Terraforming Mars

[LostElement]

I was watching a space TV show and it was about Terraforming Mars. They say it would be possible through Huge mirrors and plants. How exactly would you terraform Mars? I'd also prefer a scientific answer to get a better understanding. Thanks!

[victory143]

First step is to genetically modify bacteria to eat Iron Oxide (Mar's red surface) and produce Oxygen and Hydrogen as waste products.

[SargeRho]

That's a terribly inefficient way to do it.

Instead, you should produce super-greenhouse gasses from materials on the surface, to heat up the atmosphere, leading to degassing of dry ice, leading to warmer temperatures...and then start making oxygen.

[Albert VDS]

Mars has a thin atmosphere, you need to thicken it by putting more CO2 or other greenhouse gases.

Once it gets hot enough all the frozen CO2 will turn into gas and accelerate the process.

When you're at the point where Mars has liquid water on it's surface it's time to introduce plants to turn the CO2 into breathable air.

The last step would be introducing insects and animals to keep the whole cycle going.

[chaos_forge]

Even if you melt the entirety of Mars's ice caps, would that be enough to give it 1 atm of atmospheric pressure? I feel like it wouldn't be . . .

[Comrade Jenkens]

Even if you melt the entirety of Mars's ice caps, would that be enough to give it 1 atm of atmospheric pressure? I feel like it wouldn't be . . .

I read somewhere that it would be thick enough to not need a pressure suit but still too thin to breathe even if it was the correct gasses.

Perhaps importing more carbon based chemicals from Titan or something while getting the oxygen out of the iron oxide. (The iron would be useful in industry).

Then you would still need large amounts of water to make oceans and a lot of nitrogen to form a buffer gas.

[chaos_forge]

I read somewhere that it would be thick enough to not need a pressure suit but still too thin to breathe even if it was the correct gasses.

Perhaps importing more carbon based chemicals from Titan or something while getting the oxygen out of the iron oxide. (The iron would be useful in industry).

Then you would still need large amounts of water to make oceans and a lot of nitrogen to form a buffer gas.

Venus has lots of CO2 which could be used as a greenhouse gas, and I feel like that would cost less Dv than taking it ll the way from Titan. Also, we would be reducing Venus's atmosphere somewhat. Kill two birds with one stone, eh?

[m4rt14n]

The problem is logistics. How are you going to move huge amounts of materials interplanetary?

[Rondon]

Continuing on from Alberts reasoning and hinting at m4rt14n's point, to obtain the extra gas required, you could hit Mars with enough asteroids/comets to obtain the required greenhouse effect, must comets are made of water, Co2 and CO and methane, now presuming the comet(s) in question has half of its mass comprised of these useful greenhouse gases, you would need 6x10^17 kilograms of material, presuming you're choosing comets whose orbits are close to mars, depending on how lucky you are, you could get it between maybe 1000-2000 m/s delta V, taking the middle figure putting the asteroid on a collision course would take 8x10^20 Newtons.

That's a lot of energy, chemical rockets are out of the question, ion engines wouldn't achieve too much in the huge face of the problem, and a solar sail would take a long time and unprecedented scale. A nuclear detonation could create enough energy using a "practical" amount of mass , at a theoretical maximum you can get 3x10^10 joules per kilogram of nuclear bomb, even then this would require 30 million Tons of material! Just taking that amount to orbit with today's technology would cost nearly a 1000 trillion dollars! and that's just to take it to orbit, taking it to the comet would probably at least double the cost, and that's for the theoretical maximum, most modern warheads prefer speed/flexibility over payload efficiency.

On top of that sources are hard to quantify but id have to say we just the world just doesn't have enough nukes (How often do you get to say that? ), there are 17000 nuclear warheads in the world even the largest "only" had a mass of 27 tons, so even if they were all this massive you would have a hundredth of what you need, which means more warheads would have to created, that as well as the international ban on nuclear warheads in space and the possibility of rocket failures makes the nuclear option a political impossibility. the act of having to create more warheads would also ramp up the costs a lot, and to avoid the political challenges you would have to build the nukes off world which only further adds to the utterly astronomical bill.

Even amongst all this the Nuclear option would be several thousand orders of magnitude more efficient than chemical propulsion, which says more about how impractical it is to transport vast quantities of material around space than the efficiency of a nuclear bomb for energy per unit mass.

[Skyler4856]

NERVA may be able to achieve the delta-v required

(and can we please stay away from Orion?)

[Dodgey]

Why do we have to stay away from Orion?

[TheGatesofLogic]

Nuclear powered perfluorocarbon generators.

They last a long time, and the necessary ingredients can be found in the proper locations in the martian soil. Perfluorocarbons are better greenhouse gases than CO2 by factors of 10^3-4 when present in the right mixtures. Once enough are released to also release some of the trapped CO2, the Co2 will add to it independently causing a runaway greenhouse effect. This effect will peak twice throughout the process, the first being the CO2 release stage, and the second being the stage at which some of the Polar ice begins to melt. The ice-melt will boil rapidly and produce water vapor, which is actually a very effective greenhouse gas in its own right. The ultimate effect of this could by massive increases in atmospheric pressures and possibly lakes and seas of liquid water, opening the way to biological introduction and Gaea-type stabilization. Mind you the biosphere could take up to 4000 years to complete enough to be stable, but the intial stages might take only between 50-250 years.

[Dispatcher]

We take Ceres (I know, I want it for a moon of Venus, but first come, first served) and move it into a close orbit around Mars. This provides just enough tidal stress to induce tectonic friction, which warms the planet up somewhat; releasing some gases and binding carbon in the rock. Pressure rises as the planet warms and water begins to flow on the surface. Breathing gear will eventually still be required for you and any pets you take for a walk, but that way you can still enjoy the ultra fine dust as it penetrates into your clothes, etc.

[jwenting]

Mars has a thin atmosphere, you need to thicken it by putting more CO2 or other greenhouse gases.

Once it gets hot enough all the frozen CO2 will turn into gas and accelerate the process.

When you're at the point where Mars has liquid water on it's surface it's time to introduce plants to turn the CO2 into breathable air.

The last step would be introducing insects and animals to keep the whole cycle going.

Problem is that given its very low gravity it can't retain that extra gas, it's just float off into outer space.

So you'd also need to increase the gravitational field of the planet.

[TheGatesofLogic]

thats not true at all. titan is smaller and has a FAR denser atmosphere, despite being a moon and having some loss due to tidal interactions with saturn and its moons. Really, mars can easily hold a substantial atmosphere and estimates of the atmospheric pressure as a result of greenhouse initiagions are actually quite high.

[SargeRho]

Titan is also much further out, and of a vastly different composition. Primarily: It's colder. Much, much colder. So the atmosphere is denser. And I think it resides within Saturn's magnetic field, which gives it some protection from the solar wind. Mars doesn't have that luxury. But given enough advancement, we could replenish the atmosphere every once in a while. It'll take 2-3 billion years to erode an atmosphere that produces 1 bar of pressure away anyway, and by then, Mars too will be toast.

[Albert VDS]

Sure it will loose it atmosphere, every planet with an atmosphere will loose it eventually.

It would take millions of years too loose such an atmosphere, long enough to make it your new home and enough time to think up a way to keep it at

the right density.

[maccollo]

Problem is that given its very low gravity it can't retain that extra gas, it's just float off into outer space.

So you'd also need to increase the gravitational field of the planet.

It will loose it's atmosphere eventually, but it will hold onto it for several 100 million years at least.

We can deal with that.

[Rondon]

well Dispatcher, moving Ceres instead of one bars worth of atmospheric material, has increased the mass that needs to be moved a thousand times, but regardless of that would a tectonic force actually help? For earth the amount of energy gained form the mantle is 4000 times less than whats received by the sun, Ceres also would have smaller ratio of mass to its parent body than the moon has to earth 1/680 for Ceres/Mars to 1/81 for Moon/Earth, that said you can just move Ceres really close to mars, (not super sure about the math) if you get to within 1000km(super close) you could get 16000 times more relative force out of the Ceres moon compared to ours and its distance to us so maybe that could work in theory

Personally I prefer TheGatesofLogic approach, you still need a lot of material though and fluorocarbons probably aren't very common in the soil, which means that you'd need a lot of infrastructure to extract them, it would be really difficult though for it to require more energy than bringing the material there from another celestial body.

[m4rt14n]

What if you just hit mars with ceres. Wouldnt heat up the planet enough tp start a chain pf reaction?

[SargeRho]

And destroy the crust too.

[victory143]

And shift it's orbit.

[TheDarkStar]

And shift it's orbit.

Probably not significantly, though.

[Albert VDS]

What if you just hit mars with ceres. Wouldnt heat up the planet enough tp start a chain pf reaction?

Well it would probably cause a lot of energy exchange, partly in the form of heat, but the most important thing to note is that it would destroy Mars.

[palioxis1248]

NERVA may be able to achieve the delta-v required

(and can we please stay away from Orion?)

What's wrong with Orion??