The large mercury iron core is thanks to the magnetic field of the sun

One of the biggest arguments on the interior solar system in astronomers and scientists is the reason why mercury is a massive iron core. The dominant theory is that collisions with other organisms destroyed a large part of the rocky coat around mercury during the formation of the planet, leaving the large dense metal core inside a relatively thin crust. However, new research has offered an alternative to this dominant theory. 

The new research found that collisions are not to blame for the large mercury iron core; The magnetism of the sun is rather responsible. Researchers William McDonough and Takashi Yoshizaki have developed a model that shows the density, mass and iron content of the Rocky Planet kernel is influenced by the distance from the magnetic field of the sun.

The researchers showed that the four interior planets of the solar system, including Mercury, Venus, Earth and March, all consist of different parts of metal and rock. Their model shows that there is a gradient where the metal content in the core abandons while the planets become further from the sun. Their paper describes how this happens by showing that the distribution of raw materials in the solar system in early formation, has been controlled by the magnetic field of the sun.

The researchers found that the density and proportion of iron in the core of a rock planet are directly correlated with the strength of the magnetic field around the sun during the formation of the planet. The study suggests that magnetism should be taken into account in future attempts to describe the composition of rock planets, including exoplanets outside our solar system.

The study could affect the search for life on other planets because the composition of the nucleus of the planet is important for its potential to support life. On earth, the iron core creates a magnetosphere protecting the lives of cosmic rays. Researchers also note that the nucleus has the majority of phosphorus on the planet, which is an important nutrient for carbon life.

With the new model, the researchers determined the speed at which the gas and dust were sucked at the center of the solar system during its training. When fading in the magnetic field that would have been generated by the sun, because it was born and calculating how this field will suggest iron through dust and gas clouds. The next step of the search will be to find another planetary system similar to ours with rock planets spread over large distances from the central star and determine whether the density of the planets declines with their distance from the star.