Space. Experts reconcile the Earth and its original meteorites – Ouest-France

Belonging to a relatively common family meteorites and considered as the primary material of our planet, meteorites studied by these researchers, enstatite chondrites contain the right proportion of enstatite and iron to form the mantle and core land. So it makes good candidates for claim to have participated in the formation of the Earth. The “hic” is that they contain too significantly silicon and too volatile elements (sodium or potassium) in relation to our planet.

“ We have found a way to solve this paradox and n e offer a complete scenario of the formation of the Earth from a sample of enstatite chondrites, which had never been done before (see inset) “ said Denis Andrault, Magmas the laboratory and volcanoes Blaise Pascal University.

Loss of mass and changing the chemical composition

According to these scientists, so these are the many meteorite impacts suffered by the Earth in his youth that would have made him lose mass and would have modified its chemical composition. “While the formation of our planet involved a large number of meteorite impacts, they have eroded the surface of the early Earth. This would have happened in the first 100 million years of the existence of it “, adds Denis Andrault.

The Earth would have lost and about 15% of its mass during its formation, the researchers calculated. And enstatite chondrites Bachelor specialist concluded: “If one combines the process of erosion of the crust and the phenomenon of recondensation to the surface of other elements like aluminum and calcium, is achieved to reconcile the chemical composition of enstatite chondrites with that of Earth. “

To get these new findings, published Wednesday in the British journal Nature Communications, researchers have therefore conducted experiments at high pressures and high temperatures in the laboratory to reconstruct the process of formation of the Earth and to determine the chemical composition of its primitive crust. They then modeled the evolution of the chemical composition of the planet, after the erosion of this first crust by multiple meteor impacts.