Terraforming with a Broom

RickSmith · 2007-11-21 15:06:54

Hi nickname,
My bias is showing in my earlier post. I would like to move more mass into Phobos' orbit. With a larger moon, the long term climate variation will be less so I just think, "grab one asteroid", rather than "use up what is already there".

I know of no evidence that there is 100 mBar of CO2 in the polar caps. (My numbers suggest that you would be doing well to get 10 or 20 mBar from them quickly.) Where did you get the numbers you quote above? They seem far too optimistic.

Warm regards, Rick

nickname · 2007-11-21 17:15:53

RickSmith,

The 100mb of c02 isn't from the poles as such.
Its the reaction of carbon soot on water ice with heat from carbon bullet impactors, guessing at a 20% conversion of water to c02 and 80% non reactive carbon.

We would in fact be turning about 20% of the water on the poles into c02, some free hydrogen, some hydrocarbons, some free oxygen and some methane with the dust from Phobos.
We also get a dark layer spread all over Mars afterward that helps warming, and a quick release of other trapped gasses in the pole ice.

No reason we couldn't bring in an asteroid the do the same thing with the dust from it.
I wonder why we would go to so much trouble though when Phobos is so well positioned and so well furnished with carbon.
We could use those asteroids later to enlarge and move Phobos when a bigger stabilizing moon is needed.

We don't need to destroy Phobos either with the dust removal process, just remove the dust that will be a problem later anyway.

All the math i have done so far on the idea is all educated guesses.
Not knowing the exact composition of Phobos dust and quantity, ice quantity and exact makeup on Mars, impact of dust bullets speeds, heat from those impacts and reaction probabilities of the above.

I might be well over guessing at the created c02 and other gasses or well under guessing.
Way to many variables for me to get a solid number on.

Of all my crazy ideas to get Mars warmed in an easy fashion, i think this might be my best and has some potential if we can pin the numbers down.
Or it might be like a lot of my other ideas, close but no cigar

RickSmith · 2007-11-21 17:33:26

The 100mb of c02 isn't from the poles as such.
Its the reaction of carbon soot on water ice with heat from carbon bullet impactors, guessing at a 20% conversion of water to c02 and 80% non reactive carbon....

OK, if I understand what you are suggesting you are saying that the impacts will vaporize the bullet and some area of the impact zone. All this gas comes from the volatiles released. Is that a fair summary of your idea?

Warm regards, Rick.

nickname · 2007-11-21 19:41:22

Hi RickSmith,

You got it.

Costs us in final water totals for Mars but gains us a thick atmosphere quickly with lots of new c02.
Relatively low tech stuff we could do now with little material input from Earth.

The math/guessing is like a nightmare though

RickSmith · 2007-11-23 05:54:21

There was a weapon system that was talked about called "THOR" where you take crowbar sized objects and drop them from orbit. As they blaze thru the atmosphere they leaving behind a glowing trail of plasma which looks like a lightning bolt above what even they destroyed.

The objects dropped come in crowbar sized, fence post sized and telephone pole sized.

I am a bit curious about if there is enough stuff on Phobos to vaporize the whole of the Martian south pole, but it would likely take me 2 or 3 hours to work out an estimate. (Which I'm not going to do now.)

But let us say that you do this, dropping crowbar sized chunks of Phobos and turned all of it into gaseous CO2 and H2O. Great hot holes are everywhere on the south pole; all of the CO2 is gone and most of the water is vaporized. (It won't be all gone as the permafrost there goes deep.) The heat from the impacts will rapidly radiate away. Then the H2O will frost out, lowering Mars' albedo. Next Martian winter, the CO2 will frost out giving us larger CO2 deposits on the south pole.

As long as CO2 will frost out in the heart of winter, then any warming is strictly temporary. I think you will need something (like super green house gases) to keep it warm enough, long enough to start having the CO2 in the soil come out.

Warm regards, Rick.

nickname · 2007-11-23 06:50:21

Hi RickSmith,

Goes to show that a little twist on an idea and it can become a dreadful weapon.
Thor sounds really nasty.

These are a few of the variables i have been working with.

Dust quantity, guessing at depth on Phobos X surface area.
Guessing at carbon quantity of that dust.

Delivery of the dust in bullet format.
A few different ways to delivery then from Phobos for different impact speeds.
I've been working on ways to get the mag launcher move the bullets very fast to maximize the reactions on the poles.

Bullet sizes should be one that converts the most water to c02 for its size.
The gasses each size creates will depend on the carbon reactivity, velocity and local heat of that impact.

Landing, Collecting and launching all pretty simple on Phobos, no real math required other than bullet speed/size.

I remember seeing a long discussion about c02 here on this message board about the numbers we need to keep Mars warm permanently.
I seem to remember the total needed was 50 something mb of c02 and c02 never frosts out.

We do get some water frosts returning that lower the albedo in the winter, but they should be well offset with the non reacted carbon that is sure to be spread over most of the globe.

At 100+ mb of c02 do we even get water frosts in winter, maybe just on the poles?
If we got to 100 + mb we should also go well beyond that with contributions from Mars itself, maybe 1/2 again.
Pretty sure with those numbers c02 stays in gas format all year.

I agree with the super greenhouse gas delivery about the same time, that could go a long way to keeping the water frost off in winter.

Wonder if we could create that on Phobos also and use the same delivery method?

Rick your 3hrs of math is about my weeks worth LOL

Terraformer · 2007-11-24 09:06:31

If you grind it into dust in orbit wouldn't it burn up in the atmosphere (increased suface area)?

nickname · 2007-11-24 13:33:32

Terraformer,

Increased surface area is important to increased reaction with water ice on the poles.
The heat of each impact is important for c02 creation reactions also, so size does matter

We do have to think about the atmosphere of Mars on any small impactor, so a particular size to get past the atmosphere with little loss is needed.
That size depending on how you deliver the dust bullets, direct to pole delivery from Phobos or arching de orbit for extra speed.
Or shot away from Mars in a sloppy unstable orbit for the most impact speed.

Lots of calculations needed for sure, and lots of variables in each one.

The main calculation is how much new C02 we create with the dust quantity on Phobos at the best reaction percentages on the water ice poles.

If that number is 50-200mb new c02, then we really have a viable and simple way to alter mars for good.

With pretty rough math i get about 100mb new c02 for Mars with just 20% reaction if the poles are mostly water ice.
That is using all the loose surface carbon dust on Phobos.

Phobos has many times the loose surface dust amounts as solid carbon deposits, so a second or third poles bombardment isn't out of the question if needed.

Just guessing at the reaction rates of 20% though, because nothing like it exists to do any solid research on.

RickSmith · 2007-12-22 23:08:14

Bullet sizes should be one that converts the most water to c02 for its size.
The gases each size creates will depend on the carbon reactivity, velocity and local heat of that impact.
At 100+ mb of c02 do we even get water frosts in winter, maybe just on the poles? Pretty sure with those numbers c02 stays in gas format all year.

Hi nickname,
I think that you are totally off on your hope that with 100+ mBars of CO2 that there won't be frosts or ices on the Martian poles. Consider, speaking in rough numbers Earth gets 1300 W/m^3 in orbit and Mars gets 500 W/m^3. After getting thru our atmosphere, it is closer to 650 W/m^3 so Mars gets a base of 3/4 the heat and light that the Earth does. (The black body temperatures for Earth : Mars are, -23C : -67C.)

Now Earth has water vapor which is far and away the biggest greenhouse gas component in our air. Mars has none. Also the Martian winters are about twice as long as the winter in Antarctica. So you get months more of no direct heating at a time. Lastly a huge amount of heat is transfered polewards by ocean currents and by our thick atmosphere.

So there is no way you won't have water ice forming at the Martian poles.

******************************************************************

As for the idea of dropping pellets on the Martian poles to break the ice into a plasma, having some of it combine with the carbon (to create more CO2) and letting the hydrogen take care of itself I find it doubtful but have not thought of any really elegant way to calculate all this. Let's take things step by step and see what we come up with.

Taking carbon dust from Phobos and shooting it at Mars.
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OK, Phobos is pretty much exactly over the Martian equator. Shooting the dust that far south will mean killing the orbital velocity to the east or 2.14 km/s and giving it a new, suborbital velocity which will take it 3377 km south (Martian polar radius) in the time it takes to fall 9377 km.

Well if we were at Phobos' orbital height and put it into a polar orbit it would take another 2.14 km/s boost. But then it would be 9377 km higher than the south pole. Since it does not have to travel that far in reality (perhaps 1/3 that distance being very conservative) at a quick guess it would be around a boost of 0.71 km/s southward boost.

So (speaking in rough terms) we are looking at a delta vee of around 2.85 km/s (firing roughly west-west-south) to put a pellet on the south cap. This treats the two components of the motion as vectors, but given that we are in space and firing them, cannon like, with a near instantaneous velocity I think this is a reasonable approximation.

In the Thor weapon system the crowbars are de-orbited and dropped vertically thru the atmosphere to maximize their accuracy. Given that the ice cap is a big target, I doubt people will mind that these artificial meteors are angling in from the south.

(By the way, for these calculations I'm not trying to be super accurate. I am doing some quick 'napkin' type estimates to roughly give the feel of what numbers we are talking about.)

Now 2850 m/s is not impossible by any means. Rifles fire bullets in the range of 800 to 1000 m/s easily. So I can see no problem with a mass driver reaching those figures. You would want a fission power plant, at least, to run this.

If carbon did smash into the ice how much would turn to CO2?
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Let us say that we did drop pure carbon onto the water ice poles. How much would turn into CO2?

This is a really hard question. First, would all the carbon vaporize? From my readings of Thor, I believe the answer would be yes. One suggested use would be to use a metal crowbar (say tungsten or depleted uranium) to hit a missile silo. The metal bar punches thru, turns to plasma, and then burns in the oxygen atmosphere of inside the missile silo adding the energy of the burning metal to the energy of the kinetic kill. That ICBM is toast.

So let us assume that all of the carbon vaporizes into white hot plasma. Plenty of ice will be shattered and thrown away, but I see no reason why an equal or greater quantity of ice would not also turn to plasma. (More than equal as carbon has a far, far higher heat of vaporization than ice (carbon's temperature of liquidification is 4827°C which is VERY high.)

So we will get a wild fireball of carbon, hydrogen and oxygen (plus what ever else is around) exploding outwards. As this plasma ball cools the carbon will combine with oxygen forming carbon monoxide and CO2 (fine) hydrogen to form hydrocarbons (mostly methane) and other carbon atoms (typically forming microscopic flakes of graphite and soot). (Plus other reactive things like H2C2O (ethenone).) If we drop clays and ices, we will get a bunch of more exotic species. The methane and hydrocarbons will react with O2 and O3 and turn into CO2, but any soot will stay soot.

(You could argue that the soot could react with ozone (O3) and form CO2. True. But that O2 and O3 is formed by breaking up CO2 (which is dropped as dust someplace else) so we are not getting any net gain.)

Soot forms naturally out of carbon rich plasmas, so I expect we will have losses.

Also, let us say we have a fair bit of aluminum in our impactors (see below why this might be). Aluminum oxide forms very easily. The carbon and aluminum will fight for the oxygen, and in the long run, the aluminum will win.

Would we fire pure carbon?
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Your assumption is that we would fire carbon dust but this is weak in a couple respects. First Phobos is not pure carbon. To the first approximation, it is a 'rock dust, clay minerals, salts and soot' mixture (along with some ice deeper down).

Second pure carbon (in the form of soot) or this clay like mass is not strong. The idea behind orbital kinetic weapons is that they are long and thin with a sharp point to avoid being slowed as much as possible by the air. When a dust bolt hits the atmosphere at transonic velocities it will shake, vibrate and disintegrate, gently dropping dust on the polar cap.

We could separate out the carbon and form it into diamond and drop diamond bars on the south pole. But this is impossible right now (no one is using construction diamond bars to build sky scrapers for example). See "Diamond Age" by Neil Stapleton if you are interested.

A more 'practical' way would be to make tubes out of aluminum (which can be found in clay), dust it with carbon (heat resistant) and fill the tubes with carbon dust. You could likely (at a guess) fire fence posts carrying a carbon payload. (Fencepost sized or larger so you can get a reasonable sized payload of carbon. If the aluminum melts too easy we could cover it with ceramics from the clays.)

But suddenly we are talking a major industrial effort. You need a lot of clay to make your aluminum fence posts. Aluminum does NOT come out of clay easily. You don't have highly automated scoops dumping soil on a bullet sized mass driver sled, you have to accelerate a far heavier payload which makes your mass driver far larger and more expensive. And converting that soil into tubes and pure carbon requires a lot of energy and industrial power.

This much equipment needs maintenance so you will have a large human presence. Many reactors, etc. Living in zero gee is hard on people.

I think we are out of the 'it would be simple to do...' stage and into an industry here. But that is OK, we are changing the planet.

But it occurs to me. If we are going to be doing all of these chemical reactions anyways... why not make the CO2 on Phobos? There is plenty of O2 in the rocks. Make CO2, freeze it and drop the solid CO2 onto the Martian atmosphere below the moon. Takes a lot less energy to drop something onto the equator than the poles and we get 100% of the carbon turning into CO2.

Is there enough carbon in the top 10 meters of Phobos to make a difference?
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No time. Maybe I'll chew away at this question another time and edit my answer in here later.

However, I think not because elsewhere I worked out how many 40 km ammonia rich asteroids I need to build up a reasonable amount of N2. The answer was, "way more than I hoped". Phobos has far, far less volume than something 40 km in diameter.

Conclusion:
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My take from answering the questions above is that this is very marginal. We will need a huge industrial facility on Phobos for it to have a chance of working, it feels very wasteful to me (much of the processed matter is not used, carbon does not all turn to CO2, very non-trivial to get the carbon to the poles in a nice hot impact). For a fraction of this cost we can drop a few iceteroids on Mars with the CO2, NH3, H2O, CH4 etc. already made AND these impacts will release more carbonates and nitrates from the soil.

If we need a big industrial base it will be significantly easier to put it on the planet's surface (radiation protection, ground, some air pressure, much easier life support with local materials in easy to process states, gravity, etc.) and make some greenhouse gases.

A final thought. Most estimates of Mars' carbon dioxide reserves, think that there is plenty. CO2 is absorbed in clays, in water, in ice. There may be frozen CO2 underground year round. If we can warm the poles by 5 to 15 degrees C, almost all of these reserves will become unstable and out gas the CO2 given time enough for the heat to reach them. (We are talking decades to centuries to get most of it out.)

So I don't really think that we need to spend a lot of effort trying to make more CO2.

Warm regards, Rick.

nickname · 2007-12-23 19:17:21

Hi RickSmith,

I would just like to thank you very much for doing a lot of the nuts and bolts math of this idea.

It seemed like every time i tried it was a giant bear to try and tame.
Each little change made the last guess a total change.

The ideas can come pretty quick for a easy solution to making Mars a more Earth like place.
But when you get into the math it starts to change a bit.

Very interesting breakdown of all the needs of the idea and very well nutted out Rick.

Now your point of aluminum tubes with carbon dust replacing the carbon dust as the impact items is an interesting one.

We probably wouldn't have to search to far in the asteroid belt to find a good candidate asteroid for that.
I think your correct though that the energy costs to get it out of any asteroid will be pretty hefty.

Small selected untouched asteroid dropping on the poles sounds better and better.
Much easier anyway

Thanks again Rick *tipping Hat*

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#26 2007-11-21 15:06:54

Re: Terraforming with a Broom

#27 2007-11-21 17:15:53

Re: Terraforming with a Broom

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Re: Terraforming with a Broom

#29 2007-11-21 19:41:22

Re: Terraforming with a Broom

#30 2007-11-23 05:54:21

Re: Terraforming with a Broom

#31 2007-11-23 06:50:21

Re: Terraforming with a Broom

#32 2007-11-24 09:06:31

Re: Terraforming with a Broom

#33 2007-11-24 13:33:32

Re: Terraforming with a Broom

#34 2007-12-22 23:08:14

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