New research has cast doubt on the current theory of the origin of the Moon Facts
According to new research, in which an international team of scientists who studied isotopes of titanium in 24 individual samples of lunar rocks and soil, the current theory of the origin of the moon should be reviewed. The work done by the University of Chicago geochemist Zhunzhun Zhang in collaboration with a colleague, University of Bern, published March 25, 2012 in the electronic journal Nature Geoscience.
According to one theory, at the beginning of its existence, the young Earth was faced with a hypothetical planet, Thea, comparable in size to Mars. The collision of the Earth with the magma separated disk, which began to rotate in the orbit of the planet, gradually hardens and turns into what we call the moon. Given the laws of physics, at least 40% of the material on the moon was to belong to the Tee, and 60% — Earth. So, in the samples of the moon must be present easily distinctive geochemical components of two objects.
The new theory
According to the data of the study most of the matter that makes up the moon, of a young earth. This finding contradicts the existing theory.
The researchers compared the isotopic composition of titanium in lunar and terrestrial samples, taking into account the random variation of the composition of lunar samples due to the influence of cosmic rays. The scientists used a mass spectrometer to perform accurate measurements of titanium-50 and titanium-47 in moon rocks collected in the 70s during the Apollo missions. They found that the isotopic composition of titanium in the world similar to the composition of titanium on the moon to 99.999996%. And since it is believed that the similarity of foreign objects with the Earth (for example, meteorites) is found in one out of 150, it is likely, Thea had a different, different from the terrestrial isotopic composition. Consequently, the results of a new study show that the moon is almost entirely composed of the Earth's mantle.
In the past, the researchers compared the isotopic composition of silicon, chromium, tungsten, and oxygen in the samples of the Earth and the Moon, which show significant similarities. But it is also believed that the isotopic composition of silicon, chromium and tungsten similar to that of Mars, which is not the titanium. With regard to oxygen, the collision of Earth with Thea could be exchanged material, up to the maximum saturation is Earth, since oxygen is volatile. However, this is not true for titanium, which is not easily evaporate. Although it is hypothetically possible, it is believed that when confronted with Thea Earth could not transmit their identical composition of titanium.
A new study finds more than just one thing in common with the Earth Moon, and gives a better look at the theory of the origin of the Moon. The possibility of forming at the time of the Earth collide with the same isotopic composition of oxygen, titanium and tungsten target is almost impossible, if not impossible. On the other hand, the collision could be so strong that the unique structure of the Thea could be destroyed by the intense exchange of matter. But this development was accompanied by unrealistic conditions like very slow cooling to form at the time of the lunar disc, or a large-scale exchange of active elements. Moon could also be formed from a breakaway of the young Earth, the force of the rotation of which was too large — exceeding gravitational force.
Scientists do not reject the theory of collision. The new model could, for example, the alleged interference of the protoplanet is twice as massive Mars, in which might have changed the original isotopic composition of the young Earth, and the Moon was formed.