Our planet Earth is one of the nine planets of the Solar System, the fifth-largest among them and the third largest in location from the Sun, after Mercury and Venus. The solar system is located in the Milky Way galaxy, relatively far from its center.
In addition to the solar system in our galaxy, there are some estimates of two hundred to four hundred billion stars in our galaxy that have their planetary systems. And all these countless cosmic bodies have one thing in common - they have a round shape or rather a ball shape.
This form is the most natural due to the force of gravity inherent in all material bodies with mass. As we all know, we all consist of atoms that are influenced by different physical forces, one of which is gravity. Under the influence of the force of gravity, the atoms of matter aspire to the center, and gravity affects homogeneous atoms equally. That's why the heaviest substances and metals are concentrated closer to the nucleus of our planet, and light gases are mostly present in the stratosphere and exosphere.
Why aren't all objects round in space?
Less massed space bodies, such as asteroids, are irregularly shaped, far from the shape of the ball. The reason is the same - gravity, or rather not strong enough gravity. Asteroids, although often huge, are not massive enough to produce their gravitational force.
They are unable to attract substances from space, and therefore unable to accumulate mass over time and move into the category of dwarf planets. The only exception can be asteroids-supergiants with a diameter of 300 kilometers, the mass of which is sufficient for the emergence of forces of gravity, able overtime to give the asteroid a spherical shape.
How did the Earth become round?
All the space bodies, be they stars, planets or asteroids, were formed within billions of years from dust clouds and gas, which in turn were the result of star explosions. There are many hypotheses of the formation of the Earth, but they all agree to some extent that the formation of the planet took place in the process of concentrating matter around a larger object. Here the decisive role was played by the gravity of this object itself.
For billions of years, the substance was attracted by this object, the mass of which was becoming more and more, respectively, and gravity was getting stronger and stronger. With the accumulation of mass, the pressure in the center of the planet increased, and with it, the temperature increased. As a result, a molten mass of substance was formed, which under the influence of gravity took a spherical shape. As a result of these processes, after four and a half billion years, the Earth was formed.
What form does the Earth take? The laws of physics, for the most part, apply to both the Earth and space. One of the laws of physics says that when the body rotates, inside it there is a centrifugal force acting on its atoms in the direction of the axis of rotation. Since the Earth rotates on its axis, a centrifugal force also appears inside it, which acts in the direction of the axis of rotation from the equator line. For this reason, the Earth has not the correct form of a ball, but rather the form of an ellipsoid flattened from the poles. Thus, the diameter of our planet in the area of poles on 43 kilometers is less than the diameter of a planet in the area of a line of the equator.
Interesting fact: the highest point of our planet is Mount Everest (Jomolungma), its height is 8848 meters above sea level. Everest is located in the Himalayas, which are far from the equator. In Ecuador, which is on the equator line itself, Mount Chimborazo is located at a height of 6384 meters above sea level, more than two and a half kilometers below Mount Everest. However, if we consider the height of the mountains not from sea level, but the central point of the planet, it turns out that Mount Chimborazo is much higher than Everest.
The laws of physics dictate the forms of space bodies. Under the influence of gravity, massive bodies tend to take the form of a ball - the ideal form for when the body is not affected by other forces. One such force is the centrifugal force, which violates the ideal spherical shape of the rotating body, making it stretched away from the axis of rotation.
For this reason, the Earth has the form of an ellipse with a difference in diameters from north to south and from east to west in 43 kilometers. Bodies with insignificant mass and gravity are unable to accumulate on their surface substances found in space.
For this reason, they have the wrong shape and, even while in space for many millions of years, are likely to remain lonely fragments of once large planets. Unless, of course, they meet the planet of which they will become a part.
But don't let this planet be called Earth!