Removing 1% of Earth's Water

[CraigD]

Well, I've been working on this, and here's what I've found.

…

41.8 meters! :)

 

This value is too huge. Definitely more tham 20 feet. Will somebody having some free time bother to check my calculations? forty meters seems... kinda crazy.

Starting with the following from the wikipedia article “ocean”,

volume of ocean (V): 1340000000 km^3

area of ocean (A): 361000000 km^2

change in depth = 0.01V/A = 13400000 km^4/361000000 km^2 = about 0.037 km = 37 m, close to the 41.8 m result of Ron’s more detailed calculation.

[CraigD]

We’ve already concluded in this thread that 1% of Earth’s water is a lot of water, almost certainly more than could be practically transported from the deep gravity well of Earth to Mars. However, assuming that such a quantity of water could be delivered to Mars, via such approaches as capturing comets, a couple of interesting questions arise:

• What would Mars look like?
  Owing to the un-Earth-like topography of Mars, 1 or 2*10^16 m^3 of water would make for an un-Earth-like Martian ocean, with a single continent mostly south of the equator, and a vast polar ocean mostly north of it. Numerous small basins litter the high southern hemisphere, and a couple of great, deep basins so (Assume they’d hold water), you could distribute the water in many ways. The greatest Martian basin, Hellas Planitia, could alone hold 3*10^16 m^3, over 2% of Earth’s oceans.
  
• How long would it last?
  Mars likely lacks liquid surface water for a good reason – it’s not sufficiently massive to hold sufficient atmosphere to prevent it evaporating and being lost to space. “Big splash” terraforming would be a temporary fix – how temporary?
  
• Atmosphere and climate
  With all that water – much of it evaporated – what would the atmospheric pressure on Mars – currently less than 1 kPa (1000 ((kg*m/s)/s)/m^2), less than 1% of Earth’s, about what you experience on Earth at 30,000 m altitude (a bit higher than an SR71 Blackbird can reach) – be? High enough for a human without a pressure suit?
  

These aren’t new questions. They could likely be googled by a skilled searchist. Answering any of them from fundamental physics would be a pretty good workout.

[Boerseun]

This thread is actually quite a fun mental exercise.

 

Like you said, Craig, let's forget about the practical issues in moving 1% of Earth's water to Mars. Let's start from the assumption that you have it there. What'll happen?

 

My guess is that it would simply freeze, and over a few thousand years ablate away, and the bulk of the water would eventually migrate poleward to leave behind a dry and dusty Martian landscape, as it exists currently.

 

Having it bound to the poles, mixed with frozen CO2, won't be a completely bad thing, seeing as the ice could be actively mined by whoever gets it into his mind to settle there. And wherever it is to be used, and whatever gets spilled, will eventually end up back at the poles again. This will form a hydrological cycle in which the ice-miners (humans) play an integral part.

 

Just 2 cents' worth of flight-of-fancy...:cocktail:

[TheBigDog]

Building an atmosphere on Mars is a lost cause. You would be robbing the earth of its most precious resource, and using untold amount of her available energy to make an environment on Mars that would still probably never support human life.

 

You simply cannot turn Mars into the earth. It lacks a magnetic field to help preserve the atmosphere from solar forces. It has less gravity to hold on to a decent amount of atmosphere. So it is unlikely that under the best circumstances we could generate an atmosphere on Mars faster than it would be lost into space. If Mars had a thicker atmosphere in the ancient past, it was unable to maintain it. It lost it's abundance of life supporting resources and became a wasteland. So what will we bring to the table to change it this time?

 

It seems to me that the only way we will populate Mars is subterranean. We only need enough atmosphere and water for the tunnels and caverns that we would call home. Life would be difficult, and the whole proposition only happens if A) earth is willing to spend thousands of times more money on supporting a population on Mars than it would ever cost to support the same population on earth. Or :cocktail: we found some resources on Mars that would make it profitable to keep a population there to harvest those resources for earth.

 

I would not spend too much time on the puzzle terraforming Mars. When we populate other planets on a large scale they will not be in this solar system. They will be around other stars, and they will already have the basics for supporting humans before we get there. And that will be the grandest adventure in human history.

 

Bill

[CraigD]

Building an atmosphere on Mars is a lost cause.

Theory and data to date fail to convince me that this is so

You would be robbing the earth of its most precious resource,

I don’t think anyone’s seriously suggesting actually moving water from Earth to Mars, but just using “1% of Earth’s water” for comparison.

 

Most plans that involve importing lots of water to Mars (not all do, as there’s speculation that buried ice could provide enough liquid water for terraforming) involve getting it from comets. Though ambitious spaceflight engineering projects, in principle one can rendezvous with and maneuver a comet using mostly the comets own mass as reaction mass, for a modest expenditure of energy.

and using untold amount of her available energy to make an environment on Mars that would still probably never support human life.

Though smaller and further from the Sun than Earth, Mars still has a planet’s energy budget and resources of such engineering materials as silicates and metals, so a sensible assumption in a terraforming plan is that it would be energy-independent of the Earth’s resources. Though poor in many materials, and with an energy budget only 12% that of Earth’s, Mars still has a lot of material and energy – many times more than is currently used by all human activity on Earth.

 

I don't think enthusiasts are ready to give up on terraforming Mars.

[TheBigDog]

OK, lets walk through the exercise of bringing water to Mars with Comets.

 

Right now the atmospheric pressure on Mars is so low that it is nearly impossible to have liquid water. It goes straight from Ice to cold steam when exposed to the atmosphere. Solar wind blows away atmosphere from Mars because it has no magnetic field to protect it, and because its gravity is low. Before you can have anything other than ice, you need an atmosphere. How do you build an atmosphere? And how do you overcome the issue of the atmosphere blowing away into space?

 

Bill

[alxian]

I don’t think anyone’s seriously suggesting actually moving water from Earth to Mars, but just using “1% of Earth’s water” for comparison

 

quite so as i was wondering about robbing Venus of atmosphere that would be broken down in transit to Mars.

 

subjectively much more difficult and pointless than bring earth water to mars.. storing Venus atmosphere in tank on Mars until there was enough to release it all at once.. though dramatic and rip-off of Total Recall may be beneficial to a Mars colony as well as Venus colony. clearing up the atmosphere for ground settlements might take centuries who knows.. but space on earth will become a premium and mars will like like prime realestate at some point down the line S.A.R.

[CraigD]

And how do you overcome the issue of the atmosphere blowing away into space?

The short answer is, I believe, you can’t/don’t.

 

Barring some super-advanced (essentially sci-fi) engineering, any water and/or atmosphere added to Mars will eventually be lost. However, exploration of Mars have produced a widely-held consensus that Mars had a few 100,000 year “warm, wet” period, in which conditions were much more hospitable than they are now. A “temporary” alteration of the Martian atmosphere lasting even 1,000 years might prove of commercial value – it has, after all, a lot of “real estate”, and few commercial ventures look so far ahead that a 1,000 year in the future is considered.

[Boerseun]

I wonder if the "Martian atmosphere escaping due to abc" isn't an oversimplification of the matter.

 

Fact is, Mars has an atmosphere, the pressure comparable to an altitude of 30,000m on Earth. Which is quite a lot of air, if you keep in mind that we send 300- to 400-ton metal monsters flying well above it, on a daily basis - and under a much higher gravity load.

 

If Mars will lose anything you send there, why is there any atmosphere left? Why is there any atmosphere there currently, at all?

 

It's been hypothesised that Mars' flow erosion marks have been caused by volcanic (or impact) activity temporarily melting groundwater for a few thousand years, and then eventually freeze out again. Or, the water that was melted, will flow away, leaving erosion marks on the planet surface. It eventually seeps down into the ground again where it freezes once more. This makes the planet look like it had a "wet", thick atmosphere millions of years ago, and fuels speculation about Mars' lost atmosphere. Meanwhile, it's a punctuated operation that repeats every now and then - less often now, of course, as the solar system cleans itself of space debris over time.

 

There are even vast plains on Mars where the surface characteristics look like its a dust-covered ice sea, with all the cracks and flow marks you can find only on Earth's ice-covered seas and Europa's frozen surface. What you find on Mars don't give away the fact that its covered ice right away, seeing as its covered in dust and looks like the rest of the planet's surface. This is to be expected under the severe dust-storms found there. But there are no known processes (to the best of my knowledge) that'll create those cracks and flow shapes, apart from ice.

 

My personal guess is that there's a lot of water on Mars, subsurface. And, also, Mars has quite a substantial atmosphere for such a relatively small planet.

[CraigD]

I wonder if the "Martian atmosphere escaping due to abc" isn't an oversimplification of the matter.

I’d say that, more than oversimplification, explaining conditions on Mars involves a lot of very speculative guesswork. At this point, having collected several decades of data, a few things seem fairly certain:

• Based on direct measurement, the atmospheric pressure on Mars is far too low for liquid surface water
  
• Based on composition and arrangement of surface rocks and dust, this has not always been the case: Mars had substantial amounts of flowing, eroding, sedimenting surface water for at least thousands, likely hundreds of thousands of years.
  

My personal guess is that there's a lot of water on Mars, subsurface.

A lot of expert folk share your opinion. A lot more exploration, doing much more than just (literally) scratching the surface, need to happen before this can stop being more certain than an educated guess.

And, also, Mars has quite a substantial atmosphere for such a relatively small planet.

Here, I must disagree.

 

Here’s a quick look at the atmospheric pressure on a few moons and planets of comparable sizes

	Mass	Pressure
Earth	1	 1
Moon	0.012	 0.000000000000002
Venus	0.82	91
Mars	0.11      0.0079
Titan	0.022	 1.45
Io 	0.025	 0.0000000002

The relationship between mass and atmospheric pressure is not a straightforward one. Some very small bodies have atmospheric pressures greater than Earth's, while Mars, several times larger than Saturn’s satellite Titan, has 1/200th its atmospheric pressure, but millions of times the pressure of Jupiter’s Io, which is about the same size as Titan.

Fact is, Mars has an atmosphere, the pressure comparable to an altitude of 30,000m on Earth. Which is quite a lot of air, if you keep in mind that we send 300- to 400-ton metal monsters flying well above it, on a daily basis - and under a much higher gravity load.

I believe Boerseun’s made a unit conversion mistake. The maximum altitude of a typical commercial airliner is about 45,000 feet, or 14,000 m. The record for sustained altitude is 25,929 m, set by an SR-71 in 1976.

 

Though the surface air pressure on Mars is lower than any airplane on Earth can operate at, Mars’s lower (0.38 g) surface gravity means than flying an aircraft on mars, while substantially different than on Earth, isn’t likely to prove impractical.

If Mars will lose anything you send there, why is there any atmosphere left? Why is there any atmosphere there currently, at all?

At least a trace atmosphere has been found on every body with appreciable surface gravity that’s been observed for one. Why, and for how long any body will have its current atmosphere, is a complicated question for which I lack a ready answer.

[Boerseun]

Mea culpa. I suck. :(

 

This post actually goes to show that you should never drink without at least eating more htam you drink, or...uhhh...

 

*URP*

 

Lissen...

 

Lemme tell y ou,

 

er...

 

'kay;

 

See ya in the mornin...

[Boerseun]

Will reply Craig - I swear; this whiole thread thing is jus too complexical for mel I'm niot copping out, just gimme 24 or so hours.

 

Later,

 

Stanley

[Michaelangelica]

We may need to take out 1% to slow global warming

http://www.theenvironmentsite.org/forum/climate-change-forum/12592-water-vapour-biggest-ghg-13.html

 

Look at these interesting old techniques

Sharing Sustainable Solutions.org Information Center for Low-tech sustainability / Air Wells & Dew Ponds

 

What are the implications of finding methane on Mars?

What are the implications of finding water on Mars?

[belovelife]

Didn't pheonix lander find proof of water?

NASA - NASA Spacecraft Confirms Martian Water, Mission Extended

[Moontanman]

The whole problem of Terraforming Mars just show how much better it would be to build artificial colonies in space from materials found in space. The Lagrange points of Jupiter should be an ideal place to put such a manufacturing facility. In the future no planets will be needed, we'll build our own worlds :)

[belovelife]

I somewhat agree with you. Just the asteroid belt alone has enough matter to build a

living unit capable of supporting a colony. Although I still think that colonising mars may be good.

It would introduce humanity to a whole new level of living terms. Like the methane issue.

This could possibly be due to life on Mars. However slim chance that may be, we would have to learn to cope with this posibility. It may advance our knowledge of preventative medicine neccisary

for the possible integration with Alien species. Consider the amount of deaths from plague

caused when the europeans came to america. Now imagine that being exponetially worse.

Terraforming Mars and colonising it may be a neccisary stage in the evolution of humanity

as a galactic member. The lessons we learn could be priceless.

Like if the life on mars was extremely primitive in comparison to our own. Then we should,

after learning the base genome, be able to innoculate ourselves to be safe from the potential

viruses, and bacterial infections.

[Moontanman]

I somewhat agree with you. Just the asteroid belt alone has enough matter to build a

living unit capable of supporting a colony. Although I still think that colonising mars may be good.

 

The asteroids and other small objects like at the Lagrange points of Jupiter could be enough material to make tens of thousands of colony worlds, maybe even 100's of thousands. There Carbon content would be the limiting factor.

 

 

It would introduce humanity to a whole new level of living terms. Like the methane issue.

This could possibly be due to life on Mars. However slim chance that may be, we would have to learn to cope with this posibility. It may advance our knowledge of preventative medicine neccisary

for the possible integration with Alien species. Consider the amount of deaths from plague

caused when the europeans came to america. Now imagine that being exponetially worse.

 

Totally different thing, Microbes on the Earth are practically our twins compared to what life on Mars would be. It would be highly unlikely even if Mars had complex life forms for any disease organisms to be able to infect us. this has been discussed in other threads in this site.

 

 

Terraforming Mars and colonising it may be a neccisary stage in the evolution of humanity

as a galactic member. The lessons we learn could be priceless.

Like if the life on mars was extremely primitive in comparison to our own. Then we should,

after learning the base genome, be able to innoculate ourselves to be safe from the potential

viruses, and bacterial infections.

 

Terra forming Mars would take thousands of years, in the same time period we could make tens of thousands of artificial colonies. mars might be colonized but Terra forming it would be a different and probably overwhelming proposition when Artificial colonies with open air and lots of room would be readily available. when faced with the choice of living under ground in warrens with no open air or places to go, an artificial colony might be very alluring.