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The question is, how much nitrogen is actually needed for nitrogen fixing bacteria to work within soil?
Hi Antius,
I've found that a partial pressure of 0.5 kPa (5 mBar) is sufficient for plants to fix nitrogen (actually the bacteria in their roots of course).
I am working on the UV problem right now...from some preliminary models it looks like an early 100 mbar CO2 with only slightly enhanced oxygen levels would produce a significant ozone layer. I can't say much quantitative at the moment since I'm still working on the model, but I'll post data if/when anything comes of it.
Hi Midoshi,
I don't like to clutter up the threads with 'nice post' posts, but again I thank you for your research in finding hard to find data. (In this case finding the O2 levels needed by mosses.)
On ozone levels, Fogg in his Terraforming text says:
Joel Levine and colleagues and a group heading by James Kasting have modeled the problem and their calculations suggest that a functional ozone layer could exist at 10% the present atmospheric level of oxygen...
... Thus we might assume that the complete protection from ultraviolet light requires a column mass of O2 equivalent to ~20 mBaron the Earth (0.1 PAL); satisfactory protection from most wavelengths is possible down to a terrestrial column mass of O2 equivalent to ~2 mBar (0.01 PAL). ...
PAL = present atmospheric level (PAL) <Thanks to Midoshi for the correction.>
A bit earlier in the discussion of ozone and UV light he points out that at minimum levels of O2 we would have O3 forming near the ground which is very harmful to life. Likely we will have to depend on aquatic plants to push the partial pressure of O2 high enough that the O3 will form high enough in the air to avoid oxidizing ground level plants. Mars' higher scale height will help us here. (Ozone that forms high in the atmosphere is further away from the ground than the ozone layer is on Earth.)
See also:
Levine, J.S., Boughner, R.E. and Smith, K.A. "Ozone, Ultraviolet Flux and Temperature o fthe Paleoatmosphere," Origins of Life, vol 10, 199 to 213, 1980.
Kasting, J.F., Holland, H.D. and Pinto, J.P., "Oxidant Abundances in Rainwater and the Evolution of Atmospheric Oxygen," J. Geophys. Res., vol 90, 10,497 to 10,510, 1985.
Warm regards, Rick.
I have to make a correction. I keep running into people who claim terraforming can't be done, it's too difficult. Within the Mars Society many people claim terraforming Venus can't be done, or at best is very difficult. Both statements are untrue. Terraforming is a big job, but can be done. Venus does have water, not as much as we would like but its cloud layer is entirely water. Terraforming Venus is the reverse of terraforming Mars in several key areas: Mars requires mechanical/chemical means, Venus requires biological technology.
...
Hi Robert.
Venus' atmosphere has:
CO2...........96.3 %
N2.............03.5 %
SO2...........~150 ppm (parts per million)
H2O...........~100 ppm
Ar..............~100 ppm
COS...........<40 ppm
H2S............<40 ppm
O2..............<30 ppm
H2..............<25 ppm
CO..............~30 ppm
Ne..............~14 ppm
He..............~12 ppm
Kr...............~1.5 ppm
HCl.............~0.4 ppm
HF...............~5 parts per billion
There are strong indications that there were massive volcanic resurfacing of Venus 500 million years ago with much vulcanism since then. Given this, the tiny amount of water remaining now is disturbing. (On Earth volcanic gasses are typcially 75% water.) If all the water on Venus were to condence on the surface the water would only be ~5cm giving it even less water than Mars.
The clouds are made up of aerosol particles <10 micrometers in diameter of sulfuric acid 85% pure by weight.
"Sulfuric acid is generated photo-chemically, starting with the action of ultraviolet radiation on sulfur dioxide above the clouds (a simular proces converts SO2 to H2SO4 on Earth - See equations 4.11). It then becomes incorported in aerosol droplets which, after about a year, sink to the base of the cloud layer where they evoporate. Ultimately the heat of the lower atmosphere dissociates H2SO4 to SO3, which then undergoes thermochemical reduction by reacting witht eh CO back to SO2. The Venusian clouds are maintined in a dynamic, sulfur - cycling steady state and have little in common with terrestrial clouds, being more akin to photochemical smog in mode of formation and composition."
As for seeding the atmosphere with algea, there are many problems with this.
-- First, we know of no cyanobacteria that can live in sulfuric acid.
-- Second we know of no cyanobacteria that can live in the upper atmosphere (or indeed have positive boyancy).
-- Third, the upper atmosphere is totally lacking in Sodium, Magnesium, Potassium, Calcium, Phosphorus, Selenium, Iron, Copper, Zinc, Iodine and many other trace elements needed to form cells. (This is the same reason why it is unlikely we will find life floating in Jupiter's atmosphere.)
-- Fourth, all known life requires liquid water. None (I know of) grows in micrometer (which are smaller than bacteria) sized droplets of water (let alone concentrated sulfuric acid).
If you postulate engineering magical nano-tech you can do anything. If you postulate engineering magical blue green algae you can also do anything.
In my judgment, creating a new species that have the properties that I've listed above can't be done or (at a VERY generous best) is very difficult. Note that the engineering techniques discussed for terraforming Mars do not require the wholesale creation of wildly unique species. Or if that you postulate the ability to gene-engineer your Venus bacteria why not say that Mars is trivial to terraform by creating psychrophilic, hypobaric bacteria that produce PFC's? THAT is an easier species to create and Mars already has water.
My data comes from:
- "Terraforming: Engineering Planetary Environments" by Martyn J. Fogg and "Moons and Planets" by William K. Hartmann.
- "Extremophiles for Ecopoiesis: Desirable Traits for and Survivability of Pioneer Martian Organisms" by David J Thomas, et all (7 authors).
I feel that the very brief summary that I gave in the FAQ was fair. If you wish to argue these points further, the posts should likely be moved into the Venus thread.
Warm regards, Rick.
1/2 the light on Mars =1/3 the growth rate. ...
This is not at all what I understand. There are two types of plants, the C3 and C4 plants (refering to the chemical path followed by the carbon atom in photosynthesis.)
There are about 300,000 species of C3 plants with only ~3,000 species using C4 photosynthesis. The C4 plants are newcomers (mostly grasses but including sugar cane and maize).
If you plot the rate of photosynthesis to CO2 level, you find that as you raise the amount of light at a given CO2 level, the growth rate rapidly flattens out. This point is called the light saturation which begins at >200 micro moles of photons / m^2 / second.
TABLE OF INCREASING LIGHT LEVELS AND CO2 UPTAKE
..........................Light Level
..........................100.........200..........300..........400........500........1000.......1500.........2000
C3 Plant uptake:....4..............7............8..............9...........9.5.........10............10.............10
C4 Plant uptake:....3..............7..........10.............15...........20.........35............42.............47
Light levels measured in micromoles of photons /m^2/s of Photosynthetically Active Radiation (PAR)
CO2 uptake measured in micomoles of CO2 / m^2/s.
By the way, the levels reach about 2000 micromole/m^2/s of PAR photons on the Earth's surface.
Note that at higher CO2 levels, the C3 plants close much the gap between them and the C3 plants.
(This data comes from page 103 of Terraforming by Fogg and I am reading the values off of a graph with out a grid so the values are a bit approximate.)
Anyway, at about 1/4 Earth's light levels, C3 plants have maxed out their growth. C4 plants do much better but even they grow more slowly as you increase the light level.
In fact many C4 plants have light colored leaves to reduce the amount of light absorbed (and heat). The light level does not matter to them; it is the CO2 level that limits their growth.
So to first and second approximation it would be more correct to say, 1/2 the light = 100% of the growth. (At least for C3 plants.) In the asteroids the light should still be enough. At Jupiter orbit your plants are beginning to starve for light and would grow faster with more.
Warm regards, Rick.
Hi Midoshi,
Wow, what a great post. I always enjoy reading your stuff.
You were talking about the UV protection of water but there is likely to be a thin layer of ice on things much of the time in the early days of terraforming. Some times the electromagnetic radiation transmission thru a crystal is much different from that thru the same substance as a liquid.
I was wondering if water ice gives more or less protection to UV and water? Does anyone know?
Warm regards, Rick.
This post is a stub for now. I did some research trying to find a list of all the minerals found so far on Mars and this information is very hard to find. I'll improve this as I get more time. So far I've got...
# anorthite (CaAl2 Si2 O8 )
# ilmenite (FeTiO3)
# goethite (iron III hydroxyoxide)
# gypsum (calcium sulfate dihydrate) - depending upon the amount of moisture in the immediate Martian atmosphere, the Martian "gypsum" may be bassanite, a "partially dehydrated gypsum" or even anhydrite (anhydrous calcium sulfate)
# hematite (iron III oxide)
# jarosite (iron III potassium hyroxysulfate)
# kieserite (magnesium sulfate monohydrate)
# maghemite (iron III oxide)
# olivine (jewelry's peridot) (the midmember of the fayalite-forsterite iron magnesium silicate series)
# pyroxenes (mineral group)
# jarosite
# alumina (Al2O3)
# silicon dioxide (SiO2)
Hi Robert,
In "Mars a Warmer Wetter Planet" by Jeffrey S. Kargel he makes a strong case for CO2 clathrates existing on Mars. (A clathrate is when ice's crystal structure incorporates CO2.) This is good (Mars' CO2 reservers are higher) and bad (it is a lot harder to get at this CO2 than if it was dry ice at the south pole).
He argues that Mars is a planet that's history has been dominated by TWO volitiles, H2O and CO2. To understand Mars' geohistory, you have to consider that there will always be CO2 in solution in water and ice which changes how H2O behaves. A truely excellent read.
When I was typing up Mars Data for the FAQ I thought of a line of evidence that argues against the idea that Mars lost its atmosphere to a massive impact. Argon is highly concentrated in Mars' atmosphere. It likely started out with a dense atmosphere (rich in volitiles as it formed far from the sun). It gradually lost the other volitiles but the Ar remained at its origional partial pressure. In a massive impact Ar would be lost at the same time as the rest of the atmosphere.
Warm regards, Rick.
MARS DATA:
Orbital Data:
---------------
Semi-major axis.....1.5237 AU.......227,936,637 km
Aphelion.................1.6660 AU......249,228,730 km
Perihelion...............1.3813 AU.......206,644,545 km
Eccentricity.............0.09341233
Orbital speed
- average...............24.077 km/s
- maximum.............26.499 km/s
- minimum..............21.972 km/s
Inclination................1.85061 degrees.
Inclination................5.65 degrees to sun's equator.
Longitude of ascending node......49.578 degrees
Argument of perihelion..............286.462 degrees.
Sidereal period
- Earth days................686.9600
- Julian years..............1.8808
- Martian days.............668.5991 (sols)
Natural temperature of space craft at Mars Orbit: 5° C
Natural temperature of space craft at Earth Orbit: -47° C
(These values can be raised or lowered by the surface texture and color.)
Note: Liquid Nitrogen boils at -196°C (77K) at 1 atm pressure. Critical temperature is -146.9°C (147K).
The maximum super conduction temperature is at 138 K, is held by a cuprate-perovskite material. Sadly, even with reflective coatings we can not get super conducting temperatures at Mars orbit. (We would have to get out to the main asteroid belt before they will work with out refrigeration.)
The eccentricity of Mars' orbit varies. Around 1.35 million (Earth) years ago, it had an eccentricity of only 0.2 percent (down from about the 9.3% it has today). This variation of eccentricity is driven by gravitational effects of the other planets, especially Jupiter and Earth. In about 1000 years Mars will reach its maximum eccentricity and start declining again.
Its main cycle of eccentricity variation is 95,000 years (slightly shorter than Earth's) but there is a long period variation with a period of several million years.
Because its eccentricity is so great, the southern seasons are much more severe than the northern ones. When people speak of the 'Martian winter' they are discussing winter in the southern hemisphere when Mars is at aphelion (as far from the sun as it gets).
Physical Characteristics:
----------------------------
Equatorial Radius..............3402.5 km (53.3% of Earth's)
Polar Radius.....................3377.4 km
Oblateness.......................0.00736
Surface area....................1.448x10^8 km^2
Disk visible from Sun........35,835,616 km^2
Volume............................1.6318x10^11 km^3
Mass................................6.4185x10^23 kg
Mean density....................3.934 g/cm^3
Equatorial surface gravity....3.69 m/s^2..........0.376 g
Escape Velocity.................5.027 km/s
Sidereal rotation................1.025957 days.......24.622962 hours
Rotation velocity at equator...858.22 km/hr.....238.394 m/s
Axial tilt............................25.19 degrees
Moment of Inertia: 0.366
Albedo..............................0.15
Insolation at top of atmosphere:
- Semi-major axis...........................560 W/m^2 (43% that of Earth)
- Aphelion...................................... 468 W/m^2
- Perihelion.....................................681 W/m^2
(Since Mars spends more than 1/2 of its time further from the sun than the semi-major axis, Robert Zubrin suggests an average value of 500 W/m^2 which is easy to remember.)
On the surface, the thin dusty atmosphere reduces the above values by about 100 to 200 W/^2.
Average Temperature: -63° C or 215K
Highest Equatorial Temperature: 20° C or 293K
Coldest (South) Polar Temperature: -132° C or 141 K
The Blackbody temperature for Mars is: -67° C or 211K
(For Comparison, the Blackbody temperature of: Venus 11° C or 283 K. Earth -23° C or 249K. Ceres is -136° C or 137K. Callisto is -178° C or 95K.)
Mars has two moons, Phobos and Demos
Atmosphere:
---------------
Surface pressure............................6 to 14 mbar
--> or about 0.000014 to 0.000033 (??) grams / liter
Composition:
- CO2............................................95.72%
- N2.............................................. 2.7
- Ar.............................................. 1.6
- O2.............................................. 0.2
- CO (carbon monoxide).................. 0.07
- H2O............................................ 0.03
- NO (nitric oxide)........................... 0.01
2.5 ppm Neon (ppm = parts per million.)
300 ppb Krypton (ppb = parts per billion.)
130 ppb Formaldehyde
80 ppb Xenon
30 ppb Ozone
10 ppb Methane
Scale height................................... 11 km
mean molecular weight (g/mole) 43.34
Wind speed (at Viking site) from 0 to 10 m/s
Wind speed (at Viking site) during dust storm 17 to 30 m/s
Argon (Ar) is more enriched in Mars' atmosphere than any other planet. (When CO2 is condensing at the south pole, transitory Ar concentrations of 30% have been observed.) This is thought to be caused by Mars having thick primordial atmosphere with normal ratios of all volatile elements. Over time, the other gaseous elements escaped from the planet or were incorporated into the crust. This suggests that Mars has gradually lost its atmosphere and not had it blown away in a massive impact.
Methane (CH4) has been detected in the Martian atmosphere. Since this gas is unstable, it must have been produced in the last 100 years. Possible sources include out gassing from volcanoes or earthquakes, impact of a cometary body, bio-generation by life or finally the reaction of carbon dioxide, water & the mineral olivine (which is common on Mars) in the crust.
At Mars' temperature and pressure water vapor occasionally reaches 100% humidity. This is evidence that Mars has ample ice reserves in its crust.
A significant amount of dust particles about 1.5 micrometers across are suspended in the air. These help transfer solar heat to the air and give the Martian sky a tawny color. The very fine dust is a nuisance for colonization efforts in that it is abrasive for machinery with moving parts, is unhealthy to breathe and reduces the effectiveness of solar panels.
Moons:
--------
---> Phobos:
Orbital Data:
---------------
Semi-major axis.....9,377.2 km
Apoapsis................9,628.8 km
Periapsis................9,235.6 km
Eccentricity.............0.0151
Orbital speed average.....2.138 km/s
Inclination................1.093 degrees to Mars' equator.
Inclination................26.04 degrees to the ecliptic.
Sidereal period........0.31891023 days (7h, 39.2 min)
- (Phobos synodic period is 7h, 39.43 minutes.)
Phobos is the closest known moon to any planet. Being in an equatorial orbit it can not be seen above the horizon from latitudes above 70.4 degrees. It is well within the synchronous orbit for Mars so tidal effects are lowering its orbital radius by 1.8 meters per century. It is most likely to break up into a ring of rubble when it reaches an orbital diameter of ~7100 km. These small bodies will continue to decay and will impact along Mars' equator some millions of years later. Phobos is expected to last another 30 to 80 million years.
Phobos is inside the synchronous orbit so it will rise in the west, move across the sky in 4 h 15 min, and set in the east. This happens every 11 hours 6 minutes and so it will do this more than twice a Martian day.
Standing on Phobos looking up at Mars you would see Mars covering 1/4 of the sky. Mars would be 2500 times brighter than the full moon on Earth.
Physical Characteristics:
----------------------------
Dimensions......................26.8 x 21 x 18.4 km.
Mean radius.....................11.1 km.
Oblateness.......................from 0.31 to 0.12
Surface area....................~6,100 km^2
Volume............................~5,500 km^3
Mass................................1.07x10^16 kg
Mean density....................1.9 g/cm^3
Equatorial surface gravity....0.0084 to 0.0019 m/s^2
(This is about 860 to 190 micro-gravities.)
Escape Velocity.................0.011 km/s
Sidereal rotation................Tide locked so equal to orbital period
Rotation velocity at equator...11.0 km/hr (at longest axis' tips)
Axial tilt............................0.00 degrees
Albedo..............................0.07
Temperature......................~233K (-40 C)
Phobos (and Deimos) are very similar to carbonaceous (C-type) asteroids with albedos, densities and a spectral return close to these asteroids.
---> Deimos:
Orbital Data:
---------------
Semi-major axis.....23.460 km
Apoapsis................? km
Periapsis................? km
(These are very close to the semimajor axis as the orbit is very round.)
Eccentricity.............0.0002
Orbital Period..........1.26244 days
Orbital speed average.....1.35 km/s
Inclination................0.093 degrees to Mars' equator.
Inclination................27.58 degrees to the ecliptic.
Being in an equatorial orbit it can not be seen above the horizon from latitudes above 82.7 degrees.
Deimos is just outside the synchronous orbit for Mars. Its sun synodic period is 30.4 hours while Mars' synodic day is 24.7 hours so it moves very slowly from the east to the west in Mars' sky. In fact, it will take 2.7 days from moon rise to set from an observer on the equator.
Physical Characteristics:
----------------------------
Dimensions......................15.0 x 12 x 10.4 km.
Mean radius.....................6.3 km.
Oblateness.......................?
Surface area....................~? km^2
Volume............................~? km^3
Mass................................2.244x10^15 kg
Mean density....................2.2 g/cm^3
Equatorial surface gravity....0.0039 m/s^2
(This is about 400 micro-gravities.)
Escape Velocity.................0.0069 km/s
Sidereal rotation................Tide locked so equal to orbital period
Rotation velocity at equator...? km/hr (at longest axis' tips)
Axial tilt............................0.00 degrees
Albedo..............................0.07
Temperature......................~233K (-40 C)
References:
"Moons and Planets" by W.K. Hartmann
"Entering Space" by Robert Zubrin
Wikipedia
"Mars: A Warmer Wetter Planet" by J. S. Kargel
"Terraforming" by M. Fogg
This is the location for Information about terraforming other bodies that are not Mars.
Q--- HOW WOULD YOU TERRAFORM VENUS?
A--- Terraforming Venus is a much harder problem for two reasons. It has almost no water at all, and its CO2 greenhouse atmosphere is hot enough to melt lead on the surface. It also has a very long day and no strong magnetic field. On the bright side its gravity is the same as Earth's.
Many people suggest that we use plants of some sort to convert the CO2 to O2. Photosynthesis uses this formula:
6 CO2(gas) + 12 H2O(liquid) + photons → C6H12O6(aqueous) + 6 O2(gas) + 6 H2O(liquid)
Or in a simplified form as:
6 CO2(gas) + 6 H2O(liquid) + photons → C6H12O6(aqueous) + 6 O2(gas)
Note that for each molecule of O2 produced, you use up one molecule of water. So if you could somehow engineer some algae that could live in the cloud tops, (without many major and trace elements needed by the cells for their basic metabolism), you would create a tiny amount of O2, use up all the water and still have about 90 bars of CO2.
Martyn J. Fogg discusses this in his Text book: "Terraforming: Engineering Planetary Environments". He suggests building a diffraction grating to angle much of the sunlight away from the planet, dropping comets on the now frozen planet to give it some water, and then allow a certain amount of light thru. The massive amounts of CO2 are also a problem. It has been suggested to turn much of it into diamond and then bury it.
Terraforming Venus takes a lot more high tech effort to do and maintain than Mars.
Discussion on Terraforming Venus
Q--- WHAT ABOUT TERRAFORMING EUROPA, TITAN OR POINTS FURTHER OUT?
A--- Fogg discusses this but the problem is it gets COLD beyond the orbit of Mars. Also beyond Jupiter's orbit the sunlight in not intense enough for photosynthesis so you need artificial lights for plants (which require a truly remarkable amount of energy). However, with a sufficiently high technology, we can do magical things.
Can Small Bodies Be Given An Atmosphere?
Q--- WHAT ABOUT TERRAFORMING THE MOON?
A--- It has been widely suggested that if you could give Luna, our moon, a thick atmosphere it would last for several tens of thousands of years. Long enough to allow people to keep refilling it with comets grabbed from the Oort cometary belt.
However in this post (which I link to below) Shawn Barrett has shown that this atmosphere would only last 500 years or so. I think that that pretty much kills the idea of making Luna into a habitable planet unless we postulate some exotic means to keep the atmosphere around it.
Shawn Barrett's Post showing a Lunar Atmosphere Would Likely Only Last from 300 to 1000 Years.
The moon also lacks carbon, nitrogen and hydrogen in large quantities (and many other non-refractory elements) which will greatly increase the cost of terraforming this world. The month long day also would be very hard for Earth plants to adapt to. However, the link below talks about the problems and opportunities of improving our nearest neighbor.
Q--- HOW ABOUT TERRAFORMING OGLE-2005-BLG-390Lb???
A--- If you take me 20,000 light years then I'll give it a try!
Q--- ANY INFORMATION ON GLIESE 581?
My intention is to have this thread answer common questions about Mars and Terraforming with indexes to appropriate topics.
Q--- WHAT IS TERRAFORMING? WHAT IS ECOPOEISIS?
A-- Terraforming is modifying another planet to make it more Earth like. Some people distinguish between Ecopoeisis (spreading bacterial life to another world) and Terraforming by which they mean to allow humans to walk around on the planet's surface without life support. Most posts on this forum mean either when they talk about it. Some scientists have suggested that with a modest effort, Mars could be terraformed which is the main theme of this forum, altho some have posted on terraforming other worlds such as Venus.
Q--- WHAT ARE THE MAIN PROBLEMS FOR LIFE ON MARS?
A--- There are several problems:
--1) The first problem is the air pressure. It varies from 6 to 14 mBars. (milliBars = 1/1000 of a Bar. 1 Bar is about 99% of an atmosphere.) Earth by contrast has 1.101325 Bars at sea level. Mars is therefore at a near vacuum and multicellular life will soon die.
Info on Breathable Atmospheres.
--2) The second problem is the cold. Tho occasionally the temperature gets above freezing on the equator, most of the time Mars is far below freezing. A typical night temperature is -90C and the temperature at the south pole in southern winter is -127C. This low temperature is enough to freeze out carbon dioxide ( CO2 ). So much CO2 freezes out that the planetary air pressure drops significantly each Martian winter.
--3) A third problem is radiation. Earth's magnetic field directs much of the ionizing radiation from the sun to the polar regions. Mars has no strong magnetic field so these are spread over the whole planet. Second the atmosphere is too thin to stop cosmic rays. Third there is no ozone layer ( O3) so dangerous ultraviolet light sterilizes the surface.
--4) The low gravity complicates keeping a thick atmosphere.
--5) Finally the atmosphere is almost pure CO2. Animals and higher plants need oxygen ( O2) so anyone breathing Martian air would soon smother. There are numerous other problems but if you solve these, the rest will take care of themselves.
Q--- HOW WOULD YOU TERRAFORM MARS?
A--- There are 3 main ways suggested in the scientific literature. (I am following the suggestions of Zubrin, McKay and Fogg here.)
--1) First drop comets or icy asteroids (iceteroids) on Mars. This will thicken the atmosphere which will allow it to retain more heat via the greenhouse effect. In addition it would be good to add more nitrogen (N2) to the Martian air.
Moving Asteroids Around the Solar System.
--2) Second warm the planet with big mirrors, especially the south pole.
--3) Third add super greenhouse gases to the atmosphere. Substances such as the perfluorocarbons such as Tetrafluoromethane (CF4), Hexafluoroethane (C2F6) have been suggested. In addition Sulfur hexafluoride (SF6) and Nitrous Oxide (N2O) are possibilities. A recent scientific paper suggests Octafluoropropane (C3F8) since it blocks heat in a wide band. But putting relatively small amount of these and other gases in the atmosphere, the planet can be warmed 20 to 40 degrees.
Info on PFC's and Are they Toxic?
Info on Greenhouse Gases
How Much PFC's will we need?
Tho not sufficient on its own, darkening the polar regions with dust from an carbonaceous chondrite asteroid (or Phobos or Demos) will increase the effectiveness of light falling on the ice by decreasing its albedo.
The four methods suggested above could be done with current technology. There are other more exotic ideas on how to terraform that would require new technology, or moving massive amounts of material around the solar system so are not near term solutions.
One suggestion is 'moholes'. Giant holes that go down into the mantle of the planet to bring up heat and deep gases. Moholes are discussed in the thread below (a few posts down.)
Methods of Terraforming
If Mars had more mass things would be nicer. However, moving enough mass around to make a difference is a far, far future job.
Adding Mass to Mars.
Discussion of Orbital Mechanics Needed to Adjust Planetary Orbits.
If Mars had a giant moon, its climate would be more stable over millions of years.
Large Moons and Angular Momentum
Using self-reproducing nanotechnology is often suggested to give Mars an atmosphere by breaking apart rocks, giving Mars a magnetic field, darkening the planet and many other ideas. I have made a critique of using 'Magical Nano-tech' to solve our problems for us.
Problems With Magical Nano-technology
Vulcanism is useful for life in many ways. In the thread below people speculate on ways to get Mars percolating again.
Reheating the Martian Guts
Q--- WHAT IS 'LEVERAGE' IN TERRAFORMING?
A--- Leverage is when relatively small changes to starting conditions cause a large effect. On Mars people have noticed that if the poles could be warmed by only a few degrees a great deal of CO2 will be given off. Since carbon dioxide is a greenhouse gas, this will further warm the planet. More carbon dioxide is trapped by the cold temperatures in the soil and ice, so with sufficient warming the atmosphere could get even thicker and warmer.
Mars has had long periods in the past where it was much warmer. It seems to have two stable states, a wet and warm state and a cold near vacuum state. The hope is to be able to make a small change to flip the Martian climate into a life-friendlier area.
Q--- DOES MARS STILL HAVE WATER?
A--- Almost certainly yes. Mars is a desert not because it has no water, but because the water it has is frozen. That said, Mars seems to have a lot less water than Earth. This is because with its lower gravity and no ozone layer water breaks up into hydrogen and oxygen and the hydrogen is then lost to space.
How Quickly Does Mars Lose Air?
Q--- MARS DOES NOT HAVE A MAGNETIC FIELD. IS THAT A PROBLEM?
A--- Not a big problem but it is inconvenient in a couple ways. First the sun's solar wind strips bit of atmosphere away very slowly. This is thought to have contributed to Mars' low air pressure. Second Mars thin atmosphere is enough to protect from the sun's radiation except during a large solar flare. (Astronauts would have to go into a storm cellar during a solar storm.) If Mars had a magnetic field and the astronauts were not at a magnetic pole then they would be largely protected.
If we thicken Mars' atmosphere (to say 1 Bar) it will last for billions of years. It will also protect against solar radiation and cosmic rays better than the Earth (with a magnetic field) because Mars' atmosphere has a larger scale height than Earth.
mlomg started a thread that points out that some people think Mars is at a magnetic minimum and a magnetic field will naturally recover over thousands or millions of years. See:
Mars' Magnetic Field May Recover?
On a somewhat related note, here is a thread talking about radiation protection:
Low Mass Radiation Protection.
Q--- WOULDN'T YOU HAVE TO MAKE SOIL?
A--- Absolutely. Plants can't live in the sterile (perhaps toxic) soil of Mars. (I think that the danger of 'super oxides' in Mars' soil is over rated. Nothing that getting it wet wouldn't fix. Also Earth plants have been grown in soil made out of simulated Martian regolith with no problems.) The following links talk about soil creation:
Making soil with salt marshes.
Q--- WHAT BOOKS TALK ABOUT TERRAFORMING?
A--- I would suggest first of all "The Case For Mars" by Robert Zubrin. See also the link below:
Reviews of Books on Terraforming.
Q--- WHERE ARE BASIC FACTS ON MARS?
The game is based on Logarithms. A track shows how many people are in each population cube which about doubles for each step. Advances in space flight drop the cost of moving to Mars by about 1/2 per step. So it costs $1,000,000,000 Martian Dollars x (population track level - Cost of Space Flight + 6) to move one population cube to Mars.
Then you have to buy sufficient power to keep the base warm (based on latitude) and more power to do any industry.
Martian dollars start out worth $100,000,000 USD at the game start. As time goes buy their buying power increases. This is so that the prices can stay more constant thruout the game.
Major industries are deuterium collection, shipping strategic metal to Earth via magnetic sails, shipping supplies to asteroid bases and a host of infrastructure building actions.
Warm regards, Rick.
Rick,
Wouldn't the iron dust just all clump together in a thin ring?
Once we add a charge iron should be pulled together.An acceleration of the iron ring might be a plus.
If it accelerates we can start it in low orbit and move it into a higher one for free.(sort of free)
The question was, do we need a superconducting ring. Nickname suggested that we put a charge on a ring of orbiting iron dust and use that to give the planet a charge.
OK, let us say that we have a speck of iron with a negative electric charge rotating west to east around Mars' equator. By the right hand rule it produces a magnetic field pointing north. So an entire ring of such particles effectively gives Mars an magnetic field like Earth's, with field lines coming from the north pole and sweeping around to the south.
Each of these particles has a negative electric field so they will repeal each other. How do you keep them from spinning off right out of orbit? Ignore this problem for now.
The magnetic field all of these creates interacts with the solar wind, creating a bow shock, etc. This accelerates the charged particles in the solar wind. However the accelerating solar wind ALSO accelerates the charged iron dust via magnetic fields.
During northern summer, a disproportionate number of the solar charges will flow over the north pole. This will accelerate the iron dust to the west, deorbiting it. In the southern summer, the particles will be kicked into higher orbits. However the majority of this acceleration is from the sun facing side so the orbit will become more and more elliptical. As the orbit becomes very long, the particles will entangle with the solar wind, start spiraling along the field lines and be stripped away.
If you want to create an artificial magnetic field, keep the rotating charges on the ground. Then the acceleration given to the particles can be transfered into the giant momentum bank of the planet.
However there are a couple final things to keep in mind.
1) Sputtering of the solar wind (which strips off atmosphere) is VERY slow. One kilometer sized asteriod will provide many millions of years of volatiles. Getting one is far less effort than building a superconducting ring. (Also the magnetic ring is unlikely to last millions of years. HUMANS are unlikely to last millions of years...)
2) The Martian atmosphere (if it is put up to one atmosphere) is much thicker than Earth's because Mars has a greater scale height. So much so that it provides more radiation protection from solar flares than the Earth's atmosphere plus our magnetic field. (This result was from the summary post at the top of the article.)
So I don't see this as a pressing problem for terraformers.
Warm regards, Rick.
Projections show that a network of two to three hundred, 150 meter diameter reflectors in monolith form or a series of small clustered
groups would provide roughly the same irradiance as on earth to the Mars surface.
That can't be right. Let's do some math.
The radius of Mars is: 3398 km.
So the area of the sun's light absorbed by Mars (assuming it is a sphere) is equal to a circle of that radius.
A = PI r^2 = 3.1415... * 3398km ^ 2 = 36,274,098 km^2
The area of one of those mirrors is:
A = PI * 0.15 ^2 = 0.071 km^2 (rounding up).
So 300 of them would have an area of 21 km^2.
The insolation is about 1/2 what it is at Earth so assuming that the mirrors are 100% reflective then we would need about 36,275,000 square km of mirrors to bring the total amount of energy reaching Mars to that of Earth.
In Robert Zubrin's plan, he does not try to heat up the whole planet, just the south pole. And he suggests using a mirror 125 km in diameter.
The original question was how did Mars lose its atmosphere. I think that what happened is likely on the lines of:
1) Less iron on Mars sank to the core. Mars is enriched in surface iron.
2) Photo-disassociation of water left Mars oxygen rich.
3) This rusted the iron.
4) Lightning reacted the nitrogen creating nitrate beds.
5) The carbon dioxide is locked up in the soil, in dry ice at the poles and in water ice clathrates.
I'm not sure this is what happened of course, but I think that this by itself would explain the current conditions with out other events.
Warm regards, Rick.
Hi everyone,
Thanks for the kind words. Generally the game is less detailed than noosfractal suggested.
There are multiple colonies, controlled by different players. Also a number of colonies that are not controlled by any player will spring up as the game progresses. A key concept is each player building up their economy. However, the players automatically buy and sell with each other. There is not the situation where one player gets a monopoly and then can choose to cut out a player. If you can build (for example) computer chips, then everyone can get chips cheaper than from Earth.
A basic trade off is, "do I spend money on terraforming" (which helps everyone) "or on improving my economy?" (which helps just me). This is the 'free rider' game from game theory. Some players get victory points for terraforming so they are motivated to work on improving the world. A few don't care.
However, everything gets easier as the planet warms. You don't have to spend so much on power if the planet is warmer. Some economic improvements are easier if you have higher pressure. So even people who don't have a strong desire to terraform, have occasionally put money into improving things a bit as it helps them out now.
Usually when we play the game breaks into these stages:
- First players try to build and diversify their economy.
- Eventually it becomes cheap enough for people to start to terraform the planet. I've seen games where most people toss in some money each turn and this proceeds quickly. I've seen games where almost no one does and most of the game is played in hard vacuum.
- Near the end game some players might try to help the Martian ecology, while others work on massive projects like a sky ramp or fusion power.
Terraforming is centered around sollettas and greenhouse gasses. People can drop iceteriods but they are assumed to be small enough to not require massive evacuations. A couple of random events say that a big comet is by chance going to pass near Mars and if diverted, it may require massive evacuations.
One thing I don't have in the game is the importance of polar sollettas. I think that to get a decent amount of water near the equator, we need more heat at the poles. This way in the southern summer there is enough energy for a fair bit of the southern ice to melt.
I've simplified the spreading of life rules twice. (The first time was a state diagram that I was very proud of and it LOOKED so complex that people told me it had to be simplified before they even tried playing it.)
Currently it works like this:
1) Players may spend money to spread life. Scattering a few bacteria is cheap on the earlier levels. It becomes more expensive to hurry things as the ecology starts moving to multicellular life. If this money is paid the player advances the state of the ecology to the next level. (8 Levels currently.)
2) Players roll one ten sided die and do what it says. This can range from a free ecology advance if the conditions are clement, to no effect, to spend money to get another roll. Most effects raise oxygen, nitrogen or improves other states that will speed the spread of life.
3) Players roll a 'constraints die'. This asks you to check such things a cosmic rays, ultraviolet light or amount of biomass. If your ecological state has gotten too high it is reduced at this phase. However if things are rocking, all players can gain an economic bonus at this stage. (Less life support is needed, which directly helps your economy.)
4) Players check hard constraints. If air pressure is very low, you don't get past bacteria, for example. This phase also can drop the ecological state.
What it boils down to is if the planet warms up and gets a thicker atmosphere, the ecology will start up on its own. However it will do so very slowly. If several players push it, it can spread much faster. My game lasts around 300 years so players can not reach a breathable atmosphere. Ecopoiesis (the spreading of life to Mars) is the goal.
The highest state I've seen players reach honestly is an Antarctic Crytendaolithic ecosystem. In a game where I asked players to try to push life as far as possible, we got up to a Bryophyte Ecosystems (hornworts, liverworts and mosses) on land.
Other elements of the game are research, cost of space travel, the state of the Earth's civilization (handled by random events), massive investments, military actions and the politicking needed to gain a share in the Martian government that happens in the end game.
Like most games that try to simulate something, this game is big and complex. It takes 3 to 5 people 5 to 7 hours to play. (I've reduced this a fair bit but I can't really speed it more with out taking out elements I would like to keep.) The game has been tested about 10 times (which does not sound like much, but keep in mind that it is an effort to round up that many play testers for such a long time).
Anyway, I will boast more about my baby when it is closer to being ready for the public. For now, I was wondering what other people would like to see in such a game.
Rick
Carbon is not soil. Soil is made up of fungus, bacteria, decomposing life, grains of minerals ions, microscopic mites, etc.
The only practical way to convert a planets atmosphere is using the ungodly amount of energy provided free from the sun via plants. But to get plants you need soil, right? Unless you find a species that is autotrophic (can live in an area with out soil). If the species is cold resistant, UV resistant, acid resistant and nitrogen fixing then that is even better. Interestingly, Robert Dyck has discussed a plant that has these properties, i.e. sphagnum moss.
The peat bogs we are talking about are made of sphagnum moss, not fungus. As for bacteria they are everywhere with life. sphagnum moss produces O2, not H2S.
Do you have a reference which says 99% of a living bog is made up of fungus and bacteria by any chance? And even if they are, that is not an argument against them if they produce soil.
Rick
Hi Midoshi,
Welcome to the terraforming forums! Don't worry about the length of the posts, especially if you have interesting information to share.
The numbers you were talking about... were they discussing the amount of water needed? In any case feel free to share them, the more hard data the better! With all the craters, there should be plenty of places where we could have the poor drainage needed for bogs.
If we have beg enough mirrors warming the poles, we should get increasing amounts of water running south to north during southern summer.
Does anyone know how salty it can get before Sphagnum Moss is inhibited?
Glad to hear from you Midoshi,
Warm regards, Rick.
Hi Everyone,
I've got a game about Mars partly built and I'm currently in the polishing stage. Just wondering if anyone would like to discuss what they would like to see in their perfect Mars colonization or terraforming game.
What elements would you want to see in a Mars game? What would be the conflict? What would be the major actions that the players could do?
Warm regards, Rick
Another issue is that the higher the co2 is in the greenhouse the lower the nutricianal food value is. ...
Hi SpaceNut, everyone.
I never knew that. Do you have a reference to the study?
Warm regards, Rick
Hi RobertDyck.
I think that Terraforming Mars is possible, however, I do think it will be a huge job taking a long time. I think that your idea of using bogs as a soil factory is brilliant.
My point about bees and the Partial Pressure of CO2 is that we can have bees in domes, but it will be a long time before we have free range bees. Not only do we have to raise the oxygen partial pressure (O2 p.p.) but we have to drop the CO2 p.p. tremendously. (Which gets rid of a much needed green house gas.)
My understanding is that a buffer gas in an oxygen atmosphere acts to reduce the flame temperature. This means that some substances will burn in pure O2 that won't burn in our oxy-nitrogen atmosphere. Of course this would be given constant pressure and you are suggesting a lower overall pressure. Do you have a link or book that gives more detail on this?
By the way, a Science Fiction world that has a high O2 p.p. atmosphere can be found in Spider Robinson's and Robert Heinlein's "Variable Star". In this the world Brasil Nava (created by Guy Immega) there is a 30% O2 p.p. and wood will burn while wet (which drives how the world was planned to be colonized.) The air pressure is close to Earth's.
Warm regards, Rick
Hi Stardreamer, Noosfractal.
What Noosfractal said about long posts is absolutely correct but the article itself is scary.
The article mentions the rotten egg smell that crept into her diving mask. This gets back to my previous thread here.
http://www.newmars.com/forums/viewtopic.php?t=5272
Currently off the coast of BC, fish farms are damaging the enviroment and causing outbreaks of parasites that are decimating native salmon stocks. I used to think that fish farms were ideal, but lately I've been hearing a lot about the ecological costs.
sigh.
Thanks for the post Stardreamer.
Warm regards, Rick.
... Sphagnum moss and cyanobacteria of peat will grow in an atmosphere with no oxygen. They will require nitrogen to form protein, ideally as atmospheric nitrogen. ...
Again great posts Rob.
I don't think it is quite as easy as you think. I've done some digging and you need 0.5 kPa of Nitrogen before nitrogen fixing plants will work. You need 0.1 kPa of Oxygen before higher plants will grow. (About half that for mosses, liverworts, hornworts and the like, tho I've not been able to find numbers as hard as I would like.) I am pretty sure the first 'plants' colonists will be some variety of cyanobacteria, aka bluegreen algae.
Currently Mars has 0.0175 kPa of N2 and 0.001 kPa of O2 (rounding a bit). However an early greenhouse could have your bog to act as a soil factory for other greenhouses.
I got to thinking about bees in low O2 environments. Our lungs work because the pressure of CO2 in the air is so low that the CO2 in our blood leaves because of the "Gibbs Free Energy". (Basically this says that the CO2 goes both ways, but the pressure of CO2 in the air is so low, that almost no CO2 goes across the membrain into our blood; it is effectively one way.) However, if you increase the CO2 partial pressure, then even tho there is plenty of O2, the CO2 can't leave our blood and we smother.
I expect that insects would have the same problem in a CO2 atmosphere as we do. We need a lot of buffer gas on Mars that is not CO2.
Have you seen, "Planetary Ecosynthesis as Ecological Succession" by James M. Graham from the university of Wisconsin-Madison? This lists a variety of plants that might be of use, but it does not give many details on how they could be best used.
Would you mind making a post in my "Plants that are useful for colonization & terraforming" thread suggesting Sphagnum moss and give a link to your initial post in this thread? I'm hoping that thread can be a clearing point for plants of use. (I knew about Sphagnum moss, but never realized how perfect it is for Mars.)
Very Warm Regards, Rick.
Hi Rob Dyck.
Oops! Sorry about that. Yes you are right, I meant thank you to you.
Thanks for the information on bees & pollination.
Warm regards, Rick
I've thought about the soletta a bit. to work it would have to have a diameter larger than Mars. Otherwise, it wouldn't catch any light that would miss the planet.
Hi everyone, Kippy.
Actually this is not the case.
Robert Forward showed that a mirror could hover above the pole using light pressure. He called this a "Statite" (for Stationary satillite). Most terraforming plans use a big Satites well behind the planet so that the light they reflect will hit the planet. (So the 'south pole statite' actually hovers above and behind the north pole of the planet.)
Another way of doing this is to have satillites in polar orbit facing the sun. They form a ring around the terminator of the night day edge of the planet. They reflect light down giving them a slight lift. Now instead of having them directly over the terminator, you put them slightly behind it, so they NEED that lift to stay in orbit.
(You have to make sure that they precess so that they keep facing the sun as Mars goes around in its orbit.)
Any way there are two ways that I know of that allow you to use mirrors with out them being larger than Mars itself.
Hey Shawn,
I think that mirrors warming both the north AND south poles are needed. Otherwise the water will move to the poles and be locked up. Even with the mirrors (unless they are huge) you will get ice caps but I would like a significant amount of them to melt each year to feed rivers and lakes.
Warm regards, Rick.
Hi RobS,
Great posts! Thanks for all the work.
Some questions, the plants you mention, do they require insects to fertilize them? (The moss would not, but what about the berry bushes you mentioned?)
Do any of those plant species have minimum requirements for O2 or N2?
Warm regards, Rick
Hi Karov,
For Ceres, Pluto and Eris, they are so small that their temperature at depth is likely only a couple hundred degrees K warmer than their surfaces. For Ceres (wild guess here) it might be 300 K. For Pluto and Enis it might be 100 K.
For Titan, it has a radius of 2575 km. Luna is 1738 km. The rate that a world loses heat is inversely proportional to the square of the radius.
Luna at 1000 km is about 1800 K. Titan is larger, so this might be over 2000 K. Additionally Titan is not tide locked so it will get some heat by tidal warming. My GUESS would be from 2000 K to 2500 K at 1000 km depth.
Warm regards, Rick.
RickSmith,
At 1/4 or 1/2 bar the mechanics of moving water on Mars will be much different, Mars should accumulate snow.If we try to slowly heat Mars the outcome is sure to be a snowball Mars.
We would defiantly want to avoid the same problem on Mars, most of the super greenhouse gases we need to warm Mars don't really break down naturally in the environment.
The mirrors at the poles i think is a good idea, but would it simply re freeze with little effect on the atmosphere.
Maybe a better use of the poles is to break the h20 into its elements, then use the hydrogen to create super greenhouse gases.
Hi Nickname, everyone.
If somehow Mars gets too warm (say there is a lot more CO2 than we expect) then when we start plants creating oxygen from CO2, the temperature will drop again. Also black body radiation goes up a lot as the body gets warmer. If Mars gets hot, it will radiate the heat away faster on a wider variety of wavelengths.
Having mirrors directing heat to the poles is a good thing. Yes the snow will land at the poles. But it won't get as cold and more of it will melt come summer. I think we will want to have sollettas warming the poles to:
- melt ice and sublime dry ice.
- drive CO2 out of the soil.
- make glaciers move faster / melt (which will free CO2 clathrates).
As for using making CH4 or NH3 I have my doubts. With the perfluorocarbons, building them up with a slow trickle works because they stay around a long time. With methane / ammonia they are destroyed so quickly (especially with out an ozone layer) I wonder if it would be worth the expense.
Warm regards, Rick.