Scientists suggest that in the interior of the planet Mercury there is a layer of diamonds up to 15, maybe even 18 kilometers thick. Their hypothesis is based on data from the Messenger probe. The team of Chinese and Belgian scientists used so-called temperature models to calculate the diamond deposit. The research has already been published in the scientific journal “Nature".
Complex experiments with pressure and temperature
The team was able to back up their calculations experimentally as well: Using technically very complex pressure tests, the researchers reached the same conclusion. They have generated pressures of up to seven gigapascals. This corresponds to a weight of over 70 tons per square centimeter.
According to the authors, the element sulfur played a particularly important role in the formation of diamonds. In the probe data "Messenger" they see that sulfur is present in sufficient quantities on Mercury. A sulfur content of only eleven percent guarantees faster crystal formation.
The authors suggest that Mercury was once covered by a magma ocean. The graphite formed from the carbon in this ocean rose to the surface, and after cooling it turned into a crust. Black-gray graphite also gives the dark surface of Mercury. At the bottom of the magmatic ocean, the first layer of diamonds formed due to the pressure and temperature prevailing there, as well as the element sulfur.
A layer of diamonds up to 18 kilometers thick
Gradually, the magmatic ocean cooled to a solid mantle, at the bottom of which the diamonds accumulated. The accretion process continued with magma rising from the core to the surface until the diamond layer reached a thickness of 15-18 kilometers. However, the authors emphasize that these are only assumptions based on their calculations and experiments.
Unattainable Diamonds
Planetary researcher Philipp Reiss of the Technical University of Munich, Germany, believes that the formation of a diamond layer is actually possible under the described conditions. After all, this is not surprising, since the formation of diamonds depends on high pressures and temperatures, and these are possible on Mercury. However, Rice, who specializes in the field of mining space resources, believes that it is technically impossible to exploit the deposit.
This is because this diamond layer is located at a depth of 485 kilometers. For comparison, the deepest borehole on Earth is just over 12 kilometers. In addition, Mercury is the planet closest to the Sun, and therefore has a temperature of up to 480 degrees. The space probe is also exposed to strong radiation and the Sun's stronger gravity. Because of these extreme conditions, only two probes have been sent to Mercury so far. A third - BepiColombo - has been traveling there since 2018 and is expected to enter orbit around Mercury in 2025. It can gather additional data and confirm the diamond layer theory.