This was deduced using the so called “magnetic signature” of rocks, which, according to the scientists, showed a sudden boost in strength around that time. More precisely, the scientists say that this is a clear indication of the Earth’s new cooled iron core, which was strong enough to generate today’s magnetic field that basically shields us from the Sun’s harmful solar flares.
The Earth’s iron core is believed to be roughly 2400 km in diameter, which is 30% less than our Moon. The core reaches high temperatures, comparable to the Sun, but is cooling down at a worrying pace, according to the latest estimates from the scientists. Many scientists are not shy of making a parallel between planet Earth and Mars, when speaking about the abrupt temperature drops in the core of our planet.
Mars has long been regarded as a potentially live hosting planet, particularly in the age when its inner core was hot enough to generate magnetic fields similar to Earth’s.