Could Jupiter and Saturn Contain Liquid Metal Helium?

Article written: 7 Aug , 2008
Updated: 24 Dec , 2015

The interiors of the two gas giants, Jupiter and Saturn, are pretty extreme places. With atmospheric pressures of around 70 million Earth atmospheres, the phases of material become a bit difficult to understand. Usually when we think of a liquid metal, we have thoughts about liquid mercury at room temperature (or the reassembling liquid metal T-1000 played by Robert Patrick in the film Terminator 2), rarely do we consider two of the most abundant elements in the Universe to be a liquid metal in certain conditions. And yet, this is what a team of physicists from UC Berkley are claiming; helium and hydrogen can mix together, forced by the massive pressures near the cores of Jupiter and Saturn, forming a liquid metal alloy, possibly changing our perception of what lies beneath those Jovian storms…

Usually planetary physicists and chemists focus most of their attention on the characteristics of the most abundant element in the Universe: hydrogen. Indeed, over 90% of both Jupiter and Saturn is hydrogen too. But within these gas giant’s atmospheres is not the simple hydrogen atom, it is the surprisingly complex diatomic hydrogen gas (i.e. molecular hydrogen, H2). So, to understand the dynamics and nature of the insides of the most massive planets in our Solar System, researchers from UC Berkley and London are looking into a far simpler element; the second most abundant gas in the Universe: helium.

Raymond Jeanloz, a professor at UC Berkeley, and his team have uncovered an interesting characteristic of helium at the extreme pressures that can be exerted near the cores of Jupiter and Saturn. Helium will form a metallic liquid alloy when mixed with hydrogen. This state of matter was thought to be rare, but these new findings suggest liquid metal helium alloys may be more common than we previously thought.

This is a breakthrough in terms of our understanding of materials, and that’s important because in order to understand the long-term evolution of planets, we need to know more about their properties deep down. The finding is also interesting from the point of view of understanding why materials are the way they are, and what determines their stability and their physical and chemical properties.” – Raymond Jeanloz.

Jupiter for example exerts an enormous pressure on the gases in its atmosphere. Due to it’s large mass, one can expect pressures up to 70 million Earth atmospheres (no, that isn’t enough to kick-start fusion…), creating core temperatures of between 10,000 to 20,000 K (that’s 2-4 times hotter than the Sun’s photosphere!). So helium was chosen as the element to study under these extreme conditions, a gas that makes up 5-10% of the Universe’s observable matter.

Using quantum mechanics to calculate the behaviour of helium under different extreme pressures and temperatures, the researchers found that helium will turn into a liquid metal at very high pressure. Usually, helium is thought of as a colourless and transparent gas. In Earth-atmosphere conditions this is true. However, it turns into an entirely different creature at 70 million Earth atmospheres. Rather than being an insulating gas, it turns into a conducting liquid metal substance, more like mercury, “only less reflective,” Jeanloz added.

This result comes as a surprise as it has always been thought that massive pressures make it more difficult for elements like hydrogen and helium to become metal-like. This is because the high temperatures in locations like Jupiter’s core cause increased vibrations in atoms, thus deflecting the paths of electrons trying to flow in the material. If there is no electron flow, the material becomes an insulator and cannot be called a “metal.”

However, these new findings suggest that atomic vibrations under these kinds of pressures actually have the counter-intuitive effect of creating new paths for the electrons to flow. Suddenly the liquid helium becomes conductive, meaning it is a metal.

In another twist, it is thought that the helium liquid metal could easily mix with hydrogen. Planetary physics tells us that this isn’t possible, hydrogen and helium separate like oil and water inside the gas giant bodies. But Jeanloz’s team has found that the two elements could actually mix, creating a liquid metal alloy. If this is to be the case, some serious re-thinking of planetary evolution needs to be done.

Both Jupiter and Saturn release more energy than the Sun provides meaning both planets are generating their own energy. The accepted mechanism for this is condensing helium droplets that fall from the planets’ upper atmospheres and to the core, releasing gravitational potential as the helium falls as “rain.” However, if this research is proven to be the case, the gas giant interior is likely to be a lot more homogenous than previously thought meaning there can be no helium droplets.

So the next task for Jeanloz and his team is to find an alternate power source generating heat in the cores of Jupiter and Saturn (so don’t go re-writing the textbooks quite yet…)

Source: UC Berkeley

21 Responses

  1. Member

    Nooo! I was worried about that, I should have said: “…and no, the liquid helium cannot be used in the construction of self-aware robots.” In fact, I need to start putting disclaimers at the bottom of some of these articles in case I inadvertently spawn Lucifer Project 2!


    Cheers, Ian 😉

  2. Phillipo says

    Very Cool… Seems to me there were quite a lot of IFs in that story? I think we still have a lot to learn about the Gas planets in our solar system..

    I think it would be really cool if we could do some sort of submarine type ship to enter one of these atmospheres one day (even Neptune or Uranus would be fine). I’ve never really read a good explanation of what any of their interiors are like (except for the theory above perhaps)?

  3. marcellus says

    Phillipo is on the right track. Send a spacecraft/probe to Uranus or Neptune to orbit the planet and drop a probe into the atmosphere ala Galileo at Jupiter to see what happens at a deeper level.

    Uranus and Neptune don’t have the crushing pressures that Jupiter does and by delving into those smaller gas giants, we could get an insight into a body of more mass.

  4. David R says

    In the year 2019 a company called Skynet will launch a nuclear powered supercomputer that will penetrate the Jovian core. The supercomputer will become self-aware in the year 2020 and will launch an unprecedented offensive against the human race. The offensive will consist of liquid metal T-1000 series “Terminator” machines, otherwise known as the real Lucifer project. However, the project will be thwarted by the “12 Angry Scientists Coalition,” an elite team that will resign from the Mars Phoenix Lander Project after an angry dispute over Perchlorate. Their fury, along with the support of millions of sympathetic, folk singing hippies, will save the world. Let us unite and huddle warmly over the next conspiracy theorist fire.

  5. Stephen says

    If you looking for an “alternate power source”: I suggest you strongly consider that the Helium3 isotope could be an excellent radiological solution at the core of all our Jovians.

    more research into this rare isotope could explain how these Joavians may work like a cooler fission nuclear reactor, being exploited similarly to the russian Tokamak design.

    maybe mother nature already has created the Tokamak and we call them Jovians.

    the fact that it is “slightly less reflective”than Mercury also explains one possible mechanism for why Saturn and Neptune seem to radiate approximately 2.5 times as much energy as they receive from the sun. Its like a mirror at the core.


  6. Alphonso Richardson says

    Well it sounds odd, but actually, not entirely surprising. Remember, quantum physics lies at the heart of many processes, (not least how computers work), but it’s very nature runs counter to our experiences in the macroscopic world.
    Pushing procesess to their extremes (almost) invariably produces odd or counter-intiutive actions.
    Granted, there are a LOT of ‘ifs’ with this, but it does sound very exciting

  7. Sleepy says

    I’m not a conspiracist and I thought that you article on the “Lucifer Project” was very sensible but isn’t all that Plutonium going eventually to end up at the very center of the planet? I’m more worried about damaging life forms that we have no concept off.

  8. RL says

    Great article. It makes me want to find my chemistry and physics books!

  9. As I understand it, Jupiter’s magnetic field is generated in its outer core, hitherto thought to be hot liquid hydrogen, which is conducting,but surrounds a metallic hydrogen lattice inner core which isn’t – and that’s why Jupiter’s magnetic field has a complex quadrupole structure offset from the axis of rotation. Saturn’s core is rock and metal which is conducting. So the conducting hydrogen-helium mix could exist around those cores and be growing with time, so preserving the heat-generating mechanism.

  10. Member
    Jon says

    Let’s make some.

  11. Jeff says

    If we’re looking to study the cores of gas planets in our solar system, we need do nothing more than dissect Rush Limbaugh.

    NASA, I’m waiting for my job offer.

    Great article by the way.

  12. On Complete Cosmos, they say the interiors of the gas giants, Jupiter and Saturn have 5 large layers. Gaseous hydrogen, liquid hydrogen, metallic hydrogen, rock, and an iron core. I wonder how large the iron core is in Jupiter. So Jupiter and Saturn’s magnetic fields should each indeed have a complex quadrupole structure like Duncan Lunan said. Maybe the rocky core doesn’t have a different rotation period compared to the iron core. I believe there is helium in those hydrogen layers too, since it’s the second most abundant element. I think the reason why the rock is not above the metallic hydrogen and helium, because rock is solid at zero pressures, so the atmospheric pressures that condense the hydrogen and helium condense the rock even more, keeping it closer to the center and then the rock is condensed by the pressure of the metallic hydrogen and helium too. But the metals like iron are always beneath, even the rock. The only object where iron is the outer layer and not the inner layer is a neutron star. Black holes too, if you believe there is a dense star at the center. Uranus and Neptune are ice giants, because they are mostly made of ice. The first large layer is liquid hydrogen and not gas. Possibly because the temperature is so low. Below that instead of metallic hydrogen, it’s a mantle of ice. Then the rock, then the metal. Neptune is the densest of the gas planets. 1000 lbs on Neptune would weigh less on Jupiter. I wonder if it’s possible to build a probe that wouldn’t be crushed by the time it reaches the mantle of ices. Uranus would be the best bet, since there is no internal heat source like Neptune does. Plus, Uranus is less massive than Neptune. Although it’s 4 times the diameter of Earth and 14 times Earth’s mass, 1000 lbs on Earth wouldn’t weigh as much on Uranus. But who knows what the atmospheric pressure would be by the time the probe reached the icy mantle?

  13. Member
    Scott says

    Metallic helium wouldn’t absorb neutrinos would it? Nice source of energy. And the think of the shadow it would cast.!

  14. Adam says

    Hi All

    The interior modelling of the gas giants is always uncertain to a certain degree. Some models show Jupiter to be fully convective with all its constituents stirred and mixed because it was too hot for a distinct core to settle out. Saturn is definitely in possession of a core, but just what it is in bulk is currently educated guesswork. Recent supercomputer studies of water ice at extreme pressures indicate that Uranus and Neptune have hearts of ‘hot ice’ wrapped around their cores, themselves composed of “post-perovskite” which is a high-pressure version of that Earthly mantle material.

    The interesting thing about this new work is that the two elements form an alloy with totally new properties – seems ultra-pressure chemistry has more surprises yet!

  15. alfchemist says

    It would be appreciated if the original paper be cited. So many details are not mentioned for full appreciation. Surely, the possibility of other elements present in the inner core is worth looking into and the implications this would have when these mix with helium and hydrogen at high pressures

  16. alfchemist says

    the comet that slammed into jupiter is a clear indication of seeding of heavy elements into the core. I could only guess that this has not happened only once and not only recently. It could be going on for eons and possibly during the early stages of the gas giant

  17. R2K says

    “Phillipo is on the right track. Send a spacecraft/probe to Uranus or Neptune to orbit the planet and drop a probe into the atmosphere ala Galileo at Jupiter to see what happens at a deeper level.”

    Too much pressure and heat.

    “I’m not a conspiracist and I thought that you article on the “Lucifer Project” was very sensible but isn’t all that Plutonium going eventually to end up at the very center of the planet? I’m more worried about damaging life forms that we have no concept off.”

    Those materials wont make it to the core intact: they will shred on the way down and disperse. The volume of Saturn is HUGE HUGE HUGE. The RTG material will be like a drop in the ocean (actually less).

  18. dipankar bera says

    If really there is liquid in Jupiter & Saturn then can we carry out from threr to earth ? And if it can be done then fuel problem may be solved.

  19. MJG says

    So is that what the monolith is made from?

  20. Igor says

    I always thought that Jupiter releases
    energy through gravitational contraction


  21. Imprecator says

    Very sad. I always thought the core of Jupiter was made of carbon, a giant set of carbon under pressure, the size of Earth, a huge diamond…

Comments are closed.