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Is Jupiter’s Core Liquifying?

Jupiter, with the moon Ganymede peeking out from behind. Credit: NASA/ESA/E. Karkoschka (U. Arizona)

Jupiter, the largest and most massive planet in our solar system, may be its own worst enemy. It turns out that its central core may in fact be self-destructing, gradually liquifying and dissolving over time. This implies it was previously larger than it is now, and may dissolve altogether at some point in the future. Will Jupiter eventually destroy itself completely? No, probably not, but it may lose its heart…

The core is composed of iron, rock and ice and weighs about ten times as much as Earth. That’s still small though, compared to the overall mass of Jupiter itself, which weighs as much as 318 Earths! The core is buried deep within the thick atmosphere of hydrogen and helium. Conditions there are brutal, with a temperature of about 16,000 kelvin – hotter than the surface of the Sun – and a pressure about 40 million times greater than the atmospheric pressure on Earth. The core is surrounded by a fluid of metallic hydrogen which results from the intense pressure deep down in the atmosphere. The bulk of Jupiter though is the atmosphere itself, hence why Jupiter (and Saturn, Uranus and Neptune) are called gas giants.

One of the primary ingredients in the rock of the core is magnesium oxide (MgO). Planetary scientists wanted to see what would happen when it is subjected to the conditions found at the core; they found that it had a high solubility and started to dissolve. So if it is in a state of dissolution, then it was probably larger in the past than it is now and scientists would like to understand the process. According to David Stevenson of the California Institute of Technology, “If we can do that, then we can make a very useful statement about what Jupiter was like at genesis. Did it have a substantial core at that time? If so, was it 10 Earth masses, 15, 5?”

The findings also mean that some exoplanets which are even larger and more massive than Jupiter, and thus likely even hotter at their cores, may no longer have any cores left at all. They would be indeed be gas giants in the most literal sense.

The conditions inside Jupiter’s core can’t be duplicated in labs yet, but the spacecraft Juno should provide much more data when it arrives at and starts orbiting Jupiter in 2016.

About 

Paul Scott Anderson is a freelance space writer with a life-long passion for space exploration and astronomy and has been a long-time member of The Planetary Society. He currently writes for Universe Today and Examiner.com. His own blog The Meridiani Journal is a chronicle of planetary exploration.

Comments on this entry are closed.

  • IVAN3MAN_AT_LARGE December 21, 2011, 8:56 PM

    Yo Paul, referring to the fourth sentence of the second paragraph:

    Conditions there are brutal, with a temperature of about 16,000 degrees kelvin – [...].

    After the 13th General Conference on Weights and Measures (CGPM) in 1967–1968, the SI unit kelvin (see: Usage conventions) is simply referred to as “kelvin”, with the omission of the preceding term “degrees” to indicate that it is not relative to an arbitrary reference point like the Celsius and Fahrenheit scales.

    • Paul Scott Anderson December 21, 2011, 9:25 PM

      Ok, I’ll fix that. It was written that way as well in this Wired article that I had also used as a source:
      http://www.wired.com/wiredscience/2011/12/jupiter-core-solid-liquid

      • IVAN3MAN_AT_LARGE December 21, 2011, 10:02 PM

        Well, the dude who wrote that article got it wrong as well! :-)

      • IVAN3MAN_AT_LARGE December 21, 2011, 10:02 PM

        Well, the dude who wrote that article got it wrong as well! :-)

      • Anonymous December 21, 2011, 11:42 PM

        I’d also like to ask a question: does UT have a licensing agreement with Wired? If so, then ignore what follows.

        If not, then you need to be *very* careful about copyright infringement. I’m an administrator on Wikinews, and we’ve found that sites owned by certain companies are extremely likely to engage in legal action when it comes to copyright enforcement. If your article was on Wikinews, it would have been deleted immediately for multiple blatant copyright violations (as a preventative measure).

        For what it’s worth, Wired is owned by Advance Publications, a gigantic privately held company. It’s the same company that publishes Vogue among many other things. So they’re big, they’re rich, and they have reams of angry attack lawyers.

        When you’re using another author’s article as your source, you cannot reuse any of their phrasing except in direct quotations. You are also forbidden by US copyright law from simply rephrasing the words of another writer. Rewriting a copyrighted article sentence by sentence (while leaving the overall article structure and flow the same) is not permitted.

        What you *can* do is read a source article completely, absorb the information, and then write it in your own words. Words, structure, and flow can be copyrighted, but the ideas that they convey cannot be. Not only does this method of writing a summary article eliminate the threat of a copyright infringement notice (or additional legal action), it also makes for more readable articles:). As a reader, I’d rather read *your* words than those of someone you’re copy/pasting or rewriting.

        Also, note that it helps to read multiple articles on the same subject. This not only reduces your chances of accidentally regurgitating the same phrasing as your source, it helps reduce bias and mistakes. If you’d read more than one article you wouldn’t have made that “degrees Kelvin” error;).

        Now that I’ve said my bit, please don’t take this as a personal attack. Many blog writers don’t seem to understand that what I described above counts as a copyright violation; they think that it isn’t a copyvio unless you’re copy/pasting entire paragraphs at a time. That is incorrect.

        Until planetary copyright law becomes a bit more sane, everyone who writes on the interwebs (including me:P) need to be far more careful than they’re being.

        • IVAN3MAN_AT_LARGE December 22, 2011, 7:01 AM

          What you *can* do is read a source article completely, absorb the information, and then write it in your own words. Words, structure, and flow can be copyrighted, but the ideas that they convey cannot be.

          In other words, we have to rewrite the article in Klingon! ;-)

        • Anonymous December 22, 2011, 10:17 AM

          “Also, note that it helps to read multiple articles on the same subject. This not only reduces your chances of accidentally regurgitating the same phrasing as your source, it helps reduce bias and mistakes.”

          I thought this was an excellent suggestion, not only for reasons given, but in sense of taking an object, and viewing it from several different angles, so obtaining a more in-depth, 3-dimensional grasp of its overall facets. And, therefore, enabling one to “paint-it-out” with better rounded representation — the study subject in all its aspects.

          Examine the same object in a different light.

          Its also good for readers: Three people can have basically the same knowledge, yet if each explains it through their own perspective, thoughts and words ( their unique angle of view ), it can only serve to enrich the hearer, and, therefore, the writer.

        • Paul Scott Anderson December 22, 2011, 11:44 PM

          Thanks for the info. There was no intention to just copy the Wired article, but it was probably circulating in my mind. I was going by the first article that I linked to primarily but then someone had also pointed out the Wired one to me later on so I was probably thinking about it too much. I was also trying to get this article out as I was running a bit behind time-wise (dealing with other things) so ended up rushing it. I’ll try to be more watchful of that from now on. Geez, and I had just criticized The Daily Galaxy for doing this to one of my recent articles! ;-)

          I had been doing the blogging thing and other research for years, but this is my first major foray into freelance writing. A lot of things to get updated on and watch out for, but it’s a learning experience as I see it. I decided this year to make a big change and go in the direction that I actually wanted to instead of settling for things that were not making me happy. Space and astronomy have always been my primary passions my entire life as well as writing. I’m not a scientist, so getting more up to speed on various specifics is also a good thing for me. :-)

          • Anonymous December 23, 2011, 11:17 PM

            You’re very polite when replying to random jackasses like me on the internet. I like you:).

  • Sean Leslie December 21, 2011, 9:16 PM

    Doesn’t this blur the line between planets and brown dwarfs even further?

    • Torbjörn Larsson December 22, 2011, 2:32 PM

      I don’t think so, there are still no definitions that doesn’t observe overlaps, say in mass.

      If formation is going to be the future distinction, the first Kepler conference pitched in on the side of giant planet formation from core accretion to the exclusion (as I understood it) of disk instability formation. While brown dwarfs seems to form by the latter process.

    • Torbjörn Larsson December 22, 2011, 2:32 PM

      I don’t think so, there are still no definitions that doesn’t observe overlaps, say in mass.

      If formation is going to be the future distinction, the first Kepler conference pitched in on the side of giant planet formation from core accretion to the exclusion (as I understood it) of disk instability formation. While brown dwarfs seems to form by the latter process.

  • John Ross December 21, 2011, 9:38 PM

    “The bulk of Jupiter though is the atmosphere itself, hence why Jupiter (and Saturn, Uranus and Neptune) are called gas giants.”

    I have learned recently, via Ohio State University’s Richard Pogge, that we now refer to Uranus and Neptune as ICE giants, not gas.

    • Anonymous December 21, 2011, 11:51 PM

      Personally I think that gas giant should only refer to things large enough to have Saturn like atmospheres, but small enough that they haven’t reached maximum planetary diameter (about Jupiter diameter).

      Anything smaller should be an ice giant (or water giant, methane giant, etc, depending on the composition of the atmosphere).

      Anything larger than Jupiter but unable to sustain deuterium fusion should be a gas super-giant, indicating that it has reached maximum diameter.

      I like naming conventions based on the physical properties of the planets in question, rather than arbitrary lines in the sand:).

      • William Sparrow December 22, 2011, 12:14 AM

        Exoplanets whose size exceeds Jupiter may not be planets at all, but rather brown dwarfs.

        • magnus.nyborg December 22, 2011, 12:17 PM

          Hot Jupiters have larger diameters because they are somewhat hotter overall than Jupiter, yet i still believe they should be called planets as long as they are not massive enough to support deuterium fusion.

        • ITSRUF December 29, 2011, 1:11 AM

          Exoplanets are not planets at all since they do not orbit the sun. (Just pointing out how silly some naming conventions can be.)

        • ITSRUF December 29, 2011, 1:11 AM

          Exoplanets are not planets at all since they do not orbit the sun. (Just pointing out how silly some naming conventions can be.)

      • Torbjörn Larsson December 22, 2011, 2:39 PM

        I don’t think there is an established maximum diameter for planets as of yet. Brown dwarfs doesn’t seem to form by core aggregation like giants seems to do, hence these more star like objects are not an indicator of planet size.

      • Torbjörn Larsson December 22, 2011, 2:39 PM

        I don’t think there is an established maximum diameter for planets as of yet. Brown dwarfs doesn’t seem to form by core aggregation like giants seems to do, hence these more star like objects are not an indicator of planet size.

    • Torbjörn Larsson December 22, 2011, 2:36 PM

      Also, I have several times heard the Kepler team refer to the erstwhile (?) “snow line (frost line, ice line)” as the more generic and understandable “ice line”.

      Ice, ice, baby giant.

    • Torbjörn Larsson December 22, 2011, 2:36 PM

      Also, I have several times heard the Kepler team refer to the erstwhile (?) “snow line (frost line, ice line)” as the more generic and understandable “ice line”.

      Ice, ice, baby giant.

  • Anonymous December 22, 2011, 1:57 AM

    Whether Jupiter had a hard core at its start might depend on how gas giants are formed. Maybe the rocky core is the seed for the planet’s formation. At these temperatures it makes sense that the core is evaporating away.

    LC

  • Peter Kanssen December 22, 2011, 8:23 AM

    how do we know about the MgO?

  • Anonymous December 22, 2011, 10:23 AM

    “The core is composed of iron, rock and ice”? How can you have 40 million x Earth-atmosphere pressure, Photosphere-level temperatures below the clouds of that stormy world, with the core itself encased in a fluid of “metallic hydrogen” ( a gas compressed to a liquid-metal ocean ), and yet have “rock and ( especially ) ice”?

    What surreal physical properties and forces must be at work below such massive depth of pressure and, if theory’s hold true, heat.

    With a much larger core in its “genesis” years, the Planet may have had a dramatically different appearance, and atmospheric dynamics. I wonder how ( if at all ) that affected its real moons, were they farther out, closer in, warmer? Did that effect the deadly electromagnetic field force and strength that envelopes them?

    I have long suspected that this behemoth, and our Planetary System as a whole, had a far different appearance in its Genesis years ( before its passage through a “shooting gallery” ). Perhaps a startlingly different orbital configuration – but with the good Earth unmoved from its crowned place of habitability.

    • squidgeny December 22, 2011, 12:21 PM

      Well I’m no expert but I would guess that the immense pressures would be capable of compressing any substances into a crystalline state that technically counts as “frozen”. I’m not sure whether it’s water-ice or not though… I kinda wish that the articles here would clarify that, because water isn’t the only substance that freezes into ice ;)

      • Anonymous December 22, 2011, 1:20 PM

        You reintroduced an interesting possibility: crystallization of matter under extreme conditions. Other forms of “ice”, a form of crystallization, did not even occur to me.

        Your post seems to tie-into another of concept-challenging view regarding cores, their actual temperatures and real compositions (last Mercury article). From his thoughts, super-cold super-conduction and Electro-Magnetism came to mind (don’t ask me how it all relates), touching upon the “Dynamo Theory”.

        Your thought brings to mind Neutron Stars and White Dwarfs, with possible crystalline properties.

        Makes you wonder what you might “see” far below the depths of the Jovian tempest, or upon the blazing surfaces of star-matter in super density! Visions only for the artist’s brush of the “mind’s eye”.

    • Torbjörn Larsson December 22, 2011, 2:44 PM

      General planet formation is up in the air from Kepler’s and other’s results. So yes, most anything could have happened.

      But the Nice model and its derivatives predict so many features of the solar system so it is unlikely to be incorrect. (See the Wikipedia article, it is an impressive list of predictions.)

      That model, and especially the “ejected 5th giant” variant, puts the remaining giants and Mars at the correct places from the outset.

      And what “passage through a “shooting gallery”” do you mean? It would be interesting, but I don’t think there is any evidence of such. The Late Heavy Bombardment is claimed to be an internal affair (from isotope ratios, perhaps) and as it happens the Nice model predicts it as the influence of giant migration on remaining small bodies.

    • Torbjörn Larsson December 22, 2011, 2:44 PM

      General planet formation is up in the air from Kepler’s and other’s results. So yes, most anything could have happened.

      But the Nice model and its derivatives predict so many features of the solar system so it is unlikely to be incorrect. (See the Wikipedia article, it is an impressive list of predictions.)

      That model, and especially the “ejected 5th giant” variant, puts the remaining giants and Mars at the correct places from the outset.

      And what “passage through a “shooting gallery”” do you mean? It would be interesting, but I don’t think there is any evidence of such. The Late Heavy Bombardment is claimed to be an internal affair (from isotope ratios, perhaps) and as it happens the Nice model predicts it as the influence of giant migration on remaining small bodies.

      • Anonymous December 22, 2011, 5:09 PM

        Appreciate the feedback. I have never heard of the “Nice model”; I will give it a scan.

        I take all hypothetical models with a hefty grain of salt.

        Through the “Model” frame I hold, viewing sun-burnt Mercury, battered and apparently stripped, where it now revolves ( in an orbit that plays a part in stabilizing the System as *now* configured ), makes no sense to me – as part of an “original” formation configuration ( not to suggest I believe it was *radically* different ). And the view of a dramatic gap of an “empty” space-separation – strewn with a debris-field – strikes me with weight of impact (excuse the pun). In over-arching frame, and material compositions, there is tantalizing evidence something may have once existed there, in early light of the our Sun’s Age.

        I don’t buy the “ejection” scenario – as applied to the Solar System. Which, if I understand ( or may misunderstand ) is intimately related the Nebulae Planet-Formation Hypothesis – where you can have “Early” and “Late Heavy Bombardment[s]“. Sure, an ejection can happen in a system that falls into disorder for some reason, where “migration” may set in, as it decays. When planets begin to jump there orderly-arranged orbital tracks, so to speak.

        In stark contrast to that creation “model” frame, I believe the powerful evidence seen ( thanks to a fleet of robotic instrumentation ) – from one end of the System to the other – boldly spells-out a scenario of Catastrophe: an episode of massive Destruction, as opposed to the odd-concept of a violence-strewn process of Construction, through stormy stages of endless collisions and raining impacts – building worlds. ( A “noisy” building process filled with loud bangs, or should that be muffled thumps? )

        It has always struck me as so brutally inelegant – and clumsy: bits and pieces – rocks and boulders – “sticking” together. Computer models or no computer models.

        My “shooting gallery” phrase, you made me realize, is a poor way to describe the “episode” to which I elude, as it was not a planet-battering hailstorm of destruction from without, but from *within* – as you rightly say, “an internal affair”. (I can go no further.)

        I realize it may sound “crazy”.

        I have no computer models to back-up my belief. But a battery of supercomputers crunching through all the relevant data, might, in process, come-out with some very interesting results. LAWS are laws, and there is no way getting around what they allow – or disallow.

  • Torbjörn Larsson December 22, 2011, 2:47 PM

    metallic hydrogen

    While it isn’t the core issue here, I don’t remember that the promising results on testing a metallic hydrogen phase have been conclusive as of yet FWIW.

    It is a claim in the paper, but unreferenced.

  • Torbjörn Larsson December 22, 2011, 2:47 PM

    metallic hydrogen

    While it isn’t the core issue here, I don’t remember that the promising results on testing a metallic hydrogen phase have been conclusive as of yet FWIW.

    It is a claim in the paper, but unreferenced.

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