"And We sent down iron, wherein is great might, and many uses for men" (Quran: 57/25)
Undoubtedly, iron is the most fundamental metal for us. It is widely used in every field of industrialization. Iron played a key role in the development of human civilization by being utilized as tools that were used for many purposes like hunting, cooking, construction etc.
The scientists found out that the energy required to form one atom of iron is four times as much energy of the entire solar system. Since the energy required to form iron element is not found in our solar system, this element is accepted to be extraterrestrial. In other words, the iron element must have been sent to earth from an external source and not formed on earth.
Modern science have discovered that iron has come down from the giant stars in outer space. The heavy metals in the universe are produced in the nucleus of giant stars. These stars are much bigger stars than our sun, where the temperature reaches a hundreds of million degrees.
When the amount of iron in a star exceeds the amount that the star no longer carry, the star explodes, and it is called a "nova" or a "supernova". When a star explodes, meteors or asteroids containing iron are scattered around the space. Billions of years ago, ( before the living things were created ) a giant asteroid strike the earth, its massive iron core did not stop on the surface and it sank towards the center scattering iron over the surface . This why now the center of earth is mainly iron and there is iron embedded in rocks scattered over the earth's surface . The molten iron in the center of the earth generates the earth's magnetic field, which in turn forms the Van Allen belts that shield the earth's surface from destructive cosmic rays.
So we can conclude that iron was not formed on earth, but it was sent to earth as stated in Quran: "And We sent down iron, wherein is great might, and many uses for men" (Quran: 57/25)
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