German researcher offered a new version of the origin of the planet Theia – a cosmic body the size of Mars, which about 4.5 billion years ago collided with the young Earth and led to the formation of the Moon.
As it turns out, scientists at the Max Planck Institute for Solar System Research compared the isotopic composition of lunar and terrestrial samples and concluded: Theia did not form on the outskirts of the solar system, as initial models suggested, but right near Earth.
According to the widely accepted hypothesis, the impact between primordial Earth and Theia occurred about 100 million years after the formation of the Solar System. As a result, the Earth acquired its modern appearance, and the Moon was formed from debris thrown into space. However, Theia's exact origins are unknown.
To find out, scientists tested isotopes of iron, chromium, molybdenum and zirconium in 15 Earth, meteorite and six lunar samples returned by the Apollo missions. The isotopic configuration of a substance allows us to indicate the region in which the celestial body formed.
The results of the analysis showed that: The Moon and the Earth practically do not differ in the isotopic composition of iron – as well as some other elements, as previous studies have shown. This suggests that both objects were formed from material originating from the same region in the solar system.
The mystery of the appearance of the Moon: how the planet Theia died and what Darwin has to do with it
Scientists have modeled dozens of scenarios that could have led to the current pattern of isotope distribution. The most convincing option turns out to be that Earth and Theia formed next to each other – Theia may have been even closer to the Sun than Earth.
The author of the work, Timo Hopp, notes: “Most of the material of both planets was formed inside the solar system. Earth and Theia are most likely neighbors.”
