Giving Mars Back Its Hearbeat - 7 parts Astrobiology.net series

Rxke · 2004-06-16 08:59:13

http://www.astrobio.net/news/modules.ph … iology.net

"Summary:

At the Astrobiology Science Conference on March 30, scientists and science fiction writers faced off in front of a packed audience to debate the promise and pitfalls of terraforming Mars. In part 1 of this 7-part series, Christopher McKay advocates making Mars habitable for Martians.
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Cobra Commander · 2004-06-16 09:23:38

Somehow the idea of creating (or reviving) a biosphere of distinctly Martian life and with no express purpose of making it human friendly seems grossly wasteful. Like making a planet for pets, of a sort.

Still, higher temperatures and air pressure would be great, but if we aren't going to do anything with Mars beyond turning into a botanical garden it's a moot point.

clark · 2004-06-16 09:30:34

Garden of Poison Oak. :laugh:

John Creighton · 2004-06-16 09:36:29

Maybe in the life we create we will find the cure for cancer. Slightly more realistic then Amazon gold, is the possibility of food or raw materials, to make alcohol or plastic.

clark · 2004-06-16 09:59:53

Maybe in the life we create we will find the cure for cancer.

Parents always dream that their children will grow up to be doctors.

MarsDog · 2004-06-16 20:16:36

Martian Dome Dwellers will dream for 40,000 years, while the outside plants produce oxygen.
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No easy way to solve the oxygen problem quickly.

Gennaro · 2004-06-17 05:04:20

40 000 years? So what happened with the 1 000 years or less (depending on perhaps unknown biotechnological advances) proposed by Zubrin?

Also like to know what they mean by "burying the carbon" and what's the significance of it?

MarsDog · 2004-06-17 06:55:22

At the mentioned conference, 40,000 to 50,000 years was given, as the time to terraform for human breathable air.
To make Mars plant friendly would be quicker.
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Also like to know what they mean by "burying the carbon" and what's the significance of it?

There is a lot of carbon, potentially reacting with the atmospheric oxygen. The carbon has to be moved from the atmosphere to the geological carbon cycle. On Venus the CO2 is not fixed into the rocks. On Earth the geological carbon cycle is millions of years
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On Mars, the CO2 is frozen out, and will move into the atmosphere once warming begins. Then the carbon has to go somewhere; rocks (diamonds or carbonates) or oil as in Saudi Arabia.

Cobra Commander · 2004-06-17 08:52:25

On Mars, the CO2 is frozen out, and will move into the atmosphere once warming begins. Then the carbon has to go somewhere; rocks (diamonds or carbonates) or oil as in Saudi Arabia.

So we'll get Bush thinkin' there's gonna be oil, award the terraforming contract to Halliburton and we're set.

MarsDog · 2004-06-17 12:08:29

You are Absolutely Right - the oil and diamond cartels will want to control, and they will sacrifice all the necessary Humans.
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The 50,000 year breathable atmosphere estimate would be shortened with 100% plant efficiency. But that still leaves 5,000 years.
If sunlight, falling on Mars, is used 100% to convert CO2 to C and O2; how long would that take ?
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Refining comets and importing Hydrogen might be feasible, shortening the estimates still.

Gennaro · 2004-06-17 19:47:22

On Mars, the CO2 is frozen out, and will move into the atmosphere once warming begins. Then the carbon has to go somewhere; rocks (diamonds or carbonates) or oil as in Saudi Arabia.

With the apparent risk of exposing my enourmous ignorance, within the time frames important to us, won't the solid carbon from plants simply accumulate on the surface?
Anyway, locking it into limestone is impossible after a while. Mars has no plate tectonics to renew the stock of surface Calcium (I believe this is the "million year process"?).

In any event 40 000 years is absolutely unacceptible. We will have colonized half the galaxy by then.

Oh, well... the future is artificial I reckon.

MarsDog · 2004-06-18 00:17:20

Everyone is an expert here as exemplified by the Zurbin to Academic Conference ratio 50,000years/1,000years.
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No plate tectonics on Mars ? So much the better. Just pile all the dead plants and make a mountain, carefully, so that it does not burn. Instead of the carbon as dry ice, it will be carbon as a carbohydrate mountain. I wonder when the crude will come gushing out ?

karov · 2004-06-25 09:20:04

The problem on mars is that there the earth-like carbo-silicate plate tectonics CO2 regulator is not present. BUt, we don`t need to establish it there at all. Firstly it will be very expencive and hard task. AS proposed by Margarrita Marinova rock eating bacteria could do the job:

The hydrological cycle inevitably catches incrementaly the atmosphere CO2 and fixes it in limestone. The water-table beads are filled with carbonaceous rocks, hence - global shortage in the atmosphere, hence - ice ball Mars again. The limestone could be decomposited and the CO2 released in constant or repeated manner by rude burning the rocks. WE could punctuire the thick planetary crust and replenish the atmosphere with CO2 by artificial volcanoes (the same way as I proposed for mantle water release on Venus).

But much more "eco-friendly" way would be to use rock chewing bacteria or more sophisicated designed biota, living say only on the sea bottoms, fed with energy by some migrational process as some of the fishes... A eco-processor instaled and working only after the atmosphere is already earth-like, only to keep it composition parameters.

RickSmith · 2007-04-01 06:04:49

40,000 years? So what happened with the 1,000 years or less (depending on perhaps unknown biotechnological advances) proposed by Zubrin?
Also like to know what they mean by "burying the carbon" and what's the significance of it?

This is the time line as I see it for Terraforming Mars. I won't bother listing my references (most of them on in the Terraforming books reviews that I have been posting anyway). I have been studying this topic with some determination for half a decade, and I think these estimates are likely more accurate than most.

If anyone has questions about a particular point I make below feel free to ask about it.

YEAR 0:
Move in Solletta's over (behind) the poles to warm the high latitudes. Humans start releasing green house gasses but it will take 100 years to build up the industrial facilities to really significantly start affecting the atmosphere. Dropping some small comets on nitrate beds will speed things up but I will ignore this idea for the first 100 years or so.

YEAR 4:
All CO2 on the surface of both poles have evaporated. Mars' atm pressure is at 20 mbar and rising as the soil warms and out gasses CO2 absorbed by it. (I am being more conservative in this estimate than Zubrin here as I think that the soil will be buffered by a fair bit of ice which takes more energy to warm.)

YEAR 20:
With the pressure of CO2 rising, the air can absorb more heat and move it better. This is a positive feedback cycle. Mars is about 10 to 15 C warmer which is enough to put significant parts of the planet above the triple point of water brines. More water frosts out each year but much of it melts under the year long sunlight from the mirrors. This melting water carries heat deeper into the soil.

Note that the ice being made now is pure water and not the CO2 cathrates I believe to be common on Mars. As ice replaces cathrates, more CO2 is released into the atmosphere. The atmosphere is likely around 50 mBars.

YEAR 100:
Frosts are turning Mars white which lowers the albedo. This is balanced by the atmosphere pushing 75 to 100 mBars and a significant increase in super greenhouse gases. (Nitrous Oxide, Sulfur hexafluoride and various perfluorocarbons.) This is where the sollettas are key. Without them (say just greenhouse gasses) any water vapor just freezes out on the poles. However significant melting happens each summer at the poles as they get all day sunlight and the air is warmed at the medium and high latitudes by the solletta. The goal is that most frost melts pretty much planet wide by evening each day. If not, we must wait longer for more greenhouse gasses.

People can now walk around in winter clothing and oxygen masks. Tho cyanobacteria were likely introduced earlier they hopefully should be taking off now and spreading. They are releasing O2 to the air. Tho millennia away from a breathable atmosphere the O2 will start thickening the ozone layer and stopping more ultra violet light. (The thicker atmosphere will also be stopping 10 times more cosmic rays making moving & working on the surface safer.)

I will assume that larger mirrors are placed over the poles around this time. This will greatly speed the warming of the planet.

YEAR 100 TO 200:
A wide variety of simple plants are added to the warming Mars. They struggle for a long time. (No soil, there might be toxic dust left, high UV levels, low pressure, missing bacteria symbionts, lack of biologically fixed nitrogen and other minerals in forms that life can use, etc.) I think that it is likely in 200 years a few simple ecologies have started. These ecologies are anaerobic so much of Mars life is brown and smelly. O2 levels are rising but very, very slowly. This helps with the ozone layer.

Liquid water is common and the H20 in the air is a powerful greenhouse gas helping to keep the planet warm.

YEAR 200 TO 500:
Warming the first few meters of the soil is fairly easy but it is much slower the deeper you go. I think it likely that Mars has huge reserves of CO2 in deep brine aquifers and vast amounts of CO2 cathrates. In 500 years much of the CO2 reserve will have been released. Atmospheric pressure is likely 1/3 to 1/2 Earth's pressure and ice is melting everywhere. Permafrost, floods and snow is common. Arctic ecologies are possible in some areas.

Tho much of low laying Mars is now hospitable to life it will take centuries for life to spread to it. Humans can shorten this by doing a lot of work to try to develop widely spaced ecologies.

(Note that increasing the free O2 to 1% of Earth's level is still a big improvement. A life support system can use a compressor and some simple chemical reactions to get O2 out of the air rather than having to lug bottled air along or needing huge greenhouses for a base.)

YEAR 500 TO 2000:
Some time between 500 and 2000 years after we have started terraforming Mars a healthy ecosystem is widespread in low laying areas. O2 levels rise rapidly at first since the rocks are already oxidized. However, the problem is that some plant sucks CO2 out of the air, holds that carbon for a few years. When it dies it rots and releases the carbon back into the air as CO2. So the O2 level will rise steadily as more and larger plants grow but will stabilize at a (low) level until the biosphere can make large gains in mass. Even tho the air is not breathable, the O2 makes a significant ozone layer which protects water from dissociation and makes the surface much more pleasant.

Now arctic swamps will slowly bury unrotted peat moss like stuff which will very slowly suck CO2 out of the air. This will take the 100,000 years that McKay & others estimated for how long it would take to give Mars a human breathable atmosphere. However if humans take big trees filled with carbon, cut them down and bury them (or take them to the top of high mountains which are sterile and out of the biosphere) we can lock up the carbon. Life will have to suck new carbon dioxide out of the air.

Note that Mars cools as CO2 is absorbed, but the air pressure stays the same since O2 is replacing it. Something will have to be done to keep it warm. (More comets? More greenhouse gasses?)

I vote for comets because at this point, we will want to have a fair bit of nitrogen to buffer the air and help nitrogen fixing plants.

If we artificially bury vast amount of carbon the time to get a human breathable atmosphere can be greatly reduced. (2000 years? 5000 years?) However it has taken us hundreds of years to dig up the coal that is currently filling our air with CO2. We have to bury vastly more carbon than those coal beds and instead of giving us energy it costs energy. I suspect that this will happen in spurts with long periods where people don't bother. However a several thousand year push will give the colonists a high enough O2 content for flying insects. Once we have bees we can add millions of species of plants that need insect pollination to reproduce.

We likely will have breathable levels of O2 in the air long before the air is breathable. CO2 is toxic if the partial pressure is too high. Virtually ALL of the CO2 has to be drawn down first before people can take their first breath of unprocessed air.

10,000 to 100,000 years (depending on the the colonists):
A 'world wide' breathable atmosphere (at lower elevations). Note that in the lowest areas people might be able to breath long before someone a couple km higher. So people might push to get a breathable atm at the -4 datum, and several centuries later start pushing to allow people to breath at the -3 datum etc.

So when people ask me how long does it take to terraform Mars, the answer is complex. 50 to 100 years can make the planet a lot easier to live on, 500 years will give you ecologies, a nice thick atmosphere and a significantly improved ozone layer. 5,000 years will allow insects and I think that even optimistically it will take 20,000 years before anyone walks around on Mars with out a breather mask.

If we get fusion (especially He3 fusion) then these numbers can be sped up. Hot water could be pumped deep into frozen aquifers to release water and CO2. High powered spaceships can move a lot of mass to Mars and perhaps start giving it a nice big moon. With vast amounts of energy it is a lot easier to find fluorine, dig it up, and pump it into the air as greenhouse gasses. It is a lot easier to bury the carbon. It is easier to collect a lot of radioactives from all over the solar system and send them on a one way trip to the Martian core (to start some volcanoes). If we have generous power we might be able to shave off 10 or 20% from the times I give. If we are power starved then triple the times or just say it is impossible.

Those who talk about nano-technology saving the day or gene engineering plants to be vastly more efficient have no idea of how hard these ideas are to implement. Yes they might happen, but I have some severe doubts. A discussion on them would likely be a good post for another day.

Warm regards, Rick.

Tom Kalbfus · 2007-04-02 09:39:17

10,000 to 100,000 years (depending on the the colonists):
A 'world wide' breathable atmosphere (at lower elevations). Note that in the lowest areas people might be able to breath long before someone a couple km higher. So people might push to get a breathable atm at the -4 datum, and several centuries later start pushing to allow people to breath at the -3 datum etc.

10,000 to 100,000 years, hmm.

What if there was an Earthlike planet orbiting Alpha Centauri, that is Earthlike in respect that it has an Earthlike size and an Earthlike rate of rotation, but a largely carbon dioxide atmosphere, the pressure is high, there are oceans there already, but the temperature is a bit uncomfortably warm. Suppose we wanted to terraform that planet? Much of the techniques you applied to Mars might apply here as well. In addition we'd emply two kinds of starships, the fast ones and the slow ones. The fast ones take about 440 years to reach Alpha Centauri traveling at about 1% of the speed of light, these ships carry the robots that perform the terraforming operations on the planet, the slow ships travel 0.00044 times the speed of light, they economically carry millions of colonists in world ships that take 10,000 years to arrive at the planet orbiting Alpha Centauri. The Robots in the meantime build more of themselves and begin terraforming operations, trying to alter the planet's atmosphere in time for the colonists who arrive in the generation ships to breath the air without assistance. the thing about Mars, is that humans would live in the solar system and develop it as they try to terraform Mars. Mars would likely have a population in the billions by the time terraforming is complete, but to get the feel of a virgin planet, you might want to terraform an extra solar planet while millions of colonists wait to get there. Perhaps a form of biostasis will be developed and generations of humans wouldn't have to live and die aboard worldships as they wait to get there. The question is, how to anticipate 10,000 years of human progress, this is a period roughly comparable to the lifespan of the human race as a species.

It wouldn't work to have millions of colonists in suspended animation while robots do all the terraforming work on Mars. I suspect that people might want to settle on the planet before the planet is ready, what do you think?

RickSmith · 2007-04-03 05:21:52

Hey Tom,
I have severe doubts about magical nano-tech. However, in principle there is nothing wrong with sending highly intellegence robots ahead to prepare an easily terraformable world ahead of human exploration.

If we develope a helium 3 economy we will have the energy density to be able to go to nearby worlds in under a human lifetime.

See "Entering Space" by Robert Zubrin.

Warm regards, Rick.

Tom Kalbfus · 2007-04-03 12:38:03

Nanotech isn't the only way to go.

The other option is to build conventional humanoid robots with human levels of intelligence that are fully capable of building more of themselves and building other things. Call them Asimov bots if you like.

The fast ships would travel at 0.01c and the slow ships would travel at 0.00044c and cross 4.4 light years in 10,000 years, giving the humanoid robots 9,560 years to terraform the hypothetical planet orbiting Alpha Centauri A.

The stars that might have Earth like planets which could be terraformed would be the following:

Star ----------------------> Distance ----------> Lum. (Sun = 1.0) Slow ---------> Fast -------> Time to terraform
Alpha Centauri A -------> 4.4 light years ---> 1.3 --------------->10,000 years 440 years -----> 9,560 years
Alpha Centauri B -------> 4.4 light years ---> 0.36 --------------> 10,000 years 440 years -----> 9,560 years
Epsilon Eridani ----------> 10.7 light years --> 0.30 -------------> 24,318 years 1070 years --> 23,248 years
Epsilon Indi --------------> 11.2 light years --> 0.13 -------------> 25,454 years 1120 years --> 24,334 years
Procyon A ---------------> 11.4 light years --> 7.6 ---------------> 25,909 years 1140 years --> 24,769 years
Tau Ceti -----------------> 11.9 light years --> 0.44 --------------> 27,045 years 1190 years --> 25,855 years
Omicron Eridani A ------> 15.9 light years --> 0.33 --------------> 36,136 years 1590 years --> 34,546 years
70 Ophiuchi A -----------> 16.7 light years --> 0.44 --------------> 37,954 years 1670 years --> 36,284 years
36 Ophiuchi A -----------> 17.7 light years --> 0.26 ---------------> 40,227 years 1770 years --> 38,457 years
36 Ophiuchi B -----------> 17.7 light years --> 0.26 ---------------> 40,227 years 1770 years --> 38,457 years
HR 7703 A ---------------> 18.4 light years --> 0.20 ---------------> 41,818 years 1840 years --> 39,978 years
Sigma Draconis ---------> 18.5 light years --> 0.4 -----------------> 42,045 years 1850 years --> 40,195 years
Delta Pavonis ------------> 18.6 light years --> 1.0 -----------------> 42,272 years 1860 years --> 40,412 years
Eta Cassiopeia A --------> 19.2 light years --> 1.0 -----------------> 43,636 years 1920 years --> 41,716 years

There are three enabling technologies for this,
first is the fusion drive, a laser sail with perhaps a mag sail, or a laser accelerated stream of light sail pellets deflected off of a mag sail etc.

The second technology is the ability to build robots that are as smart and as capable as humans.

The third technology is the successful suspended animation and reanimation of complex lifeforms such as we humans.

Substituting for the third is the building of generation arks, the storage of frozen fetilized eggs and artificial womb technology with robot nannys. The embryos would be brought to term 18 years before the slow ships arrival, gestated in artificial wombs and robotic surrogate parents would raise these children to adulthood and train them in the skills they need to survive in the terraformed planet ahead. The fast ships would have brought other life forms ahead and gestated them similary, and they planet would already be sufficiently stocked with them by the time the human colonists arrive. It seems the time scales of interstellar colonization and terraforming planets match pretty well. No need for the humans to live under domes once they get there.

As you know the slow travel time is more economical for the colonists and more affordable. Suspended Animation is really required if the colonists wish to go themselves. invitro storage is required if they wish to send their children.

A generation ship where humans and animals grow live and die over a period of 10,000 years and more is a bit troublesome, with humans more than with animals. Getting an entire ecosystem in an O'Neill type babitate accelerated to 0.01c is bound to be expensive, there is no guarantee that the eco-system could be kept stable over several centuries with robot attendents. With humans over tens of thousands of years, there is no telling how that society will evolve, and the humans might evovle somewhat and have adapted to zero population growth in the conficed space of their colony, and might not be so well adapted for the new planet once they arrive, so its better is a suspended animation technology were to be developed and the colonists arrive in a sleeper ship.

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Re: Giving Mars Back Its Hearbeat - 7 parts Astrobiology.net series

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#14 2007-04-01 06:04:49

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