured out that one. Once we get that working, we need enough excess free capacity to raise and educate children to be the next generation of biosphere caretakers. We're nowhere close.
      - _rpd 12y ago
        > several should survive even a Chicxulub-class event That's an interesting proposal. I'd love to read a study on that. > But I suspect you mean something different than independent biospheres. If so, what risks are you thinking of? Well there are degrees of independence. Perhaps "isolation" in the systems engineering sense is a better term. There are a lot of high-risk probabilities that arise as technology advances - and the Fermi paradox isn't encouraging about our chances. For some example risks, let's say grey goo, cybernetically enforced self-destructive tyranny and unexpected stable artificial black hole. In some case, the light-minutes of separation may make the difference. It might make more sense to build an artificial orbital habitat at L5 or the like, but these seem so fragile compared to biospheres that could be constructed on Mars. Being out of the gravity well is a huge advantage, but the gravity on Mars is low enough that space elevators become a real possibility. Perhaps Ceres is a good compromise - lots of water, metal rich asteroids all around.
  - unabridged 12y ago
    >Honestly, probably the realistic view is that it never makes sense to colonize, or even send long-term human presence to, any planet besides Earth. I think it could make sense when we have robots that are able to mine material and construct habitats without requiring human supervision. Just build the robots, drop them off on Venus, Mars, etc, then come back in 30 years and sell condos.
    - scentoni 12y ago
      And hope they don't discover the [Zeroth Law](https://en.wikipedia.org/wiki/Three_Laws_of_Robotics#Zeroth_Law_added https://en.wikipedia.org/wiki/Three_Laws_of_Robotics#Zeroth_...)
  - grondilu 12y ago
    > At the very least, it seems like sending a robotic balloon probe to Venus to try to tool around in the upper atmosphere for an extended period of time is at least as worthwhile as sending another lander to Mars. Exactly. Enough with Mars already. Red sky, red sand and red rocks : it gets old, frankly.
  - stcredzero 12y ago
    > I think that the big obstacle to Venus is not the hostility of the upper atmosphere, it's the difficulty in getting any non-gaseous resources out of it. We can get non-gaseous resources out of Venus accessible asteroids. Venus could supply two things -- a beautiful and relatively friendly place to live and also fluorine condensed out of its atmosphere. I could envision huge aerostat supported structures hundreds of kilometers long that house electromagnetic accelerators to launch raw materials into orbit. Rotating tethers could deposit cargo carriers into the Venusian atmosphere at hypersonic speeds, to deploy ballutes and slow down through aerobraking and then to float awaiting retrieval. In doing so, the tethers would re-accelerate themselves to haul other cargo up from hypersonic aircraft. Maybe it's not economically and politically feasible now or ever, but it's tons of fun to think about. This sort of thing also demonstrates that it's not physically impossible.
  - userulluipeste 12y ago
    "Honestly, probably the realistic view is that it never makes sense to colonize, or even send long-term human presence to, any planet besides Earth." The sole point is the experience of colonizing other planet. We're not looking to get there for the resources (stop for a second and just think out of the box), we're looking to get there to be able to live there as a species.
- Amezarak 12y ago
  > At least we know how to transform CO2 into oxygen. That's so, but the atmosphere on Mars is so thin it's not as if you can step outside there either - you'd die quickly as it's well below the Armstrong limit. You still need a full-body pressure suit on Mars. Venus, FWIW, is 96.5% CO2 and has a surface pressure of 93 bar. That's a lot of oxygen if you just want to make some for your space station. Personally I hold out hope for terraforming Venus. Adding gravity or atmosphere to Mars seems like it'd be much more difficult.
  - SapphireSun 12y ago
    They were talking about adding a jet to pump CO2 out of the atmosphere. Is there a chance you could direct the jet such that it intercepts Mars in a useful way? Then you get to rebalance both the planets atmospheres at once. However, Mars has pretty weak gravity so even if you could, I don't know if it would stick around.
    - scarmig 12y ago
      Depends on the timescale. Mars obviously has an atmosphere half-life much shorter than Earth's. At the same time, if its lifetime is a million or even a couple thousand years, it might be entirely suitable for terraforming for humans, depending on the rate at which we can replenish it. Of course, at some point we have to ask questions about how renewable a resource various elements are...
- henkboyd 12y ago
  At 52km you don't need heating, and in the case of a breach the clouds would stay mostly out because of equal pressures on both sides of the dwelling. A scientific outpost, like those in Antarctica, would be highly appealing. For permanent settlement, Mars takes the cake.
- _rpd 12y ago
  > At 50 kilometers up, Venus is remarkably Earth-like ... The atmospheric pressure is a comfortable one bar, the gravity about 90 percent that of Earth's, and temperatures fall within a hospitable range of 0-50 degrees Celsius. Nothing to sneeze at, but I don't think it is an exaggeration to say that a flying habitat of sufficient reliability is orders of magnitude more difficult. Are there studies that suggest otherwise?
- ohitsdom 12y ago
  The gravity is what makes Venus appealing. Mars' gravity is so weak, and studies so far show that is a big problem on the human body.
  - danielweber 12y ago
    We don't know anything about what 3/8g does to the human body.
    - userulluipeste 12y ago
      We don't know indeed, but I'd rather bet my horses on the 9/10g than on 3/8g.
stesch 12y ago
"The Space Merchants" anyone? ;-)
- mhurron 12y ago
  Miners. Cloud miners specifically. They should probably try to keep the operation small.
nsxwolf 12y ago
Do we know what it would look like to float in these safe regions? Would it be all haze, or clear skies? What color would the sky be? What would you see if you looked down?
- smeyer 12y ago
  There are some interesting relevant plots in this presentation (found via a google search): http://www.lpi.usra.edu/vexag/meetings/STIM/presentations/Crisp_1_What_We_Know_Today_Venus_STIM_20130124.pdf http://www.lpi.usra.edu/vexag/meetings/STIM/presentations/Cr... .
agmcleod 12y ago
I didn't read it through & through, but i think the benefits of going to mars over venus is longevity. As the idea would be (provided we last long enough) that when the earth starts to swell, earth will get too hot to live on, and therefore so would venus. We'd still have time on mars before having to move further away.
- manachar 12y ago
  Current estimates put any changes to the planets from our Sun to start about 1 billion years. While I'm a fan of long term thinking, that's a bit too long to enter into any equation about which planet to colonize first.
  - agmcleod 12y ago
    Fair enough.
- aetherson 12y ago
  You mean "when the sun starts to swell," not "when earth starts to swell." And this is a laughable concern. The Sun's main sequence is predicted to last another 4 billion years. That's more time than life has existed on Earth, about 16,000x as long as homo sapiens has existed. If we're concerned with the survival something vaguely descended from homo sapiens in 4 billion years, there's little enough harm in taking another million years for our tech to get a little better before starting the project.
  - ashark 12y ago
    To nitpick, The End Of Life We Care About on Earth is only ~800 million years off[1], at the outside, barring some unforeseen catastrophe or some truly astounding planetary engineering. Still a long time, but no 4 billion years. [1] https://en.wikipedia.org/wiki/Timeline_of_the_far_future#Future_of_the_Earth https://en.wikipedia.org/wiki/Timeline_of_the_far_future#Fut...
mmanfrin 12y ago
Question to those with science backgrounds: Would it be possible to 'seed' venus with co2 crunching algae, provided we figured some way of suspending them in the atmosphere above the point where they'd cook to death? Some sort of superlight-algae that could live in the clouds and crunch the CO2 in to O2? It would grow and spread and begin reducing the pressure downwards, allowing it to also eat downwards.
- jkot 12y ago
  Not really, venus atmosphere is way too thick and heavy. It would takes millions of years. Better would be ice ring on orbit to block sunlight, or bombarding surface with comets.
  - ajuc 12y ago
    > It would takes millions of years. Why? If it works it's exponential so it should be faster than other methods.
- danielweber 12y ago
  You would need to import a lot of water for that.
- FranOntanaya 12y ago
  I think the problem could be water. The fraction of water vapor on Venus' atmosphere is ~200 times lower, although I don't know if that should factor that Venus' atmosphere would have many times Earth's mass.
- scott_karana 12y ago
  Didn't the article cover exactly such a proposal, in the 60s, by Carl Sagan? :P
- seanflyon 12y ago
  I think you need some way of binding the O2 so that it does not just recombine with the C, perhaps by importing large quantities of H2 allowing you to turn the Oxygen into water.
jkot 12y ago
Only argument for Venus atmosphere is that it sucks much less than its surface. Any asteroid would be better place. Someone must really love Star Wars.
- geuis 12y ago
  I wish the article had expanded more on the idea of removing a lot of the atmosphere. I wonder if an asteroid could be sent in such a way that it tears through the atmosphere and rips a lot out into space. The rock would pass through and back out into space.
  - grondilu 12y ago
    Venus is almost as big as Earth. Any asteroid is much, much smaller. So the amount of atmosphere you would remove would almost certainly be minute.
  - lmm 12y ago
    Very unlikely; imagine swinging a pendulum through a water tank. Gravity pulls things down, not up; you're more likely to add some vaporized asteroid to Venus' atmosphere than have it "rip a lot out". I'm trying to think of some kind of space-elevator-siphon, but there's no getting around the fact that, unless you want to expend energy to pump it, you have to have an equal amount of mass coming down as is going up.
  - userulluipeste 12y ago
    I don't like the idea of provoking the loss of mass of some colonizable planet that already has less gravity than it would be natural for us. A better solution would be to trap as much of that atmospheric mass in solid aggregation state somewhere on its ground. Our planet had a lot of atmospheric carbon too, which is now trapped mainly as coal or other kind of fossil fuels.
  - kingmanaz 12y ago
    The ~50-megaton Tsar-Bomba reputedly "lifted" the atmosphere above its mushroom cloud off the Earth and into space. The Russians allegedly had or have a 100-megaton version which could presumably perform more "heavy lifting". There are probably more scientifically-minded readers here who possess a formula which will show the ridiculous number of Tsar-Bombas needed to make Venus safe for Humanity. I've read that comets could be slammed into Venus, modifying its rotation, and somehow reducing or eliminating the runaway greenhouse effect. Of course, if mankind is at the point of being comfortable terraforming with comets, it may make more sense to point them toward the desert planet Mars.
j_baker 12y ago
There's one gaping hole in the idea though: where are we going to get water? One other interesting possibility is colonizing Mercury. It turns out to not be as crazy an idea as it seems at first. Mercury does have water, there's plenty of solar energy, and it's not too hot at the poles. The trickiest part would really be getting there. As deep as it is in the sun's gravity well, it would take 6 years to get there!
- jlebar 12y ago
  Does Mercury offer any protection from the solar wind? I (naively) expect the solar wind intensity to go as the inverse-square of distance, and I know that surviving the solar wind on Mars is a big challenge, given the lack of a magnetosphere there. I expect the difficulty would be worse by many orders of magnitude on Mercury? Not to mention that you have to survive six years with no protection just to get there; just surviving the trip to Mars is a challenge.
  - aetherson 12y ago
    If you wanted to build a habitation on Mercury, you'd either build a mobile one that stays on the dark side of the planet, or you'd stay in always-shaded areas at the walls of craters. So you're shaded from the solar wind by rock.
    - j_baker 12y ago
      You actually wouldn't have to do either of those. There's actual frozen ice on Mercury's poles, which means you have a relatively temperate environment, plenty of sunlight for energy, and water. The atmosphere and gravity situation on the other hand are about the same as Mars.
      - aetherson 12y ago
        The ice around Mercury's poles is in permanently shadowed craters. The polar aspect is what allows there to be substantial permanently shadowed areas (because the sun never rises high in the sky). Ref: http://www.space.com/27450-messenger-mercury-water-ice-photos.html http://www.space.com/27450-messenger-mercury-water-ice-photo...
aetherson 12y ago
In terms of human habitation, the big advantages of Venus' atmosphere are: 1. It has essentially Earth-normal gravity. Zero-G long-term is a death sentence for humans. The long term effects of Martian gravity are unknown. It seems safe to assume that Venus gravity is fine. 2. It is protected from impact and radiation by an atmosphere in a way that Mars or asteroids never will be. 3. It has an essentially limitless supply of carbon, oxygen, nitrogen, and sulfur available to it. 4. It is reasonably well-positioned for solar power. 5. It is relatively temperate. 6. Low pressure differential between inside a habitat and outside of one means that leaks are less severe and containment breaches are easier to react to. But there is at least one huge disadvantage: 1. Everything besides carbon, oxygen, nitrogen, and sulfur needs to be imported, either from a fantastically hostile surface, or down through reentry into an atmosphere in a deep gravity well and rendezvousing with an aerostat. That disadvantage is a pretty goddamn significant one for human habitation. But it's not a disadvantage for long-term robot probes, and it's... less... of a disadvantage for a minimal-population scientific base.
- ohitsdom 12y ago
  Succinct and accurate summary.
- astazangasta 12y ago
  Your disadvantage 1 is the result of a failure of imagination. The vast majority of life on Earth is built from nothing but carbon, oxygen,nitrogen, hydrogen, etc., and human life requires not much else. We could easily subsist on just these elements.
  - aetherson 12y ago
    Note that "hydrogen" lists among your rather crucial elements necessary for life, and does not feature in Venus' atmosphere in significant quantities. And, more so, while human life per se requires very small amounts of non-carbon, oxygen, and hydrogen elements, human technology requires very large amounts of non-carbon, oxygen, and hydrogen elements.
ChuckMcM 12y ago
I've always been surprised that NASA hasn't gone for a blimp type 'probe' for Venus. Something which floated above the clouds and allowed us to do long term observation from that point. We think in terms of "flying" through the atmosphere, but once it gets dense enough you can make the equivalent of fish to "swim" through it. With internal bouyancy compensation bladders, and a skin impervious to the atmosphere. Smaller probes swimming down into the clouds to collect data about the surface and other conditions. If nothing else it would be completely different than exploring Mars :-)
- freehunter 12y ago
  >If nothing else it would be completely different than exploring Mars Which is likely why it hasn't been done. If it's something completely different, it takes more time and money to get it working. Starting from nothing, exploring Mars and exploring Venus might both cost $100b. But if the research has already been done to research Mars exploration, sending another probe there might only cost $2b, whereas Venus still costs $100b.
  - ChuckMcM 12y ago
    No doubt you are correct in that assessment. Time to fire up Kerbel to see how much payload a Falcon 9 Heavy can get into an Earth/Venus transfer orbit :-)
    - throwaway_yy2Di 12y ago
      You can actually look up the exact number for the current Falcon (non-heavy). It's ~1,900 kg (I think), for the minimum C3 of 8.5 km^2/s^2. https://books.google.com/books?id=vpilMLP7OHQC&pg=PA112 https://books.google.com/books?id=vpilMLP7OHQC&pg=PA112 http://www.spaceflightnow.com/falcon9/001/f9guide.pdf http://www.spaceflightnow.com/falcon9/001/f9guide.pdf (page 22)
- tachyonbeam 12y ago
  My guess would be that NASA hasn't done this because they feel like they have the traditional "lander" or "descent" type of probe worked out. They've done the engineering, they know the difficulties involved. What you're suggesting requires more expensive R&D, and means that the new probe has more chance of failing. The conservative thing to do is to stick with what works. I do think you're right that the conditions are very different from Mars and this makes it possible to explore alternative approaches that may be better suited to the planet. I also believe that innovation entails some degree of risk taking. Just gotta get SpaceX onboard.
simon_ 12y ago
Could someone weigh in on the following quote? Sounds fishy / wrong to me: To put this in perspective, a balloon that is one kilometer in diameter is capable of lifting about 700,000 tons, or the weight of two Empire State Buildings. Add a second balloon of the same size and the lift capacity of these two balloons increases exponentially: it’s now capable of supporting nearly 6 million tons of weight.
- _nb 12y ago
  I'd agree, that doesn't sound right at all. Perhaps they meant doubling the size of the balloon? Doubling the diameter of a sphere indeed increases its volume many times more than double.
- someone13 12y ago
  Some back-of-the-envelope calculations suggest that first number is in the right ballpark. From [0], the lift generated by helium vs Earth air at STP is approx. 1.03 g/L. This suggests a lift of approx. 590,000 short tons on Earth: http://www.wolframalpha.com/input/?i=%28%28%28%284%2F3%29+*+pi+*+%281km%2F2%29+%5E3%29+*+1.03+g%2FL%29+*+0.9935%29+in+tons http://www.wolframalpha.com/input/?i=%28%28%28%284%2F3%29+*+... Then, if we assume that the gravity on Venus is 90% of Earth standard, you get about 656,000 short tons of lift. Note that this doesn't take into account the different air density on Venus. No idea about the "doubling" bit, though :-P [0]: http://www.chem.hawaii.edu/uham/lift.html http://www.chem.hawaii.edu/uham/lift.html
- Tossrock 12y ago
  I assume they meant that if you were to double the diameter of the balloon, it would be a superlinear increase in lifting capacity (since volume is cubic in radius). However, it wouldn't actually be exponential, and two balloons added together definitely does not equal more than the sum of their individual lift capacity.
  - jackcarter 12y ago
    To be precise, it's 8x the lifting capacity (=2^3), which would be 5.6 million tons, or "nearly 6 million".
moneytide 12y ago
Landis Calrissian
deleted 12y ago
[deleted]
cdwhite 12y ago
A related previous article: "NASA Study Proposes Airships, Cloud Cities for Venus Exploration" (http://spectrum.ieee.org/aerospace/space-flight/nasa-study-proposes-airships-cloud-cities-for-venus-exploration http://spectrum.ieee.org/aerospace/space-flight/nasa-study-p...). Discussion: https://news.ycombinator.com/item?id=8760732 https://news.ycombinator.com/item?id=8760732
scarmig 12y ago
Thought of the day, which is said mostly tongue-in-cheek: If we really must think of a planet to terraform, it seems like the best body in the solar system to work on might be... Earth. There are large swaths of it that are more or less currently uninhabitable in its polar regions, and most changes to the atmosphere we make have their greatest effects in those same polar regions. A 5C increase in global average temperatures might be a 10C or more increase in those polar regions, opening up millions of square miles for human habitation and intensive agriculture. It's even self-sustaining: about a quarter of known fossil fuel reserves are available in the Arctic, and those will become much more accessible with warming temperatures. Needless to say, there are costs elsewhere on the planet for that kind of intervention, but those are very definitely far, far smaller costs than building floating cities on Venus or reheating Mars' core. Many of those costs could even be recouped by adding a terraforming tax on new residents of polar regions and redistributing them to Bengali refugees fleeing their homes. Economically, it makes a lot more sense than investing resources in terraforming other bodies in our solar system, though it doesn't offer the same risk mitigation. Disclaimer: I think terraforming Earth, purposefully or not, is a bad idea. I think it's just a better idea than investing real resources into terraforming other planets.
- isaacdl 12y ago
  Huh. That's a very interesting thought. The first thought that pops into my head is the risk. The appeal of trying to terraform Venus (or Mars) is that there isn't a huge existing population of humans. If we mess it up, well...that's unfortunate and expensive, but we didn't just make the only place we currently have uninhabitable. The second though, pretty related to the first, is the ethical one. Do we have the "right" to do what we want to our planet, including probably causing mass extinction of existing animal life in order to terraform our planet? I'm not sure if I'm even willing to argue that one either way. Like I said, it's interesting to consider your idea. If we can be sure that anything we do to "terraform" our planet isn't at all risky in terms of human survival, you're probably right!
  - kaybe 12y ago
    Longterm, we will have to find some kind of climate control. The last ice age was not too long ago, but mankind has almost entirely lived without. A return of the glaciers would be even worse than global warming (in my estimates), and extrapolating the curves shows that the next ice age is due (were it not for the fact that we changed the atmospheric composition sufficiently to avert that for sure). Right now we already are playing around with the climate, but very uncontrolled and destructive. I'm also not in favour of using methods designed for climate control in our situation due to the risk (which is different for the different methods, and the failure results are very different also, but still) - the better solution is clearly to stop emitting CO2 - but longterm, we will need the knowledge. Best to test it on another planet first..
joering2 12y ago
"In more expansive visions, pumping Venus full of sulfur dioxide or hydrogen—or surrounding it in Sun shields—could terraform its climate into submission". Couldn't bio-genetics create some sort of virus that inhabits on Mars' or Venus' atmosphere and grows on it while converting it into friendly environment? Or am I speaking pure sci-fi?
- seanflyon 12y ago
  Even a sci-fi terraforming bacteria can't change one atom into another and Venus is very low on Hydrogen.
- ajuc 12y ago
  Virus is just the software, it requires a living cell to reproduce (run it). Bacteria or algae is your best bet.
davesque 12y ago
I'll take one.
- davesque 12y ago
  Whoops. Sorry humor police!!
glxc 12y ago
Elon Musk has got to step up god damnit
disputin 12y ago
At what depth underground does the temperature become tolerable?
- msandford 12y ago
  Probably none. The Earth's core is hotter than the surface and the surface temperature of the crust basically reflects the average atmospheric temperature. Up north in the US the average ground temperature is maybe 40F at 10ft down (which is why there are basements up north, to get below the frost line) but here in Texas the average ground temperature is about 70F. At the equator it's probably more like 90-100F. Given that Venus' atmosphere is so hot it seems likely that the deeper you go the hotter it gets.
feralley 12y ago
Humans are too cheap. They'll just pass away during the next big extinction event, despite knowing another will eventually come. We are no better than the dinosaurs so far. Setup outposts on Mars, the moon, Venus, learn to deal with radiation. Cat lovers.
vatotemking 12y ago
Curious, how will they deal with the venusian storms?
- userulluipeste 12y ago
  Even in a storm, you won't feel a thing on a big ship (over 300m) with stabilizers. And you have to understand that there is a difference between a storm which involves different mediums, like gas (atmosphere), liquid (sea) and sometimes solid maybe (the shore or some sea cliffs) and a storm which resides in one medium only. The Venusian equatorial winds which surround the planet in a few days (at 300-400 km/h) and which are pretty permanent, can be considered storm winds. Those plans with balloon deploying were designed especially to take advantage of such winds, in order to get shorter days.

253 points by cryptoz 12y ago

Would you rather be surrounded by very thin CO2 of Mars or clouds of sulfuric acid of Venus? And no possibility to live on the surface? At least we know how to transform CO2 into oxygen. Mars just seems orders of magnitude more friendly.

Arnavion 12y ago
I imagine Venus being closer to the Sun (and having a higher temperature in general due to the greenhouse effect of its atmosphere) makes it easier to generate usable energy there, RTGs notwithstanding.
aetherson 12y ago
Venus has a LOT more CO2 than Mars does. And the band that people are envisioning putting the aerosats in has, well, less sulfuric acid than does the denser lower atmosphere. Honestly, probably the realistic view is that it never makes sense to colonize, or even send long-term human presence to, any planet besides Earth. But to the extent that we want to dream of human presence on another planet, I think that the big obstacle to Venus is not the hostility of the upper atmosphere, it's the difficulty in getting any non-gaseous resources out of it. At the very least, it seems like sending a robotic balloon probe to Venus to try to tool around in the upper atmosphere for an extended period of time is at least as worthwhile as sending another lander to Mars.
- _rpd 12y ago
  > it never makes sense to colonize, or even send long-term human presence to, any planet besides Earth I don't know, establishing a second, independent biosphere is sound from a risk management standpoint.
  - celticninja 12y ago
    I agree, I think those in the other camp are the ones that only calculate whether there would be a financial benefit and return from the project.
    - TeMPOraL 12y ago
      Economy is an engine of progress, but some people raise it to the level of a God. It's a tool, not a justification. We shouldn't limit our actions only to those that turn profit, 'lest we turn into mindless drones generating entropy without much purpose.
  - dalke 12y ago
    It would be much cheaper to establish a dozen independent biospheres here on Earth than one off Earth. Put one in the Canadian Shield, another under the Australian desert, etc. If scattered well, several should survive even a Chicxulub-class event. But I suspect you mean something different than independent biospheres. If so, what risks are you thinking of?
    - tlb 12y ago
      Most people who have ever tried living in an isolated biosphere on earth decided, after some number of months, that cities and trees and sky were pretty desirable, opened the airlock and left. Possibly it would work on another planet with no return vehicle.
      - dalke 12y ago
        In any case, the first step would be to develop a long-term, viable independent biosphere. We haven't yet figured out that one. Once we get that working, we need enough excess free capacity to raise and educate children to be the next generation of biosphere caretakers. We're nowhere close.
    - _rpd 12y ago
      > several should survive even a Chicxulub-class event That's an interesting proposal. I'd love to read a study on that. > But I suspect you mean something different than independent biospheres. If so, what risks are you thinking of? Well there are degrees of independence. Perhaps "isolation" in the systems engineering sense is a better term. There are a lot of high-risk probabilities that arise as technology advances - and the Fermi paradox isn't encouraging about our chances. For some example risks, let's say grey goo, cybernetically enforced self-destructive tyranny and unexpected stable artificial black hole. In some case, the light-minutes of separation may make the difference. It might make more sense to build an artificial orbital habitat at L5 or the like, but these seem so fragile compared to biospheres that could be constructed on Mars. Being out of the gravity well is a huge advantage, but the gravity on Mars is low enough that space elevators become a real possibility. Perhaps Ceres is a good compromise - lots of water, metal rich asteroids all around.
- unabridged 12y ago
  >Honestly, probably the realistic view is that it never makes sense to colonize, or even send long-term human presence to, any planet besides Earth. I think it could make sense when we have robots that are able to mine material and construct habitats without requiring human supervision. Just build the robots, drop them off on Venus, Mars, etc, then come back in 30 years and sell condos.
  - scentoni 12y ago
    And hope they don't discover the [Zeroth Law](https://en.wikipedia.org/wiki/Three_Laws_of_Robotics#Zeroth_Law_added https://en.wikipedia.org/wiki/Three_Laws_of_Robotics#Zeroth_...)
- grondilu 12y ago
  > At the very least, it seems like sending a robotic balloon probe to Venus to try to tool around in the upper atmosphere for an extended period of time is at least as worthwhile as sending another lander to Mars. Exactly. Enough with Mars already. Red sky, red sand and red rocks : it gets old, frankly.
- stcredzero 12y ago
  > I think that the big obstacle to Venus is not the hostility of the upper atmosphere, it's the difficulty in getting any non-gaseous resources out of it. We can get non-gaseous resources out of Venus accessible asteroids. Venus could supply two things -- a beautiful and relatively friendly place to live and also fluorine condensed out of its atmosphere. I could envision huge aerostat supported structures hundreds of kilometers long that house electromagnetic accelerators to launch raw materials into orbit. Rotating tethers could deposit cargo carriers into the Venusian atmosphere at hypersonic speeds, to deploy ballutes and slow down through aerobraking and then to float awaiting retrieval. In doing so, the tethers would re-accelerate themselves to haul other cargo up from hypersonic aircraft. Maybe it's not economically and politically feasible now or ever, but it's tons of fun to think about. This sort of thing also demonstrates that it's not physically impossible.
- userulluipeste 12y ago
  "Honestly, probably the realistic view is that it never makes sense to colonize, or even send long-term human presence to, any planet besides Earth." The sole point is the experience of colonizing other planet. We're not looking to get there for the resources (stop for a second and just think out of the box), we're looking to get there to be able to live there as a species.
Amezarak 12y ago
> At least we know how to transform CO2 into oxygen. That's so, but the atmosphere on Mars is so thin it's not as if you can step outside there either - you'd die quickly as it's well below the Armstrong limit. You still need a full-body pressure suit on Mars. Venus, FWIW, is 96.5% CO2 and has a surface pressure of 93 bar. That's a lot of oxygen if you just want to make some for your space station. Personally I hold out hope for terraforming Venus. Adding gravity or atmosphere to Mars seems like it'd be much more difficult.
- SapphireSun 12y ago
  They were talking about adding a jet to pump CO2 out of the atmosphere. Is there a chance you could direct the jet such that it intercepts Mars in a useful way? Then you get to rebalance both the planets atmospheres at once. However, Mars has pretty weak gravity so even if you could, I don't know if it would stick around.
  - scarmig 12y ago
    Depends on the timescale. Mars obviously has an atmosphere half-life much shorter than Earth's. At the same time, if its lifetime is a million or even a couple thousand years, it might be entirely suitable for terraforming for humans, depending on the rate at which we can replenish it. Of course, at some point we have to ask questions about how renewable a resource various elements are...
henkboyd 12y ago
At 52km you don't need heating, and in the case of a breach the clouds would stay mostly out because of equal pressures on both sides of the dwelling. A scientific outpost, like those in Antarctica, would be highly appealing. For permanent settlement, Mars takes the cake.
_rpd 12y ago
> At 50 kilometers up, Venus is remarkably Earth-like ... The atmospheric pressure is a comfortable one bar, the gravity about 90 percent that of Earth's, and temperatures fall within a hospitable range of 0-50 degrees Celsius. Nothing to sneeze at, but I don't think it is an exaggeration to say that a flying habitat of sufficient reliability is orders of magnitude more difficult. Are there studies that suggest otherwise?
ohitsdom 12y ago
The gravity is what makes Venus appealing. Mars' gravity is so weak, and studies so far show that is a big problem on the human body.
- danielweber 12y ago
  We don't know anything about what 3/8g does to the human body.
  - userulluipeste 12y ago
    We don't know indeed, but I'd rather bet my horses on the 9/10g than on 3/8g.

stesch 12y ago

"The Space Merchants" anyone? ;-)

mhurron 12y ago
Miners. Cloud miners specifically. They should probably try to keep the operation small.

nsxwolf 12y ago

Do we know what it would look like to float in these safe regions? Would it be all haze, or clear skies? What color would the sky be? What would you see if you looked down?

smeyer 12y ago
There are some interesting relevant plots in this presentation (found via a google search): http://www.lpi.usra.edu/vexag/meetings/STIM/presentations/Crisp_1_What_We_Know_Today_Venus_STIM_20130124.pdf http://www.lpi.usra.edu/vexag/meetings/STIM/presentations/Cr... .

agmcleod 12y ago

I didn't read it through & through, but i think the benefits of going to mars over venus is longevity. As the idea would be (provided we last long enough) that when the earth starts to swell, earth will get too hot to live on, and therefore so would venus. We'd still have time on mars before having to move further away.

manachar 12y ago
Current estimates put any changes to the planets from our Sun to start about 1 billion years. While I'm a fan of long term thinking, that's a bit too long to enter into any equation about which planet to colonize first.
- agmcleod 12y ago
  Fair enough.
aetherson 12y ago
You mean "when the sun starts to swell," not "when earth starts to swell." And this is a laughable concern. The Sun's main sequence is predicted to last another 4 billion years. That's more time than life has existed on Earth, about 16,000x as long as homo sapiens has existed. If we're concerned with the survival something vaguely descended from homo sapiens in 4 billion years, there's little enough harm in taking another million years for our tech to get a little better before starting the project.
- ashark 12y ago
  To nitpick, The End Of Life We Care About on Earth is only ~800 million years off[1], at the outside, barring some unforeseen catastrophe or some truly astounding planetary engineering. Still a long time, but no 4 billion years. [1] https://en.wikipedia.org/wiki/Timeline_of_the_far_future#Future_of_the_Earth https://en.wikipedia.org/wiki/Timeline_of_the_far_future#Fut...

mmanfrin 12y ago

Question to those with science backgrounds: Would it be possible to 'seed' venus with co2 crunching algae, provided we figured some way of suspending them in the atmosphere above the point where they'd cook to death? Some sort of superlight-algae that could live in the clouds and crunch the CO2 in to O2? It would grow and spread and begin reducing the pressure downwards, allowing it to also eat downwards.

jkot 12y ago
Not really, venus atmosphere is way too thick and heavy. It would takes millions of years. Better would be ice ring on orbit to block sunlight, or bombarding surface with comets.
- ajuc 12y ago
  > It would takes millions of years. Why? If it works it's exponential so it should be faster than other methods.
danielweber 12y ago
You would need to import a lot of water for that.
FranOntanaya 12y ago
I think the problem could be water. The fraction of water vapor on Venus' atmosphere is ~200 times lower, although I don't know if that should factor that Venus' atmosphere would have many times Earth's mass.
scott_karana 12y ago
Didn't the article cover exactly such a proposal, in the 60s, by Carl Sagan? :P
seanflyon 12y ago
I think you need some way of binding the O2 so that it does not just recombine with the C, perhaps by importing large quantities of H2 allowing you to turn the Oxygen into water.

jkot 12y ago

Only argument for Venus atmosphere is that it sucks much less than its surface. Any asteroid would be better place. Someone must really love Star Wars.

geuis 12y ago
I wish the article had expanded more on the idea of removing a lot of the atmosphere. I wonder if an asteroid could be sent in such a way that it tears through the atmosphere and rips a lot out into space. The rock would pass through and back out into space.
- grondilu 12y ago
  Venus is almost as big as Earth. Any asteroid is much, much smaller. So the amount of atmosphere you would remove would almost certainly be minute.
- lmm 12y ago
  Very unlikely; imagine swinging a pendulum through a water tank. Gravity pulls things down, not up; you're more likely to add some vaporized asteroid to Venus' atmosphere than have it "rip a lot out". I'm trying to think of some kind of space-elevator-siphon, but there's no getting around the fact that, unless you want to expend energy to pump it, you have to have an equal amount of mass coming down as is going up.
- userulluipeste 12y ago
  I don't like the idea of provoking the loss of mass of some colonizable planet that already has less gravity than it would be natural for us. A better solution would be to trap as much of that atmospheric mass in solid aggregation state somewhere on its ground. Our planet had a lot of atmospheric carbon too, which is now trapped mainly as coal or other kind of fossil fuels.
- kingmanaz 12y ago
  The ~50-megaton Tsar-Bomba reputedly "lifted" the atmosphere above its mushroom cloud off the Earth and into space. The Russians allegedly had or have a 100-megaton version which could presumably perform more "heavy lifting". There are probably more scientifically-minded readers here who possess a formula which will show the ridiculous number of Tsar-Bombas needed to make Venus safe for Humanity. I've read that comets could be slammed into Venus, modifying its rotation, and somehow reducing or eliminating the runaway greenhouse effect. Of course, if mankind is at the point of being comfortable terraforming with comets, it may make more sense to point them toward the desert planet Mars.

j_baker 12y ago

There's one gaping hole in the idea though: where are we going to get water? One other interesting possibility is colonizing Mercury. It turns out to not be as crazy an idea as it seems at first. Mercury does have water, there's plenty of solar energy, and it's not too hot at the poles. The trickiest part would really be getting there. As deep as it is in the sun's gravity well, it would take 6 years to get there!

jlebar 12y ago
Does Mercury offer any protection from the solar wind? I (naively) expect the solar wind intensity to go as the inverse-square of distance, and I know that surviving the solar wind on Mars is a big challenge, given the lack of a magnetosphere there. I expect the difficulty would be worse by many orders of magnitude on Mercury? Not to mention that you have to survive six years with no protection just to get there; just surviving the trip to Mars is a challenge.
- aetherson 12y ago
  If you wanted to build a habitation on Mercury, you'd either build a mobile one that stays on the dark side of the planet, or you'd stay in always-shaded areas at the walls of craters. So you're shaded from the solar wind by rock.
  - j_baker 12y ago
    You actually wouldn't have to do either of those. There's actual frozen ice on Mercury's poles, which means you have a relatively temperate environment, plenty of sunlight for energy, and water. The atmosphere and gravity situation on the other hand are about the same as Mars.
    - aetherson 12y ago
      The ice around Mercury's poles is in permanently shadowed craters. The polar aspect is what allows there to be substantial permanently shadowed areas (because the sun never rises high in the sky). Ref: http://www.space.com/27450-messenger-mercury-water-ice-photos.html http://www.space.com/27450-messenger-mercury-water-ice-photo...

aetherson 12y ago

In terms of human habitation, the big advantages of Venus' atmosphere are: 1. It has essentially Earth-normal gravity. Zero-G long-term is a death sentence for humans. The long term effects of Martian gravity are unknown. It seems safe to assume that Venus gravity is fine. 2. It is protected from impact and radiation by an atmosphere in a way that Mars or asteroids never will be. 3. It has an essentially limitless supply of carbon, oxygen, nitrogen, and sulfur available to it. 4. It is reasonably well-positioned for solar power. 5. It is relatively temperate. 6. Low pressure differential between inside a habitat and outside of one means that leaks are less severe and containment breaches are easier to react to. But there is at least one huge disadvantage: 1. Everything besides carbon, oxygen, nitrogen, and sulfur needs to be imported, either from a fantastically hostile surface, or down through reentry into an atmosphere in a deep gravity well and rendezvousing with an aerostat. That disadvantage is a pretty goddamn significant one for human habitation. But it's not a disadvantage for long-term robot probes, and it's... less... of a disadvantage for a minimal-population scientific base.

ohitsdom 12y ago
Succinct and accurate summary.
astazangasta 12y ago
Your disadvantage 1 is the result of a failure of imagination. The vast majority of life on Earth is built from nothing but carbon, oxygen,nitrogen, hydrogen, etc., and human life requires not much else. We could easily subsist on just these elements.
- aetherson 12y ago
  Note that "hydrogen" lists among your rather crucial elements necessary for life, and does not feature in Venus' atmosphere in significant quantities. And, more so, while human life per se requires very small amounts of non-carbon, oxygen, and hydrogen elements, human technology requires very large amounts of non-carbon, oxygen, and hydrogen elements.

ChuckMcM 12y ago

I've always been surprised that NASA hasn't gone for a blimp type 'probe' for Venus. Something which floated above the clouds and allowed us to do long term observation from that point. We think in terms of "flying" through the atmosphere, but once it gets dense enough you can make the equivalent of fish to "swim" through it. With internal bouyancy compensation bladders, and a skin impervious to the atmosphere. Smaller probes swimming down into the clouds to collect data about the surface and other conditions. If nothing else it would be completely different than exploring Mars :-)

freehunter 12y ago
>If nothing else it would be completely different than exploring Mars Which is likely why it hasn't been done. If it's something completely different, it takes more time and money to get it working. Starting from nothing, exploring Mars and exploring Venus might both cost $100b. But if the research has already been done to research Mars exploration, sending another probe there might only cost $2b, whereas Venus still costs $100b.
- ChuckMcM 12y ago
  No doubt you are correct in that assessment. Time to fire up Kerbel to see how much payload a Falcon 9 Heavy can get into an Earth/Venus transfer orbit :-)
  - throwaway_yy2Di 12y ago
    You can actually look up the exact number for the current Falcon (non-heavy). It's ~1,900 kg (I think), for the minimum C3 of 8.5 km^2/s^2. https://books.google.com/books?id=vpilMLP7OHQC&pg=PA112 https://books.google.com/books?id=vpilMLP7OHQC&pg=PA112 http://www.spaceflightnow.com/falcon9/001/f9guide.pdf http://www.spaceflightnow.com/falcon9/001/f9guide.pdf (page 22)
tachyonbeam 12y ago
My guess would be that NASA hasn't done this because they feel like they have the traditional "lander" or "descent" type of probe worked out. They've done the engineering, they know the difficulties involved. What you're suggesting requires more expensive R&D, and means that the new probe has more chance of failing. The conservative thing to do is to stick with what works. I do think you're right that the conditions are very different from Mars and this makes it possible to explore alternative approaches that may be better suited to the planet. I also believe that innovation entails some degree of risk taking. Just gotta get SpaceX onboard.

simon_ 12y ago

Could someone weigh in on the following quote? Sounds fishy / wrong to me: To put this in perspective, a balloon that is one kilometer in diameter is capable of lifting about 700,000 tons, or the weight of two Empire State Buildings. Add a second balloon of the same size and the lift capacity of these two balloons increases exponentially: it’s now capable of supporting nearly 6 million tons of weight.

_nb 12y ago
I'd agree, that doesn't sound right at all. Perhaps they meant doubling the size of the balloon? Doubling the diameter of a sphere indeed increases its volume many times more than double.
someone13 12y ago
Some back-of-the-envelope calculations suggest that first number is in the right ballpark. From [0], the lift generated by helium vs Earth air at STP is approx. 1.03 g/L. This suggests a lift of approx. 590,000 short tons on Earth: http://www.wolframalpha.com/input/?i=%28%28%28%284%2F3%29+*+pi+*+%281km%2F2%29+%5E3%29+*+1.03+g%2FL%29+*+0.9935%29+in+tons http://www.wolframalpha.com/input/?i=%28%28%28%284%2F3%29+*+... Then, if we assume that the gravity on Venus is 90% of Earth standard, you get about 656,000 short tons of lift. Note that this doesn't take into account the different air density on Venus. No idea about the "doubling" bit, though :-P [0]: http://www.chem.hawaii.edu/uham/lift.html http://www.chem.hawaii.edu/uham/lift.html
Tossrock 12y ago
I assume they meant that if you were to double the diameter of the balloon, it would be a superlinear increase in lifting capacity (since volume is cubic in radius). However, it wouldn't actually be exponential, and two balloons added together definitely does not equal more than the sum of their individual lift capacity.
- jackcarter 12y ago
  To be precise, it's 8x the lifting capacity (=2^3), which would be 5.6 million tons, or "nearly 6 million".

moneytide 12y ago

Landis Calrissian

deleted 12y ago

[deleted]

cdwhite 12y ago

A related previous article: "NASA Study Proposes Airships, Cloud Cities for Venus Exploration" (http://spectrum.ieee.org/aerospace/space-flight/nasa-study-proposes-airships-cloud-cities-for-venus-exploration http://spectrum.ieee.org/aerospace/space-flight/nasa-study-p...). Discussion: https://news.ycombinator.com/item?id=8760732 https://news.ycombinator.com/item?id=8760732

scarmig 12y ago

Thought of the day, which is said mostly tongue-in-cheek: If we really must think of a planet to terraform, it seems like the best body in the solar system to work on might be... Earth. There are large swaths of it that are more or less currently uninhabitable in its polar regions, and most changes to the atmosphere we make have their greatest effects in those same polar regions. A 5C increase in global average temperatures might be a 10C or more increase in those polar regions, opening up millions of square miles for human habitation and intensive agriculture. It's even self-sustaining: about a quarter of known fossil fuel reserves are available in the Arctic, and those will become much more accessible with warming temperatures. Needless to say, there are costs elsewhere on the planet for that kind of intervention, but those are very definitely far, far smaller costs than building floating cities on Venus or reheating Mars' core. Many of those costs could even be recouped by adding a terraforming tax on new residents of polar regions and redistributing them to Bengali refugees fleeing their homes. Economically, it makes a lot more sense than investing resources in terraforming other bodies in our solar system, though it doesn't offer the same risk mitigation. Disclaimer: I think terraforming Earth, purposefully or not, is a bad idea. I think it's just a better idea than investing real resources into terraforming other planets.

isaacdl 12y ago
Huh. That's a very interesting thought. The first thought that pops into my head is the risk. The appeal of trying to terraform Venus (or Mars) is that there isn't a huge existing population of humans. If we mess it up, well...that's unfortunate and expensive, but we didn't just make the only place we currently have uninhabitable. The second though, pretty related to the first, is the ethical one. Do we have the "right" to do what we want to our planet, including probably causing mass extinction of existing animal life in order to terraform our planet? I'm not sure if I'm even willing to argue that one either way. Like I said, it's interesting to consider your idea. If we can be sure that anything we do to "terraform" our planet isn't at all risky in terms of human survival, you're probably right!
- kaybe 12y ago
  Longterm, we will have to find some kind of climate control. The last ice age was not too long ago, but mankind has almost entirely lived without. A return of the glaciers would be even worse than global warming (in my estimates), and extrapolating the curves shows that the next ice age is due (were it not for the fact that we changed the atmospheric composition sufficiently to avert that for sure). Right now we already are playing around with the climate, but very uncontrolled and destructive. I'm also not in favour of using methods designed for climate control in our situation due to the risk (which is different for the different methods, and the failure results are very different also, but still) - the better solution is clearly to stop emitting CO2 - but longterm, we will need the knowledge. Best to test it on another planet first..

joering2 12y ago

"In more expansive visions, pumping Venus full of sulfur dioxide or hydrogen—or surrounding it in Sun shields—could terraform its climate into submission". Couldn't bio-genetics create some sort of virus that inhabits on Mars' or Venus' atmosphere and grows on it while converting it into friendly environment? Or am I speaking pure sci-fi?

seanflyon 12y ago
Even a sci-fi terraforming bacteria can't change one atom into another and Venus is very low on Hydrogen.
ajuc 12y ago
Virus is just the software, it requires a living cell to reproduce (run it). Bacteria or algae is your best bet.

davesque 12y ago

I'll take one.

davesque 12y ago
Whoops. Sorry humor police!!

glxc 12y ago

Elon Musk has got to step up god damnit

disputin 12y ago

At what depth underground does the temperature become tolerable?

msandford 12y ago
Probably none. The Earth's core is hotter than the surface and the surface temperature of the crust basically reflects the average atmospheric temperature. Up north in the US the average ground temperature is maybe 40F at 10ft down (which is why there are basements up north, to get below the frost line) but here in Texas the average ground temperature is about 70F. At the equator it's probably more like 90-100F. Given that Venus' atmosphere is so hot it seems likely that the deeper you go the hotter it gets.

feralley 12y ago

Humans are too cheap. They'll just pass away during the next big extinction event, despite knowing another will eventually come. We are no better than the dinosaurs so far. Setup outposts on Mars, the moon, Venus, learn to deal with radiation. Cat lovers.

vatotemking 12y ago

Curious, how will they deal with the venusian storms?

userulluipeste 12y ago
Even in a storm, you won't feel a thing on a big ship (over 300m) with stabilizers. And you have to understand that there is a difference between a storm which involves different mediums, like gas (atmosphere), liquid (sea) and sometimes solid maybe (the shore or some sea cliffs) and a storm which resides in one medium only. The Venusian equatorial winds which surround the planet in a few days (at 300-400 km/h) and which are pretty permanent, can be considered storm winds. Those plans with balloon deploying were designed especially to take advantage of such winds, in order to get shorter days.