Oceans of Liquid Diamond May Exist On Neptune and Uranus

January 18, 2010 by John Messina, Phys.org weblog

When scientists melted diamond under ultra high temperatures and pressure and reduced both temperature and pressure the solid diamond chunks floated on top of liquid diamond. Credit: Getty Images
(PhysOrg.com) -- Scientist explains how it may be possible for the planets Neptune and Uranus to contain liquid diamond oceans.

The research was conducted by taking detailed measurements of the melting point of diamond. When diamond is melted it behaves like water during freezing and melting, with solid forms floating atop liquid forms. Diamond is a very hard material which makes it difficult to melt. Measuring the melting point of a diamond is very difficult because when it's heated to very high temperatures the diamond changes to graphite.

Since it's the graphite and not the diamond that turns to liquid, scientist are faced with the problem of melting the diamond without it turning to graphite.

Scientists can get around this problem by exposing the diamond to extremely high pressures by blasting it with lasers. The diamond is liquefied at pressures 40 million times greater than that found at Earth's sea level.

[b]Neptune:[/b] By Neptune's diamond oceans! NASA

When the pressure is lowered to 11 million times greater than Earth's and the temperature drops to about 50,000 degrees, chunks of diamond start to appear.

Scientists discovered something they didn't expect, after the pressure kept dropping the temperature of the diamond remained the same, with more chunks of diamond forming. The chunks of diamond did not sink but floated on top of the liquid diamond, creating diamond icebergs.

These ultrahigh temperatures and ultrahigh pressures are found in huge gas giant like and Uranus.

Neptune and Uranus are estimated to be made up of 10% carbon. A large ocean of liquid diamond could deflect or tilt the out of alignment with the rotation of the planet.

The only way scientists can know for sure if liquid diamond exists on these gas giant planets is either by sending a scientific to one of them or by simulating the conditions on earth. Both methods would be very expensive and take years to prepare.

The paper is published in Nature Physics.

Explore further: Superconductivity in diamond

More information: Nature Physics 6, 9-10 (1 January 2010); doi:10.1038/nphys1491

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3 / 5 (2) Jan 18, 2010
Diamond lattice is well known by fact, it clearly violates the rule, the highest strength, the more dense lattice. It even violates the rule, the highest strength, the higher number of the closest neighborhoods (i.e. coordination number). The correct rule is, the higher strength, the closer atom distances in the lattice together with least number of closest atoms possible.

Therefore the atomic packing factor of diamond cubic lattice is far from most compact arrangement of spheres with face-centered cubic (FCC) unit cell of 74% packing efficiency, so it could really behave like ice at the water during melting. The most dense matter could appear like nested dodecahedron foam or streaks of dark matter.
4.8 / 5 (4) Jan 18, 2010
"The most dense matter could appear like nested dodecahedron foam or streaks of dark matter."

Probably not.
not rated yet Jan 18, 2010
Dodecahedron is most regular Platonic solid with smallest number of sides, so it forms a shape of density fluctuations inside of most compact particle systems.
4.3 / 5 (3) Jan 19, 2010
How strange that there may be a diamond in Uranus. I guess only time will tell if this is indeed true, no doubt after scientists have used the arsenal of methods at their disposal to determine the truth.
3.8 / 5 (4) Jan 19, 2010
Scientists will probe Uranus to extract diamonds, that shit is worth a lot!
Jan 19, 2010
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1 / 5 (1) Jan 20, 2010
In order to mine Uranus, we would have to set up a colony there. This could prove expensive.
not rated yet Jan 21, 2010
really? a colony? The pressure is melting diamonds, what are you going to use to protect... whatever you have on the surface? I'm sure we'll have the ability to manufacture diamond like strength armor well before we have the ability to mine Uranus for diamonds.

Crazy awesome!
not rated yet Jan 21, 2010
we would have to set up a colony there.
We couldn't survive near large planets, not saying inside of them. The daily radiation at the surface of Io moon near Jupiter exceeds lethal dose more then 2000x.
5 / 5 (1) Jan 24, 2010
People....the "surface" gravity of Neptune and Uranus is about ten to eleven times stronger than earth. Even ignoring the pressure, the most powerful rocket humans have ever made cannot achieve orbit from Neptune's or Uranus' surface..

Only a Nuclear Fusion rocket or anti-matter rocket could ever work, and even ignoring the pressure concerns, those would cost more to make than the value of the diamonds you could ever possibly extract.

Also, any space probe would be totally destroyed long before it even got far enough into the atmosphere to detect "Liquid diamonds" or "diamond icebergs".

The pressure would smash the molecules of the circuitry or cameras into it's optimum lattice per pressure, hundreds or even thousands of miles before it got far enough in to do the needed science, and you'd have a rock falling to the surface....then that would get crushed to diamond itself, or whatever mineral forms of the metals it's made of at those pressures...
not rated yet Jan 27, 2010
Don't use a rocket to get down there and back, use a balloon. And don't use a computer to guide it, use simple mechanical devises like a barometer. A bucket on a rope could scoop up some liquid diamond, and the heat from those depths could melt a bracket releasing a counterweight which would allow your probe to rise gently to the "surface".

Of course the whole thing would probably have to be made of diamond and cost an unholy fortune.

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