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Space Science

SimEarth: Terraforming Mars by the Numbers 41

Posted by timothy from the plug-in-values-for-q dept.
An anonymous reader writes "Today NASA has an online terraforming simulation based on the McKay/Zubrin/Fogg model of Mars' weather modification. The simulation shows that the greening of Mars can be done in at least three ways: 1) mirrors melting stored carbon dioxide in tropical soil and polar dry ice; 2) a fluorocarbon (CFC) factory; 3) blowing a vent thruster in the side of a methane-rich asteroid and engineering a collision (perhaps many impacts, but a mere 0.3 km/s impulse drive if using an outer solar system asteroid, such as Chiron, beyond Saturn). Irrespective of the merits or wisdom of these huge engineering projects, their simulation allows moving back the clock to a previous time when Mars was blanketed by greenhouse gases, and thus much warmer."
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SimEarth: Terraforming Mars by the Numbers More

SimEarth: Terraforming Mars by the Numbers

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  • The Martians won't allow this (Score:3, Funny)

    by uncoveror ( 570620 ) on Monday December 16, 2002 @03:57PM (#4901143) Homepage
    We will never terraform Mars. We will never colonize Mars. It is already inhabited by an advanced underground civilization called the Zhti Ti Kofft, [uncoveror.com] and they are getting tired of us. We better leave Mars alone, or we could be toast!
  • 3) blowing a vent thruster in the side of a methane-rich asteroid and engineering a collision
    ...and carry the impact live on pay-per-view. Might even make a profit.

  • Magnetic field. (Score:4, Interesting)

    by gmiller123456 ( 240000 ) on Monday December 16, 2002 @04:15PM (#4901321) Homepage
    What do they plan to do about the fact that Mars has a very weak magnetic field, which is why it lost its atmosphere to begin with?

    Without creating a large magnetic field to shield mars from the solar wind, any terraformation will only be temporary.

    • Re:Magnetic field. (Score:4, Insightful)

      by Bob Kopp ( 1551 ) on Monday December 16, 2002 @07:17PM (#4903006) Homepage
      It's not clear whether Mars had a thick atmosphere to lose. If it did, though, there's only two things that could have happened to the heavy molecules (e.g. CO2) that it contained: they could have been sequestered in reservoirs such as carbonates (not much of which have been yet found), or they could have been lost to space through non-thermal processes. In the last 3.5 billion years on so, the major non-thermal loss process is sputtering by the solar wind, as you say.

      Whether a terraformed planet is usably terraformed is a matter of time scales. Models suggests that between 0.1 and 3 bar CO2 could have been lost through sputtering over a period of about 3.5 billion years. Taking the maximum rate, this is an annual loss of less than 1 part per billion per year, or 0.1 bar in 100 million years. Thus no significant loss due to sputtering would occur on the time scale of human civilization.

      I vaguely recall seeing calculations for the duration of an atmosphere on a terraformed Moon. IIRC, even such an atmosphere might last for useful time scales; a 1 bar Earth-like atmosphere might last for several thousand years before being lost due to thermal escape and sputtering.

    • Not reading the story, I bet not. I have had many simular discussions with people regarding this. Our best solution... Is to take a lot of fissionable material, a big, deep hole... perhaps a single nuke... or many nukes, and hopefully start a large enough fissionable reaction that the planet's core can be reheated. The general theory that I'm aware of is that the planet's core began to cool (its a fairly small core, slow orbit, a good distance from the sun. Perhaps we could use some of those good ol nukes to get that planet going.... NOT to be confused with that movie "The Core".
      • Our best solution... Is to take a lot of fissionable material, a big, deep hole... perhaps a single nuke... or many nukes, and hopefully start a large enough fissionable reaction that the planet's core can be reheated.

        The amount of material required would be on the order of 10 trillion metric tonnes. That'd be a bit heavy to lift over there.

        It would be cheaper to just build solenoid windings around the planet to induce our own field, if we decide a magnetic field is useful.
        • I'm not talking replacing the core... just adding to it's nuclear material... I'm sure all the nuclear waste on earth would be a good start... Well... Whatever we do to colonize that planet, it needs to be done somehow. Preferable.. the natural way. We would need a space elevator at both ends... some sort of large scale transport ship that could millions of tons at impulse drive speeds.

          Anybody have any other suggestions for adding energy and fuel to an a cold nuclear reactor to make it very hot (like.... many thousands of degrees hot) in a reletivly short amount of time.
          • I'm not talking replacing the core... just adding to it's nuclear material.

            My point was that you'd have to add an amount of material comparable to that in the Earth's core to provide an adequate heat flux (well, maybe a quarter that due to smaller Martian surface area).

            This isn't a stalled core that needs to be kick-started. This is a core that just produces way too small an amount of energy. Even the Earth's core is almost certainly sub-critical, regardless of the story-du-jour on Slashdot.

            In summary, I think a far larger amount of effort would be needed than you are assuming.
            • Not really, because what were counting on is the decay to perpetuate the generation of energy. There gets to be a point, in anything, even in storage sites where you have enough material near by that heat starts to be generated. I remember a post from a few years ago how one of the storage sites had air tempatures that were hitting like 110 in some areas... Were not trying to heat the surface eather, were trying to get the core to generate enough heat and energy to strenthen it's magnetic field. So it retains an atmosphere, and so that the sun can heat the surface. Really, a good study of mars, and it's core would have to be performed... like we would have to drill down as far as possible.. before we could ever even attempt anything such as this. Really, we just need to add enough fissionable material so that the overall radioactivity of the martian core goes up just enough to start the gradual process... Once we get it back on track, it should keep it's self going like a good old nuclear reactor.... until it will need more fuel... at that point, we should have transporters and we could beam enriched uranium into the martian core.

              • Re:Magnetic field. (Score:3, Informative)

                by Alsee ( 515537 )
                we just need to add enough fissionable material so that the overall radioactivity of the martian core goes up just enough to [melt the martian core]

                You are completely missing the scale of energy here. A nuke is zero compared to the core of Mars.

                The entire Earth's stockpile of nuclear weapons is about 5000 megatons explosive yeild. 1 megaton is 4.2e+15 joules. The entire nuclear stockpile is then 2.1e+19 joules. There's 1055 joules in a BTU (sorry for jumping units, it was the most convient method when I was researching the numbers). So the stockpile is 2e+16 BTU. It takes about 50 BTU to heat 1 cubic foot of iron or dirt by 1 degree F (sorry, I'm American chuckle).

                You can therefore heat a 51.4 mile cube of Mars by 1 degree F.

                If you preffer metric, you can heat a 42.3 km cube of Mars by 1 degree C. (km is smaller than mile, but a degree C is bigger than a degree F)

                Nukes are great at vaporizing buildings and flattening SQUARE miles, but they are useless melting BILLIONS of CUBIC miles of anything. A nuke has zero energy when you start talking about planets.

                -
                • Oh, I agree... But I'm not talking about the surface, nor am I just talking about the bombs that exist... I'm talking about all the bombs, all the nuclear wastes, and anything else that we don't need that is radioactivly decaying, through it in a big.... very very deep hole... near molten rock (if none, oh... lets say 2/3 to the center of the planet, put all that stuff down there... ofcourse, already have the hole fairly sealed, and detonate some warheads to accelerate the breakdown/increaze the amount of energy that will be released at that given time.
                  • Oh, I agree... But I'm not talking about the surface, nor am I just talking about the bombs that exist... I'm talking about all the bombs, all the nuclear wastes, and anything else that we don't need that is radioactivly decaying

                    What part of "we'd need 10 trillion metric tonnes to generate the required amount of energy" aren't we getting through to you?

                    All of the radioactive waste we're likely to produce over our lifetime as a civilization is less than the required amount.
                    • What part of "we'd need 10 trillion metric tonnes to generate the required amount of energy" aren't we getting through to you?

                      He thought you meant the core was 10 trillion tons. He has no clue you meant 10 trillion tons of uranium. Hmmm, are you sure it's not more like 1 trillion? 10 seems a little high by my calculations. chuckle.

                      He said:

                      I'm sure all the nuclear waste on earth would be a good start

                      Well to finish up my math, the entire earth's supply of nuclear weapons works out to about one billionth of what you'd need. So no, earth's current nuclear waste would NOT be a good start.

                      -
  • I really miss that game. Is it abandonware yet?

    • Re:speaking of SimEarth... (Score:4, Informative)

      by eggstasy ( 458692 ) on Monday December 16, 2002 @04:28PM (#4901481) Journal
      Erm, there is no such thing as abandonware... All PC game copyrights will expire long after we're all dead and buried unless someone in the government decides to shorten them or the original author forfeits them.
      Downloading old games is as illegal as downloading newer ones. Even if no one is selling them. Even if the company is long gone and all programmers died. It's still copyright infringement because it's still copyrighted, what with the insane length copyrights have these days...
      • if i own an object and drop it on the side of the road, and don't come back for months ... that doesn't change the fact that i own the object. if someone else comes along and asks if it's been abandoned -- the answer is probably yes. the question is then: if he/she picks it up and uses it, is that illegal? will anyone come after him/her for doing so?

        even if i own the object and -could- complain, by having abandoned it i've stopped paying attention. thus, it's rather safe to use, even though it's someone's property. not by legality, but by practicality.
      • Downloading old games is as illegal as downloading newer ones. Even if no one is selling them. Even if the company is long gone and all programmers died.

        Not necessarily. You can still download all the Zork games here [csd.uwo.ca]. As far as I can tell, this is perfectly legal, though I don't know if Infocom waived it's copyright. I agree that copyright lengths are not what they should be, but there are obviously ways around it.

  • shouldn't we preserve the nature of Mars, like we do here on Earth?;)

    *j*

  • O, really? (Score:2, Insightful)

    by frotty ( 586379 )
    According to Robert Zubrin, president of Pioneer Astronautics and The Mars Society, "We are much closer today to sending people to Mars than we were to sending people to the moon in 1961."

    How are we going to get around the fact that being away from Earth for approx three years would mean that every cell of your body would be transversed by a galactic ray? Or being in 0 gravity for all that time will essentially weaken the heart to the point that you couldn't return to Earth quickly?

    • Re:O, really? (Score:3, Interesting)

      by Rick the Red ( 307103 )
      "Insightful"? Insightful is realizing the trip to Mars doesn't have to be zero-G. Ever hear of a centrifuge? Send two ships. Tether them. Spin about common CG.

      • Re:O, really? (Score:1, Interesting)

        by Anonymous Coward
        That's not an inconsequential engineering problem. You have to deal with making sure that the anchor between the two ships can hold up to the force of them seeking to tear apart from each other for three years. Then, you have to worry about how to handle course corrections while spinning, hooking up and accelerating to a 1G force, and detaching and braking once you arrive. These are not trivial tasks for multi-ton objects carrying passengers, lander units, and enough supplies and fuel to make the round trip. Furthermore, what sort of planning to you do for in case the tether between the two ships breaks?
        • I didn't say there weren't problems, but the original poster seemed to assume there was no choice but zero-G for the round-trip.

          To address your points, you don't have to spin the whole package, just the living quarters. The recent Mars mission plans I've seen all involve multiple ships; this isn't going to be an Apollo one-shot-direct-from-Earth's-surface mission. And the planning for a broken tether is simple: redundant tethers. You don't hang a gondola from a balloon with one rope, and you wouldn't tether these ships with one cable.

    • Re:O, really? (Score:3, Interesting)

      by Idarubicin ( 579475 )
      How are we going to get around the fact that being away from Earth for approx three years would mean that every cell of your body would be transversed by a galactic ray?

      I'm going to assume that you're making a statistical argument about cosmic rays, and not talking about some novel weapon developed by Martians for the war of the worlds.

      Estimates of radiation exposure for interplanetary travel (that I've seen) are typically around 50 to 100 rem per year of exposure. Delivered over a brief period, this dose would indeed cause serious effects. Spread out evenly over the course of a pair of six month trips (say) this dose is much more manageable. Radiation workers in Canada and the United States are already permitted up to 5 rem per year. I know a few people (doctors who have been involved in clinical radiation therapy) who have received lifetime work related doses of more than 50 rem, and they seem pretty healthy still. There would be a continuous low level of cellular damage, but not above the rate that the body can easily repair. There would also be an increase in lifetime cancer risk of anywhere from 0.1 to 10% depending on who you ask. I'd certainly be willing to take that chance for the opportunity to go to Mars. Even a dose of 150 rem associated with a three-year journey is not intolerable, since it is delivered over an extended period of time. I have to die of something; it might as well be cancer. The health data associated with my demise could also be quite valuable.

      Incidentally, even if every cell in your body was exposed to a cosmic ray, that's not particularly alarming. Damage would have to be done to genetic matter in the cell nucleus to kill or mutate the cell--and the nucleus isn't that big a target. Cells can also repair some types of radiation-induced damage to DNA.

      • As a cancer patient myself, I can tell you now, you do NOT want cancer. While I have been in remission for 6+ years now, I've had several friends fall out of remission and die from various cancers (from lukemia to non-Hodgkins Lymphoma). The treatments (radiation (max dosage (I forget the exact rem number)) and chemo-therapy (experimental)) are DEFINITLY not something I would want to go through again, nor would I wish cancer upon my worst enemy. But hey, what do I know. Perhaps your masochistic.

  • Never had a long term atmosphere... (Score:3, Insightful)

    by Ioldanach ( 88584 ) on Monday December 16, 2002 @08:18PM (#4903529)

    Or, it could all be futile. New analyses [yahoo.com] indicate that the martian atmosphere came and went in spurts. Not only was there never a long term atmosphere, there wasn't a long term body of water. That is to say, occasionally there were impacts large enough to transform the planet into an atmosphered planet with liquid water, they lasted no more than a few (hundred) years at a time.

  • (It's only karma...)

    I'm sure we've all heard the phrase: "Men are from Mars, Women are from Venus"

    This phrase is typically used to describe how different men and women think at times, as if they are from completely different planets.

    Personally speaking, I think the choices of who-got-what-planet are remarkably suitable. Especially considering that Mars has a thin Carbon-dioxide/Nitrogen atmosphere and an averate temperature of -87C, and Venus has a thick atmosphere of carbon dioxide and carbonic and sulfuric acid, and an average temperature of 453C.

    I feel this adequately explains why women always complaining that they're too cold, and men keep turning the thermostat down. They're clearly out of their natural element.

    So, the next time a woman nags you for messing something up, remind them whose planet is at least worth considering for (re?)habitation.
    =Smidge=
  • You gotta love their units. From the article:
    Scientists have proposed building mylar mirrors that would have a diameter of 250 km (155.34 miles) and cover an area larger than Lake Michigan
    and

    The sudden raise in temperature would melt about a trillion tons of water, which is enough water to form a lake, with a depth of one meter, that could cover an area larger than the state of Connecticut

    I'm glad to know that the proposed terraforming of Mars is using the common units of "Connecticuts" and "Lake Michigans".
    • "The US Senate has featured .4 Connecticuts of Kennedies during the 20th century" or "when Butafuco's yard was searched by cadaver dogs, 3.6 Lake Michigans of assorted mobster parts were discovered buried..."
    • I'm glad to know that the proposed terraforming of Mars is using the common units of "Connecticuts" and "Lake Michigans".
      No kidding - we all know that the SI units for area and depth are Football Fields and Swimming Pools!
  • From the article:

    Forty such missions would double the nitrogen content of Mars' atmosphere by direct importation, ... If one such mission were launched per year, within half a century or so most of Mars would have a temperate climate ...

    Am I the only one that thinks smacking 40, 2.6KM asteroids into a planet isn't going to leave it in such a hospitable form?

    What about all the dust that those suckers are going to throw up? Wouldn't that block the sun and keep the planet cool?

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