The formation of the Earth took place more than 4.5 billion years ago, in an orbital dance with space rocks responsible for the building blocks of the planets present in the Solar System. From this, the Earth developed with three main rock layers, they are: crust, mantle and earth's core — the inner core is located between 5100 km and 6370 km below the surface.
After going through the entire primitive development process, the cosmic object reached a diameter of 12,756 kilometers. It is no wonder that researchers, engineers and geologists have significant difficulties in drilling extensive holes in the surface.
For example, today, the super-deep Kola well in Russia is considered one of the deepest holes ever dug on Earth. After almost 20 years of excavations, approximately 12.2 kilometers were drilled from the earth's surface.
“What happens on the surface of the Earth is directly related to its interior. About 4.6 billion years ago, Earth formed from a hot cloud of dust orbiting a blazing sun. As the planet cooled, dense elements concentrated in the planet's core, while lighter elements formed the mantle. A thin, rigid crust formed on the surface. A constant cycle of heating and cooling in the mantle drives the movement of plates at the Earth's surface,” is described in a publication from the California Institute of Technology (Caltech).
Although drilling 12.2 kilometers is considered hard work, it is not even half of what is needed to reach the first layer of the Earth. To reach the initial layer, excavation professionals need to dig a hole up to 100 kilometers deep. Despite this, such an operation is not yet possible with currently available excavation machines.
A thought experiment that many scientists have already imagined is: would it be possible to dig a hole from one point on Earth to another?
The question does not have a simple answer, but TecMundo gathered information from experts in the field to explain a little more about the topic. Check out.
A hole in the Earth
To drill the first layer, professionals would need to dig up to 100 km, however, the biggest problem would be pressure. For every three meters of digging, atmospheric pressure increases once; that is, the pressure would increase significantly when there are many kilometers to be excavated. For example, at the end of the Kola super-deep well, the pressure can be up to 4,000 times greater than sea level.
In addition to the three main layers, the Earth's interior also has the following layers: asthenosphere, lithosphere, troposphere, stratosphere, mesosphere, thermosphere and exosphere. Source: Getty Images
In a hypothetical situation where scientists manage to excavate the first layer, They would still need to drill much more to reach the Earth's mantle, which is approximately 2,800 kilometers thick. So, if the super-deep Kola well took approximately 20 years to excavate 12.2 kilometers, imagine how long it would take to excavate the mantle.
After excavating a hole almost 2,900 kilometers deep, scientists would reach the beginning of the Earth's core. After almost 5 thousand kilometers, they would reach the planet's inner core. From there, they would continue drilling the rocks to return to the mantle and the first layer of the Earth, however, on the other side of the Earth.
“The further you fall, the weaker gravity becomes, because more and more of the Earth's mass is above you, canceling out the gravity coming from the other side of the Earth. Additionally, as you fall, air pressure increases, causing the air to exert more force against your movement. As gravity weakens and air resistance increases, your speed steadily decreases”, describes a publication on the website of West Texas A&M University, in the United States.
Piercing the Earth from one end to the other
In addition to all the difficulties in equipment for excavation, scientists would also experience difficulties in relation to extreme pressure and temperatures.. The outer core itself has a hot cast iron alloy that can reach temperatures ranging between 4,000 and 5,000 degrees Celsius; therefore, equipment that would not melt during drilling would be needed.
A hole drilled from one point on Earth to another, on average, would reach 12,700 kilometers away. Source: Getty Images
In the inner core, the pressure is so high that it keeps the nickel and iron in a solid state, even at extremely high temperatures — it is so high that it reaches up to 350 million times atmospheric pressure. After a certain point, the drill would begin to be pulled towards the core due to the Earth's gravity. When going beyond the core, the drill would need to fight against gravity, as it would be pulled 'up', towards the surface.
Currently, there is no equipment powerful enough to drill the entire Earth; Reaching the planet's core is impossible with current technology. However, imagining that this was possible and scientists created a tunnel that crossed the planet, a theoretical trip at high speed would only take 42 minutes and 12 seconds to reach the other side.
Even if scientists managed to reach the planet's inner core, they would go through great trouble reaching the other side of the planet. It's as if they went through the same problems twice: first, to get to the center, then to leave the center and reach the opposite side of the excavation.
Did you like the content? Always stay up to date with other curiosities about our planet Earth here at TecMundo. If you wish, take the opportunity to learn more about the new layer of the Earth that may have arisen through a chemical reaction with water.