Uranus and Neptune May Have "Oceans of Diamonds"

Third Position writes "Oceans of liquid diamond topped with solid 'icebergs' of the precious gems could be on Uranus and Neptune. The first-ever detailed research into the melting point of diamond found it behaves like water during melting and freezing — with its solid form floating on the liquid. A large diamond ocean on one or both of the planets could provide an explanation for an oddity they both share: unlike Earth, they do not have magnetic poles that match up with their geographical poles." The article doesn't mention what the pressures might be like in these outer-planets environments, but the researchers found that liquefying diamond requires 40 million times Earth's atmospheric pressure at sea level.

Comments

Much as I'd love to make a great pun about uranus.

[cmowire]

The possibilities of exploring the outer "ice giants" is massive. I think, at least. I may not even make the pun because I think the idea of exploring them is so interesting.

Submarines are designed to handle a test depth of maybe 1600 ft which means maybe 50 bar of pressure. At that pressure, the atmosphere of Uranus is a little below freezing. The gravity is less than Earth. I suspect that with correct ballasting you could make a metal sphere float in the atmosphere for quite some time by keeping the insides pressurized to a convenient atmospheric pressure. So sticking around for a while isn't hard.

I can't find any good information on the radiation environment there and if you could put humans in the little bubble circling Uranus.. um.. yeah, I lied above.

Re:For the dull knives in the drawer

[reverseengineer]

My guess is that the difference in density may be strongly dependent on the pressure. At standard conditions, diamond is actually the densest form of pure carbon, and at atmospheric pressure, carbon sublimates instead of melting. It seems possible to me that liquid diamond is more compressible than solid diamond, such that the liquid density is more variable than the solid density with respect to pressure. Under a relatively low applied pressure (well, still gigapascals), diamondbergs would sink. At some phenomenal pressure, the densities would match and solid would be neutrally buoyant in liquid. Above that pressure, the atoms in liquid diamond would be more crushed together than those in the diamond lattice, and the crystal would float. The inherent strength of the cage-like solid diamond structure makes it energetically favorable, despite the atoms being farther apart.