More than 3.5 billion years ago, the Earth “devoured” a cosmic object very similar to Mercury that hit it. This is stated by a team of geochemists from the University of Oxford in an article published in Nature.
Experts affirm that the shock was fundamental for the development of life as we know it, since it provided the core of our planet with radioactive elements that would be fundamental for the formation of the magnetic field . This protects the Earth from the radiation that, coming from space, constantly bombards it.
According to the authors of the study, for a structure such as the Earth’s magnetic field to emerge, certain radioactive elements, such as potassium, thorium or uranium, must remain in the nucleus, which release heat by decay. However, these compounds, which bind with oxygen to form very light oxides, do not combine well with the iron that makes up most of the nucleus .
Therefore, in principle they should not be in their vicinity, but closer to the surface . The Oxford researchers have discovered, however, that certain sulfides, sulfur compounds in which oxygen is not present, favor the combination of iron and radioactive elements. The question is: how did they get to the heart of the planet?
In his opinion, this could have occurred as a consequence of a collision with a celestial body the size of Mars, but very similar to Mercury in its composition, rich in sulfur and poor in oxygen .
Experts emphasize that this idea not only explains that uranium has remained in the Earth’s core, which would have ended up causing our magnetic field, which has existed for 3.5 billion years, but also fits with a hypothesis that the Moon it would have been formed after a similar cataclysm .
