Should Mars be Terraformed?

[Tattila the Hun]

They ought to nuke the polar ice caps in mars, to institute super-greenhouse-effect. Worked in Total Recall (I think)....

Would it work?

[Straybow]

If you take a statistics course you'll find out that most natural processes subject to decay or dissipation have c² or log-normal distributions. Let's say the average is 250ky. It cannot be less than 0ky, yet it could be almost any length greater than 250ky. The assymetric boundary conditions are part of what defines the distribution.

Typically, the curve rises sharply to an early peak, and the trailing slope is gentle. The average will be near the peak, but the trailing slope means that the standard deviations s aren't going to be linearly spaced. The +1s interval will be 250ky + nky, but the +2s interval will not be 250ky + 2nky but farther out. Can you visualize what I mean?

I don't trust the scientists who say a field reversal could happen "anytime in the next 1000 years." The next 1000 years is way outside our ability to predict, especially for processes we know squat about. The only thing we can do is measure the field in many locations and model it as a series of dipole moments in 3D, each decaying at different rates.

The last I saw there were a dozen dipoles in the model, and much uncertainty about decay rates (or growth rates in some cases) for the minor ones. The predominant dipole has been decaying with a half-life of 1400 years for the last 400 years. They guess at what threshhold the reversal might come, based on relative strengths of induced magnetism in igneous rocks.

Since that decay rate cannot be extended backwards more than 2-3 half-lives before the magnetic moment becomes too large to fit with observed induced magnetism the model can't be predictive of a process that extends for hundreds of half-lives (250ky+).

Hence I say with absolute confidence that the eggheads who make predictions on this are full of…

themselves.

[Ned]

Straybow, all we really know is that a statistically overdue reversal is in process. We have no idea what the threshold is for a reversal or what causes the different rates of reversal. Probably, the worst thing for the world is a slow reversal, one that take years, decades, millenia during which time the ionic winds from the Sun blast our atmosphere, stripping it away and heating it at the same time, perhaps killing the ozone layer, and inundating the world in harsh ultraviolet light and much higher radiation levels.

But a slow decay that is what seems to be happening now.

[Dr Strangelove]

Originally posted by Ned
Straybow, all we really know is that a statistically overdue reversal is in process. We have no idea what the threshold is for a reversal or what causes the different rates of reversal. Probably, the worst thing for the world is a slow reversal, one that take years, decades, millenia during which time the ionic winds from the Sun blast our atmosphere, stripping it away and heating it at the same time, perhaps killing the ozone layer, and inundating the world in harsh ultraviolet light and much higher radiation levels.

But a slow decay that is what seems to be happening now.

Are you sure that magnetic field reversals ocur every 250,000 years? If magnetic field reversals were slow wouldn't you expect mass extinctions coinciding with field reversals?

[My Wife Hates CIV]

Originally posted by Lord Merciless
Magnetic field has no effect on gamma rays.

hmmm... i kinda thought this was the case also. what are all you rocket scientists talking about?? it's the atmosphere that blocks stuff like this... i thought. spacecraft need to be launched to view gamma rays from space as they dont reach the surface. but the spacecraft do not orbit high enough to be outside earths magnetic field. i could be wrong.

as far as warming up mars. maybe in a billion years when the sun is a bit brighter it will warm up on its own. a long time to wait i guess. perhaps get a big rock and orbit it around mars in a way to drag the planet in a bit.

[rah]

Yes, whatever effort done will require many many years for it to have an overall effect. So it would make sense to take any possible initial steps while we wait for the technology and desire to catch up.

RAH

[Ned]

Originally posted by Dr Strangelove


Are you sure that magnetic field reversals ocur every 250,000 years? If magnetic field reversals were slow wouldn't you expect mass extinctions coinciding with field reversals?

Dr. Strangelove, yes. Apparently the last one occurred 1 million years ago.

As to the mass extinctions - and the emergence of new species - I would think so if the reversals lasted a long time. I haven't even heard of any studies on this, though. From the article I quoted, it appears that we really do not understand what will happen if we lose our magnetic field. But there is a lot of speculation about dramatic effects in the upper atmosphere.

[Kidlicious]

Originally posted by Kamrat X
How? It´s not like the wealth of Mars will be equally distributed among people on Earth. It will go into the pockets of big business, just like it does on this planet.

The capital\labor ratio would create higher wages.

[Ned]

I suspect the only thing that operates on Mars in the future will be machines. I do not see colonization if the radiation problem is as bad as it seems.

[yavoon]

at the very least Ned we could live in radiation sealed areas and develop plants that could withstand it. I guess thats not the very least. but its certainly a skeptics compromise.

[Willem]

Originally posted by Sava
I think it will be more than that. If the US gets to be as dense as China or Europe, you are looking at more than 10b.

But one of the main reasons the US is growing is because of immigration. First generation immigrants generally have larger families than long term residents. In a generation or two, their offspring will cotinue the trend of industrialized nations and produce less children than is required for population growth.

[Willem]

Originally posted by Ned
Paramount's latest sci-fi thriller, The Core - directed by Englishman Jon Amiel, and starring Hilary S**** and Aaron Eckhart - depicts a world beset by just such a polar reversal, with radiation sweeping the planet.

The solution, according to the film, to be released next year, involves scientists drilling into Earth's mantle to set off a nuclear blast that will halt the reversal.

It doesn't strike you as suspicious that this article promotes a movie that's in development? I've read other articles, one over at BBC online, that have pointed to this one and debunked it entirely, claiming it's simply a PR piece.

PS Here's a quote from one article on the BBC web site.

Whatever happens will not happen quickly. It will take thousands of years and there is no evidence that when it has happened in the past it has seriously affected life on Earth.

[Ned]

Originally posted by yavoon
at the very least Ned we could live in radiation sealed areas and develop plants that could withstand it. I guess thats not the very least. but its certainly a skeptics compromise.

Agreed. But terraforming will not work so long as the basic cause of the loss of atmosphere still exists: no magnetic field.

We are going to have to figure on how to restart that before we can do anything else. On possiblity would be to maneuver a bunch of large asteroids into striking the planet to heat it up again. But I am sure that such actions would also leave the planet surface unihabitable for upwards of several million years.

[Dr Strangelove]

Originally posted by Ned


Agreed. But terraforming will not work so long as the basic cause of the loss of atmosphere still exists: no magnetic field.

The Earth's magnetic field wards off ionized radiation, but does it have any effect on the retention of atmospheric gases? Either way, large amounts of an inert gas would also be needed because a pure oxygen atmosphere would be unstable (and toxic).

We are going to have to figure on how to restart that before we can do anything else. On possiblity would be to maneuver a bunch of large asteroids into striking the planet to heat it up again. But I am sure that such actions would also leave the planet surface unihabitable for upwards of several million years.

Hey, here's an idea: instead of slamming the asteroids into the surface of Mars, how about slamming them into Demos and Phobos? Perhaps if the moons were sufficiently large the tidal forces exerted on Mars would be enough to heat up the core of the planet sufficiently to liquify it, and hence form the convection currents of liquid magnetic metals that generate the Earth's magnetic field.

[Ned]

Originally posted by Dr Strangelove


The Earth's magnetic field wards off ionized radiation, but does it have any effect on the retention of atmospheric gases? Either way, large amounts of an inert gas would also be needed because a pure oxygen atmosphere would be unstable (and toxic).

AFAIK, the solar wind would blow and broil away our atmosphere just as it did Mars'. I suspect the phenomenon takes hundreds of thousands of years, at a minimum. But who knows?