We recently found out that Pluto has a molten core. Since the Moon is bigger than Pluto should the Moon have had a molten core at some point in time?

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    $\begingroup$ Do you have a source for a molten core? There's talk that Pluto might have a liquid watery ocean below it's surface, but that's not the same as a liquid core. universetoday.com/14315/is-there-life-on-pluto $\endgroup$
    – userLTK
    Commented Aug 1, 2015 at 2:20
  • $\begingroup$ @userLTK: In terms of Pluto's geology (Plutology?), liquid water should count as a molten core, shouldn't it? Since most of the surface seems to be ice, with nitrogen ices &c being the active elements... $\endgroup$
    – jamesqf
    Commented Aug 2, 2015 at 4:37
  • $\begingroup$ @Jamesqf, well,I don't want to debate the specifics of what molten means (water vs rock), but if others wish too take up that point, they can, but where I'm pretty confident debating this argument is that Pluto's theoretical liquid ocean isn't at it's core at all, but near the surface. Below the surface to be sure, but closer to the surface than the core. It's not a liquid "core" at all. $\endgroup$
    – userLTK
    Commented Aug 2, 2015 at 6:02

1 Answer 1


About one-third of the near side of the Moon is covered by basaltic plains, called Mare. These plains are evidence that molten rock once flowed on those areas of the Moon and that in its early history the Moon experienced volcanism.

NASA analysis of Apollo era seismic data indicates the Moon has a core similar to Earth: a solid central core within a molten outer core.

The molten Lunar core is small compared to the size of the Moon and the Moon's mantle is so thick that molten rock from the core can no longer reach the surface of the Moon.

From my review of NASA's New Horizon's website, there is no statement about the composition of Pluto's core. Two other sources, News.com and Space.com make different statements about Pluto's core.

News.com states,

Essentially, it looks as though Pluto has a molten radioactive core and tectonic plates.

Whereas, Space.com states,

The dwarf planet probably has a rocky core surrounded by a mantle of water ice, with more exotic ices such as methane, carbon monoxide and nitrogen ice coating the surface.

These comments appear to be conjecture and are not official NASA releases based on NASA acquired data from the New Horizons probe that flew past Pluto.

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    $\begingroup$ Minor nitpick, but plural of Mare is Maria :) $\endgroup$
    – TildalWave
    Commented Jul 26, 2015 at 7:37
  • $\begingroup$ If the Moon contains a molten core similar to Earth's, it cannot have molten rock. It would be molten metal. $\endgroup$ Commented Feb 3, 2019 at 19:22

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