Home » World » Did the moon form a huge collision?

Did the moon form a huge collision?

I.In today’s research, it is not often the case that there are questions that people have been dealing with for millennia. But astronomy is comparatively rich in such topics, and a prominent example of this is the question of how our moon was formed: answers can be found both in myths and religious writings and on the basis of empirical science. It seems fascinating that the treatment of this question continues to receive new impulses. Scientists from the University of New Mexico are currently trying one study published in “Nature Geoscience”to remove one of the last major contradictions in the largely accepted theory of the origin of the moon.

Sibylle Anderl

This attempt is based on a centuries-long history of competing approaches. Immanuel Kant in 1755 and in a similar form Pierre-Simon Laplace in 1796 assumed that the moon and earth were created together as a double system in the early solar system. This idea was worked out by Carl Friedrich von Weizsäcker in 1944. By contrast, George Darwin, son of the famous evolutionary biologist, published the theory in 1879 that the moon had once erupted from the rapidly rotating earth. Supporters of this approach speculated that the Pacific Basin was a “scar” testimony to this incident. Another model, represented by American chemist Harold Urey, postulated that the moon and earth formed at different locations in the solar system, but that the moon was later captured by the earth’s gravitational field.

Contradicting theories and data

The empirical data that was collected at the same time conflicted with all of these theories. If the moon and earth had a common origin, they would have to be similar in their chemical properties. However, the earth has a significantly higher average density and a much higher iron content than the moon. However, the density of the mantle is comparable to that of the moon. This would speak for the spin-off theory. But if the moon had broken out of the earth, its orbital plane should be in the equatorial plane. Instead, it deviates only slightly from the ecliptic. Also, the earth never seems to have rotated fast enough for this scenario. Certain chemical similarities contradict the independent formation of the moon and earth. The observed relative frequencies of the oxygen isotopes 16O, 17O and 18O are almost identical in both. Capturing the moon also appears to be difficult to achieve from a celestial point of view.

See also  VIDEO⟩ Strong train and bus collision in Sweden - Abroad - News

In 1975 and 1976, two astronomical publications presented another hypothesis: The moon was formed in a gigantic collision between the proto-earth and an Mars-sized planetoid, called “Theia”. Parts of the mantle and planetoid were pulverized, Theia’s iron core melted into the earth’s core, the resulting debris cloud clumped to the moon. Since an astronomical conference in 1984, this scenario has been considered an accepted hypothesis. But she cannot explain one thing: If the moon was largely made of Theia material, why are the frequencies of its oxygen isotopes so similar to those on earth? It is unlikely that Earth and Theia were chemically similar. So is the collision hypothesis wrong?

Is the similarity an illusion?

The current study now claims that the problem disappears through a more differentiated approach. The isotope frequencies are only practically identical if average values ​​are taken from different types of moon rock. But if one examines different types of rock separately – deep from the moon’s mantle to surface rock – then a clear spectrum of different isotope frequencies would result. In particular, lunar mantle material is statistically meaningfully heavier isotopically than earthly material and thus testifies to Theia’s chemistry. From this finding, they conclude that Theia must have had a higher proportion of the 17O oxygen isotope than Earth.

Specifically, this results in the following scenario: Within the debris cloud, which largely consisted of Theia material with earthly material admixture, the silicates that were enriched with heavy isotopes first condensed to the lunar magma ocean. The isotopically lighter material did not settle until later and formed the outer layer of the moon, which today resembles that of the earth. This explanation is attractive and could actually provide an answer to one of the open questions of the collision model. However, the measurements still have great uncertainties. Further investigations of various types of moon rock will show whether this picture continues to harden.


Leave a Comment