The cosmic body that struck the Earth and led to the formation of the moon about 4.4 billion years ago may have also supplied large quantities of water to our native planet, making it habitable, scientists have found.
Earth is the only earth planet with a great deal of water and a relatively large moon that stabilizes the Earth's axis. Both are essential for the development of life on Earth.
The moon was formed when the Earth was hit by a Mars-sized body, also called Theia.
Until now, scientists have assumed that Thea originates from the inner solar system near the Earth.
The study, published in the journal Nature Astronomy, shows that Theia comes from the external solar system and supplies large amounts of water to the Earth.
"Our approach is unique because it first allows us to link the origin of the Earth's water to the formation of the Moon," said Torsten, "but simply without the Moon, there is probably no life on Earth." Klaine, Professor of Planetology at the University of Münster in Germany.
The earth is formed in the "dry" internal solar system and it is therefore a little surprising that there is water on Earth.
Earlier research has shown that the solar system is structured so that "dry" materials are separated from "wet" materials.
"Carbon" meteorites, which are relatively rich in water, come from the external solar system, while the drier non-carbonate meteorites come from the inner solar system.
While previous studies have shown that carbon materials are probably responsible for the supply of water to Earth, it was not known when and how this carbon material – and thus water – came to Earth.
"We used molybdenum isotopes to answer this question." Molybdenum isotopes allow us to clearly distinguish between carbon and non-carbon material, and as such represent a "genetic footprint" of material from the external and internal solar systems, "said Gerrit Budde, Munster.
The measurements show that the isotopic composition of molybdenum on Earth lies between those of carbon and non-carbon meteorites, indicating that part of the Earth's molybdenum originates from the external solar system.
The chemical properties of molybdenum play a key role because, as it is an iron-loving element, most of the earth molybdenum is in the nucleus.
"The molybdenum that is available today in the mantle of the Earth therefore originates from the late stages of Earth formation, while the molybdenum from earlier phases is entirely in the core," said Christoph Burkhardt, second author of the study.
The results show that for the first time the carbon material from the external solar system arrived on Earth late.
Researchers found that most of the molybdenum in the mantle of the Earth was delivered by the protoplanet Theia, whose clash with the Earth 4,4 billion years ago led to the formation of the moon.
However, since much of the molybdenum in the mantle of the Earth originates from the external solar system, it means that Tea herself also originates from the external solar system.
According to scientists, the collision has provided enough carbon material to take into account the total amount of water on the Earth.