Finding a valuable treasure under the surface of Mercury

A new study has shown that Mercury may contain a thick layer of diamonds hundreds of miles below its surface.

The findings, published June 14 in the journal Nature Communications, could help solve mysteries about the planet's composition and its strange magnetic field.

The planet has puzzled scientists for decades, as its magnetic field is weak (only 1% as strong as Earth's) and it has a massive core for its tiny size.

Although it is the smallest planet in the solar system, it is the second densest planet.

Scientists appear to have discovered interesting new details about the planet, as the new study suggests that the boundary of Mercury's core mantle includes a layer of diamonds .

NASA's MESSENGER spacecraft, the first to visit Mercury in 30 years, has mapped the entire planet and revealed that its surface is rich in carbon.

Scientists believed they were looking at the remains of an ancient layer of graphite that had been pushed up to the surface. This theory suggests that Mercury once had a molten surface layer or magma ocean that contained a large amount of carbon. As the planet cooled, this carbon formed a graphite crust.

Scientists have long suspected that the temperature and pressure of the mantle are the right conditions for carbon to form graphite. Because it is lighter than the mantle, graphite appears on the surface.

But newer evidence suggests that Mercury’s mantle may be 80 miles (50 kilometers) deeper than previously thought. That means the pressure and temperature at the core-mantle boundary are much higher, and these extreme conditions could force carbon to crystallize, forming diamonds.

To study Mercury's interior, scientists used a combination of high-pressure and temperature experiments and thermodynamic modeling.

They were able to achieve pressure levels seven times those found in the deepest parts of the Mariana Trench (the deepest point on Earth's surface, which has a pressure a thousand times greater than that felt at sea level).

Under these conditions, scientists examined how minerals in the planet's interior melt and reach equilibrium.

The diamond layer is thought to be between 15 and 18 kilometers (9 and 11 miles) thick. The paper suggests that the crystallization of Mercury's core created a layer of diamonds at the core-mantle boundary, but it's currently inaccessible. The minerals are buried about 485 kilometers (300 miles) below the surface, and space explorers would first have to contend with the planet's intense heat.