Asteroid mining

[lemur]

This is a neat idea. What kind of materials can you get from asteroids? How would a moon elevator work and why would it use less energy than rockets, and how much less? Also, why not just send robots to mine the asteroids where they are and just bring the really valuable stuff to Earth? Is there really that much use for a lot of iron (I assume this is the main metal astroids consist of)?

[Ophiolite]

This is a neat idea. What kind of materials can you get from asteroids?

Almost anything your heart desires.

 

Volatiles:

For life support - H2O, N2, O2

For propulsion - H2, O2, CH4, CH3OH

For agriculture - CO2, NH4OH, NH3

For metallurgy - CO,H2S,Ni(CO)4,Fe(CO)5,H2SO4,SO3

For refrigeration SO2

 

Metals:

For construction - Fe, Ni

Precious metals - Au, Pt, Pd, Os, Ir, Rh, Ru, Re, Ge

 

Semi-Conductors

Si, Al, P, Ga, Ge, Cd, Cu, As, Se, In, Sb, Te

 

Based on Table 1, Ross, S.D. Near-Earth Asteroid Mining

 

Ross references this paper: J. S. Kargel, Semiconductor and precious-metal resources of metallic asteroids, Princeton Conf. on Space Manufacturing, Space Studies Inst., 1997.

In it Kargel estimates the value of a 1km metallic asteroid as "exceeding that of the worlds proven economic reserves of nonmetallic and metallic mineral resources".

 

Or you may like a more modest proposalsuch as robotic mining of a couple of thousand tons of volatiles which are moved to low Earth orbit to provide raw materials for early stage space industrialisation.

 

Sorry Swanson, I was composing my response when you posted your note. Delete my post if you wish, but frankly I find lemur's question to be on topic. I interpret the OPs interest as twofold, in both the mechanics and the economics of the process.

Edited April 27, 2011 by Ophiolite

[Airbrush]

The same elements and compounds that make up the Earth are also found in asteroids. So, anything you can find on Earth can also be found and mined from asteroids. There may be asteroids with huge gold or diamond deposits, like nothing we have ever seen on Earth. We would have to search for the materials, and when we find something interesting robots can do the work, and the low gravity will make it easier to transport it towards Earth.

[Moontanman]

I think the Trojan asteroids would be our best best, lots of volatiles, and organics. I think space construction will be with carbon Nano tubes more than metals so the possibility of organics and maybe even hydrocarbon ices would make them good targets for colonization. There are more than one million Trojans larger than 1 kilometer in orbit near Jupiter, they are all relatively close together and would be easier to exploit than the main belt asteroids that are much further apart and in widely varying orbits.

[Widdekind]

The same elements and compounds that make up the Earth are also found in asteroids. So, anything you can find on Earth can also be found and mined from asteroids. There may be asteroids with huge gold or diamond deposits, like nothing we have ever seen on Earth. We would have to search for the materials, and when we find something interesting robots can do the work, and the low gravity will make it easier to transport it towards Earth.

 

Diamonds are formed, only under high pressures -- pressures characteristic, only of the interiors, of large, planetary-scale, bodies. Diamonds, per se, may not be common occurrences, in meteoroids, or asteroids (except through shock formation, from impacts, with other bodies).

[Airbrush]

Diamonds are formed, only under high pressures -- pressures characteristic, only of the interiors, of large, planetary-scale, bodies. Diamonds, per se, may not be common occurrences, in meteoroids, or asteroids (except through shock formation, from impacts, with other bodies).

 

Cannot a supernova create enough pressure to create diamonds?

 

Is it correct to say that asteroids are solidified "droplets" of a supernova?

 

Suppose someday a robotic probe discovers a huge deposit of gold on an asteroid. That could potentially reduce the value of the metal to the value of iron or other common metal.

Edited April 28, 2011 by Airbrush

[Moontanman]

It's also unlikely there will be large pure deposits of precious metals like gold or silver or even copper, it is thought, by some at least, that biological processes concentrate there metals on the earth. At the very least geological processes are required to concentrate then and this doesn't occur on small bodies.

[lemur]

It's also unlikely there will be large pure deposits of precious metals like gold or silver or even copper, it is thought, by some at least, that biological processes concentrate there metals on the earth. At the very least geological processes are required to concentrate then and this doesn't occur on small bodies.

Do various metals separate and stratify within a star? If so, I would be surprised if a supernova would completely homogenize the mixture. It seems more likely that there would be marbling in remnants like astroids.

[Airbrush]

Do various metals separate and stratify within a star? If so, I would be surprised if a supernova would completely homogenize the mixture. It seems more likely that there would be marbling in remnants like astroids.

 

 

On Earth plate techtonics churns the crust bringing heavier metals and diamonds to the surface, or blasted from volcanos. But when a star supernovas I would agree with Lemur. Even though metals sink to the center of a molten blob of supernova, it can frequently be liberated. Suppose a giant "droplet" of supernova solidifies then later collides with another and they both break into pieces. There is a good chance the heavier metals in the center would be exposed to easy access.

Edited April 28, 2011 by Airbrush

[Widdekind]

Cannot a supernova create enough pressure to create diamonds?

 

Is it correct to say that asteroids are solidified "droplets" of a supernova?

 

SNs create more than enough pressure, presumably, to squash carbon into diamonds ("electron chemistry") -- they create so much pressure, that they squash carbon atoms together ("nuclear fusion"), into other, heavier, elements (like N, O, S, Fe).

 

SNs spew out heavy-element enriched, chemically polluted, 'star soot'. The word "droplets" paints a picture, of a molten liquid -- that's a state of matter, which only exists, at high densities & pressures, characteristic of planetary conditions, not the diffuse "polluted soot dust" spewed into space's vacuous void, by SNs. And, asteroids only re-accumulate, from microscopic mineral dust grains, millions of years later -- there's no "fast-and-direct" solidification, of SN debris, straight into full-fledged asteroids (they have to gradually build up, from nanoscopic bits & pieces).

 

(anybody disagree??)

[Airbrush]

And, asteroids only re-accumulate, from microscopic mineral dust grains, millions of years later -- there's no "fast-and-direct" solidification, of SN debris, straight into full-fledged asteroids (they have to gradually build up, from nanoscopic bits & pieces).

 

(anybody disagree??)

 

Thanks for the info Widdekind. That is new to me. So the results of a SN is such a fine disbursed plasma gas that when it cools it becomes a giant cloud of microscopic particles of different elements that later combine randomly. The elements don't get "sorted".

Edited April 28, 2011 by Airbrush

[Moontanman]

I think it's also worth pointing out that much of the elements produced are short lived radioactive isotopes of other wise stable elements and they release a lot of heat as they decay. It's how partial melting can occur on relatively small bodies.