French scientists have refuted a hypothesis related to the origin of the Moon.

Astronomers of the Paris Institute of Geophysics found that the existing hypothesis of the origin of the Moon—according to which the celestial body was formed after the collision of the young Earth with the hypothetical planet Theia, the size of Mars—can’t explain the mineral composition of the Earth’s satellite. According to these scientists, a computer model shows that the Moon should be much smaller for this hypothesis to be true.

Scientists from the Institute of Geophysics of Paris were actively working on the study of the appearance of the Earth’s satellite. So, they compiled a computer model of the alleged collision of the planet Earth and the planet Theia.

The researchers conducted more than two billion simulations of the collision of the Earth and Theia. Scientists came to the conclusion that the Earth’s mantle as a result of such a collision should contain much more cobalt and nickel than it contains now. Thus, the Moon could not have formed at all as a result of the collision of the Earth and Theia.

However, there is another version proposed by scientists from the South-Western Institute of Colorado, according to which after the collision, the young Earth was subjected to numerous impacts of small space bodies. Such a bombardment, called late accretion, changed the content of chemicals in the planet, enriching its core with gold, silver and platinum.

Dr Robin Canup, co-author of the study, said: “These simulations also may help explain the presence of isotopic anomalies in ancient terrestrial rock samples such as komatiite, a volcanic rock.”

“These anomalies were problematic for lunar origin models that imply a well-mixed mantle following the giant impact.”

“We propose that at least some of these rocks may have been produced long after the Moon-forming impact, during late accretion.”