What does our planet have inside you? How did the Earth’s core form , in what time immemorial did this happen? All these issues have long worried humanity. But many scientists wanted to quickly find out what was in the depths? But it turned out that studying all this is not so easy. Indeed, even today, having all the modern facilities for conducting all kinds of research, mankind is able to drill wells into the bowels of the earth for only some fifteen kilometers - no more. And for full-fledged and comprehensive experiments, the required depth should be an order of magnitude greater. Therefore, scientists have to calculate how the Earth’s core was formed using a variety of high-precision instruments.
Earth exploration
Since ancient times, people have studied rocks that are naturally exposed. The cliffs and slopes of the mountains, the steep banks of rivers and seas ... Here you can personally witness the bedrock, which probably existed millions of years ago. And in some suitable places, wells are drilled. One of the deepest ones is on the Kola Peninsula. Its depth is fifteen thousand meters. The mines that people break through for mining also help to study the internal structure of the Earth. The core, of course, they can’t get. But on the other hand, scientists can extract rock samples from these mines and wells, learning in this way about their change and origin, structure and compositions. The disadvantage of these methods is that they are able to study only land and only the upper part of the Earth's crust.
Reconstructing the Earth’s Core
But contactlessly penetrate deeper and deeper scientists help geophysics and seismology - the science of earthquakes and the geological composition of the planet. Using the study of seismic waves and their propagation, it is found out what both the mantle and the core consist of (it is determined similarly, for example, with the composition of fallen meteorites). Such knowledge is based on the data obtained - indirect - about the physical properties of substances. Also today, modern data obtained from artificial satellites in orbit contribute to the study.
Planet structure
Scientists were able to understand by summarizing the data that the structure of the Earth is complex. It consists of at least three unequal parts. In the center is a small core that surrounds a huge mantle. The mantle occupies about five sixths of the entire globe. And from above everything is covered by a rather thin outer crust of the Earth.
Core structure
The core is the central, middle part. It is divided into several layers: internal and external. According to most modern scholars, the inner core is solid, and the outer is liquid (in a molten state). And the core is very heavy: it weighs more than a third of the mass of the entire planet with a volume of just over 15. In the core, the temperature is quite high, it ranges from 2000 to 6000 degrees Celsius. According to the assumptions of science, the center of the earth consists mainly of iron and nickel. The radius of this heavy segment is 3470 kilometers. And its surface area is about 150 million square kilometers, which is approximately equal to the area of ​​all continents on the surface of the Earth.
How did the Earth’s core form?
There is very little information about the core of our planet, and it can only be obtained indirectly (there are no samples of core rocks). Therefore, theories can be expressed only hypothetically about how the Earth’s core was formed. The history of the Earth has billions of years. Most scientists adhere to the theory that in the beginning the planet was formed as quite homogeneous. The process of isolating the kernel began later. And its composition is nickel and iron. How was the core of the earth formed? The melt of these metals gradually descended to the center of the planet, forming a core. This was due to the larger specific gravity of the melt.
Alternative Theories
There are opponents of this theory, citing their own, quite reasonable reasoning. First, these scientists question the passage of an alloy of iron and nickel into the center of the core (which is more than 100 kilometers). Secondly, if we assume the release of nickel and iron from silicates similar to meteorites, then a corresponding reduction reaction should have occurred. She, in turn, had to be accompanied by the release of a huge amount of oxygen, forming atmospheric pressure of several hundred thousand atmospheres. And there is no evidence of the existence of such an atmosphere in the past of the Earth. Therefore, theories were put forward about the initial formation of the nucleus in the formation of the entire planet.
In 2015, Oxford scientists even proposed a theory according to which the core of the planet Earth consists of uranium and has radioactivity. This indirectly proves both the continued existence of the magnetic field near the Earth, and the fact that in our time our planet radiates much more heat than was supposed by previous scientific hypotheses.