What would be the first thing humans would mine on Jupiter?

Question

Jupiter is a terrible place to be, but for a number of artistic reasons, I'd like to have my story take place there and only there. "Mining", or resource extraction by any other name, is the usual reason cited for sending human beings to live in terrible places. The reasons NOT to do so are usually economic in nature, as the resources extracted are not worth the investment required to enable people to survive in a terrible place.

What would likely be the first thing we'd find economically viable to mine on Jupiter? I really don't want to handwave this thing the target material away, as it may have a direct impact on the environment I create to be my setting. EDIT: I'm willing for the required tech to be powered by phlebotinum.

EDIT: Emphasize this, restate that... The unspoken assumption, I guess, is that something HAS been found to be economically and technically viable to mine on Jupiter. I would like a reasonably well-thought-out opinion on what that first material for which these conditions might be true could be.

Answer 1

Skimming various gasses from the Jovian atmosphere or using superscience to extract metallic hydrogen from deep below the surface only taps a small amount of the potential resources available. Since you explicitly said "Jupiter" and not the Jovian system, I will set aside the 67 moons or thousands of asteroids on the L4 and L5 trojan points.

Jupiter has a tremendous amount of heat energy, and emits 2X the energy in the infrared band than it receives from the Sun. At that distance from the Sun, solar arrays will either be insufficient or need to be massively larger than comparable arrays on Earth for the same power output. Tapping the heat energy from Jupiter would provide energy for industrial activities throughout the system.

The planet also has a massive magnetosphere 19,000 X greater than Earth. The motion of Io through the magnetic field creates and electric current much like a wire moving through a magnetic field does in a classic science experiment. In Jovian space, the flux tube has a current flow of about 2 trillion watts, another rich energy source for a Jovian civilization.

The intense radiation fields surrounding Jupiter could also be considered a resource, since using radiation to manipulate or change materials is a known technique, the amount of radiation flux would allow manufacturing isotopes or possibly transmutation on an industrial scale. Workers on the shop floor will need heavy duty shielding, otherwise they will be spending their retirement as night lights.

Answer 2

Mining metallic Hydrogen might be a possibility, but I am unsure what happens when you move it out of the pressure and what goes on from there.

Second and probably more fun for a story...Helium-3. Most Helium on Earth is Helium-4 (two neutrons and two protons at its center)...on Earth it's a silly ratio of 99.999986% Helium 4. However Jupiter has a much heavier concentration of Helium 3 than we find elsewhere (measurable in parts per million, not parts per billion). Apparently it was more common in primordial (solar nebula) than it is now.

It's heavily disinguishable from Helium 4 (which has an overall spin of 0 making it a Boson) while Helium-3 has an overall spin of one half making it a fermion. This gives it some interesting applications.

Helium-3 has some interesting Cryogenic applications and a few medical uses. It's also exceedingly useful for neutron detection. We can lab create it, but not the easiest and not in high concentrations (and what we create it from is a major component in Nuclear weapons). Oh, on that note it can be used for fission applications and likely weaponized.

Wiki actually suggest that the proposal of mining Jupiter for it.

Mining gas giants for helium-3 has also been proposed.[61] The British Interplanetary Society's hypothetical Project Daedalus interstellar probe design was fueled by helium-3 mines in the atmosphere of Jupiter, for example. Jupiter's high gravity makes this a less energetically favorable operation than extracting helium-3 from the other gas giants of the solar system, however.

https://en.wikipedia.org/wiki/Helium-3

Answer 3

• Hydrogen, water, ammonia, all skimmed from the atmosphere rather than mined from the surface. Ammonia contains nitrogen, so with the water and a carbon asteroid you can start building greenhouses.
• Helium-3. Getting it out of Saturn's more shallow gravity well would be smarter, but if you're in the area anyway ...

Answer 4

Jupiter is a huge gravity well, so the only logical thing will be to

mine gravity

If you want to get helium or hydrogen to earth, it need less energy to get it from Uranus (as getting off Jupiter is horribly hard).

But with exotic or more conventional technology, you could convert gravity into something of value.

Currently we use centrifuge to create local higher gravity.
Up to 20% (I lost the source. In fact it can be arbitrary high if you want really depleted tail or super-rich fuel) of the output of a nuclear plant is used to separate uranium isotope with centrifuge. So, simply throw a bag of uranium in the core and get it back up with a balloon could make sense.

To justify batch large enough to require doing it on Jupiter, computer industry could have unlimited use for 28Si

Answer 5

Jupiter is a whole big stack of hydrogen and helium. The only thing really useful you would get would be one of those. Hydrogen isn't really in limited supply, especially if you have the surplus energy to extract it from water. Helium is in high demand if you ask some people, not so much if you ask others. The biggest trace material would be methane, which could also be useful.

The mechanics of getting either of them out of Jupiter, make it unlikely that either would be worth your while, no matter what the prices. Jupiter has a massive magnetic field that causes very heavy radiation. Galileo had all sorts of glitches caused by the radiation field while orbiting Jupiter, and Pioneer 11 lost the pictures it took of Io before it could transmit them. Cassini, on the other hand, didn't have any radiation problems around Saturn. Notwithstanding the fact that humans would die immediately in Jupiter's orbit, even a robot mining station would be better off near Saturn.

Mining anything else out of Jupiter is pretty much a nonstarter. Even if the core of Jupiter was solid unobtainium, the temperature at the core is about 36000K and 3000 GPa (both of which are too high to compare with anything except the sun and fusion bombs). Technology is going to be way into the handwavian principles before that is feasible.

The last option, which may or may not be what you are asking about, is Jupiter's moons. The big four moons are combination of rocky/iron core and icy volatiles, primarily water with a little ammonia. Other elements present in the surface layers include magnesium, iron bearing-hyrated silicates, cabon dioxide, and sulfur dioxide. The rocky-iron cores are too deep to be useful targets or mining.

The smaller moons have a similar composition to the surface layers of the big moons. Since you can achieve escape velocity on a pogo stick from some of the innumerable moonlets around Jupiter, it is probably easier to get minerals/volatiles there than from the big moons. They are also (mostly) farther from the radiation. Lastly, in addition to many moons of varying sizes, there are also the farther away Trojans, which share an orbit with Jupiter instead of orbiting Jupiter.

What I think is your best explanation for mining is trying to obtain volatiles for a space colony. Lets say that people are living in space stations in the inner solar system, growing their own food. They are going to need water and ammonia for the plants, water for the people (and industry?) and lots of other chemicals for fertilizer (phosphates, sulfur, potassium, etc) or industrial uses. Those things are plentiful on earth, but not cheap to get into space. It is easier if you just bring them from somewhere else in space. The asteroid belt is long on rocks and metals, and short on water and ammonia and such. The closes way to bring such things to a space habitat in earth orbit would be from Jupiter or its Trojans. The big advantage of dealing with Jupiter and any radiation concerns is that it is many AU closer than Saturn, even though Saturn is a more welcoming system and has great ring-tourism value and a uniquely large source of methane, if you are in to that.

Answer 6

Jupiter has comparatively a lot of ³He left from the formation of the solar system. Possibly the most interesting feature of ³He is use as fusion fuel. ³He fusion reactor is probably easily doable at the same level of technology where mining Jupiter is, you just need to get loads of ³He somehow. Here's a quote from Wikipedia explaining why we'd want just ³He:

The appeal of helium-3 fusion stems from the aneutronic nature of its reaction products. Helium-3 itself is non-radioactive. The lone high-energy by-product, the proton, can be contained using electric and magnetic fields. The momentum energy of this proton (created in the fusion process) will interact with the containing electromagnetic field, resulting in direct net electricity generation.

The mining probably started at the other gas giants, with less deep gravity wells, because it is a lot easier. But Jupiter is closest to the inner solar system and therefore advantageous as soon as you have the tech to mine it. So this would set the natural stage of solar system exploitation and technology level.

At that level of technological development, where colonizing the solar system is well underway, any gas giant would have ³He fueling station for ships, but Jupiter might dominate the ³He exports to the inner solar system, because it is much closer in time and energy, and being much easier to police against piracy (if you want that type of activity). Exports could happen by a mass driver shooting huge electrically charged balloons (probably made out of graphene) filled with ³He, which would the be caught at the destination with electromagnetic nets (the electric charge wouldn't leak very much in hard vacuum). Other mining products shipped the same way would include at least Deuterium (there are at least 2 types of useful ³He fusion: ³He+³He and Deuterium+³He).

So you would have pumping and refinement stations orbiting Jupiter, with long pipes going down to the atmosphere, with a pump at the bottom (or possibly even the refinement system at the bottom, but it's quite a harsh place...). Stations would be powered by fusion reactors using the very ³He they mine. To counter the drag of the pipes, they'd probably use what would essentially be fusion rockets to expell the normal hydrogen left over from the refinement back to Jupiter.

Rest of the economical activity (and therefore political power) would follow from the practicalities and control of these pumping and refinement stations, much like it now does at Earth from the oil fields, setting the backdrop for your story.

Answer 7

I don't know of a material that Jupiter would be good for. However, it has one attribute that's unbeatable in our solar system. It has crazy amounts of pressure. Perhaps your intrepid miners are actually foundry workers, and they have to use this immense pressure to create some exotic form of material. For example, when a common iron alloy is processed a certain way, under pressure, you produce a steel that is unparalleled for making (space) warships. With respect to shrugging off high-speed impacts and absorbing harmful radiation, it performs 100x greater than the next best material. Yadda.

Now you have a hellish place to work and it is of extreme strategic importance.

Answer 8

Jupiter is "the" place in the solar system

1. Energy Sources

Io is very hot due to the tidal friction. It is a very good place to put geothermal power plants and beam the energy to a more friendly and hospitable moon like Europa or Ganymede. This makes an interesting setting, Io is a very instable place, so the power plants will need constant repairs or rebuilding. Deal with that may make colorful adventures. Energy production and water allows for big populations to settle in huge cities, even needing to rebuilding power plants each year may be cost effective.

Helium 3 is always interesting. As I understand fusion reactors can be far cheaper and smaller with Helium 3 than it is with traditional H-D reactions we are trying to do on earth.

Fission Reactors based on thorium and uranium are very good in the surface of colder planets and moons. That because the nuclear fuel produces heat and the difference between the heat and the environment temperature moves the turbines. On spaceships heat dissipation is very difficult and then nuclear reactors are smaller. Even then, NASA has only enough plutonium to make more 3 more missions. Not something that can run a civilization. On colder planet or moons it is easier. The problem is mining the uranium and thorium and sending to where will be used. Rocky planets and asteroids should have lots of Thorium and the jupter system have two big moons that can have thorium mines: Io (again) and Callisto. Not counting the asteroids.

Mine the energy belts like Thucydides proposed. I do not know if is that simple, but there is a lot of power in Jupiter radiation belts.

2. Environment

Heating a cold place takes lot of energy. Less colder moons will allow bigger settlements. Thats why I would place the bulk of the civilization outside Earth in Europa and Ganymede. Those moons are heated by Jupiter tidal forces and are not as colder than most moons. They are closer to Io that have lots of geothermal energy. They are closer to Io and Callisto that should have lots of thorium. This will not be enough to warm up those moons. Habitats will probably will look like Halley station on south pole.

Ice or Water is important because can be Hydrolized to make breatheable oxygen. Those moons have lots of amonia which can be broken to make nitrogen atmospheres which are essential to plant life.

3. Gravity

Gravity is an important factor. Mars have lots of resources, but it will be cheaper to mine them from the asteroids and small moons. Less energy is needed in the transport. The same goes to the habitats. Small moons with lots of water allows transports to take less energy to land.

This is a big differential to Jupiter. It is the place of the solar system. Lots of resources. Less colder moons. Probably will be the center of a space civilization.

4: Science-Fantasy

Jupiter has a very powerful electromagnetic field. Only the sun has a bigger one and for obvious reasons we can't be close to the sun to use it or study. Maybe you can push a fantasy element on your scenario and say it is an requirement for opening wormholes, some kind of FTL, or simple is the place of the LHC of your era.

5: Dyson Swarm

A setting with a Dyson swarm will place the solar collectors as close to the Sun as possible to catch the most energy with minimal surface. I would guess that a Dyson swarm would be near mercury orbit, probably even closer to the sun. That mean that closer to the Sun would be a no fly zone. To avoid crashes we will probably need layers of orbits and this could take as much as the orbit of Venus. With that kind of energy output we would need places with lots of water and minerals. Again Jupiter and the belt are a good place. With that kind of energy, a planet like Earth can overheat. To go to a colder place could be a good idea. But beyond Jupiter raw materials become more and more scarse.

An Dyson Swarm can be a game changing technology. By focusing a small percentage of the Sun's output in the outer solar system moons, they may be heated up to resemble Earth. This may even allow to strip Venus, Uranus and Neptune from the bulk of their atmospheres to make their surfaces accessible to humans.

Obs

Remember that you don't need to choose between a form of energy or another. A civilization will probably develop Thorium reactors first, then Io Geothermal Power Plants; then Helium 3 reactors; then a way to harvest Jupiter radiation belts and then a Dyson Sphere.

As we have primary world power source in Oil, we have a lot of others at the same time. Brazil primary power source is Hydroelectric, because of its geography and climate. It is kind like Jupiter which have abundancy of some kinds of energy sources that are scarse in the rest of the solar system.

This does not mean we would not have massive presence of humans in all planets or moons in such a setting, but Earth and Jupiter would probably will be the centers. Mars and Venus can become as rich as Earth, but their gravity is a problem. Mars and Venus gravity is way higher than moons which means more energy to get things in orbit, making them less attractive to mining resources to be carried elsewhere. They would only be big economical centers if terraformed. Mars can be warmed by thorium reactors to get a denser atmosphere and allow bacteria to make the atmosphere breathable. A sunscreen can cool Venus enough to allow bacteria to make its atmosphere breahable. In both cases will take centuries to do it and the resources needed (mirrors and thorium) has to be mined somewhere. Is too much material to take from the surface of the planets (except mercury). Probably the civilization has to be space fairing even before the terraformation begin. Meaning that Jupiter system will probably will get colonized first. Maybe Ceres and other larger asteroids get colonized even before.

Mercury have a slow rotation, and have speculation about a zone that never gets sun in craters in the north and south pole. Mercury probably is an interesting place for mines. Since they have to mine in the night side, the factories will be on wheels. To keep it in the night side the factories will have to move an average of 10Km/h or 6mi/h in the equator, less than that closer to the poles. In a mechanical problem they can remain still for 30 days, plenty of time to fix problems. Since mercury is heavy, it may have lots of uranium and other heavy metals. It is the best place to put a mine to produce mirrors for the Dyson swarm. Low gravity to get things into orbit, lots of raw materials, lots of solar energy. Not very practical for habitation tough. Make cities on wheels or in permanent darkness of craters may not be practical. The lack of water is also a factor. Meaning, industrial and scientific outpost.

Answer 9

You can't mine anything on Jupiter, as you can't mine on Jupiter, as Jupiter lacks a solid surface to dig into. However, one could try to get into a low planetary orbit and then place a gas extractor with a long pipe down to get to the gaseous contents of the atmosphere.

To our current knowledge, the atmosphere of Jupiter by volume is made up from mostly:

• 88-92% Hydrogen $H_2$ (ca. 74% mass)
• 8-12% Helium $He$ (ca. 24% mass)

Spectroscopy shows that the deeper layers of the atmosphere might be split by mass roughly the following: 71% $H_2$, 24% $He$ and 5% other elements. Speculations speak of a solid, metallic hydrogen core, but that is not proven or disproven.

So from what we know at the moment, Jupiter is a viable source for easily obtainable Hydrogen. Hydrogen is a very versatile material:

• Any Hydrogen is a highly reactive gas, that can diffuse through most metals, even if slow. So a simple tube closed with one end and then sucking out anything that gets in is a pretty sure way to get 99% pure hydrogen in that atmosphere.
• Hydrogen is the main component of many fuels and other chemicals: With a few catalysts it can be used pretty varried:
  • Methanol: $CO+2H_2 \longrightarrow CH_3OH$, which is good as a fuel and chemical.
  • Ammonia: $N_2 + 3H_2 \longrightarrow 2NH_3$, which can be refined to hydracine, a rocket fuel.
  • To bind carbon-mono-oxyde (which can be made from carbon-di-oxyde with catalysts) in the Fischer-Tropsch-Process and make longer carbohydrates, which in turn can be used as fuel
• Both of its isotopes (Deuterium and Tritium, $^2_1H$ and $^3_1H$), are the ingredients current nuclear fusion reactors need to work. Because the huge body is mostly hydrogen, even the small trace ammounts theses occur in naturally could make it a viable resource depot for a ship that has to refuel it's fusion reactor.

However, even if you can find a method to extract the hydrogen from the atmosphere without killing the operators in the hazardous area Jupiter himself creates (Jupiter has radiation and micro asteroids, that make even flybys not too easy), hydrogen (and oxygen!) could be cheaper and easier acquired by just cracking water from asteroids. However, it (or even better: its moon Europe) is the most easy to "hit" stop to 'refuel' on the way out of the solar system.

Answer 10

It is hard to "mine" Jupiter as it is gas giant, means main mass of it is gas, hydrogen an helium in particular.

But it is a nice place(sic!) to scoop gases.

Fun fact is that gaseous upper layer of it is not so tick actually, proportion could be seen (it looks about right for me) on on wiki picture about composition of Jupiter(pic)

Although it have to be noticed that Jupiter is big, and even 0.3% of methane means entire earth like planet made from that methane. This is a lot, considering that entire Asteroid belt is estimated to be 4% of mass of the Moon(which is smaller then earth, 1.23% of Earth mass).

So even trace amounts of gases from Jupiter are significant amount indeed.
0.3% could create earth size body (Jupiter methane 0.3%)
0.003 moon mass/size body (Jupiter hydrogen deuteride 0.003%)
0.0001% replace asteroid belt (four belts of water 0.0004%, six belts of ethane 0.0006%)

• numbers from wiki and they are given in terms of volume, not the mass, so technically my statements above are incorrect, but as size of Jupiter is 1321 times of earth volume, and 99.99xxx% of Jupiter is liquid (atmosphere is few thousands km tick max compared to 70000 km radius of Jupiter - it is mostly liquid gas giant) those volume percentages are percentages of liquid gases. Ratio of liquid percent(volume percents) to mass percents is about $\approx4$. This way we are talking not about 4 belts of water but one belt, not six belts of ethane but 1.5 - that is by mass, by volume we talking about 4 and 6 belts (roughly).
• another thing to consider, that concentration of heavy elements is higher deeper it is, and concentration from wiki are for upper layer, so probably we talking not about 1 belt of water but more, not 1.5 belts of ethane but more.
• also density differs significantly between H, He, and more heavier stuff, so numbers are conventionality just to get in touch with scale of that thing.

After making such pointless statements I ask you to just believe that even trace amount of concentration in Jupiter should be taken seriously, no matter is that volume, or mass.

When you go to mine Gas giants (we have few of them)? - when sources like belt is not enough for you, and when you seeking for light elements.

Actually getting hydrogen as it is, pure hydrogen, makes some sense - Jupiter is easiest source of it, with huge quantities of it. (closest is the sun, but there are some troubles with that). It makes sense because I see humans are constantly concerned them self about water, and as far as I know there is lot of oxides in crust of planets(in form of oxides, like SiO₂), and using hydrogen it is possible to make lots of water from those rocks (and lot of computer chips as by product).
Ceres which is 1/3 of that asteroid belt(by mass) (according to that wiki picture) - expected to contain enough water, amounts are expected to be compatible to amounts of it on Earth.

Another great use of Jupiter's hydrogen is to exchange it to more heavier stuff from the sun. And trace amounts there are even bigger numbers then with Jupiter. I tried (but failed, and run out of space for answer) to describe that in my moving planet answer significant amount of answer is about Jupiter interaction, and getting that hydrogen useful.

TL;DR

You go to gas giant's and Jupiter in particular when you need moon sizes of stuff, when you starlift, when you need carbon, when you need water components. If there is good enough ³He excellent, take it. In general when you are interested in planet/moon size compatible amounts of something(with starlifting specially)

Getting something deeper then from few thousands km below 1bar level - is no go. There could be some indirect or sophisticated solutions - but it gets not so easy because of pressure. You could expect to be able to get something near 100 GPa pressure level, but I see no options atm for much more then that. Hm, or do I - hm lucky it is gaseous thing with low melting point and low density - it could be like but artificial tornado, or whirlpool. Probably possible way to lift heavier stuff from deeper layers. Also it is possible to create flows which also might be used to lift heavier things (our use existing flows to take advantage) - it might be so that gravity of Jupiter made lot of separation work for us, and it is just a question to use the results. Deep areas of core or just core, are not so much interesting in therms of resource, very interesting as science, but not as resource, in first place because of there are sources of heavy elements which are less extreme to access - belt, planets, moons.

I personally would go to mine carbon on Jupiter. Reasons are: carbon is very handy as possible construction material in form of nanotubes, there is a lot of it, much more then on Venus, and it is more near then other gas giants.

Second is ³He - there is insane amount of it if that is right Helium-3, Solar nebula (primordial) abundance

• ... ratio in the atmosphere of Jupiter, measured by the mass spectrometer of the Galileo atmospheric entry probe. This ratio is about 1:10,000, or 100 parts of ³He per million parts of ⁴He.

Helium is 10% by volume of Jupiter, it means ³He concentration is 10ppm in atmosphere. 10 particles per million of particles of jupiter H+He mix, or 10 cubic meters per 1 million of cubic meters.

Deuterium

• ... The abundance of deuterium in the atmosphere of Jupiter has been directly measured by the Galileo space probe as 26 atoms per million hydrogen atoms.

As hydrogen is roughly 90%, it means 23ppm concentration of D in atmosphere

Congratulations, we have our Klondike and gas station - 2in1.

Helium-3

• for some reason I have not payed attention to that fact, even o.m.'s answer did not drew enough attention for the subject, but now everything is clear.
• that makes sense if you have thermonuclear reactors which works with He3, and there are some thoughts against it. Looks like solvable problem, by using non-Maxwellian plasma or by different temperatures of He and D components. Some numbers about reactions this, that for my self. But everything is not so simple with that topic, should be expected as we do not have it yet.

First of all 10ppm ³ He is very good, it is better then moon sources which are 1.4-15 ppb concentrations, and much much much bigger quantities of it in Jupiter, and it is easier to extract(process is a bit more straightforward), and there is lots of Hydrogen which is also very very very handy in that situation. Considering all that greatness of situation - 5 a.u. is no distance, and Jupiter is my favorite planet in solar system starting from now, 'Love it.

Potentially He3+D releases 3.474e+14J per kg.
Escape velocity for Jupiter is 59.5 km/s, or 1770125000 J/kg (non reactive launch systems)
Or it is 196257 kg leaving Jupiter per each kg of ³He+D used as fuel for that process.
Or (at 1 bar pressure) roughly 2 million cubic meters of atmosphere of Jupiter, where (with 10ppm) should be 20 cubic meters of ³He, which is roughly 2.67kg of ³He.

For each kg of ³He+D spend in reaction(it is 0.6kg of ³He and 0.4kg of D), we lift 2.67 kg of ³He to orbit around sun. So even without sorting components of atmosphere, and just by lifting it in bulk quantities - potentially we get more then we spend - I call that profit.

Good thing about that mixture it is ready, after sorting ³He, H, D, ⁴He - to be used in thermonuclear space craft engine - where He3+D are energy source and H is reactive mass. ISP of that mixture should be something around 9900 sec (97km/s exhaust velocity) (khm, if I used my blackmagic correctly).

And hypothetical tanker should be able to deliver 80% of that content, within 20km/s delta-v, I call it good enough to deliver it to our moon base gas station or earth orbit gas station, or mars gas station.

Efficiency of processes involved(mostly reactor efficiency) is not dig deal, until energy output of reactor is positive. Inefficiency could be compensated by more refining in place without lifting(refine station in jupiter atmosphere), but even bulk lift is ok up to 22.5% efficiency(0.6/2.67 how much helium we have spend and how much we get back).

Overall theoretically process might have great potential for exponential grow even without tricks.

Neptune have 19% of Helium, Uranus 15% of Helium - so they are also considerable options, despite distances. Saturn with 3% helium not so much, as helium source(although it can be concentrated) - so all 4 are considerable options for "mining".

For reasons above and might be others - It make sense just scoop stuff that is on top of that gas giant - everything is useful.

Answer 11

To the best of my knowledge, the idea that Jupiter has a solid core is not proven. With that said, it has plenty of fluid metallic hydrogen to put a boat on, so maybe you could dredge for material.

Let's call out a few assumptions that I think have to hold true for this to be at all feasible:

1. Somehow the operators of this mining process are not killed by intense gravity, radiation, electricity, chemical processes, high-speed metallic wind, temperature, etc.

2. Somehow the equipment used in the mining operation is similarly impervious

3. Somehow you can get material off of Jupiter (anti-gravity, I suppose)

Assuming all those things held, then I would say that just harvesting the fluid metallic hydrogen would be worthwhile. The huge compression it's under would make it a very space-efficient source of material for use as a propellant or for use in some sort of controlled reaction process.

Also, since Jupiter's (possible) core's construction is unknown, you can make it be anything! Arthur C. Clarke proposed in his novel 2001 that the core was made of diamond, given the high pressure and temperature. We don't really know any better at this point (again, to my knowledge), so you could just go with that.