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well you said it: we know exactly how to heat up mars (greenhouse gases) but its not so clear how to cool down venus. also mars has water.
by modzu 7y ago
well you said it: we know exactly how to heat up mars (greenhouse gases) but its not so clear how to cool down venus. also mars has water.
- hathawsh 7y agoWe don't need to cool it down. We could float a platform about 49.5 km above the surface of Venus, where the temperature and pressure nearly match the earth at sea level. To launch a probe, we could simply drop it from the platform. This article about Venus is very enlightening: https://en.wikipedia.org/wiki/Atmosphere_of_Venus https://en.wikipedia.org/wiki/Atmosphere_of_Venus
- turtlecloud 7y agoWhat if your float thing pops? Everyone sinks and dies??
- crispyporkbites 7y agoWe don't need to cool Venus down, but in a few hundred years we might need to cool the earth, so learning how to do that on Venus might be a good idea.
- modzu 7y agomy comment was in response to parent saying venus was a better candidate for colonization than mars. but i am totally on board with exploring venus, although im not convinced the atmospheric issues are significantly lesser than the surface, just different (hurricane winds, sulfuric acid, etc)
- stickydink 7y agoHow would we float a platform at that height?
- djakjxnanjak 7y agoWe can float things in the earth atmosphere at sea level. My completely ignorant prior is that we should be able to do it there too, if the temp and pressure are the same.
- ncmncm 7y agoMuch better: the air at normal pressure is much denser, so ordinary breathing air supports a balloon.
- yholio 7y agoBy attaching it to a steel balloon filled with breathing gas, which can provide lift in the Venusian atmosphere. Inside the baloon you get a really nice habitat with the correct Temperature, pressure and gas composition for humans to live in.
- aeternus 7y agoOther than a basically unlimited supply of CO2 however, what would the advantage be compared to a just a space station? With Mars, you can mine building materials from the surface.
- colordrops 7y agoYou can live there long term since there is gravity.
- Baeocystin 7y agoIs Mars' gravity too low for long-term habitation? I know that we know that zero-G is a negative, but do we have any idea if it's a threshold that needs to be reached, a linear response to G-force that scales from untenable to fine, etc?
- BurningFrog 7y agoThe only way to really find out is to go there and live for a while :)
- colordrops 7y agoI would imagine that it's going to be a gradient. Just like any other form of exercise, the more effort you put in, the more positive effect. Humans would need to put in much less effort on Mars. Once we are spread across the solar system there will probably new exercise systems for 0 and .3 G environments.
- 7y ago
- hathawsh 7y agoMost methods of flying things through Earth's lower atmosphere should apply well to Venus at 50 km: balloons, planes, helicopters, etc. To gather energy for rotors, maybe we could siphon heat from below to power a generator or other type of converter. Just playing with ideas. :-)
- stcredzero 7y agoSend your mining robot below. It cools itself with phase change liquids, but also opens high pressure tanks to the 90 bar atmosphere. When you hoist it back, just plug those pressure tanks in to turbines connected to generators. That wouldn't be a huge amount of power, but maybe wildcat prospectors could operate like that in the early days.
- Sophistifunk 7y agoLisa, in this house we respect the laws of thermodynamics!
- stcredzero 7y agoWhy not use liquid oxygen as the phase change liquid? Then the gas could be caught in a bladder tethered to the ground. When it comes time to ascend, use it as a balloon? There must be some way to exploit the temperature difference between the surface and 50km up, without mega-engineering.
- taneq 7y agoHmm, maybe some variant of a solar updraft tower where hot lower atmosphere gases are siphoned up to generate power and heat lifting balloons?
- bdamm 7y agoWould it be enough energy to compensate for the work you'd need to do to lift the robot back up? Presumably there's some energy gained from sending it down but not enough to bring it back, especially since it is coming back heavier. I just don't know how to work the math on that.
- wuliwong 7y agoJust because you are at sea level, you can't suddenly float stuff in the air. I like your optimism though. :) I was imaging a floating city like cloud city in star wars [0]. [0] https://www.starwars.com/databank/cloud-city https://www.starwars.com/databank/cloud-city
- tfha 7y agoThis is a bit more thought out than perhaps OP applied, several theretical investigations have been done into floating cities on venus and it more or less comes down to building blimps out of gasses like nitrogen and oxygen. Because the venus atmosphere is so dense, this would actually work.
- pinewurst 7y agoVery cool NASA video: https://www.youtube.com/watch?v=0az7DEwG68A https://www.youtube.com/watch?v=0az7DEwG68A
- ryacko 7y agoHave you heard of Murphy's law? Floating above Venus provides the benefits of a gravity well, but there's the danger of sudden buoyancy loss.
- bdamm 7y agoEverything about exploring space and planets is a rebut to Murphy's law.
- sfkdjf9j3j 7y agoI wouldn't say we know exactly how to heat up Mars. Without a magnetic field, any atmosphere we conjure out of the polar regions would escape into space. We are far, far closer to completely reversing the effects of climate change on Earth than we are to teraforming Mars.
- modzu 7y agowell obviously we'd need orbiters that generate an artificial magnetic field my man! http://www.nifs.ac.jp/report/NIFS-886.pdf http://www.nifs.ac.jp/report/NIFS-886.pdf
- BurningFrog 7y agoYeah, but I believe it takes ~10 million years for a Mars atmosphere to escape. So it could be entirely feasible to treat the Mars atmosphere as a tire, that you "inflate" every now and then to keep the pressure constant.
- garmaine 7y agoThat would be a very wasteful use of precious volatiles though. But we could kick up a magnetic field with superconducting rings around the poles though.
- BurningFrog 7y agoLosing 0.00001% per year is not "very wasteful" to me. There are ideas for putting up a magnetic field based on putting a contraption in whichever L1/L2... point is between Mars and the Sun.
- garmaine 7y agoConvert that into tonnes, and then calculate how much biosphere could be supported with that volatile weight. And once it is gone, it is gone. It’s not a renewable resource. You’d be trading away billions of years of future Martian biosphere.
- jcranmer 7y agoMars' atmosphere is 95.3% carbon dioxide, which means that the problem we have to solve is not "how do we inject craptons of greenhouse gas into the atmosphere" but "how do we stop the solar wind from stripping away the atmosphere," which is not a problem we have a clear idea as to how to solve.
- JonDav 7y agoVenus has more carbon dioxide in its atmosphere and has the added bonus of the surface being pressurized like you are deep sea diving....
- aweawesome 7y agoSure but we got to survive till we could clear carbon dioxide
- HALtheWise 7y agoContrary to popular belief, the rate that solar wind strips Mars atmosphere is so ridiculously low that we can comfortably kick the problem of stopping it down the road a few hundred thousand years. If we manage to generate a habitable climate by terraforming with additional heat and atmosphere, adding a magnetic field becomes a very low priority.
- garmaine 7y agoWe do know how to cool Venus. Build a sun shade. It’s an old idea, and a simple idea, and there’s lots of engineering literature on how it can be reasonably accomplished.
- jbay808 7y agoCarl Sagan once proposed an interesting concept of terraforming Venus by floating some kind of bacteria in its atmosphere. The bacteria would be constantly drifting down to the surface and dying, but with no predators and ample resources, multiplying quickly enough to replace the losses, and small enough to be kept aloft by air currents. Gradually they would transform the carbon back into solid mass, and bring the atmospheric pressures and temperatures down to earth levels. Later on in his career he decided against that scheme, but with our progress in biotechnology, it might be the only feasible approach. https://en.m.wikipedia.org/wiki/Terraforming_of_Venus https://en.m.wikipedia.org/wiki/Terraforming_of_Venus