Carbon, an essential element for life, can be found on the entire surface of the Earth. But how he got here is still a mystery.
When 4.4 billion years ago an object the size of Mercury crashed into a young Earth, it was probably this cosmic collision that opened up our planet to carbon. This is evidenced by a new study.
This assumption may explain the paradox that scientists have been tormenting for so long: how our planet still contains carbon on the surface, if it should have disappeared a long time ago. Some theories suggest that the early carbon contained on the surface should have been in a boiling state or stuck in the very core of the planet.
“The task is to explain the origin of volatile elements, such as carbon, which remain outside the core (in the mantle of the planet),” said study co-author and lead author Rajip Dasgupta and researcher at the Institute of Geochemistry of the Chinese Academy of Sciences in Guangzhou Yuan Li said .
Some scientists have previously suggested that carbon could have originated from meteorites, which sometimes crash into Earth. But further research revealed problems in this theory.
“The problem is that in that period of time when there were an abundance of these elements on the planet, we did not identify any known meteorites that could produce the necessary amount of volatile elements in the silicate part of the Earth,” said Lee. The key to the solution was the modeling of the new composition of the Earth’s core, based on updated studies of Mercury and Mars made over the past decades. Based on the data, the opinion has arisen that our core may be more complex than just the accumulation of iron, nickel and carbon.
It is believed that the core of Mars contains a lot of sulfur, and in Mercury - silicon. The research team conducts various experiments with the elements. To do this, take the rocks and squeeze them in hydraulic presses, creating an imitation of high pressure and temperature, lower than the surface of the Earth.
Their results show that carbon can stay away from the core and at the same time remain in the mantle of the Earth, if in the core itself iron is combined with silicon or sulfur. Then how did carbon appear? It could have been the great clash that happened billions of years ago.
“There is a scenario that explains the carbon to sulfur ratio and the abundance of carbon. According to him, an embryonic planet like Mercury, in which the core enriched with silicon has already been formed, has collided and is absorbed by the Earth, ”said Dasgupta. “Because of the massiveness of the body, the dynamics could work in such a way that the core of a foreign planet mixed with our core, and the carbon-rich mantles joined with the mantles of the Earth.”