Making Mars Habitable

[psychotick]

Hi,

Odd question - all my questions are odd I suppose! Was working on a plot for a space opera based on life on Mars and the asteroid belts perhaps in the next hundred years, and wondered, what would it take to make Mars more habitable.

I had a theory which I'm sticking to, that the first thing it needs is more gravity so it can retain an atmosphere. And at present the only way we know how to do that would be to increase its mass. So my thought was to use the spent asteroids, after they've been mined for metals etc. Simply I suppose blow them up in low Mars orbit and let the dust settle - literally. So my question is, would this be at all feasible? How many and how big would the asteroids have to be? And how high could you get the gravity? Fifty percent Earth's? How much would you need it to be to hold a proper breathable atmosphere? (Also it occurred to me that some of those asteroids might contain water (ice) and frozen oxygen, so dropping them off might help with that side of things too.) Seizmic effects might be an issue I suppose too.

Any thoughts?

Cheers, Greg.

 

[Nick B]

Mars used to have a thicker atmosphere, it lost it due to its electromagnetic field died. Without a magnetic field, the solar wind simply blew the atmosphere away. So it isn't case of mass and gravity but of creating a magnetic field, which potentially could be done by reheating the core perhaps? Or, in a more fictional way, possibly creating a an artificial magnetic field using some sort of technology?

Increasing Mars's mass would increase gravity, but it wouldn't make any difference to having an atmosphere without a magnetic field to protect it.

 

[chrispenycate]

If you had a thicker atmosphere it would take thousands, maybe hundreds of thousands of years to leak away. In geological time, this is an eyeblink, but in terms of human history, it's most of it. So if you crash volatiles onto it - probably comets, as being conveniently mobile - not only will it increase thermal energy by conversion of kinetic and gravitational potential, (which, in turn, will increase the loss rate of atmosphere, but we need more warmth anyway) but increase greenhouse effect. Obviously, we're not going to get a breathable mix with such primitive techniques - which leads me to suggest that a hundred years is way too short. Try a thousand. Have you read the Kim Stanley Robinson Coloured Mars series?

 

[zmunkz]

I agree with the earlier posts. The broad strokes would be: generate a lot of green-house gases, then plant trees.

Increasing green-house gases could be done very slowly with microbes, or reasonably fast using some kind of factories that could manufacture CFCs from the martian air and soil (or a solar mirror). If you get the temperature up only a handful of degrees, it starts a chain reaction by melting the south polar cap and releasing lots of carbon dioxide into the new atmosphere, which feeds back on the global temperature and continues until the entire cap is melted. At this point we expect the surface would be warm enough to sustain liquid water, and the temperature to be survivable for humans and plant life. The next step is the slow process of planting lots of trees to convert some of that CO2 into oxygen.

Once terraformed, many processes would need to be ongoing to counter the solar wind dissipation that results from not having a magnetic field, but as mentioned above, the dissipation would be slow and ongoing over many many years, not something that needs to be solved prior to beginning habitation.

Although a full atmosphere would help with the radiation problem (particularly in the ultraviolet range) it would do little to protect us from higher energy ionizing radiation, which on Earth is deflected by the magnetic field. You need some solution to this for long-term above ground habitation.

Here is the wikipedia overview, and here are some scientific discussions.

 

[ralphkern]

The direct anwser to your question about using asteroids to increase Mars's gravity is.... unfeasible at best.

Mars's mass is 38% that of Earth's.

The Moon, for comparison is 1.2% the mass of the Earth.

So you'll need 10 Moon size masses to accomplish your goal of rasing the mass of Mars to 50% that of Earth's. (or one Mercury sized body at 18% Earth mass to bring it up to 56%)

Mars's atmosphere, such that it is, is nearly all CO2 anyway.

An 'easy' way of creating an artificial magnetosphere would be to surround the planet in loops of conducters and run electricity through it. That will help preserve an atmosphere if you can get one.

Simply heating the world won't give a breathable atmosphere. There is a different atmospheric makeup which will need to be manipulated, horrendous radiation and probably a load of other things to consider too.

If you want my two pence worth. If you want a terraformed Mars in the hundred years timeframe... don't delve into it in too much depth - it can't happen without increadibly difficult problems being overcome.

If you want to world-build (both narratively and literally) - mention something about superconducting rings wrapped around the planet. Have huge patches covered in some kind of magic dark lichen to bring the CO2 levels down and up the oxygen content of the atmosphere (and absorb more sunlight to heat the world). It wouldn't be Hard SF... but at least you've given it a nod and the readers will say 'tick box, you've thought about it.'

 

[Cory Swanson]

100 years is awfully short. Not only do you need to liquefy the core, but you need to bring an atmosphere there. Microbes would be feasible, but they need something to metabolize. I think crashing comets and asteroids could potentially bring those gasses there, so long as you are selective.

I think any process that could accomplish this is on the scale of thousands of years.

 

[zmunkz]

The shortest timescale I've seen is 500 years, assuming nearly unlimited financial resources. Other sources cite it as well over a thousand years.

 

[psychotick]

Hi,

Thanks Guys. Interesting stuff. Wasn't suggesting by the way that the process was completed around a hundred years from now. Just begun. The story is merely set a hundred odd years from now when the great task is underway.

Creating an artificial magnetosphere is an interesting idea by the way. But liquifying the core doesn't seem useful to me to be. Even if it was possible, as I understand it the thing that makes our core generate such a useful field is that it's spinning iron. How do you start a core spinning? (Please don't mention the movie!)

However, I read through the sources you guys found, and another question occurred to me. How much of the Martian atmosphere was lost due to solar winds? And how much due to piss poor gravity? It seems to me that the two go hand in hand. In order to create a breathable atmosphere on a gravity poor planet you need a larger atmosphere - more column feet of air pressing down - and the higher the atmosphere runs, the easier it is for the solar wind to blast away bits of it. You need both acting together.

Cheers, Greg.

 

[Chinspinner]

Hi,

Thanks Guys. Interesting stuff. Wasn't suggesting by the way that the process was completed around a hundred years from now. Just begun. The story is merely set a hundred odd years from now when the great task is underway.

Creating an artificial magnetosphere is an interesting idea by the way. But liquifying the core doesn't seem useful to me to be. Even if it was possible, as I understand it the thing that makes our core generate such a useful field is that it's spinning iron. How do you start a core spinning? (Please don't mention the movie!)

However, I read through the sources you guys found, and another question occurred to me. How much of the Martian atmosphere was lost due to solar winds? And how much due to piss poor gravity? It seems to me that the two go hand in hand. In order to create a breathable atmosphere on a gravity poor planet you need a larger atmosphere - more column feet of air pressing down - and the higher the atmosphere runs, the easier it is for the solar wind to blast away bits of it. You need both acting together.

Cheers, Greg.

The problem with Mars is its size. The core cooled= no friction between molten iron= no magnetic field= nothing to deflect the solar wind. Lower gravity is just a result of its smaller mass, but it is largely irrelevant. The smaller mass resulted in the core cooling faster than on Earth and the loss of the magnetic field that allowed the atmosphere to blow away.

So without creating a magnetic field you cannot sustain an atmosphere. Realistically, the only way you could do so would be such a huge undertaking it would be beyond the capabilities of Earth for a vast period of time.

 

[StuartBurchell]

It would be simpler to colonise by making the bases and colonies under domes (and make them strong enough to withstand those sand storms that last for months). Doesn't help with your question, but it is more practical in the next hundred years or so.

 

[Vertigo]

I don't think big gravity is necessarily that essential to the presence of an atmosphere. Take Pluto which we now know has an atmosphere; it is smaller than our moon; its mass is 1.3E22 compared to the Moon's mass of 7.3E22. So the Moon is five times more massive than Pluto but has no atmosphere.

Also worth noting that a magnetosphere is not necessarily the only way of retaining an atmosphere. Earth has a magnetosphere but neither Mars nor Venus do and Mars has only a thin atmosphere but Venus a very dense one. Definitely still some science questions to be answered on this one.

Another thing is that I believe recent findings show that Earth, Mars and Venus are currently all losing atmosphere at about the same rate.

 

[cgsmith]

Best books I read about this were Kim Stanley Robinsons Red, Green and Blue Mars books. And he did a brilliant job of doing the terraforming.

Have just found this for you though...

"
Talking to SETI's Blog Picture Science podcast, Robinson explains that his ideas about terraforming Mars, back in the 1990s, were based on three assumptions that have been called into question or disproved:

1) Mars doesn't have any life on it at all. And now, it's looking more likely that there could be bacteria living beneath the surface. "That's going to be very hard to disprove," says Robinson. "We could be intruding on alien life."


2) There would be enough of the chemical compounds we need to survive. In particular, we need a lot of nitrogen — and scientists had expected there to be a lot, based on the ordinary distribution of elements in planetary accretion. But there's much less nitrogen on Mars than we'd hoped.

3) There's nothing poisonous to us on the surface. In fact, the surface iscovered with perchlorates, which are highly toxic to humans, and the original Viking mission did not detect these. We could use bacteria to dispose of them, but it would be a very long-term process."

These are somethings that if you can explain away nicely you'd be able to buy yourself some credibility for some more fantastical things. + would be interesting and I'd definitely read.

 

[Old_Man_Steve2016]

A couple other things to consider (and write about) when discussing martian colonization, especially beginning phases.

• Toxic soil. Curiosity found perchlorates in the soil. It would kill the crops and probably make astronauts sick if they touched it a lot. This Chemical Might Make Colonizing Mars More Dangerous
• Food delivery. Until they get the soil worked out, any residents will need food brought in from Earth. This was part of the plot of The Martian, but there's no reason why you can't work it in either. It could be a detective story (who stole the food), an adventure story (where did the food pod land) or a survival story (we're out of food who do we eat first I know let's eat the fat one No not me please not me)
• Solar flares. These could really muck up the equipment.
• Communication delays. Not being able to talk to relatives in real-time would get to anyone, unless they didn't have them to begin with. You can play this in many ways.
• National Rivalries. The US isn't the only interested party in a Martian colony. Or even in Mars itself. You could have rival nations competing with each other to get to prize landing zones or straight up stealing zones from each other (damn you China I wanted the Tharsis basin Haha suck it Yankee first past the post) You could even have one group with many Martian colonies but a rival group in charge of Phobos/Deimos/the third moon whose name I can't remember/satellite networks/space elevators.
• Taxes. If the colony is not tax-exempt, expect problems to arise from this. Should Mars Colonists Have to Pay U.S. Income Taxes?
• Bones.
• Boning.
• Boners. Not that boner, the other kind of boner.

 

[Vertigo]

Best books I read about this were Kim Stanley Robinsons Red, Green and Blue Mars books. And he did a brilliant job of doing the terraforming.

Have just found this for you though...

"
Talking to SETI's Blog Picture Science podcast, Robinson explains that his ideas about terraforming Mars, back in the 1990s, were based on three assumptions that have been called into question or disproved:

1) Mars doesn't have any life on it at all. And now, it's looking more likely that there could be bacteria living beneath the surface. "That's going to be very hard to disprove," says Robinson. "We could be intruding on alien life."


2) There would be enough of the chemical compounds we need to survive. In particular, we need a lot of nitrogen — and scientists had expected there to be a lot, based on the ordinary distribution of elements in planetary accretion. But there's much less nitrogen on Mars than we'd hoped.

3) There's nothing poisonous to us on the surface. In fact, the surface iscovered with perchlorates, which are highly toxic to humans, and the original Viking mission did not detect these. We could use bacteria to dispose of them, but it would be a very long-term process."

These are somethings that if you can explain away nicely you'd be able to buy yourself some credibility for some more fantastical things. + would be interesting and I'd definitely read.

I loved Robinson's hard science, which I found utterly fascinating but sadly I hated his writing which I found frankly bland - his characters in particular - and filled with bad grammar and clumsy sentences that were often really difficult to fathom.

 

[cgsmith]

I loved Robinson's hard science, which I found utterly fascinating but sadly I hated his writing which I found frankly bland - his characters in particular - and filled with bad grammar and clumsy sentences that were often really difficult to fathom.

You see, this is why I don't know much grammar

Admittedly, trying to write a novel with bad grammar knowledge isn't a best case scenario but I always hear people not enjoying books and writing because they can't get over the authors use of grammar, and I think that's kind of sad. Ignorance is bliss maybe.

 

[Chinspinner]

I don't think big gravity is necessarily that essential to the presence of an atmosphere. Take Pluto which we now know has an atmosphere; it is smaller than our moon; its mass is 1.3E22 compared to the Moon's mass of 7.3E22. So the Moon is five times more massive than Pluto but has no atmosphere.

Also worth noting that a magnetosphere is not necessarily the only way of retaining an atmosphere. Earth has a magnetosphere but neither Mars nor Venus do and Mars has only a thin atmosphere but Venus a very dense one. Definitely still some science questions to be answered on this one.

Another thing is that I believe recent findings show that Earth, Mars and Venus are currently all losing atmosphere at about the same rate.

As I understand it, Venus does have a magnetic field (albeit less than Earth), but it also has a very thick ionosphere that deflects solar winds and fluctuates towards and away from the planet surface depending upon the strength of solar wind; essentially Venus' atmosphere is like soup.

 

[Vertigo]

As I understand it, Venus does have a magnetic field (albeit less than Earth), but it also has a very thick ionosphere that deflects solar winds and fluctuates towards and away from the planet surface depending upon the strength of solar wind; essentially Venus' atmosphere is like soup.

Doing a quick check you are right but it is very much less than Earth's and a very different beast:

In 1967, Venera 4 found Venus's magnetic field to be much weaker than that of Earth. This magnetic field is induced by an interaction between the ionosphere and the solar wind, rather than by an internal dynamo in the core like the one inside Earth. Venus's small induced magnetosphere provides negligible protection to the atmosphere against cosmic radiation. This radiation may result in cloud-to-cloud lightning discharges.

 

[Vertigo]

You see, this is why I don't know much grammar

Admittedly, trying to write a novel with bad grammar knowledge isn't a best case scenario but I always hear people not enjoying books and writing because they can't get over the authors use of grammar, and I think that's kind of sad. Ignorance is bliss maybe.

I agree it is sad, but, sadly(!), even though my own grammar is certainly not brilliant, I can't help but notice it and then I just get pulled out of the story and when that keeps happening I just get frustrated.

 

[russ2]

I saw a NASA expert on TV who said 200 years tops if we threw our resources at it. I think there a lot of ideas, like importing gases from Jupiter. Melting the Martian polar caps (water vapor is a greenhouse gas), using magnifying screen in orbit to raise the temperature. And of course GM plant life to put O2 into the atmosphere. Like the guys above said it takes millennia for the solar winds to blow the air into space, so gravity is not such a problem.
Then there are lots of other problems like solar radiation, food supplies, not to mention those pesky Martians (LOL).

I really like Sf stories that explore these issues. I think one of the best are the Zeke Hailey books. Even though they're for YA, all kinds of ideas are weaved into the text. The Infinity Trap is the first book and a good place to start. I like the low tech ideas as the books go along, as well as the hard science solutions. And of course there's the unique way the story uses a famous feature on Mars for human habitation. I think the author must be a scientist but the stories are still fun.

 

[Vertigo]

I believe the polar caps are mostly frozen CO2 but then that is a greenhouse gas as well! But an awful lot of extra atmosphere material would need to be added.