Surprise! Jupiter's ocean moon Europa may not have a fully formed core

One reason Europa might not have a fully formed core is that it likely formed at much colder temperatures than Earth did, due to the icy moon's greater distance from the sun. This means that, as Europa's building blocks came together, they may not have melted and separated into a metallic core and rocky mantle.
That is perhaps sloppy writing. The paper discuss with a simple model how the moon's accretional heat doesn't suffice to form a core. It then claims that slow accretion would tend to make the accreting body match the circumjovian disk temperature it formed in (estimated to have had 200-300 K temperature).

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