Editor’s Note
New research suggests Mercury may harbor a vast diamond layer beneath its surface, formed from graphite under extreme pressure during the planet’s early history.
A new study has emerged regarding Mercury, the smallest planet in the solar system and the closest to the Sun. This planet may have a diamond layer up to 18 kilometers thick hidden beneath its surface. Mercury was formed approximately 4.5 billion years ago. Diamond formation likely began shortly thereafter. It is believed that the newly formed planet had a layer of graphite floating atop a deep magma ocean. Using a machine called the Anvil Press, a team of researchers recreated that ‘ancient’ scorching environment.
This machine is used to understand how materials behave under extreme pressure and is also used in the production of synthetic diamonds.
The team placed a synthetic mixture of elements, including silicon, titanium, magnesium, and aluminum, inside a graphite capsule, mimicking the theoretical composition of Mercury’s interior in its early days. The researchers then subjected the capsule to pressure nearly 70,000 times greater than that found on Earth’s surface and temperatures up to 2000 degrees Celsius. Scientists believe this replicated the conditions on Mercury billions of years ago.
When the sample melted, scientists used an electron microscope to observe changes in chemistry and minerals and found that the graphite had transformed into diamond crystals. The researchers said this mechanism not only tells us about the secrets hidden beneath Mercury’s surface but could also provide more information about planetary evolution and the internal structure of exoplanets with similar characteristics. Mercury is the second densest planet after Earth. Its core is also made of a massive metal.