A recent study published in Nature Communications has uncovered fascinating insights into Mercury, the first planet in our solar system. According to the study, Mercury might harbor a substantial layer of diamonds beneath its surface, potentially stretching hundreds of miles down.
Lin’s analysis of Mercury’s high carbon composition
This revelation came from Yanhao Lin, a staff scientist at the Center for High-Pressure Science and Technology Advanced Research in Beijing. Lin’s analysis of Mercury’s high carbon composition led him to hypothesize that unique processes within the planet’s interior might have occurred.
Notably, Mercury possesses a magnetic field, albeit weaker than Earth’s. This finding aligns with observations from NASA’s Messenger spacecraft, which identified unusually dark regions on Mercury’s surface as graphite, a carbon variant.
Scientists theory about formation of Mercury
Scientists theorize that Mercury formed from a cooling magma ocean, enriched with silicate and carbon, a process similar to the formation of other terrestrial planets. As the magma crystallized, it formed the planet’s crust and mantle, while metals agglomerated to create a central core.
Historically, it was believed that the mantle’s temperature and pressure conditions were optimal for converting carbon into graphite, which would then rise to the surface due to its lower density.
2019 study about Mercury
However, a 2019 study suggested that Mercury’s mantle could be deeper than previously thought, by up to 50 kilometers (80 miles). This depth would subject carbon to greater temperatures and pressures, possibly leading to its crystallization into diamond instead.
To explore this possibility, a team of Belgian and Chinese researchers recreated Mercury’s conditions using carbon, silica, and iron mixtures, with iron sulfide added to mimic the presumed sulfur-rich composition of Mercury’s ancient magma ocean. They subjected these mixtures to extreme pressures using a multiple-anvil press, simulating conditions deep within Mercury.
Their experiments, reinforced by computer simulations, indicated that minerals like olivine likely formed in the mantle. However, when sulfur was introduced, the mixture required significantly higher temperatures to solidify, conditions under which diamond formation would be more plausible.
Diamonds role in Mercury’s geothermal dynamics
The team’s models also suggest that diamonds could have formed during the cooling and solidification of Mercury’s inner core, later rising to the core-mantle boundary due to their lower density. These diamonds, if present, could form a layer approximately 15 km (9 miles) thick. However, the extreme depth and temperatures on Mercury make the prospect of mining these diamonds unfeasible.
Lin also proposed that the presence of diamonds might play a role in Mercury’s geothermal dynamics, facilitating heat transfer between the mantle and core. This process could create temperature variations and the movement of liquid iron, generating the planet’s magnetic field..