A startling discovery by a NASA spacecraft suggests that the smallest planet in our solar system could hold untold wealth beneath its surface.
Based on data from NASA’s MESSENGER space probe, scientists have concluded that Mercury, the planet closest to the sun, may have a 10-mile-thick layer of diamond mantle. Space.com reported:.
Mercury’s surface, particularly its dark patches of graphite, a type of carbon, has puzzled scientists for decades.
The spots suggest that the inner planet may once have had an ocean of carbon-rich magma, and that the spots may have formed when the magma seeped to the surface.
The same geological processes likely formed the carbon-rich mantle as well, but new data and a reassessment of the planet’s surface mass suggest that the mantle is made of precious diamonds rather than graphite.
“Given our new estimates of the pressure at the mantle-core boundary, and the knowledge that Mercury is a carbon-rich planet, we calculate that the carbon-containing mineral that forms at the mantle-core boundary is diamond, not graphite,” team member Olivier Namur, an associate professor at the Catholic University of Leuven, told Space.com.
“We thought this must have a major impact on species differentiation. [the distribution of an element or an allotrope amongst chemical species in a system] “The difference between carbon, diamond and graphite on Mercury,” Namur added.
According to Space.com, MESSENGER, which stands for “Mercury Surface, Space Environment, Geochemistry and Ranging,” was the first spacecraft to orbit Mercury, launched in 2004 and between 2011 and 2015, mapping the entire planet and collecting data on its geology and magnetic field.
The team, who published their findings in the journal Nature Communications, used a high-volume press to recreate conditions beneath Mercury’s crust, where temperatures can reach 3,950 degrees Fahrenheit.
The tests allowed scientists to learn how minerals found on the planet reacted in the planet’s early history.
“We believe that diamonds could have been formed by two processes. The first was the crystallization of a magma ocean, but this process could only have contributed to the formation of a very thin diamond layer at the core/mantle boundary,” Namur told the outlet. “The second, and most important, is Mercury’s metallic core.”
Mercury’s core was completely liquid when the planet formed about 4.5 billion years ago, and slowly crystallized over time.
“Because the liquid core contained carbon before crystallization, crystallization concentrates carbon in the residual melt,” Namour said. “At some point, a solubility threshold is reached and the liquid can no longer dissolve the carbon, and diamonds form.”
Diamonds, which are less dense than metals, floated to the top of Mercury’s core and became lodged between the core and the mantle, forming a 0.62-mile-thick diamond layer that continued to grow over time, Namur said.
Namur said the shocking discovery highlights differences in the formation processes of the other inner planets with solid surfaces: Venus, Earth and Mars.
“Mercury formed quite close to the sun, probably from a carbon-rich dust cloud. As a result, it has less oxygen and more carbon than other planets, which led to the formation of diamond layers,” Namur said.
“But the Earth’s core also contains carbon, and various researchers have already suggested that diamonds form in the Earth’s core,” he added.
