Baxter mines and the nitrogen problem

Rusakov · 2012-12-22 02:32:23

There's a paucity of nitrogen on Mars. Even if we managed to find pure nitrate beds in the Martian crust, it still wouldn't be enough to make both a buffered atmosphere and rich soil. One alternative is to get nitrogen from Titan, but transporting that much is problematic. In the end, nitrogen would be a limiting factor in a future Martian ecosystem.

Or would it be?

In the book Manifold: Space by Stephen Baxter, the protagonists used a device to drill deep down into the mantle of the moon to reach water and volatiles. The idea being that comets and asteroids delivered them billions of years ago and that some of them would still be contained in certain minerals.

The book called it a "Paulis mine" but here I'll call it a Baxter mine.

What implications does this have for Martian nitrogen? If sometime in the future a Baxter mine is possible, then we could prospect for nitrogen in the Martian mantle and release it. Considering the volume of the mantle, there might be more than enough needed both for an atmospheric buffer gas and soil nutrition.

This is just speculation on my part, but if it's true, it could make terraforming Mars much easier than it would otherwise be.

RobertDyck · 2012-12-22 06:54:31

We don't require as much nitrogen as Earth. Mars will always have a thinner atmosphere than Earth. That's just a fact. We don't need as much nitrogen as Earth has. In fact humans can breathe just fine with 3psi. In fact Denver, Colorado, has 2.528psi partial pressure oxygen. That's calculated using the pressure altitude calculator on the website of NOAA, then calculate oxygen. Earth has 20.9% oxygen. Air Force studies have shown strong, healthy fighter pilots can endure as little as 2.0psi partial pressure oxygen as long as total pressure doesn't get too low. That's young, strong individuals, and after they went through several weeks of high altitude training. With pure oxygen, they can endure 2.5psi; that's the absolute lowest pressure. At 2.0psi pure oxygen, it's a question of how many minutes before the pilot blacks out.

Metric conversions:
3.0 psi = 206.8 mbar
2.528 psi = 174.306 millibars (partial pressure oxygen at Denver)
2.5 psi = 172.368925 mbar (round off to 172)
2.0 psi = 138 mbar

The text book "Terraforming: Engineering Planetary Environments" by Martyn J. Fogg cites 2 research papers that estimate Mars surface pressure when all dry ice is sublimated. One estimates 200 mbar, the other 300 mbar. Since then the orbiter Mars Express used ground penetrating radar. It found polar ice cap at the south pole. The water ice is too pure to call it permafrost, that's a polar ice cap, just covered in a skiff of dirt. It extends to 60° latitude and 3.7km thick. If the south polar ice cap alone were melted the water would cover all of Mars 11 metres deep. But it wouldn't cover Mars evenly, tops of mountains would stay dry, and low lying areas like the ancient ocean basin in the north would fill. So where did the ocean? Found it! But they also found a large deposit of dry ice embedded within the water ice. No one has re-calculated Mars surface pressure after these new findings, so I use the higher of the previous two estimates.

With 300 mbar CO2 atmosphere, we have quite a lot to start with. Earth has 1013.25 mbar total pressure at sea level, but it's substantially lower at higher altitude, and humans don't need all that. Humans need oxygen. And if you measure barometric pressure that precisely, it fluctuates with weather. The point is there's enough CO2 to convert into something else. Humans need O2, and we can't endure much CO2. Earth has 0.03% CO2. We can handle a bit more, but at 2% humans get headaches. Symptoms get worse with increased concentration, a couple hours at 10% CO2 can be lethal. Plants are starved of CO2 on Earth, but if we increase it that causes global warming and smells stuffy. Mars needs global warming, if we accept a different atmosphere (and different smell) then Mars could have a little more CO2 than Earth. But not too much. If we take 0.5% CO2, using Earth pressure at sea level, that works out to 5.06625 mbar partial pressure. Round that off to 5 mbar. So with 170 mbar O2 + 5 mbar CO2, that's still a lot less than 300. Some carbon will be consumed by plants. But that means Mars has enough carbon.

The point is we don't need very much buffer gas. A little will do. Human lungs dehydrate if total pressure is too low. At 170 mbar pure oxygen, you require near 100% humidity to avoid lung tissue cracking and bleeding. But 300 mbar total pressure is enough to avoid that.

Transporting atmospheric gas from another body is just WAY too expensive. We have to work with what's on Mars. The big question is what nitrates exist on Mars.

Years ago some scientists told us the atmosphere escaped into space. Now we find there's enough dry ice to restore Mars atmosphere. Then those same scientists told us the water escaped into space. But we found enough water ice to re-fill the ancient ocean. Now those same scientists are tell us nitrogen escaped into space. Fool me once, shame on you, fool me twice, shame on me. These scientists have already fooled us twice, now they're trying a third time. I believe the nitrogen is still there somewhere. Venus has more nitrogen than Earth, it's just swamped in vast quantity of CO2. In fact Venus has 6 times the mass of nitrogen as Earth's atmosphere. One possibility is life on Earth has consumed a lot, it's necessary for protein and DNA. Venus is smaller than Earth, it has 90% surface area and 90% gravity, so Earth should have started with equal or more than Venus. Mars is smaller, so started with less. But Venus has 95.something% CO2. Mars today has 95.something% CO2 (it fluctuates with Mars weather). Mars should have started with 95.something% CO2 when it had hundreds of millibar pressure. The CO2 froze as dry ice, but nitrogen boils at -195.79°C at Earth atmospheric pressure; at lower pressure it boils at even colder temperatures. Mars isn't cold enough to liquefy nitrogen. But it could have chemically combined with other stuff to make nitrates. So where are the nitrates?

Sojourner was the little rover on Mars Pathfinder. Spirit and Opportunity are the larger rovers. They looked for nitrates, but didn't find any. Mars Phoenix also failed to find nitrates. Now Curiosity has a small drill, I'm hoping it finds nitrogen compounds.

Last edited by RobertDyck (2012-12-24 00:08:37)

Terraformer · 2012-12-22 17:59:01

Humans can tolerate, at the least, 80mb partial pressure CO2 if acclimatised. Sheep have gone to 120mb partial pressure. Do we still have the minimal Martian terraformed atmosphere thread? Midoshi posted the sources for those figures there.

Midoshi · 2012-12-22 22:05:16

Terraformer,
Yes, we did manage to regain some of the Minimal Martian Terraformed Atmosphere thread. I addressed some of the issues regarding nitrogen in this post. The review of mammalian response to elevated CO2 levels that you referred to is a few posts before that.

By the way: Sorry I haven't been posting recently! I just got a new job as a research scientist on the MAVEN mission, and we're pretty busy making sure we're ready for launch next year.

louis · 2012-12-23 13:11:51

Another point we don't need soil as such. Soil is quite a wasteful way of growing plants. We could grow them hydroponically which means the nitrogen in the feed is relatively well-targetted I would think. Assuming we eat about 1kg of plant stuff a day on say an average 30 day cycle, the total amount of plant feed required per person might be as low as say 50kg (wild guesstimates on my part), which they can bring with them. As long as there is very efficient recycling, only a limited amount of "topping up" will be required.

Terraformer · 2012-12-23 15:06:54

But that kind of defeats the purpose of terraforming...

Antius · 2012-12-23 15:47:45

CO2 is relatively easy to liquify. Liquid fuel and oxygen production on a heavily colonised Mars would sift through huge amounts of atmospheric gas each year. The residual atmospheric gas (when stripped of CO2) would be predominantly nitrogen and argon. This exit gas could be converted into ammonia using the Haber process. This requires heating a mixture of N2 and H2 to ~500 centigrade at high pressure for several hours. The argon would uneffected by the process.

The hydrogen could be cheaply produced on an industrialised Mars using thermochemical processes driven by Gas Cooled Fast Breeder reactors, which would also use seperated CO2 as coolant. The same reactors could provide the process heat needed to drive the Haber process and water gas-shift methane/oxygen production in the same chemical refineries. The ammonia would be a potent bioavailable fertliser and could be cheaply produced even from relatively rarified atmospheric nitrogen.

Excess methane could either be released into the atmosphere as a direct greenhouse gas, or with relatively simple modifications to the water gas shift reaction, ethylene could be produced. This would then react chlorine and flourine harvested from salts is Martian regolith to produce CFCs, a more potent group of greenhouse gases.

On Mars, a huge array of industrial chemicals (including ammonia) could be produced using compact nuclear powered chemical refineries, processing the local elements. The reactor systems themselves are light enough to be imported from Earth, provided that shielding and coolant are sourced locally.

louis · 2012-12-23 20:34:49

Terraformer wrote:

But that kind of defeats the purpose of terraforming...

Well I see the prime purpose as establishing human civilisation on Mars. Terraforming comes second. I think once you have a substantial human presence on Mars - let's say 100,000 to one million - then you can begin the terraforming process in earnest.

JoshNH4H · 2012-12-25 00:37:20

Louis- Isn't this predicated on the idea that we are already at that point?

In general, there presumably are some volatiles sequestered within the planet. As always the question is how much and how hard they are to release. I believe midoshi has suggested in the past both that only minimal amounts of nitrogen (5 mb or greater) are needed to allow nitrogen fixation, and that there significant reserves of solid nitrogen in the crust. The Martian ecosphere will most likely be relatively nitrogen poor compared to ours, but if the amount of nitrogen in the air is say 25-50 mb with the rest being in the ground I don't think there will be much suffering from the loss.

Also, welcome back Antius!

RobertDyck · 2012-12-25 18:20:28

Antius wrote:

This would then react chlorine and fluorine harvested from salts is Martian regolith to produce CFCs, a more potent group of greenhouse gases.

CFC destroys ozone. Mars gets 43% as much sunlight as Earth, but without ozone the full UV-B and UV-C get to the surface. That kills living things, sterilizing the planet. And exposed human skin would not just get severe sunburn, but skin cancer.

CFC is Chloro-Fluoro-Carbon. BFC is Bromo-Fluoro-Carbon. Bromine also destroys ozone; not as much as chlorine, but also something to avoid. What we do want is PFC (Per-Fluoro-Carbon) which is just fluorine and carbon, nothing else. And SF6 (sulphur hexafluoride).

Void · 2012-12-26 20:05:12

Well I see that you are not strictly talking about Nitrogen, so perhaps you will not be angry if I type a some lines in the form of a related question about the possiblity that Carbon has been bound to Nickle and Iron in the Martian crust. I am at best an amateur and can run with speculation, as long as I don't overdo it and annoy you.

I am thinking of something like the Mond process, with Iron/Nickle impactors interacting with the low level of Carbon Monoxide in the Martian atmosphere, over billions of years.

I have been trying to understand what happens in the Exosphere of Mars, and it appears from my reading, that Oxygen is lost, but for the most part Carbon is not. Apparently water sublimated from ice bodies in the soil and poles replenishes the lost Oxygen as H20 is split into Hydrogen (Which floats away), and the Oxygen hangs around for a time, converting some Carbon Monoxide into CO2. At some point UV light splits Oxygen off, and this can cause "Hot Oxygen" molecules which can escape from the atmosphere.

So, this has caused me to wonder. The Carbon is not very enriched with Isotopes, (Unless I have the wrong information). 3%
So, if not so much Carbon has been lost to space, where did it go? Some is in Dry Ice in the polar caps, I understand.

Understanding the whole historical process of atmospheric components, could be related to figuring out where your Nitrogen is. I have no direct notion of that, but am a bit suspicious that after Hydrogen it would be the easiest to loose to space, because the Oxygen that is lost to space apparently must first be split from CO2 in the very upper atmophere.

Against what I suggest is that there is a greater amount of free Oxygen than Carbon Monoxide in the atmophere. However for it is the notion that Carbon Monoxide is much more strongly bonded to Hemoglobin than Oxygen. And am I wrong that that is involving Iron?

I have read some materials that suggest that in the early days of the solar system, Carbon could be ejected from the Martian atmosphere because of a different character of the sun, perhaps a much stronger solar wind and perhaps a different spectrum?

Initially I was going to run with the idea that Carbon could be sequestered in the Crust as Hydrocarbons, but of course I know that is sort of a no no, as the oil industry only considers that most oil comes from prehistoric life that has decayed inside the crust, and the little of it is abiotic. I have no answer for that.

However I remembered previous threads here about the Mond process, and wonder if the orginal atmosphere of Mars might have had more carbon in it, and if Carbon Monoxide bonding to reduced metals dropping in from space could have removed some Carbon from the atmosphere.

More of a set of questions, not as much a theory.

I know you have people here who might shed some light on it if they feel like it.

If you have to tell me that I am wrong, I will just consider that learning.

Koeng · 2012-12-27 00:13:57

Just a minute ago I checked out marsdrive and DysonB made this idea... note the below is totally him-

In Mayan times a Chinampas was created by building layers of soil and vegetation upon a shallow marsh. Trees are then planted at the corners to root the plot into the marsh.

The way the Chinampas could be created on Mars would be rather simple. First an area 300 feet long by 50 feet wide would be marked off in one of the polar regions or regions that have ice or snow. There would be a thirty foot walking path around the Chinampas between the dome and the ditch. The ditch would be five feet deep. In the bottom of the pit heat piping would be placed so that frozen ice would first be melted and then piped through the heating piping much the same way that a radiator creates heat in a home. Next a two foot thick blocks of ice would be placed on the heating pipes. Hot water is ran through the heating piping that then melts the ice blocks making a small pond. Martian soil is then placed into the pit causing it to become muddy. Because of the heating piping the mud will remain a little solid. As the heat backs the Martian soil the nutrients on the soil along with bacteria will be released where they will begin their jobs of doing what they do.

More and more layers of Martian soil is then added until the weight creates a compact chinampas. Once the chinampas is compact enough vegetables and other leafy greens would be planted that could then be eaten by Martian colonists.

The Dome or fence would be sixteen feet tall, would be made of Gorilla Glass, because Gorilla Glass is the be all for space colonization and terraforming needs where the glass would contain special cells that would enhance any sun light that passes through the panes so that the correct UV light is let in and that which is not needed is blocked out.

As the plants grow they will release oxygen which can then be collected for other uses. The carbon dioxide along with nitrogen would be piped in from the outside through special vents to feed the plants the nutrients that they need to produce oxygen.

Further uses of the Chinampas would be created to grow Cynobacteria that would then be able to create oxygen and nitrogen for the colonies use.

http://www.mpg.de/621120/pressRelease201003241

http://www.ozgate.com/in...tes/mars_atmosphere.htm

http://scienceforkids.ki...stry/atoms/nitrogen.htm

http://www.mpg.de/621120/pressRelease201003241

I know that what I am looking for is here in these articles somewhere.

Basically the process that I am looking for is to also pipe nitrogen and carbon dioxide into the Chinampas where bacteria would convert it into oxygen for human use, plant use and other bacteria use where the other bacteria would create by products would further be needed to create a nourishment base for the Chinampas.

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#1 2012-12-22 02:32:23

Baxter mines and the nitrogen problem

#2 2012-12-22 06:54:31

Re: Baxter mines and the nitrogen problem

#3 2012-12-22 17:59:01

Re: Baxter mines and the nitrogen problem

#4 2012-12-22 22:05:16

Re: Baxter mines and the nitrogen problem

#5 2012-12-23 13:11:51

Re: Baxter mines and the nitrogen problem

#6 2012-12-23 15:06:54

Re: Baxter mines and the nitrogen problem

#7 2012-12-23 15:47:45

Re: Baxter mines and the nitrogen problem

#8 2012-12-23 20:34:49

Re: Baxter mines and the nitrogen problem

#9 2012-12-25 00:37:20

Re: Baxter mines and the nitrogen problem

#10 2012-12-25 18:20:28

Re: Baxter mines and the nitrogen problem

#11 2012-12-26 20:05:12

Re: Baxter mines and the nitrogen problem

#12 2012-12-27 00:13:57

Re: Baxter mines and the nitrogen problem

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