Which theory is stronger, that iron came from outside or was formed within earth?

Question

Where is the current body of science learning towards, that iron came from meteor or it was somehow formed on earth?

Answer 1

Iron, along with all the elements in the universe, can only be created through nuclear reactions of subatomic particles. Such reactions only occur naturally in extreme environments such as the center of a star. In fact, a star like our own sun can only make elements up to iron on the periodic table and even that only happens in the very last moments of the star's life! Anything heavier than iron is created during cataclysmic events called supernovae, and a star has to be quite big to go out with a bang like that. So the idea that iron somehow formed on the earth is entirely unrealistic. Our best theories on the origin of the solar system show that the planets formed at the same time as our sun during the collapse of a very hot and dense molecular cloud, forming a solar nebula. The terrestrial planets started as a conglomeration of dust grains that eventually formed planetesimals, which continued to collide over several million years to make the large rocky bodies they are today. Since our early sun was far too hot at this time for volatile molecules to exist, these planetesimals were made of metals with high melting points like iron and nickel, as well as silicate minerals. That is likely the reason why the Earth has an iron core. Hope that helps.

Parker