Differences between the sides of Earth's moon are due to a colossal ancient impact, according to new research.
The visible side of the Moon is very different from its non-Earth facing part. On the side of the Earth's satellite visible to us, lunar seas predominate — these are dark spots on the surface, which are the remains of ancient lava flows. The far side of the Moon is full of craters and there are practically no lunar seas. Why the two sides of the moon differ from each other scientists have been trying to find out for a long time. And now they have a new hypothesis, which says that this is due to a giant impact that happened billions of years ago near the south pole of the moon.
That the two sides of the moon are different was first discovered by secular and American spacecraft in the 1960s of the last century. It turned out that the surface of the Moon on its far side not only has more craters, but, as shown by later space missions, there are completely different chemical elements than on its visible side.
The lunar seas that we visible from Earth — this is the result of lava flows, which appeared due to volcanic activity. But why are there no such dark spots on the far side of the Moon? Scientists from Brown University decided to answer this question.
Using computer simulations, scientists set out to look at what could have happened a long time ago, long before any volcanic activity on the Moon's surface. Researchers have recreated a powerful impact on the surface of the moon that changed it billions of years ago and formed a huge crater in the south of the far side of our satellite, called the South Pole-Aitken Basin.
«We know that, that big impacts, like the one that formed the South Pole-Aitken Basin, should create a lot of heat. The question is how this heat affects the internal dynamics of the Moon», says Matt Jones of Brown University.
As a result, scientists have found that a collision with a large space object should have created a massive plume of heat that spread through the bowels of the moon. This plume brought to the visible side of the Moon a set of rare earth elements and heat-producing elements. This concentration of elements may have contributed to the volcanism and lava flows that created the lunar seas. But such processes did not occur on the far side of the Moon.
The new hypothesis is consistent with another difference between the far and visible sides of the Moon. Many regions on the moon facing us are known to contain chemical elements such as potassium and phosphorus, as well as heat-producing elements such as thorium and other rare earth elements. But they are not on the far side of the moon. But scientists discovered these elements during computer simulations of volcanic activity on the Moon.
According to scientists, the results of a new study provide an answer to one of the most important mysteries of the Earth's satellite. But for now, this is only a hypothesis and more research is needed to test it.