Earth and Mars were hardly formed with materials outside Jupiter

the the earth s Mars From the material that largely originated in Solar System inside; Only a small percentage arose outside orbiting Jupiter.

This was reported by a group of researchers led by the University of Münster (Germany) the findings in the journal Science Advances. They provide the most complete comparison to date Isotope composition Earth and Mars are the original building materials for the inner and outer solar system.

Some of this material is still very much around today without change in a meteorites. The study’s findings have far-reaching consequences for our understanding of the process that formed the planets Mercury, Venus, Earth and Mars. Theorem that the four rocky planets It has grown to its current size by accumulating millimeter-sized dust pebbles from the outer solar system that is not sustainable, according to the authors.

About 4.6 billion years ago, in the early days of our solar system, a disk of dust and gas revolved around the young sun. Two theories describe how the rocky inner planets formed over millions of years from this original building material.

according to theory Older, dusty inner solar system lumpy to cut It is gradually getting bigger and bigger to reach the size of our moon. The collisions of these planetary embryos eventually resulted in the production of the inner planets Mercury, Venus, Earth, and Mars. However, a newer theory favors a different growth process: millimeter-sized “pebbles” of dust migrate from the outer solar system toward the sun. Along the way, they accumulated in the planetary embryos of the inner solar system, and step by step, they enlarged it to its current size.

Both theories They are based on theoretical models and computer simulations designed to reconstruct the conditions and dynamics of the early solar system; Both describe a possible planetary formation path. But which one is correct? What process actually happened?

To answer these questions in their current study, the new study team determined the exact composition of the rocky planets Earth and Mars. “We wanted to find out whether the building blocks of Earth and Mars originated in the outer or inner solar system,” Dr. Christoph Burckhardt of the University of Münster, first author of the study, said in a statement.

To this end, isotopes of titanium, zirconium, molybdenum and the rare metals found in minute traces in the silicate-rich outer layers of both planets provide important clues. Isotopes are different types of the same element, differing only in the weight of their atomic nuclei.

Scientists assume that in the early solar system these and other metallic isotopes were not evenly distributed. Rather, its abundance depended on the distance from the sun. Thus, they contain valuable information about where the building blocks of a particular object originated in the early solar system.

as a reference for Isotope Inventory Originally from the outer and inner solar system, researchers used two types of meteorites. These boulders generally came to Earth from asteroid belt, the region between the orbits of Mars and Jupiter. Considered largely pure substances since the early solar system. Whereas the so-called carbonaceous chondrites, which can contain a small percentage of carbon, originated outside the orbit of Jupiter and later moved into the asteroid belt due to the influence of the rising gas giants, their carbon-poor cousins. , non-carbonaceous chondrites are real children of the inner solar system.

The exact isotopic composition of the layers outer rocks They are accessible from Earth and both types of meteorites have been studied for some time; However, there have been no complete, comparable analyzes of Martian rocks. In their current study, the researchers examined samples from a total of 17 Martian meteorites, which can be assigned to six typical types of Martian rocks. In addition, scientists have investigated for the first time the abundances of three different metallic isotopes.

samples of Martian meteorites They were first sprayed and subjected to complex chemical treatment. Using a multifactorial plasma mass spectrometer at the Institute of Planetary Science at the University of Münster, the researchers were able to detect small amounts of isotopes of titanium, zirconium and molybdenum. They then ran computer simulations to calculate the proportion by which building materials found today must be combined in carbonate and non-carbonate chondrites on Earth and Mars to reproduce the measured structures.

In doing so, they considered two different stages of accretion to explain the different histories of titanium and zirconium isotopes, as well as isotopes of molybdenum, respectively. unlike Titanium and the Zirconium, the molybdenum It mainly accumulates in metal planets heart. Therefore, the small amounts still present today in the silicate-rich outer layers were only added during the last stage of the planet’s growth.

The researchers’ findings show that the outer rocky layers of Earth and Mars have little in common with the carbonaceous chondrites of the outer solar system. They make up only about four percent of the original building blocks of both planets. Prof. Dr. Thorsten Klein from the University of Münster, who is also director of the Max Planck Institute for Solar System Research in Göttingen, says. “Therefore, we cannot confirm this theory of inner planet formation,” he adds.

But the composition of Earth and Mars also does not quite match that of the non-carbonaceous chondrite. Computer simulations indicate that a different type of building material must also be in operation.

“The isotopic composition of this third type of building material as deduced by our computer simulations indicates that it must have originated in the innermost region of the Solar System,” explains Christoph Burckhardt. Since objects very close to the Sun have never been scattered in the asteroid belt, this material has been almost completely absorbed into the inner planets and is therefore not found in meteorites. “The ‘missing building materials,’ so to speak, we no longer have direct access to today,” says Thorsten Kleine.

the strike It does not change the results of the study of the theory of planetary formation. Christoph Burckhardt concludes that “the fact that Earth and Mars seem to contain the material of the inner solar system is well suited to the formation of the planets from the collision of large bodies in the inner solar system.”