The natural satellite of Earth represents an object, very unusual to Solar system. The other day scientists have put forward the new theory explaining how the Moon has got there where she is today, having introduced some amendments in the modern theory of huge collision. On October 31 in the article in the Nature magazine has stated provisions of the new theory the leading author of a research professor Sara Stewart from the University of California.
The sizes of the Moon are rather big in comparison with the planet around which she rotates. Besides, on the chemical composition she is almost identical with Earth, except for some volatile compounds which have evaporated far back in the past. It also distinguishes the Moon from any other large object in Solar system, Sara Stewart explains. She emphasizes that any other body in Solar system differs on the chemical composition.
Traditionally the theory of an origin of the Moon which can be read in any classical textbook sounds as follows. At the end of the period of formation of Solar system there has come the phase of “huge collision” when hot objects of the size of the planet faced with each other. An object of the size of Mars has touched other space object which in a consequence has developed in the planet Earth. At the same time a part of substance has been rejected in space spaces — from this piece and the Moon was created. At collision Earth has received a considerable gain of speed of rotation therefore round its pivot-center the planet did one turn in only 5 hours. Throughout the millennia the Moon moved away from Earth, and the speed of rotation of the planet was slowed down therefore by the present moment days began to last 24 hours.
This theory has been output by scientists during observations of a present orbit of the Moon, interrelations of the rotary moment of system Earth — the Moon and tidal forces between these two objects.
However, this traditional theory isn’t deprived of contradictions and open questions. One of them is the structure of the Moon, surprisingly similar to Earth. Another is that if the Moon was created from the substance rotating around the equator of Earth, then and her orbit would have to rotate concerning the equator. However the present orbit of the Moon is inclined by five degrees concerning the equator, and it means that some else, not considered by this theory energy has to influence movement of the Moon.
Professor Stewart and her colleagues (the employee of the American Institute of SETI Matiya Cook, Douglas Hamilton from Universiteta shtata Merilend and Simon Locke from Harvard University) have developed alternative model which explains these disagreements of the traditional theory.
In 2012 Cook and Stewart have offered that a part of the rotary moment of system Earth — the Moon could be transferred to system Earth — the Sun. It has provoked more vigorous collisions at the beginning of process of formation of planets.
According to new model, as a result of high-energy collisions a large amount of the evaporated and melted substance from which Earth and the Moon have been created was formed. The earth as a result of this process rotated with a two-hour interval round its pivot-center, and the axis of rotation has been directed towards the Sun.
As collision could be more vigorous, than the traditional theory, material from Earth and the object which has faced it assumes could mix up, and Earth and the Moon have been created from the same material then also their chemical composition was analogous.
In process of delay of speed of rotation at the expense of tidal forces, the Moon moved away from Earth, hasn’t reached the point called by a point of “transition to Laplace’s plane” when force of influence of Earth on the Moon became less, than gravitational forces of the Sun yet. It has led to the fact that a part of the rotary moment of system Earth — the Moon has been transferred to system Earth — the Sun. It significantly hasn’t affected Earth orbit around the Sun, but has turned Earth vertically. At this moment as the model constructed by team of professor Stewart shows, the Moon rotated around Earth under a big corner, concerning the equator.
During several tens millions of years the Moon continued to move away slowly from Earth, hasn’t reached yet the second point of transition, transition of Cassini after which the tilt angle of an orbit of the Moon concerning the equator of Earth has changed approximately by five degrees.
The new theory elegantly explains features of an orbit and the chemical composition of the Moon, proceeding from the only huge collision right at the beginning. No additional intermediate steps were required to push this process, professor Stewart claims.