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Space Science

Will Astronauts Ever Visit Gas Giants Like Jupiter? (technologyreview.com) 132

Trying to get an up close and personal look at the solar system's gas giants is a tricky and dangerous journey. From a report: Jupiter, like the other gas giants, doesn't have a rocky surface, but that doesn't mean it's just a massive cloud floating through the vacuum of space. It's made up of mostly helium and hydrogen, and as you move from the outer layers of the atmosphere toward the deeper parts, that gas grows denser and the pressures become more extreme. Temperatures quickly rise. In 1995, NASA's Galileo mission sent a probe into Jupiter's atmosphere; it broke up at about 75 miles in depth. Pressures here are over 100 times more intense than anything on Earth. At the innermost layers of Jupiter that are 13,000 miles deep, the pressure is 2 million times stronger than what's experienced at sea level on Earth, and temperatures are hotter than the sun's surface.

So clearly, no human is going to be able to venture too far down into Jupiter's depths. But would it be safe to simply orbit the planet? Perhaps we could establish an orbital space station, right? Well, there's another big problem when it comes to Jupiter: radiation. The biggest planet in the solar system also boasts its most powerful magnetosphere. These magnetic fields charge up particles in the vicinity, accelerating them to extreme speeds that can fry a spacecraft's electronics in moments. Spaceflight engineers have to figure out an orbit and spacecraft design that will reduce the exposure to this radiation. NASA figured this out with the triple-arrayed, perpetually spinning Juno spacecraft, but it doesn't look as if this would be a feasible design for a human spacecraft. Instead, for a crewed spacecraft to safely orbit or fly past Jupiter, it would have to keep a pretty significant distance away from the planet.

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Will Astronauts Ever Visit Gas Giants Like Jupiter?

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  • by Way Smarter Than You ( 6157664 ) on Thursday July 09, 2020 @01:51PM (#60279960)

    With sufficient science-magic they were in close orbit of a white dwarf and walked on the surface as well. Orbiting Jupiter at rand $safeDistance for predetermined range of safe wouldn't require magic. We already have the science for that part if we could get people there. Landing and walking around is obviously a science-magic requirement.

    • Orbiting at a safe distance? How about fleeing from a giant jellyfish in a balloon?
    • by spun ( 1352 ) <loverevolutionary&yahoo,com> on Thursday July 09, 2020 @02:25PM (#60280098) Journal

      I read that book when it first came out like thirty-some years ago and I still remember it. Robert Forward had some amazing scientific ideas. Couldn't write characters or dialogue very well, but his science was spot-on.

      Now, IIRC it was an actual neutron star and humans never walked on the surface using our own technology. It was neutron-stuff aliens that walked no the surface, and they lived millions of times faster than us. So once we'd started communicating with them, they advanced to ultra-tech in just a few of our days.

      What there was, was a way of dealing with very high G acceleration using an aerated liquid that had the same average density as the human body. Which would really work. Forward postulated it could protect humans from up to 40-50G acceleration.

      In another book of his (I think it was one of his books of scientific essays) he came up with an actual "anti-gravity" concept, just squeezing an asteroid down to 1/1000 its size and encasing it in diamond. It would have a 1G gravity field very close to it, so if you some how got it down to Earth and suspended it on some pillars, there would be zero G directly underneath it.

      So, not "science magic" necessarily, just regular old unobtanium.

      • Ooooooh yeah right it was a neutron star. I read it when it was newly published so I'm a bit fuzzy on the details.

        I loved the parts describing the politics and life at the surface. The humans were pretty fucking dull.

        • by spun ( 1352 )

          I also liked his time travel book. It was based on the concept that you could go back in time, but not change anything any conscious observer had ever seen. Like, really weird coincidences would pop up and, say, prevent you from killing your younger self. This then became a big plot point the characters used towards the end of the book to get stuff done.

      • Fun book, but the "living faster" bit always seemed pretty questionable to me. Gravitational time dilation would mean time was passing slower for them, though I suppose assuming neutronium "quark chemistry" operating far faster than atomic chemistry could explain the difference.

        There's still the issue though that with them living so much faster, intelligent life must have basically arisen as the humans were entering the star system or they would have already been godlike when we arrived. I don't recall th

        • by spun ( 1352 )

          Well, they lived faster because they were based on nucleons, not chemicals. Nuclear reactions take place millions of times faster, was the explanation I recall. I could be misremembering but I think there was some sort of religion-based cultural stagnation that accounted for them not progressing. It was the plucky young rebel who communicated with the humans and changed society, IIRC.

          • I forgot about that. Still, seems very unlikely that any such religious stagnation would last for the equivalent of thousands or millions of years.

            • by spun ( 1352 )

              Went and looked up a plot synopsis to remind myself (I read it in 1980 when it came out) and the neutron star is very young, in fact, the supernova that formed it was said to be the source of radiation causing mutations that created homo sapiens! Forward basically hung a lampshade [tvtropes.org] on the timing.

              The neutron star did not cool enough for life to form on it until about 3,000 BC. Plant analogues did not form until 1,000 BC, animals came much later, and the proto-civilization did not invent tool use until 2032.

              • I suppose lampshading is the authoritative get out of geek-rage free card... :-D

                And it's not like every science fiction story involving aliens at a similar technological level to us isn't assuming exactly the same sort of preposterously unlikely timing.

    • Animals that can withstand 1000bars of pressure already exist in our oceans perhaps one day bio-engineering science can design a human that can do the same. Well I'm not so sure it would still strictly qualify as a human but still.
      • To a fair approximation, 1000bars is equivalent to a depth of about 10km below sea level. The deepest parts of the ocean are just over 11km deep, and do have metazoan (multicellular) life forms in them. That's not even 1% of the area of the oceans, but it's there.

        The behaviour of organisms under pressure is not intuitive to most people (well, much of chemistry isn't intuitive to most people). If pressure changes are over a period of some hours to days, most organisms can survive considerable changes in pre

    • by shess ( 31691 )

      With sufficient science-magic they were in close orbit of a white dwarf and walked on the surface as well. Orbiting Jupiter at rand $safeDistance for predetermined range of safe wouldn't require magic. We already have the science for that part if we could get people there. Landing and walking around is obviously a science-magic requirement.

      The article isn't about gravity, it's about radiation. In Dragon's Egg, there was substantial pages devoted to handling gravity by using unobtanium masses, but not much on handling radiation. I'm not going to reread it this afternoon for this comment, but the main radiation concern I recall was the radiation from a cheela probe's sensors during an encounter (well, just the probe and the cheela were problem enough). The Starquake of the second book would simply x-ray fry the humans, end of their story.

  • by Camel Pilot ( 78781 ) on Thursday July 09, 2020 @01:53PM (#60279968) Homepage Journal

    In conformance with Betteridge's law of headlines -> "Any headline that ends in a question mark can be answered by the word no"

    • by shanen ( 462549 )

      In conformance with Betteridge's law of headlines -> "Any headline that ends in a question mark can be answered by the word no"

      I've been trying to figure out the mechanism of Betteridge's Law... It seems to involve the dynamics between click-bait and a one-way function? It wouldn't be an eye-catching headline if the answer was "Yes"? But in the first place the article (or whatever) should be an actual story rather than a basis for speculation. Is there a tautology in here, or is it closer to an oxymoron?

      If I had to ask a question on this topic, I think it would be "Why would they want to?" This is a job for robots if ever there was

      • "If I had to ask a question on this topic, I think it would be "Why would they want to?" This is a job for robots if ever there was one."

        Exactly! "Victory Unintentional" by Isaac Asimov is a funny robot short story doing just that.

        https://en.wikipedia.org/wiki/... [wikipedia.org]

    • I think this one breaks that law, well if you assume humanity will last that long. The question states "ever" so if we give ourselves say a million years to work it out we probably could. The question is will humanity survive long enough to do it. We are just taking baby steps at the moment and really explored about 0% of the universe, who knows?

      • The question is will humanity survive long enough to do it.

        The real question is "what is human?" Based on history, it's unlikely that homo sapiens sapiens will be around in a million years. But successor species probably will be.

        That quibble aside, the hardware required to go to Jupiter isn't significantly more advanced than what we have now. We could do it now, if we were willing to spend a metric fuckton of money doing it....

        • by lgw ( 121541 )

          Yeah, people seriously underestimate what changes a century of progress brings. Space flight technology over the next 100 years will improve as dramatically as the changes between the first Wright Brothers flyer and SpaceX's rockets. If we can understand today how something could be done, with no new physics, then it will likely be productized in a century.

          • by rbrander ( 73222 )

            Space flight technology over the next 100 years will improve as dramatically as the changes between the first Wright Brothers flyer and SpaceX's rockets. ...just changing "SpaceX" to "Apollo 11", I read that exact sentence about 90 times in 1969. And after half that interval, I can tell you that the SpaceX rocket is only a smidge better than the Saturn V in basic rocket-equation efficiency.

            Indeed, the movie "2001" reflected what they thought would happen in 32 years, and as you know, the giant wheel space

            • by lgw ( 121541 )

              So your argument is really "Stanly Kubrick was wrong, therefore no meaningful progress"? You're going with that?

              There was almost no progress over the 30 year period from 1980 to 2010 because NASA is so damn useless, but there has been massive progress in the past 10 years.

    • In conformance with Betteridge's law of headlines -> "Any headline that ends in a question mark can be answered by the word no"

      Headline: "Can Any Headline that Ends in a Question Mark be Answered by the Word No?"

    • Exactly, but this time the "No" is in TFA, so why moderators approved it ?!?
      • so why moderators approved it ?!?

        Well ,you've answered that yourself. You've loaded the page, and even made a comment. These are the metrics by which the editors go - or more precisely, by which the site charges for advertising.

        Did you think there was some other "meaning" to the site? I'm no fan of advertising (ad-blockers for everywhere), but that doesn't prevent me from submitting things that interest me to the editors (NB : "moderators" are the general readership, as I'm sure you know).

    • by dryeo ( 100693 )

      Why? While Jupiter has radiation problems, orbiting further out would be safe and Saturn doesn't have the radiation problem and exploring the upper atmosphere is quite possible.

      • That's my thought too. As gas giants go, Jupiter is the least approachable due to the high gravity, pressure, and intense radiation. Both Neptune and Uranus actually have gravity close to Earth's which would make exploration of the atmosphere by manned craft actually viable.

        • by dryeo ( 100693 )

          While their gravity is close to Earths, the gradient seems different leading to quite a bit higher escape velocity, 21.38 Km/s for Uranus, 23.56 for Neptune, compared to just over 11 for Earth, so not that easy to visit, though lots easier then Jupiter's 60 odd. I think we'll be visiting their satellites long before we try to do more then probe their atmospheres. And with Jupiter and Saturn, there are a lot of resources orbiting them.
          https://en.wikipedia.org/wiki/... [wikipedia.org]

  • From TFA:

    For the time being, until we find out how to build a spacecraft using materials that could guard human astronauts from all these elements, any up-close exploration of the gas giants will have to be through robotic spacecraft.

    I would think that with Augmented Reality and Virtual Reality you could build a probe that could transmit 'sensory' info to a human a safe distance away. You would still probably need to be in the neighborhood so that the roundtrip delay from you to the probe wouldn't be too bad.

    Would feel like you are there but you would physically not be in danger of having your atoms scrambled.

    • well, giving the limitations of the speed of light, the engineers driving the VR remote drones to build the bridge on Jupiter [wikipedia.org] need to be in the Jovian system, either in some orbital station or on one of the moons.
    • I would think that with Augmented Reality and Virtual Reality you could build a probe that could transmit 'sensory' info to a human a safe distance away.

      Again, to what benefit? Why put humans in the loop?

      Any such system is going to be constrained, totally, by the sensors you choose to put onto your "probe". So a robotic probe would be precisely as informative as one containing humans, and a lot cheaper and lighter. Plus, if one of them breaks, you have dead ironmongery disappearing into the depths, not an

  • Why not? (Score:4, Interesting)

    by Roger W Moore ( 538166 ) on Thursday July 09, 2020 @02:00PM (#60279990) Journal
    It may not happen in our lifetimes but if we develop the technology which enables human exploration of the solar system - which will almost certainly require some means to shield radiation due to solar flares - why would we not explore the gas giants as well? Indeed, Jupiter's and Saturn's moons are some of the most interesting bodies in the Solar system.
    • All These Worlds
      Are Yours Except
      Europa
      Attempt No
      Landing There
      Use Them Together
      Use Them In Peace
      • Clearly even in the future, we are still going to have some bloody Brexiteering monolith still trying to keep us out of anywhere sounding like Europe. How depressing.
        • Even in the future, if we discover an omnipotent monolith that gives us technological and evolutionary advancement, Remainers will still say its stupid xenophobic racist that should be ignored when it tells us to stay away from the EU. :-)

      • by sconeu ( 64226 )

        Get rid of the last two lines. They aren't in the book.

    • Yup.

      Once we get to a point where we can properly shield a craft well enough to not radiate human beings on the trip to and from Jupiter, we'll have probably figured out how to properly shield a craft well enough to protect from Jupiter's radiation. It's a know need that people are already attempting to tackle. In order to be safe enough for long-term space exploration of any kind we're going to need to move shielding tech a long, LONG way forward.

      For the record, I don't see that happening any time soon, b

  • Space is dangerous.
  • by schwit1 ( 797399 ) on Thursday July 09, 2020 @02:03PM (#60280002)

    And other Jovian moons. Going to Jupiter itself would be a one-way trip.

    • It's a deep gravity well to climb out of, that's for sure. You are going to carry a boat load of fuel to get out of that.

      • Unless you can harvest fuel and oxidizers locally, or we are no longer reliant upon chemical propulsion that requires big heavy oxidizers (nuclear thermal, for example).

  • “Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.” -- Douglas Adams
  • Yes and no (Score:4, Funny)

    by Waffle Iron ( 339739 ) on Thursday July 09, 2020 @02:10PM (#60280028)

    Astronauts will technically get there, but the mission will quickly get terminated by the malprogrammed AI in their spacecraft's computer system. The final fate of the astronauts will be murky and too confusing for most observers to figure out.

    • Astronauts will technically get there, but the mission will quickly get terminated by the malprogrammed AI in their spacecraft's computer system. The final fate of the astronauts will be murky and too confusing for most observers to figure out.

      They could get around that by not teaching the AI the song "Daisy" and not sending astronauts named "Dave". Also, by not giving secret instructions that make the AI go crazy.

      • Also, by not giving secret instructions that make the AI go crazy.

        Sorry, AI's are ALREADY crazy. They just appear normal when you stop testing them and you'd better hope specks of dust on the lens doesn't obscure something actually important.

        One [nature.com]
        Two [theverge.com]
        Three [wired.com] Machine learning works by finding subtle patterns in data, many of which are imperceptible to humans. This renders systems based on machine learning vulnerable to a strange kind of confusion.

        • One attempt to address this is to combine DNNs with symbolic AI, which was the dominant paradigm in AI before machine learning. With symbolic AI, machines reasoned using hard-coded rules about how the world worked, such as that it contains discrete objects and that they are related to one another in various ways. "Deep learning is so useful in the short term that people have lost sight of the long term," says Marcus, who is a long-time critic of the current deep-learning approach.

          I'm glad that finally some

  • by SuperKendall ( 25149 ) on Thursday July 09, 2020 @02:31PM (#60280124)

    Your question of orbiting a gas giant is vaguely interesting, but what really needs to be asked is - how hard would it be to make a Cloud City replica in a gas giant atmosphere, for the purposes of tourism/mining/disposing of political prisoners?

    • by mark-t ( 151149 )

      It would require a gas giant with a habitable temperature belt of oxygen.

      Oxygen, however, is fairly heavy as gasses go... there's actually only one elemental gas heavier. It's unlikely that Oxygen would be at a high enough altitude in a gas giant's atmosphere that the pressures would be manageable.

      • by sconeu ( 64226 ) on Thursday July 09, 2020 @03:50PM (#60280504) Homepage Journal

        Oxygen, however, is fairly heavy as gasses go... there's actually only one elemental gas heavier

        Really? Lets see... O2 has a mass of 32 Atomic units (each atom has mass 16).
        F2, mass 38.
        Cl2 mass 70
        Ar mass 40
        Continue down the list of noble gases. So there are way more than one heavier elemental gas.

        • by mark-t ( 151149 )
          You are correct. My bad. I forgot completely about the Noble gasses, and also didn't realize that Fluorine was actually denser than Oxygen. While generally density increases with atomic mass, this is not uniformly true for the entire periodic table and I thought Fluorine was one of the exceptions.
          • by sconeu ( 64226 )

            No worries, and sorry for the sarcasm. But then, this IS /., after all...

            • by mark-t ( 151149 )
              Still, a planet with that many elements heavier than oxygen is probably more likely to be a rocky world than a gas giant, I would think...
          • and also didn't realize that Fluorine was actually denser than Oxygen.

            The density of gases is proportional to the mass of the particles of that gas. Didn't your school course in Physical Chemistry teach you anything? It's pretty basic.

            If you go beyond single element gases you get interesting (and industrially important) gases like nickel pentacarbonyl and urnaium hexafluoride, whose gas phases are rather important.

            • by mark-t ( 151149 )

              The density of gases is proportional to the mass of the particles of that gas

              And inversely proportional the the volume that those particles occupy, and because not all atoms are the same size, some higher numbered elements are actually *less* dense than some lower numbered ones. As I said, I thought Fluorine was one of the exceptions... there's at least one around there in the periodic table, but I'm not entirely sure where it is if it's not Fluorine.

              • That only becomes a significant (well, unavoidable) factor at high pressures or for very large molecules (e.g. long hydrocarbon chains). Both of which are conditions for being a long way from "ideal gas" conditions as considered at school ... and straight into van der Waals (yeah, him of the eponymous Forces [wikipedia.org]) corrections to the ideal gas model. Which comes in at first or second year university, depending on your curriculum.

                In the ideal gas model the (unphysical) approximation is made, explicitly, that the

        • I don't suppose there's any situation where concentrated Ozone would be stable, is there? That would give it a mass of 48, higher than anything in your list besides Cl2 (but not higher than the heavier noble gases, and I guess the heavier halogens at sufficient temperature).

          To the OP's point, conceivably if over time (and given sufficient ozone producing lightning, which Jupiter possesses), the upper atmosphere of Jupiter might be depleted of the oxygen atoms by the sinking of ozone. Probably not, though:

          • I've seen reports of the colour of liquid ozone (darker blue than LO2, itself a it bluer than pure water), so it's sufficiently stable for that. But it would be a rather strong oxidising agent, so I'd avoid putting any organic material near it myself. Blast walls, boiled-leather underpants and chainmail gloves not excepted.
    • by Necron69 ( 35644 )

      You're forgetting the gravity aspect. Jupiter's gravity is roughly 2.5G and nobody wants to live in that environment for an extended period. Nobody even knows if humans could survive that.

      - Necron69

      • by Chaset ( 552418 )

        Well, it's a gradient, just as with the pressure and temperature. For a while, I had a little fun imagining what a floating habitat on Jupiter would be like. I looked up the temperature/pressure gradient vs. altitude and found that if you go deep enough where the temperature and pressure are "nice", you do end up in the 2.5G-ish zone. (I hope I remembered that right) However, if you went high enough so that the gravity is ~1G, the pressure is low, but there is still enough there so that you don't have to

      • by tragedy ( 27079 )

        We could certainly survive it. I know I can give a piggyback ride to someone 1.5 times my weight. If that's distributed evenly over my entire body, it shouldn't be a huge problem. I imagine I would get pretty tired though, but we do have existing exoskeleton systems that could help us bear the weight and our bodies would adapt to help bear the weight. Long term, I imagine it would wear on the body pretty hard though. Any Jupiter habitat would obviously have to be floating in some layer of Jupiter's atmosphe

        • Perhaps a better comparison than piggy-backing would be people who become overweight. Let's say someone who is 5' 8" and weighs 140 lbs (I hear someone asking for metric...). In 2.5g, they would weigh 350 lbs. There are of course people of that height and weight. (Google images...) While they tend to be unhealthy, I think a person of normal build who weighed that much because of gravity could adapt. They'd undoubtedly put on muscle, and it might be hard on their heart (and I certainly wouldn't want to

    • In our solar system, cloud city would be best built on venus. If you're 50 km up, temperatures range from 0 to 50 degrees C, and the pressure is around 1 atm. At that altitude the atmosphere is also significantly denser than Earth's, so you can build your cloud city as a giant floating blimp, which circles the planet every four Earth days or so on the prevailing winds.

  • It worked with America and Australia.

  • by PFritz21 ( 766949 ) on Thursday July 09, 2020 @03:13PM (#60280294) Homepage Journal
    This is a story about visiting the gas giants in our solar system, AND NO ONE IS MAKING A JOKE ABOUT STAYING AWAY FROM URANUS?!?! Geez...
  • Once space travel becomes cheap enough, I imagine a rich billionaire or Red Bull sponsored thrillseeker might try it as a stunt, so I wouldn't rule it out.

  • Not sure there will ever be serious human colonization elsewhere in the solar system unless people want to live in tunnels.
  • by mi ( 197448 )

    But would it be safe to simply orbit the planet? Perhaps we could establish an orbital space station, right?

    Why? Other than, perhaps, mining the helium (and, maybe, even hydrogen) one day, what else would such a station do even in theory?

    Just to "do awesome science"? We've had ISS for that purpose for what, 20 years now? $150 billion later, where are the achievements to write home about [wikipedia.org]? This is all [independent.co.uk] — rather underwhelming, frankly...

    • If humankind becomes a spacefaring species, we extend our lifespan beyond that of Earth. Figuring out how to put humans in the atmosphere of gas giants expands our options for planets beyond rocks like ours. And if you consider that eventually the Sun will make Earth uninhabitable (assuming we don't do it ourselves first) then at a minimum we want to get to the outer planets.

      Why do you find output from the ISS underwhelming? I'll admit it's not flashy, but we need to know what microgravity and space environ

  • All other things being equal, even if jupiter did have a solid surface astronauts couldn't land there as gravity is 2.5 times that of earth and aside from being unable to stand or breath properly theyd probably have a heart attack in hours. And if they survived that their ship would require as yet uninvented engines to escape the gravitational well and reach orbit to return home.

  • It isn't Clarke's "Meeting with Medusa" that I'm thinking of; the image that got to me was in the "sequel", the "Medusa Chronicles" put out in 2016 by hard-science-for-real writers Stephen Baxter and Alastair Reynolds.

    The book had scenes in the clouds of Saturn, at very high altitude, again with the giant balloons. What stopped me was that they said there was an altitude in Saturn's atmosphere where

    a) the pressure was around 1 bar - so, no oxygen, but no trouble going outside and coming back in, need a lo

    • by dryeo ( 100693 )

      Venus would be a better choice if you want to hang out in the sky. At the right altitude (50 miles?) one ATM pressure, 90% of a G gravity, about 20C temperature and our atmosphere is a lifting gas there, so living in something like a blimp would work. It is also the easiest planet to get to as well, even an Apollo could have done a flyby with the 3rd stage used for living quarters after burning up the fuel.

      • By coincidence, I submitted a story about Venus [slashdot.org] yesterday. Hasn't passed the editors yet, but it may do.
        • by dryeo ( 100693 )

          Good submission. I've wondered the same thing.

          Your sig, I think birds are a type of dinosaur would be more accurate. Like marsupials being a type of mammal.

          • Thanks on the submission.

            "Birds are a clade within the Dinosaurs, sharing a number of synapomorphies with the rest of the clade" ... is slightly more accurate, but trips off the tongue about as well as I dance.

  • We, as a species, most likely won't live long enough for the technology and knowledge to advance to the point where we will ever have manned missions to Jupiter. Hell, we can't even convince folks to wear masks during a pandemic. Who are we kidding ? :|

    We're far too busy building new weapons, methods of killing each other off and squabbling over irrelevant shit in the grand scheme of things.
    As a result, the inevitable asteroid will eventually swing by and do its thing and we won't even be a distant memory

  • Will humans ever visit gas giants? Given that they're a massive convenient source of hydrogen and other useful gasses I think the answer is a resounding "obviously", assuming we do actually colonize space.

    Will humans actually enter the planets atmosphere, and even reach the surface, rather than just orbiting it to get fuel from the automated atmosphere mining equipment? If we're in orbit, it seems inevitable it will happen eventually.

    The real questions are, will those visits be intentional, and will anyon

    • Given that they're a massive convenient source of hydrogen

      A "massive convenient source" is a contradiction in terms.

      Yes, they're massive. That means (this is the difficult bit) they have a lot of mass. That means they have a lot of gravity. Which means it takes a large amount of energy to get that hydrogen (or whatever other gas) to anywhere else. Which is very inconvenient.

      Find a convenient small ice ball - say, a thousand cubic kilometres of ice with a bit of ammonia and rock. Mine some ice. Melt it to

      • >Find a convenient small ice ball...
        Absolutely a great idea for the near term - mining gas giants is very much a "future technology" project (like I said, eventually...)

        > a lot of gravity [...] means it takes a large amount of energy to get that hydrogen (or whatever other gas) to anywhere else.

        Actually, not nearly as much as you'd think, once you advance past using rockets. Consider - escape velocity from Earth is ~11,200m/s, or 62MJ/kg - equivalent a bit less than two gallons of gas per kg, or arou

        • mining gas giants is very much a "future technology" project (like I said, eventually...)

          Then by your own description, mining gas giants will be a thing done when the future has progressed to the point that we've already mined a high proportion of the "small bodies" of whichever solar system you're looking at at that time. Looking at the history of resource exploitation on Earth, that would be on the order of half the "small body" mass of the system, though it is somewhat complicated by the much greater dis

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