The research based on the first detailed measurements of the melting point of diamond, found it behaves like water during melting and freezing, with solid forms floating atop liquid forms.
"Diamond is a relatively common material on Earth, but its melting point has never been measured," said Eggert. "You can't just raise the temperature and have it melt, you have to also go to high pressures, which makes it very difficult to measure the temperature."
Other groups, notably scientists from Sandia National Laboratories, successfully melted diamond years ago, but they were unable to measure the pressure and temperature at which the diamond melted.
A large diamond ocean on one or both of the planets could provide an explanation for an oddity they both share.
The two giant gas planets, unlike Earth, do not have magnetic poles which match up with their geographical poles.
As much as 10 per cent of both planets is carbon, and a liquid diamond ocean could deflect the angle of the magnetic field out of alignment with the planet's rotation, the researchers believe.
In laboratory conditions which simulated pressure levels on the gas planets, the scientists found that little crystals of solid diamond formed like icebergs in the liquid carbon they created.
Dr Jon Eggert, of the Laser Shock Equation of State (EOS) group in the Department of Physical and Life Sciences Directorate at Lawrence Livermore National Laboratory in California, said: "The idea of significant quantities of pure carbon existing in giant planets such as Uranus and Neptune has gained both experimental and theoretical support.
"It is now accepted that the high-pressure, high-temperature behaviour of carbon is essential to predicting the evolution and structure of such planets.
"An ocean of diamond could help explain the orientation of Uranus' and Neptune's magnetic field."
“As most of us know, diamonds are just about the toughest material there is on the planet, and in order to liquefy it you have to put it at pressures over 40 million times of that on the earth and you also have to heat it to unimaginable temperatures. And researchers working in a lab figured out in a genius way to take diamonds, solid diamonds, and they liquefied it – and to their surprise it acted just like water. A solid diamond floated just like an iceberg on liquid diamonds,” author and commercial space entrepreneur Jeff Manber told RT.
“This goes a long way towards helping us understand what is going on in these two planets, because on Neptune and Uranium they act in certain way that was puzzling, and now we are beginning to understand. Because they are made of carbon, because of the high pressure, because of the temperatures – there are probably vast oceans of diamonds. Just imagine having an ocean filled with liquid diamond and diamond icebergs,” he added.
When the pressure fell to only 11 million-times Earth sea level and temperatures dipped to 50,000 degress Celsius, solid chunks of diamond began to appear in the liquid.
As the pressure continued to drop more and more chunks formed in the liquid diamond, and did not sink. With most materials the solid state is more dense than the liquid state - with water one of the few exceptions.
The new article is published in the journal Nature Physics.
Via - Telegraph , Russia Today , Discovery News
Categories:
Astronomy
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