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If Mars were provided with a breathable atmosphere by some means in the
future, how long would it take to be lost to space? |
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"Roger Stokes" wrote in message
... | If Mars were provided with a breathable atmosphere by some means in the | future, how long would it take to be lost to space? | More to the point, could you generate it fast enough to not lose it to space, and then could you get a viable set of organisms that would keep things in some kind of equilibrium as exists here. My gut feeling is no, you could not do it. The lack of an apparent active magnetic field to protect the surface etc from radiation is another problem you have of course. Maybe you would have more luck seeding Venus with some specialised bio-engineered organisms....:-) Brian -- Brian Gaff.... graphics are great, but the blind can't hear them Email: __________________________________________________ __________________________ __________________________________ --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.537 / Virus Database: 332 - Release Date: 06/11/03 |
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In article ,
Brian Gaff wrote: My gut feeling is no, you could not do it. The lack of an apparent active magnetic field to protect the surface etc from radiation is another problem you have of course. Not a big problem with a dense atmosphere. The surface radiation dose on Earth at the North Magnetic Pole -- where Earth's magnetic field supplies essentially no shielding -- is not substantially higher than elsewhere on Earth. -- MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer pointing, 10 Sept; first science, early Oct; all well. | |
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"Brian Gaff" writes:
"Roger Stokes" wrote in message ... If Mars were provided with a breathable atmosphere by some means in the future, how long would it take to be lost to space? More to the point, could you generate it fast enough to not lose it to space, and then could you get a viable set of organisms that would keep things in some kind of equilibrium as exists here. My gut feeling is no, you could not do it. Then your gut would be wrong. Mars can hold onto an atmosphere for the better part of a BILLION years: ariel.igeofcu.unam.mx/~hdurand/bolinvcien/volumen1/atmosmarte1.html. The lack of an apparent active magnetic field to protect the surface etc from radiation is another problem you have of course. Even if the Earth had =NO= magnetic field, its atmosphere would provide a radiation shield equivalent to several meters of water. Maybe you would have more luck seeding Venus with some specialised bio-engineered organisms....:-) Don't hold your breath. Venus's main problem is that it has =FAR= too MUCH atmosphere, and almost no water to speak of. Life needs water (unless you consider drexlerian nanomachines "life") and Venus doesn't have it. Furthermore, absent water, there is no plausible method for converting Venus's excess 90 atmosphere's worth of CO2 into something non-gaseous --- and whatever one comes up with is going to cover Venus to a depth of several hundred meters to a kilometer deep. -- Gordon D. Pusch perl -e '$_ = \n"; s/NO\.//; s/SPAM\.//; print;' |
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In article ,
Roger Stokes wrote: If Mars were provided with a breathable atmosphere by some means in the future, how long would it take to be lost to space? Geologically, not long; by human standards, quite a long time -- I think the estimate is millions of years, although it undoubtedly depends on some guesswork about details. -- MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer pointing, 10 Sept; first science, early Oct; all well. | |
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"Brian Gaff" writes:
"Henry Spencer" wrote in message ... In article , Roger Stokes wrote: If Mars were provided with a breathable atmosphere by some means in the future, how long would it take to be lost to space? Geologically, not long; by human standards, quite a long time -- I think the estimate is millions of years, although it undoubtedly depends on some guesswork about details. OK, but the fact is it cannot be a stable system, and I still feel that the technology to make a breathable atmosphere fast enough to outweigh the losses is jut not possible, at least not if you need to have a stable ecology. "Stable" on what timescale? Even a "mere" million years is pretty darned long on human terms !!! Indeed, no human institution has survived unchanged for even a couple of centuries, let alone a couple aeons. Even the Earth's ecology will not be "stable" forever --- the slow increase in the Sun's luminosity will render it uninhabitable in a few billion years. It may depend on if there is water in a sufficient quantity somewhere that could be eventually liberated safely on the surface. Even a "mere" million years is plenty of time to figure out something else. For example, if one were to import a few good-sized KBOs, it would supply more water than is in all of Earth's oceans --- and there are a =LOT= of KBOs out there... -- Gordon D. Pusch perl -e '$_ = \n"; s/NO\.//; s/SPAM\.//; print;' |
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In article ,
Gordon D. Pusch wrote: Geologically, not long; by human standards, quite a long time -- I think the estimate is millions of years... OK, but the fact is it cannot be a stable system... "Stable" on what timescale? Even a "mere" million years is pretty darned long on human terms !!! Long before even one million years have elapsed, we will certainly have the ability to manipulate Mars's atmosphere in vastly more powerful ways, eliminating the need for natural stability. (As for whether it's safe to rely entirely on artificial life support, we already do that in many places. Much of the Los Angeles area has little or no natural fresh water.) Indeed, no human institution has survived unchanged for even a couple of centuries, let alone a couple aeons. In fact, to my mind the biggest weakness of terraforming is simply that it takes too long. A project that lasts millennia is virtually certain to be obsolete and no longer interesting before it is finished. Never mind the details of holding together the project's own organization; more important is whether it will still have *customers* at the end. When people can walk on the surface of the Moon without external life support (because they have internal life support), will they *care* about terraforming Mars? That day is *not* millennia away. A terraforming project taking a single century might be realistic. Even that is a bit borderline, but it might be worth some investment. But none of the near-term terraforming ideas can get results that quickly. -- MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer pointing, 10 Sept; first science, early Oct; all well. | |
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![]() Henry Spencer wrote: Indeed, no human institution has survived unchanged for even a couple of centuries, let alone a couple aeons. In fact, to my mind the biggest weakness of terraforming is simply that it takes too long. A project that lasts millennia is virtually certain to be obsolete and no longer interesting before it is finished. Never mind the details of holding together the project's own organization; more important is whether it will still have *customers* at the end. Endeavors requiring efforts longer than an election term are vulnerable. -- Hop David http://clowder.net/hop/index.html |
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Hi all
"Brian Gaff" wrote in message ... Henry's excellent post snipped OK, but the fact is it cannot be a stable system, and I still feel that the Sorry but there are no such things as stable systems when you are dealing with beasties the size of planetary atmospheres. Do you think Earth's atmosphere is stable? Surprise, surprise, it has changed its composition so many times by such great degrees in the last 300 million years that it left fossil evidence (like piles of dead creatures and plants) thereof. technology to make a breathable atmosphere fast enough to outweigh the losses is jut not possible, at least not if you need to have a stable No one who has seriously studied Mars or terraforming is talking about making the Martian atmosphere breathable without technological aids in the foresee-able future. It will take too long, no matter what you do (unless you're talking magic Van-Neunmann (sp?) machines and even then it takes awhile). The real goal is to provide enough atmosphere to warm up the planet and protect the surface from UV and cosmic radiation and to get an eco-system. And this denser atmosphere once established will last without much maintenance for anything between hundreds of millions to a billion years. That is way longer than humanity needs to bother thinking about. A thousand years ago our ancestors were cleaving each other in two with axes. A million years ago our ancestors were picking flees off each others backs. A hundred million years ago our ancestors were snacks for the few dinosaurs who could bother to hunt out the miserable little rodent sized parasites that we are. Five hundred million years ago Earth was a sterile ball of cooling rock. If we can get an atmosphere that has a half-life (50% will remain) after a hundred million years then we've done immeasurably better than we needed to. Our descendants, their descendants, and people who will not even remember than Mars was once a lifeless world will have plenty of atmosphere to protect them for millenia to come. ecology. It may depend on if there is water in a sufficient quantity somewhere that could be eventually liberated safely on the surface. Mars already experiences temperatures (briefly and in rare, equatorial zones) where liquid water exists. Once you start raising the temperature with extra green houses gases (which BTW carbon dioxide is a lousy example of, methane much better, industrial CFCS, even better, Martyn Fogg mentioned another catogory of semi-exotic gases whose names I can not now remember that make all other look quite silly though). Once you've got more liquid water you've got more water vapor (green house gas), and new erosion. Erosion puts additional CO2 back into the atmosphere, driving the cycle even faster. Once you've got liquid water, you can also start doing swell things like getting stands of arctic pines growing out in the permafrost. Once they get going the planet is yours for the taking. Brian -- Brian Gaff.... graphics are great, but the blind can't hear them Email: __________________________________________________ __________________________ much snipped Regards Frank |
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