Diamond Made: Giant Planets Are A Possibility

Some stars in the Milky Way could be harboring giant terrestrial planets containing up to 50 percent diamonds, a new study suggests.

However, these "carbon super-Earths", if they exist, could not be habitable

According to Science Daily, the findings comes from a laboratory experiment which recreated the temperatures and pressures of Earth's lower mantle to discover what happens to carbon inside planets in other solar systems.

It also aimed to find out whether solar systems that are rich in carbon could produce planets that are mostly made of diamonds.

The researchers used what they learned from the experiments to construct computer models of the minerals that form in planets composed with more carbon than Earth.

The findings, which were presented by researchers Wendy Panero, associate professor in the School of Earth Sciences at Ohio State, and doctoral student Cayman Unterborn at the American Geophysical Union meeting in San Francisco, showed that it is possible for planets that are as big as fifteen times the mass of the Earth to be half made of diamond.

"Our results are striking, in that they suggest carbon-rich planets can form with a core and a mantle, just as Earth did," Panero added. "However, the cores would likely be very carbon-rich -- much like steel -- and the mantle would also be dominated by carbon, much in the form of diamond."

According to Panero, unlike Earth's core is mostly iron, planets that form in carbon-rich solar systems would have to follow a different chemical recipe and this has direct consequences for the potential for life.

Thus, while Earth's hot interior results in geothermal energy makes our planet habitable, a carbon super-Earth's interior, would quickly freeze as diamonds transfer heat immediately. These planets would have no geothermal energy, no plate tectonics, and no magnetic field or atmosphere, the researchers said.

The findings could have implications for planetary science due to the discovery of hundreds of planets outside our solar system.

"To date, more than five hundred planets have been discovered outside of our solar system, yet we know very little about their internal compositions," said Unterborn.