New Surprising Theory Explains Mercury’s Big Iron Core

Planet Mercury amazes scientists for plenty of reasons. Despite being a hot world due to its relatively short distance from the Sun, the smallest planet from the Solar System, or the fact that it lacks any moons and rings, Mercury also has a surprisingly big iron core beneath its surface. However, the planet’s size diameter is 3.030 miles, meaking it comparable to the size of the continental US.

For a long time, astronomers had a prevailing theory for the iron core from Mercury: collisions with other space objects during the solar system’s formation blew away much of the rocky mantle of Mercury, leaving the large metal core inside. But according to a new study that SciTechDaily speaks about, scientists now have a different scenario for what might have happened in the history of the smallest planet from our Solar System.

The Sun’s magnetism is the culprit

New research done at the University of Maryland reveals that proximity to the magnetic field of the Sun can determine the interior composition of a planet. Takashi Yoshizaki and William McDonough from Tohoku University and the University of Maryland, respectively, managed to develop a model that shows how the density, iron content, and mass of a core belonging to a rocky planet can be influenced by the distance from the magnetic field of the host star.

McDonough declared, as cited by SciTechDaily:

The four inner planets of our solar system—Mercury, Venus, Earth, and Mars—are made up of different proportions of metal and rock,
There is a gradient in which the metal content in the core drops off as the planets get farther from the Sun. Our paper explains how this happened by showing that the distribution of raw materials in the early forming solar system was controlled by the Sun’s magnetic field.

The new study paper was published in the journal Progress in Earth and Planetary Science.