Elon Musk says he will put millions of people on Mars.

[Skipjack]

3000 tons

How many tons of raw materials a day do you have to process for that?

[williatw]

Hey, I am willing to learn new stuff and new info is always good. But this does seem to me like they are underestimating the size of an entire planet. Think of the entire industry and transportation of earth and what it has really done to the climate here (very little). I mean, all the green house gasses on earth (including the ones they are proposing which are present here as well and by far not all are manmade either) have managed to raise the temperature so little that people are still arguing about the temperature increase being actually true.
Even if these proposed gasses are 16000 times are efficient, one would need the equivalent of about 1 million fully industrialized people (and the equivalent of their factories and transportation) to even make a small dent in the temperature on mars. One would probably need even more to actually cause the runaway effect that was predicted there. It would take thousands of these factories and an infra structure to supply them with raw materials to do all this.

Quoting McKay: To bring "just a few parts per million" of PFCs to the Red Planet would be a monumental task, both expensive and time-consuming. We must manufacture PFCs on Mars from the materials on the planet; there is no other practical way.
No one is saying it would be easy..just the best idea so far considered. Think one million colonists is over stating (not like we are really trying to warmup the planet just an outgrowth of our use of fossil fuels), though I would agree probably many thousands of colonist. Wouldn't imagine something that ambitious happening until there was such a substantial human presence on mars, but they would be "industrialized" from the start.

[choff]

Some SF movies have suggested life could survive in deep ravines on Mars. Underground colonies would have better luck than anything on the surface. I just wish there was some way to terraform Venus, the gravity and orbit are better suited, just too darn hot!

[Skipjack]

Choff, I have been thinking about Venus a lot lately as well. Venus does have a lot of advantages, as you say.

The biggest problem with Venus that I see is the makeup of the atmosphere. This is some very nasty stuff!
One would have to somehow change the makup of the atmosphere. If we e.g. were able to develop a self replicating organism, that is resistant to the temperature and the corrosive atmosphere that could then literally eat the components that we dont want (and settle as dust on the ground), this could actually work.
Another approach could be lowering the temperature. There are concepts for geo engineering here on earth that are meant to fight global warming. Maybe we can apply the same to Venus?
Or maybe a combination of concepts...
How about we open a new thread for that and do some collaborative tinkering?

[hanelyp]

At the right altitude over Venus, temperatures are comparable to Earth surface. If a microbe could maintain such altitude, temperature wouldn't be a problem. But if the objective is to process CO2 into free O2 + leftovers, the leftovers will have a tendency to react with the O2 to remake the CO2. Microbe constructed O2 balloons might help both problems.

One idea I've had is that if sun shades could cool Venus for an extended period, much of the CO2 would reach with local rocks. High altitude microbes might be engineered to modify day vs. night side albedo.

Another problem terraforming Venus is the rotation rate. Crashing an asteroid into the planet to fix that would spill a fair amount of the excess atmosphere.

[williatw]

... just a few parts per million of the super-greenhouse gases ...

Let's examine that.

The Mars Atmosphere is 25 teratonnes, according to Wikipedia, so 1 part per million would be 25 million tonnes. Let's say that you have 25 factories in production. If each factory produced roughly -

3 tonnes per day- about 1000 tonnes per Earth year, 1000 years for 1 million tonnes
30 tonnes per day- about 10,000 tonnes per Earth year, 100 years for 1 million tonnes
300 tonnes per day - about 100,000 tonnes per Earth year, 10 years.

Now, is 1 part per million enough, or do we need 10 or 100 parts per million? How much mass needs come from Earth for each factory?

I wrote, "Let's examine that." I've examined, my conclusion is that a planet is a big place. Now, you examine. I await your conclusions.

Lets see from wikipedia: http://en.wikipedia.org/wiki/Nitrogen_trifluoride

The STD enthalpy of formation of NF3 is -31.4kJ/mol. Crude measure of how much energy it takes to make. Works out to be about 1.5MW of continuous power to make the 300metric tons per day. Not counting the cost of mining martian regolith & transporting the raw materials to the factories. 100 of them on Mars seem doable powered by polywell or one of the those modular reactors like Hyperion: http://en.wikipedia.org/wiki/Hyperion_Power_Generation
Each one produces 70MW thermal 25MW electrical power (looks like each one could easily run 10 factories).
You said 10yr to make 1ppm of the gas with 25 factories. Why don't we go with 100 factories instead, & lets assume we need 30ppm. So assuming: 10yrX30=300yrs. But I an assuming 100 instead of 25 factories and NF3 is about 3X times more potent than PFC's. So 300yrX25/100/3= get about 25yrs from the time the 100 are operational. Assuming the colony pop by the time they start serious construction is 50K or better, if only 20% of colonist involved that gets us a labor force of 10,000 highly skilled laborers

[Aero]

MSDS

EXPOSURE LIMITS:
NITROGEN TRIFLUORIDE:
10 ppm (29 mg/m3) OSHA TWA
10 ppm (29 mg/m3) ACGIH TWA
10 ppm (29 mg/m3) NIOSH recommended TWA 10 hour(s)
10 ppm (30 mg/m3) UK OES TWA
15 ppm (44 mg/m3) UK OES STEL

[williatw]

MSDS

EXPOSURE LIMITS:
NITROGEN TRIFLUORIDE:
10 ppm (29 mg/m3) OSHA TWA
10 ppm (29 mg/m3) ACGIH TWA
10 ppm (29 mg/m3) NIOSH recommended TWA 10 hour(s)
10 ppm (30 mg/m3) UK OES TWA
15 ppm (44 mg/m3) UK OES STEL

Okay but remember we would not be breathing it...it is being outgassed into the Martian air which is unbreathable. Even after all the CO2 and water has outgassed the Martian air would be unbreathable anyway. Mars would have a thick atmosphere with warm climate liquid water on the surface but you would still need a breathing mask with O2(though you could get by with normal clothing, no spacesuit). If you were breathing the mars air without a breathing mask you would asphyxiate in minutes, 10 hr exposure limits would be the least of your problems.

[IntLibber]

http://www.newscientist.com/article/mg2 ... ?full=true

http://nextbigfuture.com/2011/12/elon-m ... ns-of.html
He does not say how he will pay for it...but low billions sound like private would work. sounds like "Bank of Mars is good to go". viewtopic.php?t=3383

I am very much a supporter of the idea that humanity should make Mars habitable, but I have been dismayed by recent speculation that the lack of a powerful magnetic field surrounding Mars will allow life destroying radiation to hit the surface, thereby rendering it unfeasible to survive there.

Now I and some of my friends have speculated as to the possibility of creating an artificial magnetic field for Mars, but it is still an open question whether such an idea is feasible.

Also, the absence of a significant moon is another detriment for the planet. Likewise the recent discovery that the solar wind seems to be sweeping up great chunks of the Martian atmosphere and throwing it out into space. (As it is also doing to Earth.)

Mars needs more mass and quite likely more water. Perhaps we could steer some asteroids\comets\debris into it to create a bigger moon, and maybe raise the mass?

Mars is going to need a lot of terraforming to become a decent planet.

Not a lot. If we build a CFC production facility on Mars that would equal the human CFC output annually prior to the montreal protocol, and released all that CFC into the martian atmosphere, within 10 years, it would be warm enough to outgass enough CO2 to push the atmospheric pressure over 300 millibars and make 60% of the martian surface a shirt sleeve environment for most of the year. All you would need is an oxygen mask, but no pressure suit would be necessary. Thats when you introduce plants on a wide scale and you convert some of the CO2 into O2, but the atmosphere will be thick enough to equal that on top of Everest, which is more than thick enough to protect life forms on the ground and in the water. it will also melt the martian glaciers and cause the northern basin to fill and become a shallow ocean.

[Diogenes]

Some SF movies have suggested life could survive in deep ravines on Mars. Underground colonies would have better luck than anything on the surface. I just wish there was some way to terraform Venus, the gravity and orbit are better suited, just too darn hot!

A few years ago, I speculated on the notion of putting talc (or some better substance) into the Lagrange point between Venus and the Sun, and carefully puffing it into a cloud. Likewise, talc could be put into a smeared orbit around the planet in order to provide further temporary shading.


This idea is relatively easy. (Hell, we could perhaps even use moon dust and a mass driver of some sort. ) Don't know how much cooling might be had by this technique, or how long such a cloud might last in the Lagrange point, but it might last decades or centuries.


Anyone got a better idea?

[krenshala]

http://www.newscientist.com/article/mg2 ... ?full=true

http://nextbigfuture.com/2011/12/elon-m ... ns-of.html
He does not say how he will pay for it...but low billions sound like private would work. sounds like "Bank of Mars is good to go". viewtopic.php?t=3383

I am very much a supporter of the idea that humanity should make Mars habitable, but I have been dismayed by recent speculation that the lack of a powerful magnetic field surrounding Mars will allow life destroying radiation to hit the surface, thereby rendering it unfeasible to survive there.

Now I and some of my friends have speculated as to the possibility of creating an artificial magnetic field for Mars, but it is still an open question whether such an idea is feasible.

Also, the absence of a significant moon is another detriment for the planet. Likewise the recent discovery that the solar wind seems to be sweeping up great chunks of the Martian atmosphere and throwing it out into space. (As it is also doing to Earth.)

Mars needs more mass and quite likely more water. Perhaps we could steer some asteroids\comets\debris into it to create a bigger moon, and maybe raise the mass?

Mars is going to need a lot of terraforming to become a decent planet.

Not a lot. If we build a CFC production facility on Mars that would equal the human CFC output annually prior to the montreal protocol, and released all that CFC into the martian atmosphere, within 10 years, it would be warm enough to outgass enough CO2 to push the atmospheric pressure over 300 millibars and make 60% of the martian surface a shirt sleeve environment for most of the year. All you would need is an oxygen mask, but no pressure suit would be necessary. Thats when you introduce plants on a wide scale and you convert some of the CO2 into O2, but the atmosphere will be thick enough to equal that on top of Everest, which is more than thick enough to protect life forms on the ground and in the water. it will also melt the martian glaciers and cause the northern basin to fill and become a shallow ocean.

A friend of mine had an interesting idea to help terraform mars: send cold adapted kudzu cuttings to the planet (being very careful not to release any of it here on earth ).

The drawback to this plan is also its advantage. That stuff just won't die, except to cold, currently. He said he accidentally ran over a plant with the lawnmower once, and every single piece of leaf and vine turned into a new kudzu plant. Being in South Carolina, during the next summer each of those cuttings would grow 8 to 16 inches (20 to 40 cm) a day.

And it can be manufactured into a large number of useful items just as hemp plants can.

[Diogenes]

Some SF movies have suggested life could survive in deep ravines on Mars. Underground colonies would have better luck than anything on the surface. I just wish there was some way to terraform Venus, the gravity and orbit are better suited, just too darn hot!

A few years ago, I speculated on the notion of putting talc (or some better substance) into the Lagrange point between Venus and the Sun, and carefully puffing it into a cloud. Likewise, talc could be put into a smeared orbit around the planet in order to provide further temporary shading.


This idea is relatively easy. (Hell, we could perhaps even use moon dust and a mass driver of some sort. ) Don't know how much cooling might be had by this technique, or how long such a cloud might last in the Lagrange point, but it might last decades or centuries.


Anyone got a better idea?

After further thought, the solar wind would probably blow it away rather quickly.

[KitemanSA]

After further thought, the solar wind would probably blow it away rather quickly.

Plus the fact that the L1 point between the sun and Venus is not stable to begin with. Nothing placed there will stay there without active re-centering. Only the L4 and L5 points, which would provide no shade) are three dimensionally stable. And I suspect that Mercury would play hob with Venus' L4&5.

How bout dipping some of the CO2 out of Venus' atmosphere and sending it to Mars? Two (snap-snap) two (clap-clap) two planets at once.

[D Tibbets]

The perhaps biggest problem with Venus, is that as it heated up any water evaporated, ant then as it reached the top of the atmosphere it was split by UV radiation and the hydrogen was lost to space, much of the oxygen probably ended up in CO2. Without water, any kind of biological activity like photosynthesis is impossible. Mars has lots of water (ice) that could be harvested, Venus may have none. Also, the scale of atmosphere management is much different. On Mars you only have to change the atmospheric density by ~ 1 Earth atmosphere. On Venus the change would need to be ~ 400 atmospheres.

Dan Tibbets

[rjaypeters]

After further thought, the solar wind would probably blow it away rather quickly.

A few years ago, someone posited putting lots of relatively small, smart mirrors at the relevant Lagrange point (L1) to reflect a small fraction of insolation.*

The twist was the mirrors would not attempt to completely retro-reflect the light back toward the sun, but deflect it juuuuust enough to miss the planet. The small deflection of the light momentum kept the Lagrange orbit relatively undisturbed and the each mirror would arrange the pointing vector to assist orbit maintenance.

IIRC, the author thought the tiny satellites would have two small mirrors on "wings" to develop the torques for pointing.

*The idea was part of an article describing geo-engineering (maybe in Popular Science) to protect Earth from global warming, but I saw the idea had wider application.