Scientists explained why the reverse side of the moon differs from Earth with the visible part, according to the portal Eurekalert.
This became known in the mid-twentieth century, when the Soviet Union managed to obtain the first images of the "dark side of the satellite". Previously, astronomers believed that visible from our planet of the dark "spots" on the moon are traces of dried up seas and oceans ("Maria" — "sea" in Latin). They also assumed that the same marks covered and the reverse side of the moon, but in the end, both assumptions were incorrect.
It turned out that it is not "Mary" and the craters, probably of volcanic origin. In addition, it was found that they covered a small part of the invisible hand satellites – one percent, while the visible part is about a third filled with craters. To explain the causes of heterogeneity of the territory of the moon for a long time scientists could not.
In the new study, a team of astronomers from Tokyo Institute of technology, the University of Florida, new Mexico and the NASA Space center the Lyndon B. Johnson proposed an answer to this question. Scientists believe that differences in the surface on different sides due to the uneven distribution of substances in group KREEP. They were found in lunar rocks, which in the 70-ies of the last century was brought to earth by the astronomers of the American mission Apollo. In the acronym KREEP K is potassium, REE – rare Earth (rare Earth elements) elements cerium, erbium, europium, and P is phosphorus.
Using the results of observations, laboratory experiments and computer modeling, the researchers came to the conclusion that the heat from the radioactive decay of these elements allowed to melt solid rock on the moon, which on its surface appeared craters.
The items were distributed unevenly on the surface of the satellite. On "light" side of the moon, according to scientists, the rocks were enriched in radioactive uranium, potassium and thorium, so it was formed more craters.
