Opinions on My Terraformed Mars texture

Impulseman · 2007-05-27 23:10:24

Hello everyone,

I am new here and would like to get some input on a Terraformed Mars texture I creating for the space simulator Celestia. I have been a texture artist and creator in that community for over five years now. I started this texture over a year ago and it’s just now coming into the final stretches. A few questions had been raised as to what the weather patterns would be like on a terraformed Mars. So I decided to start and search for information to integrate into the texture. This is what the texture looks like at this point with and without clouds and rendered in 3D in Celestia.

This texture is of a Mars in a very advanced form of development, with a higher than average sea level, anad an atmosphere art about 2.5 bars at sea level.

The main thing I am trying to find out is if anyone has done in modeling on how the weather patterns on a Terraformed Mars would work. Mainly I am centered on hadley, ferris, and polar cells. I do know that they are created by the Coriolis Effect. I also know that the denser or thicker the atmosphere, the more of these cells are expected. But I also know that a planets size would also come into play. On Earth there are a total of six cells, three in the northern hemisphere and three in the southern. Theoretically if Earth atmosphere was two to three times thinker the number of cells would increase as well. So taking this into account, and scaling this to a planet the size of Mars, that would possibly bring the count of hadley, ferris, and polar cells back to the same count as the Earth. So again has anyone modeled this in anyway? Any information would help and any comments on the texture are welcome.

Thanks in advance and thank you Spatula for the welcome in another thread.

Spatula · 2007-05-28 11:38:28

Note that clouds would move around the tall volcanoes, since they're lower. I wouldn't rule out ice on them of some sort. Water would definitely be able to perform deposition into ice at those temperatures and pressures, even if they're too high to experience liquid water.

The poles would also have a very substantial amount of ice on them.

Cold planet, Mars. Not as comfortable as Earth, but a lot of comfort can be lost before you reach inhospitable levels.

Impulseman · 2007-05-28 16:06:07

Do we know how much moisture the atmsphere would be holding at those elevations. I was figuring that it would be fairly dry at those altitudes, but of course I may wrong. I had made and earlier render were I had all the mons burried under ice caps. If it is posible for moisture or ice to be at these elevation, than I may reintroduce the ice caps, of course we loose the great volcanoes as interesting feature as they will be burried.

Spatula · 2007-05-28 18:44:34

Well, Mars currently has an atmosphere thousandths of times as thick as Earth, and it manages to have water ice in large quantities deposited onto the surface. This ice moves each year, depending on the local weather.

Seems like the same mechanisms could cause ice formation from sublimation/deposition on the mountaintops.

And I think you'd still see the topography. Sunlit sides of the mountains would have no ice, for instance. Shadows or twilight would allow ice to collect.

nickname · 2007-05-28 19:41:16

spatula,

Very well though out.
I had to think about your ideas of the shadows for a bit on the volcanos.
I think your are correct in the ice formation and sunlight properties on such tall natural structures on Mars.
What an amazing sundial they would be

Now will a terra formed Mars have blue oceans and dark blue sky?
My guess is reddish oceans due to so much iron oxide on the surface, and light blue skies less well lit than Earth. ?

nickname · 2007-05-28 19:44:37

Impulseman,

Nice work on both pictures

Spatula · 2007-05-28 22:27:44

It is a bit confusing just to think about how this atmosphere would work. Earthlike temperatures and chemistries, but under a third of the gravity. On Venus we can expect pretty similar stuff to happen, but with small planets like Mars?

Maybe we're all wrong and clouds and currents would form completely differently.

The pressure would be the same as on corresponding altitudes on Earth, but the actual density of a cubic meter of air would be higher. Would this affect water chemistry? Would this affect altitude temperatures? I don't know.

Impulseman · 2007-05-28 23:33:56

This is what I do know at this point. Mars at its present time has two hadley cells, one in the northern hemisphere and one in the southern hemisphere. These cells are what are responsible for moving moisture from the equatorial zones up to the polar zones and depositing it as ice. These hadley cells are driven by the coriolis effect as the planet’s rotation is dragging the atmosphere with as it rotates. On Earth, the thinker atmosphere breaks these cells into more cells that rotate in opposite directions. I believe we would see the same effect on Mars, equatorial air flowing westward and temperate zones flowing eastward, and the polar turning westward again. I know this is starting to get into some serious system dynamics here. But I am trying to take all this into consideration in the process.

About the images, they are not just pictures; they are actual screen captures of a fully 3D globe with this Mars texture working in real-time. Here is another example.

Thanks for your time.

noosfractal · 2007-05-29 00:49:02

Hi Impulseman, these are some very wonderful visualizations - thank you for making them. It is hypercool that you are thinking about Hadley cells and the like. Unfortunately I think you are a little ahead of the curve here I'll offer my guesses, but I think you need a Mars global climate model to get good answers.

I think the thicker atmosphere (x2.6) and lower gravity (x1/2.6) balance each other out to leave the lower solar radiance (~45%) as the main thing we have to account for when looking at the poleward rotation. I think less driving energy means the loops will be larger and slower. So the Ferrel cell would be smaller if it exists at all (may be push the lower latitude from 30 to 35 or 40). Even on Earth the Ferrel cell is more of a mixing area than a well defined rotation. Slower poleward rotation means lower Coriolis effect (Mars rotates at about the same rate as Earth), so the "trade winds" and the "jet streams" will be slower as well - so bigger loops in the East-West direction as well.

If you are going to get into circulation models, you might also want to think about ocean currents, which have a fairly large effect on climate on Earth.

If your coding skills are up to it, EdGCM ( http://edgcm.columbia.edu/ ) has code and basic maps for Mars ( http://dev.edgcm.columbia.edu/browser/MarsGCM ) but you would have to alter things for the terraformed world.

Antius · 2007-05-29 05:34:13

Looks wonderful.

But 2.5 bars at sea level? On Mars, that equates to an atmospheric column density 6.5 times that of Earth. Where do you plan to get that much gas? Bearing in mind that most of it cannot be oxygen.

Spatula · 2007-05-29 11:16:10

Nitrogen, and getting it will be one of the most difficult, expensive accomplishments in our little terraforming brigade. I actually don't know how to get that much. A small amount will come from Mars.

dryson · 2007-06-16 18:16:07

A terraformed Mars would be a totally different planet then what it is now.
All the old notions of how Martian weather would be would be gone. We know that Earth is habitable because of the ozone layer that protects us from the suns UV rays. With atmopshere on Mars the ozone layer would also at the same trap the gases like it does here on earth effectively changing everything.

I was recently watching a special on The History Channel about Mars and the polar caps. If what is specualated about Mars' polar caps having hydrogen, and the other elements that make water, which when
coupled with the process of trees taking in carbon dioxide that produces sugar or energy along with creating oxygen which every lifeform as we know it needs in order to survive can show that by just taking maybe o
ne hundred tree saplings to Mars planting them close to the close the polar caps may initate the process of producing a breatheable atmosphere like that of Earth. Of course irrigation would have to either be
designed and taken to Mars along with some glacial water, why glacial water, because glacial water contains microbes that survive in that type of environment and would help in the growth of the trees.
Or irrigation could be designed to melt and would then be pumped from the Martian polar ice/water caps to the roots of the tree. The upside to this expieriment could possibly see the trees grow at a very
rapid state given that trees thrive on carbon dioxide and produce oxygen. Perhaps this is why the Redwoods in California grow like they do and are so enormous, they may have been the first trees to clean the
atmosphere of CO2 thus making oxygen that other lifeforms grew from. The down side is the PH level of the Martian soil, but the upside to this is when the glacial ice water along with the microbes and the
trees interact together the PH level may possibly be changed to suit the needs of the growing trees and microbes. The only way to find out is by conducting the expierement on Mars.

Try adding various species of trees to your model ranging from one too 1000 year old trees. This along with varrying heights of the trees will make for a very different weather pattern.

Spatula · 2007-06-16 20:01:41

Speaking of Nitrogen, I actually did think of a way to get large amounts of Nitrogen to Mars finally.

There are a lot of TNOs that should have a high percentage of Nitrogen frozen throughout them. That part of the solar system is cold enough to keep the room temperature gas locked in solid form. Redirect the most Nitrogen rich comets on a trajectory that crashes them into Mars. This has to be done quickly, of course, since they'll leak gas all the way over.

StarDreamer · 2007-06-17 09:21:57

Dryson;

The wrench in this idea of trees on Mars is the temperature -- about 80 below in most places at least at night. So I don't think sequoias or dawn redwoods will do well there. We will have to be very selective about which trees we take -- just Antarctic species, zone Zero-A.

Trees depend on water. If the water freezes, the tree dies. Sugars can change the freezing point of water, but not enough to permit life on Mars. Also, no soil -- the "soil" on Mars is inorganic. Really just pulverised beach sand, like the Sahara.

I wonder if you could catch CO2 in the liquid state between solid and gas and then dissolve sugars into the liquid CO2, to change its triple point curve and allow it to remain liquid in the veins of trees -- CO2 sap.

dryson · 2007-06-17 10:56:00

Dryson;
The wrench in this idea of trees on Mars is the temperature -- about 80 below in most places at least at night. So I don't think sequoias or dawn redwoods will do well there. We will have to be very selective about which trees we take -- just Antarctic species, zone Zero-A.
Trees depend on water. If the water freezes, the tree dies. Sugars can change the freezing point of water, but not enough to permit life on Mars. Also, no soil -- the "soil" on Mars is inorganic. Really just pulverised beach sand, like the Sahara.
I wonder if you could catch CO2 in the liquid state between solid and gas and then dissolve sugars into the liquid CO2, to change its triple point curve and allow it to remain liquid in the veins of trees -- CO2 sap.

Trees would have an impact on the temperature of the entire planet, we know that trees produce oxygen that when the oxygen mixes with the other gases of Earth they form ozone which protects us from UV rays that would otherwise turn the planet into a mars like surface, the ozone also acts like a thermal insulator that traps the gases and keeps them from dissapating into space. If there are not any trees then there are not any water producing clouds, if there are not any water producing clouds then there are not any trees, they go hand in hand in the regenerating cycle.

Yes the surface is like the Sahara, so too was this planets soil at one time as well. Try this notion on soil making. We know that when something alive dies bacteria feed on this decay, whether it be wood, leaves, flesh, ect. The microbes break the cellular structure down until any organice material is gone. The microbes then evolve and wait unitl their next meal, gross isn't? it As these microbes begin to die theirself they leave behind their own orgainc mixture of their cellular structure along with what they have diggested and left as waste, this waste has moisture in it or small amounts of carbon and H2O. If this mixture now becoming a layer of soil is able to retain it's moisture then eventually other microbes will feed off of this waste which will spwan other microbes that will have adapted to the environment, Each generation of microbial that is born and then dies builds upon the last generation thus eventually creating a layer of soil that
has nutrients in it to support a tree. When this tree dies and falls over the process is started all over again until you have a planet like Earth, this process would not happen overnight but could take thousands of years to complete. Eventually the sand like surface would be covered by microbes living and dying, compound upon compound, pressure then diamonds and other materials like oil and methane gases are formed, anyway,the only problem is if the soil loses the moisture then what is left is the cellular structure of the microbes compressed into tiny grains of sand. Ths is how an uncontrolled planet would evolve.

But as humans we could erect greenhouses dig out maybe 20 by 100 feet area of Martian soil replace it with good old decaying compost, layer the compost with the Martian soil, too much nitrogen in the compost will burn young roots of the tree, water the trees, allow some of the Martian atmosphere in and then release the oxygen back into the atmosphere.

I did an expieriment like this when I was yonger and lived on a farm, I took a clear two litter Pepsi bottle and a green two litter Mt. Dew bottle, the ones that had the plastic base to them that was glued to the bottom, I cut the base off filled that base with nothing but soil, I didnt add any seeds or nutrients, I then took the top portion of the bottle and duct taped it to the base, i screwed the cap on as tight as i could get it. I then set them on the window ledge and about three weeks later grass had started to grow. I never added water but the gases that were trapped inside from the decaying material coupled with the suns UV rays created moisture that ran down the side of the bottle that kept the moisture moist. In a few weeks the first signs of growth were creeping out of the soil. Grass. What was interesting as well was the Mt Dew bottle produced a greener grass.

As Einstein said it's all relative, not relative like that but relative.

StarDreamer · 2007-06-17 16:45:23

Dryson;

We all understand how an ecosystem works.

How do you propose to keep your stand of 100 trees alive for 10000yrs while they make oxygen? The problem is not the chemical process. The problem is the scale of the project and the vast distances involved.

Planetary climates have equilibria. Earth's equilibrium is friendly to the life which has evolved here and the life which has evolved here has in no small way contributed to establishing this equilibrium. But Earth has been in other equilibria in the past, including a snowball phase of global ice and tropical phase of frost-free polar regions. Earth may revisit either of these in the future. Venus is resting at an equilibrium as well and it will take a tremendous, stupendous effort to push the planet out of that equilibrium and into a new one. Same for Mars -- it is in an equilibrium state. The gasses which could benefit its climate are locked in ice and soils. The planet can only warm up by the release of those gasses and those gasses shall never be released so long as the planet remains cold. Absence of liquid water deters life; absence of life deters elemental cycles; absence of elemental cycles of oxygen and carbon and water caps potential for change and so forth. It is both a vicious circle and a virtuous circle -- virtuous from its own point of view because it is content to be as it is (it is in equilibrium), but vicious from our point of view, simply because it is not as we would like it to be. But that is our problem, not Mars' problem.

In a nutshell, it is a "chicken and egg" problem and it cannot be so easily reduced to such a simple solution. Which is the chicken and which is the egg? I don't think we have even gotten so far as that.

dryson · 2007-06-18 19:36:20

First you need to let your notions of what you know go. Microbials that formed somehow after the planet cooled is what created life on this planet,
Once these microbials are introduced into an environment like Mars, either a rapid change or a slow change will take place. Grass and trees would not springup over night. The first part of the expieriment would have saplings placed in containers that after the Martian soil had been
conditoned with earthen compost and a underground irrigation system installed to provide water that the roots of the trees would burrow into the soil to get to a change would take place. After about a three months the containers would then be removed to see how the saplings would interact with the Martian atmosphere.

Orginisms within the soil and water would most likely change very rapidly due to their single cell structure. This when coupled with the microbes that may be in the soil wil also cause a change. I call this evolutionary adaptation - whereby a single celled orginism when introduced into an unfamiliar environment changes its cellular composition to adapt and survive in it's new environment.

If the same procees of photosynthesis begins to occure then the trees will begin to produce oxygen which would then combine with the other gases in the atmosphere creating another change until an ozone is formed which would then trap heat that would then spur the growth rate of the saplings that much more, it would probably take more then a hundred saplings, probably more like a million, the 100 was just a number thrown out there.

The second part of the expieriment would have greenhouses established around the planet that would grow saplings and other oxygen producing greenery. As the greenhouses become overcrowed new greenhouses would be built transfering new saplings to other areas of Mars. When enough of Mars had been covered with greenhouses the oxygen that would have been gathered into storage tanks would then be released into the atmosphere, most likely causing a near instant reaction within the Martian atmosphere. The only difference between number one and two would be that number two would have more earthen soil and compost mixed together

It's starting to sound like you are just trying to throw other connatations
out there to make it sound like you are informed.

Like I said I lived on a farm and have done numerous expieriements along this line of creating an ecosystem in a bottle. I suggest you study a little more. Not to be mean.

StarDreamer · 2007-06-18 21:30:30

Dryson;
Way up in northern Canada, there's this line on the maps called "the tree line". The tree line marks the boundary of the tree form of vegetation. It is a real line. You can walk right up to it and see trees here, no trees there. And the trees that subsist on the tree side of the tree line? For the first few miles, they are not very impressive trees -- stunted, twisted, misshapen by the wind, tortured and very very very slow growing. Nature's bonsai. You can see the tree line on the slopes of high mountains too. The Alps have a tree line -- I have crossed this line in Switzerland and seen it. The Rockies also have a tree line.

Okay. Mars is absolutely wholly and completely 100% no exceptions NORTH of this tree line. Which would be the wrong side of the line for your purposes. Which is why we cannot turn life loose on Mars and not expect it to all freeze stiff inside of two minutes.

But let's talk about this. How about lichens?
See: http://en.wikipedia.org/wiki/Lichen

Lichens are often the first to settle in places lacking soil, constituting the sole vegetation in some extreme environments such as those found at high mountain elevations and at high latitudes. Some survive in the tough conditions of deserts, and others on frozen soil of the arctic regions. Recent ESA research shows that lichen can even endure extended exposure to space. Some lichens have the aspect of leaves (foliose lichens); others cover the substratum like a crust (crustose lichens); others adopt shrubby forms (fruticose lichens); and there are gelatinous lichens.
The European Space Agency has discovered that lichens can survive unprotected in space. In an experiment led by Leopoldo Sancho from the Complutense University of Madrid, two species of lichen – Rhizocarpon geographicum and Xanthoria elegans – were sealed in a capsule and launched on a Russian Soyuz rocket on 31 May 2005. Once in orbit the capsules were opened and the lichens were directly exposed to the vacuum of space with its widely fluctuating temperatures and cosmic radiation. After 15 days the lichens were brought back to earth and were found to be in full health with no discernible damage from their time in orbit.

Okay, so this looks very encouraging. It may indeed be possible for lichens to survive on Mars and lichens are a symbiosis of fungi and algae. But "survive" is not "flourish". Even in the Arctic, it takes a lichen colony a good 100yrs to cover over a decent-sized rock. So a lichen colony on Mars would need centuries and centuries to register any lasting change in its environment. Unless we propose to send several tonnes of lichen to Mars every year for 100yrs.

RobertDyck · 2007-06-24 11:35:03

It's all about water and temperature. The ground penetrating radar on Mars Express found a polar ice cap under the dirt at the south pole. In places it's 3.7km deep.
Mars Express radar gauges water quantity around Mars’ south pole - 15 March 2007

The amount of water trapped in frozen layers over Mars' south polar region is equivalent to a liquid layer about 11 metres deep covering the planet.

Of course it would flow down hill, not spread evenly. This looks like enough to fill the ancient ocean basin in the north.

Furthermore the atmospheric pressure on Mars is governed by the winter pole; south half of the Martian year, north the other half. Air pressure is the equilibrium between CO2 gas and dry ice at the cold pole. Every spring the dry ice completely sublimates and re-freezes at the opposite pole; which of course is having autumn. If you warm both poles at once above the sublimation temperature of CO2, it will significantly increase air pressure. Furthermore many people believe there is dry ice adsorbed onto soil particles below the surface. "Adsorb" means accumulating on the surface of particles, not soaked in. If you warm the deep soil above sublimation temperature then that CO2 will be released as well. Will it increase surface pressure above 170 millibars, at least at the bottoms of valleys? I think so, but until we have a measure of the CO2 budget of Mars it's only a guess. That pressure is sufficient that those who spend weeks in high altitude training can breathe pure oxygen, so you can go outside wearing nothing but warm winter clothing and an oxygen mask. Actually I suspect there's enough CO2 to raise the pressure well above 170 millibars. Also remember the hypobaric chamber plant experiments done by Guelph University; they found plants can grow in pressures as low as 10 kPa (100 millibars), as long as they have plenty of water. Below that pressure they wilt, but perk-up when pressure is restored. In fact, they found plant growth rate does not slow with reduced pressure. Again, as long as you provide plenty of water; the lower the pressure the more water they need. Their intention was to demonstrate a greenhouse on Mars could endure pressure loss, the plants would revive as soon as pressure is restored. In a greenhouse any water transpired through leaves will condense on the walls and run back down into soil trays, so water isn't a concern. Outside water will be a concern, but an ocean will certainly go a long way.

So the conclusion to all this is how much heat can you provide? The tree line in Canada is dictated by water and temperature. Actually the tree line angles north along the Mackenzie River valley, all the way to the Arctic Ocean. Further east in Nunavut territory there's almost no trees. Heat will cause ocean water to evaporate, causing rain clouds. Rain will transport water in land. Again this comes back to the same conclusion: how much heat?

RobertDyck · 2007-06-24 11:38:28

Oh, your texture shows the ocean wrapping around Mars, extending to the south. Mars has an ocean basin the north, but the south has high altitude. Don't expect continents on Mars, instead a single ocean basin with the rest of the planet as land. There will be lakes, especially in craters. Hellas Basin will form a sea at its bottom.

Other than that, great job! I could never do art work like that.

Impulseman · 2007-06-24 18:00:00

Actualy I don't have the oceans reaching all the way down as seen here.

I did elevate the water level of the oceans a bit, taking into consideration that other sources of water could be found, like comets and asteroids.

RobertDyck · 2007-06-24 20:34:37

There's so much water that now the only reason to look for comets or ice asteroids is for nitrogen. Mars Sojourner didn't find any nitrogen in the soil, and the atmosphere consists of only 2.7% nitrogen with a pressure that hovers around 7 millibars. I haven't heard Spirit or Opportunity finding any soil nitrates either, but they've made a lot of discoveries. I suspect there's nitrate deposits in the soil somewhere, we just haven't found them yet. I came up with a hypothesis that soil nitrogen is in the form of alkali metal nitrides such as sodium nitride. If water touches that it will decompose into sodium oxide and ammonia. Mars Express found traces of ammonia in the atmosphere, this is my idea of where it comes from. This would mean that soil close to the surface where heat from the sun can melt permafrost will release water that decomposes that nitride. That's why nitrides are deep below the surface. It may be wishful thinking but it does explain the ammonia.

So, how would your texture be affected by adjusting water for only what's there? No comets or asteroids?

Ps. Your topography map looks great, but your images in the first post still look like there's an edge of an ocean on the left and right limbs of the planet in the southern hemisphere. The atmosphere is a thin line, not broad blue like you drew it. That's my only criticism. Other than that it's great.

nickname · 2007-06-25 05:45:39

I'm still wondering if water will be blue at all on Mars.

So much free iron oxide all over the place leaching into the water should make for rusty red/brown water.

The reflection of those water bodies should also alter the color of the sky to a pinkish or purple color.
Similar to the color we see today on Mars from the surface reflection.

I don't think a terraformed Mars will look much like Earth at all.

Swimming in reddish water as the sunset changes the pink/blue sky to purple sounds very unusual though

Impulseman · 2007-06-25 11:46:20

RobertDyck,

The images I first posted are screencaps of what this texture looks like in the space simulator Celestia. What you are seeing is the atmosphere and the effect of how it scatters light in a think Martian atmosphere. This is all being done in 3D in realtime. I only used Photoshop to crop and resize the screen captures. These atmospheric effects are coded into the program for acuracy, so what you are seeing is pretty darn close to what Mars atmosphere would look like f it were 2.5 times of what it is here on Earth, and made of the same gases. If I took a few screen captures of the Earth with the same settings what you would see is just about what it looks like from orbit in real life. Thats how acurate the program is, for the most part. Of course nothing is perfect.
As for water level, I have several earlier textures that have the water level set at what is expected to be the average. In my own mind I chose to raise the water level for the main reason is the water makes a great heat sink. The more you have the more heat it can store for later needs and weather tuning. Earth is covered with over 75% water. To make Mars more like Earth I went for larger oceans as well. More water has many other benifits as well. But I am not a climatologist so I don't have all the details.

nickname,

I believe you are right about the water color, at least early on in the process. The water would probably be stained by all the iron oxied. But this is a full blown, fully terraformed Mars of lets say at least 50,000 years in the future. By that time bacteria, and other life forms, and other weathering processes would have washed most of the iron oxide away and tranformed the oceans into rich bio deverse habitats. All that iron oxide would have been consume very early on by transplanted plankton. So the seas would have gone from brown to green in probably a very short time. While vegitation on the land would be locking the rest away in the soil as it formed. So really having blue/green oceans some 50,000 years in the future is very much a posibility. It all depends on how far our technology goes an how fast we can get the process started.

And actualy a fully terraformed Mars would probably look very diferent from Earth simply by the way the land and seas are laid out. But life would make it look very similar in many ways. That is were this texture comes into play, the total end product.

RobertDyck · 2007-06-26 00:31:27

Hmm, thanks for pointing out the 2.5 bar atmosphere. I doubt there's enough gas on Mars to do that.

Earth at one time had a thick CO2 atmosphere like Venus, but CO2 dissolved in the ocean where it combined with dissolved calcium to form calcium carbonate. Precipitated calcium carbonate formed limestone. When CO2 dissolves it forms carbonate ion, CO3 with a charge of -2. The extra oxygen comes from water; normally water is in balance between H2O and ions of H+ an OH-. Carbonate will take the O from OH- to release another H+ ion, leaving 2 of them. This makes water slightly acidic. Igneous rock with plagioclase feldspar will weather via moving water into clay, releasing calcium, magnesium and iron. Since these are released via water, they will form oxides. Calcium oxide will combine with carbonate to form calcite: CaCO3. If there's also magnesium oxide in the water it will form dolomite: CaMg(CO3)2. Calcite and dolomite will precipitate to form limestone. There's very little plagioclase feldspar left on Earth, but it's predominant on Mars.

To terraform Mars we want to keep atmospheric pressure. We don't want to weather plagioclase feldspar into clay and limestone; that would sequester CO2. Clay also consumes water; how much water do we have to work with? But plants will convert CO2 into O2, the formula is:
6 CO2 + 6 H2O -> 6 O2 + C6H12O6
That last molecule is a simple sugar, a monosaccharide. This will polymerize to form polysaccharides such as pectin, starch, cellulose, lignin or hemicellulose. One H is released from one monosaccharide, one OH from the other forming a water molecule. The overall reaction to form cellulose is:
6n CO2 + 5n H2O -> 6n O2 + (C6H10O5)n

The reason I point this out is that forming an oxygen atmosphere with plants will convert CO2 into O2 on a 1:1 molecular ratio. Ideal gas law dictates that pressure is determined by heat, volume and number of molecules. With the ability to expand indefinitely into space, gravity is the determinant instead of volume. But you still get the same pressure regardless how much CO2 you convert into O2.

We do want an atmosphere with substantial O2 for a couple reasons. UV light interacts with O2 to form O3 (ozone). Ozone will absorb UV, breaking it down into O2. As long as you don't do anything to destroy ozone in the upper atmosphere, expect an equilibrium that leaves the same UV intensity at the surface as on Earth.

As for nitrogen, unless we find dramatic soil nitrate deposits we won't be able to afford a nitrogen atmosphere. Even moderate nitrate deposits will have to be left as nitrate, spread on farm fields as fertilizer. We need enough to get into plants for a thriving ecosphere, not lazing about in the upper atmosphere.

Ever read the text book "Terraforming: Engineering Planetary Environments" written by Martyn J. Fogg? I have it on my bookshelf. He calls for several massive chemical plants releasing industrial quantities of greenhouse gas to warm Mars. He explained CFCs are not a good idea because they destroy ozone, but PFCs and SF6 would work quite well. He numerically calculates like final atmospheric pressures. I'll have to read it again, but the problem is estimating how much CO2 we have to work with.

One point in that book is the likely soil nitrogen compounds: soda-nitre (NaNO3) and saltpetre (KNO3). These are both alkali metal nitrates. Reduction will form nitride. Experiments have shown current conditions on Mars will form superoxides from basalt, will they reduce nitrates? I'm again looking for the source of ammonia. I think measuring the concentration of ammonia will let you trace the origin, and that will pin point a nitrogen compound deposit in the soil.

So, back to the original question, how much atmosphere. According to table 6.1 in that book, the atmosphere contains ~7 mbar pressure, polar caps <a few mbar, adsorbed in regolith <280 mbar by Fanale et al. or <190 mbar by Zent et al. If we use the lower estimate of regolith adsorbed in the soil we get a total of 197 mbar surface pressure. Remember I said we need a minimum of 170 mbar pressure for humans to breathe. There's a long discussion of nuclear mining to break-down rock minerals to release CO2 and O2, but I wouldn't count on those; too expensive and too much chance of releasing toxic gasses. This book also claims 10 mbar partial pressure of CO2 is the toxic limit. If we form perfluorocarbons such as CF4, C2F6, C3F8, etc. from carbonate minerals and fluorine minerals then we can really produce an atmosphere. But notice the total pressure is roughly 197 mbar, not 2.5 bar.

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#1 2007-05-27 23:10:24

Re: Opinions on My Terraformed Mars texture

#2 2007-05-28 11:38:28

Re: Opinions on My Terraformed Mars texture

#3 2007-05-28 16:06:07

Re: Opinions on My Terraformed Mars texture

#4 2007-05-28 18:44:34

Re: Opinions on My Terraformed Mars texture

#5 2007-05-28 19:41:16

Re: Opinions on My Terraformed Mars texture

#6 2007-05-28 19:44:37

Re: Opinions on My Terraformed Mars texture

#7 2007-05-28 22:27:44

Re: Opinions on My Terraformed Mars texture

#8 2007-05-28 23:33:56

Re: Opinions on My Terraformed Mars texture

#9 2007-05-29 00:49:02

Re: Opinions on My Terraformed Mars texture

#10 2007-05-29 05:34:13

Re: Opinions on My Terraformed Mars texture

#11 2007-05-29 11:16:10

Re: Opinions on My Terraformed Mars texture

#12 2007-06-16 18:16:07

Re: Opinions on My Terraformed Mars texture

#13 2007-06-16 20:01:41

Re: Opinions on My Terraformed Mars texture

#14 2007-06-17 09:21:57

Re: Opinions on My Terraformed Mars texture

#15 2007-06-17 10:56:00

Re: Opinions on My Terraformed Mars texture

#16 2007-06-17 16:45:23

Re: Opinions on My Terraformed Mars texture

#17 2007-06-18 19:36:20

Re: Opinions on My Terraformed Mars texture

#18 2007-06-18 21:30:30

Re: Opinions on My Terraformed Mars texture

#19 2007-06-24 11:35:03

Re: Opinions on My Terraformed Mars texture

#20 2007-06-24 11:38:28

Re: Opinions on My Terraformed Mars texture

#21 2007-06-24 18:00:00

Re: Opinions on My Terraformed Mars texture

#22 2007-06-24 20:34:37

Re: Opinions on My Terraformed Mars texture

#23 2007-06-25 05:45:39

Re: Opinions on My Terraformed Mars texture

#24 2007-06-25 11:46:20

Re: Opinions on My Terraformed Mars texture

#25 2007-06-26 00:31:27

Re: Opinions on My Terraformed Mars texture

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