Astronomers discovered evidence of where the celestial body came from, which collided with the Earth 4.4 billion years ago.
The land is the only one of internal stony planets of the solar systemwith a significant amount of water. But where did the water on our home planet come from, there are many hypotheses. Recently tiny grains from a near-Earth asteroidItokawaprovided evidence that the water hit Earth during a planetary birth with comets and asteroids. Other astronomers suspect that the origins of the earth’s water are related to ourThe moon and its origin, which is not fundamentally contrary to the previous thesis.
The celestial body that collided with young Earth about 4.4 billion years ago and also created the moon may have come here from external solar system. Illustration:NASA
Planetologists from the University of Westfälisch-Wilhelms-Münster (WWU) also came to this conclusion. The team under the leadership of Gerrit Buddha was able to show that water came to Earth with the formation of the Moon about 4.4 billion years ago. The Earth satellite was formed as a result of a shock impact on the Earth of a body the size of Mars, which was calledTheia. Until now, experts have assumed that the hypothetical planet Theia was born in the inner solar system near the Earth. And now scientists fromMunster can prove that Theia most likely came from the outer solar system, from where protoplanet and delivered a large amount of water to Earth.
Carbon and non-carbon meteorites
Since the Earth was formed in the water-poor inner solar system, it can be assumed that it was also dry. And in order to understand why there is still water on Earth, one needs to go on a journey into the past, when the Solar System was formed about four and a half billion years ago. Earlier studies have shown that so-called “carbon” meteorites originate from the outer solar system, while “non-carbon” meteorites originate from the inner solar system. Carbon meteorites are relatively rich in water, and studies have shown that water on Earth probably originates from such bodies. However, it was previously unknown when and how this carbonaceous material – and, therefore, water – hit the Earth.
“To answer this question, we used molybdenum isotopes. Molybdenum isotopes allow us to clearly distinguish between carbon and non-carbon materials – they, so to speak, represent the “genetic” imprint of material from external and internal solar systems, ”explains Buddha. Published in Nature Astronomy, measurements show that the isotopes of Earth’s molybdenum are located just between carbon and non-carbon meteorites. Therefore, part of the earthmolybdenumcomes from the outer solar system. The chemical properties of molybdenum play a key role in this context, because molybdenum, as an iron-loving element, is located on our planet mainly in the earth’s core.
Evidence of origin Teyi
“Molybdenum, which is available to us today, comes from the later stages of the Earth’s formation, while molybdenum in the Earth’s core comes from the earlier phases of its formation,” explains Christoph Burckhardt, co-author of the study. These results show for the first time that carbonaceous material from the outer solar system came to Earth relatively late.
Researchers look even further. They confirm that mostmolybdenum in the earth’s mantle was brought here by the protoplanet Thea, the collision with which led to the formation The moon4.4 billion years ago. But since most of this molybdenum comes from the outer solar system, this means that Theia herself also comes from the outer region of the solar system. According to scientists, this collision was enough to deliver to Earth a sufficient amount of carbonaceous material, which is responsible for the total amount of water on Earth.
“Our approach is unique because for the first time it allows us to associate a water source on Earth with the formation of the Moon. If it is oversimplified, then we can say that without the moon there would be no life on Earth, ”says Torsten Klein, a professor of planetology at WWU.