From Wikipedia on superconductivity of metallic hydrogen:

In 1968, Neil Ashcroft put forward that metallic hydrogen may be a superconductor, up to room temperature (~290 K), far higher than any other known candidate material. This stems from its extremely high speed of sound and the expected strong coupling between the conduction electrons and the lattice vibrations.

If a planet like Jupiter has lots of hydrogen, is it likely it could be a giant superconductor? What effects could this have & how can we look for or detect such a thing?


1 Answer 1


Yes, and that's believed to be the source of Jupiter's gigantic magnetosphere. It is also a possible explanation for bizarre cooling of Cassiopeia A. So that's at least two immediate effects of large quantities of metallic hydrogen present in a celestial body; formation of a magnetosphere and faster cooling of their outer cores. Both of these effects are measurable. Magnetosphere of Jupiter was and still is measured by deep space probes, orbiters, any flyby spacecraft. Its side-effects also cause magnetic reconnection events with the Sun's magnetic field, causing polar aurorae and radio frequency emissions that can be observed remotely, some of them even with amateur radio astronomy equipment. And cooling of the outer core is measurable through Jupiter's density (its mass to volume ratio) that can also be inferred through data obtained with observational astronomy. In 2020 Snider et al4 metalized hydrogen sulfide at 267 GPa and detected superconductivity at a critical temperature of 287K or 15C, the highest so far and validating previous theoretical work on high pressure superconductors5.

  • $\begingroup$ Is Jupiter or another large body referred to anywhere directly as a 'superconductor', or is the word unnecessary in this case? As Jupiter increases density at maximum volume, will we see the field grow? $\endgroup$ Commented Jan 25, 2014 at 12:59
  • $\begingroup$ The word is unnecessary. $\endgroup$
    – TildalWave
    Commented Jan 25, 2014 at 16:03
  • $\begingroup$ @TildalWave, are you confusing superconductivity with regular conductivity? I don't understand how this answers OP's question. $\endgroup$ Commented Apr 2, 2015 at 2:10
  • 1
    $\begingroup$ @ninemileskid No. Theory of superconductivity of WDM is pretty sound and indeed observed (indirectly) where predicted. It's a bit tricky to confirm this experimentally though. For the theoretical part, check e.g. Determining the Properties of Dense Matter: Superconductivity, Bulk Viscosity, and Light Reflection in Compact Stars (PDF). For experimental part, see e.g. SLAC's public lecture: Jupiter in a Bottle $\endgroup$
    – TildalWave
    Commented Apr 2, 2015 at 6:58
  • $\begingroup$ I think another reason people don't call Jupiter a superconductor is that only the liquid metallic hydrogen is a superconductor, and that's far from being all of Jupiter. It would be a little like saying "the Earth is an electrical conductor" just because its core is iron. (The core is a smaller fraction, but the principle is the same.) $\endgroup$ Commented Dec 7, 2020 at 18:51

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