Mercury’s surface shows evidence of thousands of impacts that occurred in the early solar system. Photo: NASA
The closest planet to the Sun received so many impacts that it would now host a reserve of gems 16 times greater than that on Earth, according to a new study.
Mercury, the closest planet to the Sun, could host more than 16,000 billion tons of diamonds in its crust, according to a recent study based on computer simulations that covered its 4.5 billion years of geological life.
The research was led by Kevin Cannon, a planetary scientist at the Colorado School of Mines in the United States, and his findings were presented at the 53rd Lunar and Planetary Science Conference.
Like many other planets in the solar system, when Mercury was a young world it was covered with oceans of magma that then cooled and crystallized various minerals. Only graphite (a naturally occurring form of carbon) persisted as a first layer of the planet. Later it would just be covered by volcanic activity.
However, in a violent period called the Late Heavy Bombardment (or LHB), the constant impacts of meteorites and comets on Mercury caused large impact craters in its crust and brought out the graphite layer. From space, these depressions are observed as the darkest areas of the planet.
But according to Cannon’s simulations, the collisions also generated high pressure and temperature that transformed graphite into diamond, the hardest mineral in nature on Earth and one of the most precious.
Thus, in the event that the graphite layer was 300 meters thick when the collisions occurred, between 30% and 60% of the entire amount would have been converted into this precious mineral.
As a result of the shocks, 16,000 billion tons of diamonds would have been generated, many of them in tiny fragments and buried near its surface.
This abysmal number of gems would be 16 times greater than the estimated reserve on Earth, according to the Massachusetts Institute of Technology (MIT).
Furthermore, while Cannon acknowledges that impacts after the LHB period may have destroyed some diamonds, the loss may have been “very limited.”
Unexplored diamond deposits
Mercury is a hostile planet for human presence due to its proximity to the Sun and its light atmosphere, which causes daytime temperatures of 426°C and night temperatures of -143°C, according to NASA.
For that reason, to explore whether there is such an amount of diamonds in hot rock, the best option is space instruments.
MESSENGER, a NASA space probe that mapped Mercury between 2008 and 2015, was unable to detect the diamond deposits because the mineral does not emit many near-infrared wavelengths.
For that reason, experts expect BepiColombo, a joint mission of the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA), to meet this goal by 2025, when they fully adjust their orbit around the planet.