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Space Science

Is Jupiter Dissolving Its Rocky Core? 181

sciencehabit writes "Jupiter is the victim of its own success. Sophisticated new calculations indicate that our solar system's largest planet, which weighs more than twice as much as all of the others put together, has destroyed part of its central core. The culprit is the very hydrogen and helium that made Jupiter a gas giant, when the core's gravity attracted these elements as the planet formed. The finding suggests that the most massive extrasolar planets have no cores at all."
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Is Jupiter Dissolving Its Rocky Core?

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  • Re:Weight? (Score:5, Informative)

    by camperdave ( 969942 ) on Monday December 19, 2011 @03:26PM (#38425754) Journal
    No. It is estimated by the orbits of it's satellites, using Kepler's laws. If you know the period, eccentricity, and size of a satellite's orbit, you can work out the mass of the object that the satellite is orbitting. It has nothing to do with how much of that object is solid.
  • by Trepidity ( 597 ) <delirium-slashdot.hackish@org> on Monday December 19, 2011 @03:33PM (#38425820)

    There's some evidence beyond only mineral composition for the earth's core, mostly from seismic data; the discontinuities observed in seismic wave travel put constraints on what has to be the case at different layers. At least, it's more data than we have about the interior of Jupiter, which afaik is entirely based on mineral composition and modeling.

  • Re:Ho Hum (Score:5, Informative)

    by rahvin112 ( 446269 ) on Monday December 19, 2011 @03:34PM (#38425838)

    We know A LOT about the cores of the planets in the solar system from extensive study (including molten, material and other stuff that can be determined from external study). It appears you are talking about examining extrasolar planets. We don't have the capability, and it's doubtful we will, at least in our lifetime. Voyager1 just left the solar system and it's moving at ~35k MPH and it was launched in the 70's, most of the people that designed it are retired or dead and Voyager1 will be dead long before it reaches any other star.

  • Re:Ho Hum (Score:5, Informative)

    by Anonymous Coward on Monday December 19, 2011 @03:36PM (#38425854)

    The Magnetosphere helps keep solar winds from stripping our atmosphere away from us.

  • Re:Ho Hum (Score:5, Informative)

    by boddhisatva ( 774894 ) on Monday December 19, 2011 @03:36PM (#38425856)
    What maintains our atmosphere is the magnetic field generated by the liquid mantle rotating around the core. The magnetic field deflects the solar wind which would blow it off. It's thought by some that Mars lost it's atmosphere and surface water when the liquid mantle cooled and solidified. Mars has no magnetic field.
  • Re:Ho Hum (Score:5, Informative)

    by John_Booty ( 149925 ) <.johnbooty. .at.> on Monday December 19, 2011 @03:38PM (#38425894) Homepage

    I knew the core was supposed to be the cause of our magnetosphere

    That's a large part of the answer right there! The magnetosphere acts as a shield to keep a lot of harmful particles from the solar wind away, things which would work to strip away the atmosphere. Mars is an example of what can happen to planets that lack this. (Obviously, Mars' lower gravity works against it in this regard as well) []

  • Re:core is icey hot? (Score:4, Informative)

    by ZombieBraintrust ( 1685608 ) on Monday December 19, 2011 @03:38PM (#38425896)
    Ice doesn't mean cold water. Ice is solid water. Water is liquid, solid, or gass depending on temperature and pressure. There is alot of pressure at the core of Jupiter.
  • Re:Ho Hum (Score:5, Informative)

    by wierd_w ( 1375923 ) on Monday December 19, 2011 @04:51PM (#38426728)

    Look at the composition.

    Venus's atmosphere is very low in certain molecules.
    Elemental oxygen.
    Water vapor
    Et al.

    What it is high in, are comparatively dense gasses.
    Sulfuric acid
    Carbon dioxide

    The solar wind is highly energetic, but is comprised of small atomic mass particles. They lack the kinetic energy to strip away very heavy gasses with strong intermolecular forces. Water, while having strong intermolecular forces, is a very light molecule, and the high energy particles have sufficient energy to break the single covalent bonds that hold it together. This means the cosmic wind rips it apart, and then scours it out into space. Sulfuric acid and cabron dioxide, on the other hand, are very heavy, gravitate deeper into the gravity well, and in the case of co2, have double covalent bonds that are quite powerful. The solar wind doesn't have enough oomph to rip it apart, and the molecules are too heavy to easily blow away.

    Mar's armosphere is actually sabotaged by a weak and incomplete magnetic field. It has many small and weak diploles extending from the surface. Under the influence of the solar wind, this actually pinches off large chunks of atmosphere during heavy flares from the sun. This is why mars has such a pronounced atmospheric loss, compared to venus, which doesn't have any discernable mgnetic field at all. If you note, the atmosphere mars does have is comprised of what? Co2.

  • by Migraineman ( 632203 ) on Monday December 19, 2011 @04:52PM (#38426750)
    To expand this a little -

    Through fusion, lighter elements like hydrogen and lithium may be combined (nuclear). This process will provide a net energy output up to "iron."

    Through fission, heavier elements may be disassociated (nuclear). This process will provide net energy output down to "iron."

    When all you have left is iron, making something else via nuclear methods requires the addition of energy. Thus, "everything decays to iron" represents a lowest energy state from a nuclear perspective. But don't worry, the heat death of the universe [] won't happen for a long while.
  • Re:Ho Hum (Score:5, Informative)

    by Thiez ( 1281866 ) on Monday December 19, 2011 @06:39PM (#38427786)

    Neither. As the sun gets older, it gets brighter (according to wikipedia, about an 10% increase in luminosity every billion years). At some point there will be no more liquid water available because the surface of our planet is too hot. This will happen long before the sun turns into an actual red giant, which in turn will happen long before it runs out of fuel.

I've got a bad feeling about this.