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http://www.space.com/scienceastronomy/0 … found.html
See also: http://en.wikipedia.org/wiki/Kuiper_belt about the size distribution...
If really out there we have on disposal QUADRILLIONS ( N x 10exp15 !!!!!!!! ) of 100 meter in diameter ice "rocks", than these with diam. of 10m are ~10exp4 times more numerous, and the 1m ones are 10exp8 times more numerous than the 100m ones... Taking about 0.5x10exp9 of kg mass per the 100m wide ones... than the shear mass of the 100m ones should be in the order of the Earth_mass...
Because the number increases 10 000 times with each tenfold decrease in the diameter, but the mass falls with 1000 times -- each tenfold decrease in diameter puts us in class with about 10 times more shear mass... ~1 earth mass for the sum of all 100m ones, ~10 for the 10m ones -- ~100 ( ???!!!) for the one meter wide meteoroides... Such size distribution ratios are not so smooth -- cause the coalescence vs. fragmentation trends break the curve -- but this resolves the "mistery of the missing mass"... In KBO there were postulated and simulated about 30 earth masses -- and that`s exactly where they are -- in pieces of dozens of meters wide... TNO meteoroids!
Perfect for handling:
1. Send a little automated factory provided with solar power collectors -- still abundant solar power between 30 and 55 AU ( although the KB should go further up to at least 1000 AU intermixed with the Innermost Oort cloud...). In order to conentrate earth level of focused solar power on 1 meter wide body -- one needs only about 40 meters wide concentrator. In order to make the concentration system orientation independent -- make spheres - plastic tubes engulfing the whole object...
... the automated factory produces:
1.1. plastic sheat ( say 5 grams per square meter - areal dencity) with some photovoltaic vacuum dispersed coating... which serve as energy converter AND radar sensor...
1.2. Free-electron lasers -- for propulsion, communication, detection...
2. The plastic back seals into spheroid shape around the target 1m - to 10m wide and uses the solar power to feed the laser which evaporates volatiles from the body in order to inflate the bag and to increase the power collection surface.
3. The volatiles ( mainly hydrogen) "fried" with the FEL or directly with the electron beam ( cause the FEL is nothing more than a TV set with irregulary arranged magnets ) -- are used as super high specific impulse jet...
4. If the system of gasbag producers replicates once a year , than in several decades including the trip time ( you just decelerate the packaged piece of ice from its very modest less than 1 km/s orbital velocity and it falls down towards the Sun... the trick is the planet which needs volatiles to be on the way of the fall...)
Such way in geometrical progression, and if these KB iceteroids are so numerous , all the inner planets could be provided with hydro- and atmosphere: The Gallileans , Mars, the Moon, Mercury... for literally no price --
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I haven't thought extensively about the outer solar system, but how much solid mass in terms of frozen C02,N, or H would be required to create 1bar of pressure on Mars?
If a number of comets 100m-1km in diameter could be introduced to Mars, without an impact that obscures the surface, how many would it take?
If the caps and regolith don't posses enough gas, and clearly there isn't enough Nitrogen, I think impacts are the most efficient way to import volatiles. Deep Impact showed that we can land a craft on a similar body.
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I haven't thought extensively about the outer solar system, but how much solid mass in terms of frozen C02,N, or H would be required to create 1bar of pressure on Mars?
If a number of comets 100m-1km in diameter could be introduced to Mars, without an impact that obscures the surface, how many would it take?
Zubrin says 40 billion tons of ammonia (4 asteroids, each 2.6 km in diameter) ...
http://www.users.globalnet.co.uk/~mfogg/zubrin.htm
Welcome to New Mars, by the way.
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Thanks for the welcome fractal.
I'm a little new to the quantitative side of the terraforming debate. Do you have any idea, how many bodies of such composition are believed/known to exist?
It seems to me harvesting volatiles from small cosmic bodies would be a realistic and relatively expedient way to import volatiles. Of course the best course would probably be to start with greenhouse gases like Ammonia and Methane, to see if the caps really contain the amounts of CO2 that some seem to think. My guess is that there won't be anywhere near a bar's worth of CO2 in the caps, but of course this is good for trying to create a biosphere, because there should be room to introduce Nitrogen and other gas volatile s, without creating an overpressured atmosphere.
It seems like several asteroids of the right composition and size could put us on the relative fast track to a warmer Mars.
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I'm a little new to the quantitative side of the terraforming debate. Do you have any idea, how many bodies of such composition are believed/known to exist?
There are a group of suitable bodies between Saturn and Neptune called the Centaurs ...
http://en.wikipedia.org/wiki/Centaur_%28planetoid%29
... all the ones we can see are way too large, but we have every reason to believe that such groupings obey a power law distribution (e.g., crater size on Luna and the planets) so we should be able to take our pick. If not, we will have to go out beyond Neptune to the Kuiper belt ...
http://en.wikipedia.org/wiki/Kuiper_belt
... where there are very many suitable objects.
It seems to me harvesting volatiles from small cosmic bodies would be a realistic and relatively expedient way to import volatiles.
The thing that makes it work is that we can use the bodies' own volatiles to move it. Just add (probably nuclear) energy.
Of course the best course would probably be to start with greenhouse gases like Ammonia and Methane, to see if the caps really contain the amounts of CO2 that some seem to think. My guess is that there won't be anywhere near a bar's worth of CO2 in the caps
No, recent MARSIS (ground penetrating radar) data has the poles as nearly pure water ice with just a dusting of CO2. Good news in one way, bad news for terraforming though. The SHARAD instrument on the Mars Reconnaissance Orbiter (safe in orbit, just about to begin science observations) should give us even more data.
but of course this is good for trying to create a biosphere, because there should be room to introduce Nitrogen and other gas volatile s, without creating an overpressured atmosphere.
There isn't going to be a problem with overpressure. Because of the lower gravity, it'll be a challenge hanging onto any volatiles that we do import. Also, a lot of nitrogen is needed for plant growth, and, of course, it would be nice to have an atmospheric composition closer to Earth's.
It seems like several asteroids of the right composition and size could put us on the relative fast track to a warmer Mars.
Yes indeed. There is a bit of a dilemma though. Should we postpone any colonization until after bombardment (the energies released will be unprecedented)? Or do we need to give Mars some new ammonia moons and the Martians a way to mine them?
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noosfractal,
Maybe not an actual moon/asteroid capture for mars, but a very bad orbit that places lots of stress on the asteroid.
If the orbit is sloppy enough it will break up and fall in pieces to mars.
Even with this more gentle approach I wouldn't want to be living on mars at the time.
With so much rust and peroxide on mars i doubt the poles will have much co2, but ground chemistry below the surface might surprise us as to contents with warmth.
Nitrogen is only really needed for plants.
Peas and beans and a host of other plants do well with little, so engineering nitrogen fixing bacteria might go a long way to reducing nitrogen needs.
Or we can grow everything in greenhouses that cycle what nitrogen we have introduced in an area.
Science facts are only as good as knowledge.
Knowledge is only as good as the facts.
New knowledge is only as good as the ones that don't respect the first two.
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Maybe not an actual moon/asteroid capture for mars, but a very bad orbit that places lots of stress on the asteroid.
If the orbit is sloppy enough it will break up and fall in pieces to mars.
Even with this more gentle approach I wouldn't want to be living on mars at the time.
That's an interesting idea, but as you say the big pieces are still a threat. May be some automated moon miners could be set up to provide a steady stream of ammonia rain.
With so much rust and peroxide on mars i doubt the poles will have much co2, but ground chemistry below the surface might surprise us as to contents with warmth.
Well the atmosphere is currently 95% CO2, so it was a good guess that the poles were frozen CO2, but it doesn't seem to have turned out that way. You're right though, how the Martian soil responds to heating and changed atmospheric conditions is a big unknown right now. It may release a bunch of CO2 or it may soak it up like a sponge. Hopefully the planned MSL will give us a little bit more data on this front, but it won't be able to give us a wide area survey. We'll probably have to wait for a manned mission for solid results.
Nitrogen is only really needed for plants.
Peas and beans and a host of other plants do well with little, so engineering nitrogen fixing bacteria might go a long way to reducing nitrogen needs.Or we can grow everything in greenhouses that cycle what nitrogen we have introduced in an area.
But once plants can grow in the wild, they can really help the terraforming process - making oxygen, reducing albedo, stabilizing soil, providing habitat, the beginnings of a robust Martian biosphere - so it'd be great to have plenty of nitrogen for them. It might be harder to bring in more nitrogen later.
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I haven't thought extensively about the outer solar system, but how much solid mass in terms of frozen C02,N, or H would be required to create 1bar of pressure on Mars?
If a number of comets 100m-1km in diameter could be introduced to Mars, without an impact that obscures the surface, how many would it take?If the caps and regolith don't posses enough gas, and clearly there isn't enough Nitrogen, I think impacts are the most efficient way to import volatiles. Deep Impact showed that we can land a craft on a similar body.
Why do we want any CO2? The partial pressure of CO2 is already the same as it is on Earth. What we really need to do is add nitrogen, oxygen and water.
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noosfractal,
A direct thumping impact might be better or worse way to go, all depends on that ground chemistry like you say.
Gentle approach if the ground chemistry isn't going to help us, and we want to terra form relatively quick without much surface damage or dust.
The heat from an impact might be a good or bad thing.
Guess we will have to wait to see what is really below the surface.
Or maybe even a direct impact with one of the moons might yield even more chemical goodies.
We could probably terra form Mars much easier without anyone living on it than we could with anyone there.
Anything we do would be a risk after it has colonists.
I guess if we are bringing ammonia to mars we probably could alter the plant life to respond directly to is as a source of energy instead of nitrogen, or at minimum with little nitrogen.
I bet a few plants on earth already are pretty good at using bacteria to get energy directly form ammonia.
I think the nitrogen problems on mars will be in the very long time scales before we have to worry about it anyway.
We will probably have a few hundred to few thousand years before any terra forming effort produces a stable enough place for plant life to exist on the surface.
First stock to buy on Mars as a colonist will be anything to do with greenhouse equipment.
Science facts are only as good as knowledge.
Knowledge is only as good as the facts.
New knowledge is only as good as the ones that don't respect the first two.
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Tom Kalbfus,
We might not need to add anything to Mars to make it a habitable place.
If the poles are indeed mostly H20, then just bringing in super greenhouse gasses will release it as the temperature rises.
We might even be able to make those super greenhouse gasses on mars or one of the moons.
Nitrogen might be all Mars needs after that.
Where we get that from is a good question.
Science facts are only as good as knowledge.
Knowledge is only as good as the facts.
New knowledge is only as good as the ones that don't respect the first two.
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Theres a reason why all those votiles are so abundant in the outer solar system and not in the inner sollar system.
How do we intend to insolate these objects on their journey inword?
"Yes, I was going to give this astronaut selection my best shot, I was determined when the NASA proctologist looked up my ass, he would see pipes so dazzling he would ask the nurse to get his sunglasses."
---Shuttle Astronaut Mike Mullane
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The bigger problem is not identifing or how to get them from where they are, but how much of the same items that we seek, will we expend to get them from where they are, to where we need them.
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SpaceNut,
Commodore,
Deep impact told us a lot about the inside of a comet, if we did the same thing on mars it would reveal exactly what we need to go get and how much.
I agree that getting as little as we need for mars is all we should get.
No point in overkill of items we might not need.
If its small amounts of things we need then conventional methods will work fine.
If its larger quantities we need then asteroids/commets are probably the way to get them to mars.
Science facts are only as good as knowledge.
Knowledge is only as good as the facts.
New knowledge is only as good as the ones that don't respect the first two.
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Or maybe even a direct impact with one of the moons might yield even more chemical goodies.
That's a really interesting idea. We'd have to be careful not to change the orbit of the moon too much - they aren't that big.
We could probably terra form Mars much easier without anyone living on it than we could with anyone there.
Anything we do would be a risk after it has colonists.
That's the dilemma. My guess is that there will be colonists before there is sufficient funding for terraforming.
I guess if we are bringing ammonia to mars we probably could alter the plant life to respond directly to is as a source of energy instead of nitrogen, or at minimum with little nitrogen.
I bet a few plants on earth already are pretty good at using bacteria to get energy directly form ammonia.
Actually ammonia + water = fertilizer, although ammonium nitrate (ammonia + nitric acid) is gentler on the soil.
I think the nitrogen problems on mars will be in the very long time scales before we have to worry about it anyway.
We will probably have a few hundred to few thousand years before any terra forming effort produces a stable enough place for plant life to exist on the surface.
Yeah, you're probably right. The atmosphere of Mars is 2.5% nitrogen already, so there'll be plenty to work with for the first settlers.
First stock to buy on Mars as a colonist will be anything to do with greenhouse equipment.
I think Mars Energy LLC might be a good buy as well
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Theres a reason why all those votiles are so abundant in the outer solar system and not in the inner sollar system.
How do we intend to insolate these objects on their journey inword?
I don't think we would. Just take boil-off into account when selecting the target.
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The bigger problem is not identifing or how to get them from where they are, but how much of the same items that we seek, will we expend to get them from where they are, to where we need them.
Zubrin says ...
http://www.users.glbalnet.co.uk/~mfogg/zubrin.htm[/url]"]Consider an asteroid made of frozen ammonia with a mass of 10 billion tonnes orbiting the sun at a distance of 12 AU. Such an object, if spherical, would have a diameter of about 2.6 km, and changing its orbit to intersect Saturn's (where it could get a trans-Mars gravity assist) would require a DV of 0.3 km/s. If a quartet of 5000 MW nuclear thermal rocket engines powered by either fission or fusion were used to heat some of its ammonia up to 2200 K (5000 MW fission NTRs operating at 2500 K were tested in the 1960s), they would produce an exhaust velocity of 4 km/s, which would allow them to move the asteroid onto its required course using only 8% of its material as propellant.
Gravity assist is our friend.
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noosfractal,
I think the Mars moon impact would be a cool way to slow an impactor down, but as you point out an easy way to destroy a moon.
If we did use such a method we would want to know the contents of the moon as it would be pretty easy to leave Mars with a debris ring for countless eons.
Last thing we would want would be a sun shield we cant remove.
Ammonia in its raw form diluted with water will be very difficult for most plants to use.
We would have to be very careful on how much we imported to mars, to much could be just as bad or worse than none.
Even human urine that is a small percentage of ammonia continually used in an area will kill plants on earth.
Anaerobic bacteria should have a nice environment though.
Using the 2.5% or mars atmospheric nitrogen with ammonia to create ammonium nitrate would produce a huge quantity of fertilizer for Mars.
Getting what we need to Mars...
Instead of trying to move a single asteroid to mars with brute force we could move two with a tether between them.
If we use difference in speed or gravity between the objects we should be able to move one of them with little or no brute force.
Or we could do a gravity assist of smaller object to larger ones.
Moving a 1km object with a 10km objects gravity etc.
Science facts are only as good as knowledge.
Knowledge is only as good as the facts.
New knowledge is only as good as the ones that don't respect the first two.
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I think the Mars moon impact would be a cool way to slow an impactor down, but as you point out an easy way to destroy a moon.
If we did use such a method we would want to know the contents of the moon as it would be pretty easy to leave Mars with a debris ring for countless eons.
Last thing we would want would be a sun shield we cant remove.
It would look kinda cool from Earth though Seriously, though, it might be desirable to move one of the moons into a higher so that it doesn't interfere with the Martian space elevator (which would use the other moon as its counterweight).
Using the 2.5% or mars atmospheric nitrogen with ammonia to create ammonium nitrate would produce a huge quantity of fertilizer for Mars.
Yeah, the first settlers will be fine. But we'll need more to turn Mars green.
Instead of trying to move a single asteroid to mars with brute force we could move two with a tether between them.
If we use difference in speed or gravity between the objects we should be able to move one of them with little or no brute force.
Oh interesting! An MX tether assist from the Kuiper belt. Have you seen any calculations on this idea? How would it work? Find a large Kuiper object with a moon. Tie the moon to the object. Reel it in. Then let it go when it is pointed the right direction. I wonder what sort of delta-v you could get this way?
Or we could do a gravity assist of smaller object to larger ones.
Moving a 1km object with a 10km objects gravity etc.
Yes, definitely - even if the tether idea can't work, you could give the moonlet a running start.
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You actually only need to move Phobos if the elevator is stationary, but what if its not? What if you rotate Phobos and then extend two cables from it so that each end in not moving in relation to the ground when it touches down, sort of like the spokes of a giant invisible wheel. I think it would take less energy and reaction mass if you tried to spin up Phobos that to move it from its orbit. Phobos would stay in its orbit, and two or more cables would extend from its surface, each one would be the same length as Phobo's minimum orbital altitude. You could have one cable, two, four, maybe eight all radiating outward from phobos and there would be a number of spots where the cable would touch down, and it could hook onto something and then fling it into space. Phobos has quite alot of mass and momentum, so it could fling quite a bit from Mar's surface and into orbit. You could extend a similar cable from Deimos and time the rotation just right so that it always misses Phobos.
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noosfractal,
That would be a cool fireworks display when an asteroid hit a Martian moon.
You could probably sell tickets to that
I haven't done any math or seen any on the tether to so if its viable.
Not sure the delta v would be big enough to do the tether all alone, but good enough to start something moving towards a gravity assist or a few gravity assists.
At worst we could cut the brute force methods to maybe 10% the original needs.
In the kb we got to have many moons and many objects that will offer good assists to speed up objects we start moving.
It would be nice to move those 1 or 2 km objects to mars without having to build a monster spacecraft to move asteroids all with brute force.
Probably 1 or 2 of those well selected kb asteroids and lots of super greenhouse gas on mars and we would see mars a much altered place.
Maybe if the ground chemistry is good at mars just the super greenhouse gas will do what we need with no importation. (i have my doubt we are that lucky)
No doubt we could mass produce greenhouse gasses right on Mars with elements that already exist there.
Tom Kalbfus
Will Mars need an elevator?
With 1/3 gravity and thin atmosphere it isn't a difficult place to build a mass driver or small conventional rockets to get into orbit.
Science facts are only as good as knowledge.
Knowledge is only as good as the facts.
New knowledge is only as good as the ones that don't respect the first two.
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Maybe not, we could probably leave the Moons alone. The place we do need an elevator is on Earth, it doesn't matter if we can lift things easily off of Mars, if our main problem is getting people off Earth. Some kind of conveyor type of system will be required to get large numbers of people off of Earth. We can hardly utilize the resources of the Solar System if we're stuck on one planet. A Martian elevator would make Mars more compedative with the asteroids. I think the place where the bulk of humanity is going to live will be in free floating space colonies that rotate to produce their own gravity. I think long term residency on Mars will produce human adaptation to its low 0.38-G gravity field, that sort of limits the places humans from that planet can go, and I'm not sure whether their will be long term health problems. We already have enough problems of not getting enough exercise and becoming obese under a full 1-G of gravity!
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Hi Everyone,
Mars likely started off with a simular mix of volitiles as Earth. Then, where then has all of Mars' Nitrogen gone? The most likely theory (in my opinion) is that lightning has reacted the nitrogen in the air, producing nitrates. This would mean that underground there would be large nitrate beds (much like the ones they have discovered under Earth deserts).
Large impacts by iceteriods (planetoids made up largely of ice, dust and frozen gasses) can vaporize some of these nitrate beds back into nitrogen gas. Thus you get the nitrogen from the iceteroid (likely in the form of ammonia) plus a bonus from deep in the ground.
Don't worry about the form of the nitrogen. Once we have enough in the air, nitrogen fixing bacteria can put it into organic forms.
While nitrogen is not at all a green house gas there are a number of reasons why we would like to add more to Mars' atmosphere.
1) A thicker atmosphere can store more heat as vibrational energy in the molecules.
2) A thicker atm. can move more heat with wind and convection currents. In particular it is better at moving heat from the equator poleward.
3) Nitrogen will act as a buffer gas for the oxygen we hope to add.
4) Acts as greater radiation shield.
5) Protects against smaller meteors.
6) N2 will provide more distance between our (potential) ozone layer & the ground.
7) Needed for nitrogen fixing plants.
8) Any gas is valuable in Mars' near vacuum right now.
Basically, tho not a green house gas, we would like to add a significant amount of N2 to Mars' air. Any extra nitrogen is a bonus if we can get it.
I think that the Martian colonists will be the only ones willing to pay for volitiles from the Kuiper belt so they will make sure that the iceteriods don't smash their domes. I could easily see dumping the stuff on the southern highlands while the bases are built on the equator and just north of the equator.
Warm regards, Rick
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