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Water covers about 70% of the Earth’s surface and is crucial for the maintenance of life, but the way it reached our planet is the subject of long scientific debate, reports AFP, cited by Agerpres.
Researchers from a French team on Thursday revealed a new theory that our planet has been rich in water since its origins, which has existed in abundance in the rocks that make up the Earth.
Cosmochemist Laurette Piani, coordinator of this study carried out by the Center for Petrographic and Geochemical Research of the CNRS – University of Lorena and published in the journal Science, explained to AFP that this discovery contradicts the dominant thesis that the water was brought in later by the asteroids and comets that bombarded the “blue planet”, which in its infancy was a completely dry celestial body.
This hypothesis was favored by too high temperatures in the Solar System, which would have prevented the water from condensing and agglomerating along with other ice solids.
French researchers have analyzed meteorites called “chondrite-instatite”, which have the particularity of having a chemical composition close to that of Earth. This detail indicates that they are similar to rocks that have been part of the Earth’s structure since its formation.
By measuring the hydrogen content of 13 of these relatively rare meteorites, French experts found that early rocks on Earth contained enough hydrogen to provide, by extrapolation, at least three times the amount of water in the Earth’s oceans.
“We found that the isotopic composition of hydrogen in the chondrite state was similar to that of water stored in the Earth’s mantle,” said Laurette Piani.
The isotopic composition of the current oceans is in turn compatible with that of a mixture that contains 95% water of these chondrites, an additional element that supports the thesis that these rocks are at the origin of terrestrial water.
The study authors also found that the nitrogen isotopes in these meteorites are similar to those of terrestrial nitrogen.
According to Laurette Piani, the study does not rule out a later supply of water from other sources, such as comets, but the French specialist insisted that meteorites in the chondrite state have contributed significantly to the appearance of water since the formation of the planet. our.
The study by French researchers “adds a crucial and elegant piece to this puzzle of scientific theories,” wrote Anne Peslier, a NASA researcher, in an editorial accompanying the research presentation.
