Mercury's molten core Options

[Guest_AlexBlackwell_*]

The embargo won't be lifted for a few more hours, but note that the May 4, 2007, issue of Science will have an interesting paper Margot et al. (and accompanying Perspectives piece by Sean Solomon) regarding Mercury and a possible molten core, a paper that also makes the cover.

[nprev]

What I find most mysterious is how Mercury could have such a disproportionately large and at least partially still liquid core yet have a thick crust with no evident prior surface activity and apparently little in the way of a mantle.

Does this perhaps suggest that Mercury did indeed form further out, cooled rapidly, yet had a rapid rotation rate and was re-heated during its orbital migration inward by dynamic tidal braking as it settled into the 3/2 spin resonance and significantly eccentric orbit while its core "re-melted"? Sort of like a thick-skinned Io in some ways...

Another point to consider is Venus' rotational resonance with Earth. Something very interesting and not at all obvious may have happened to all three planets in the early days.