Nearly, 550 million years ago, Earth’s magnetic field was reduced to less than 10 percent of its strength today.
Our Earth is the only planet in the Solar system where life exists, and the reason behind it is Earth’s magnetic field that acts as a protective shield against the solar wind. However, things were not always the same. Scientists and researchers have discovered a shocking fact about it. According to John Tarduno, a professor of geophysics at the University of Rochester in New York, our earth’s magnetosphere was on the verge of complete collapse before the introduction of multicellular life on our planet. In effect, it means that there would not have been life in the form we know it today on Earth. The study revealed that our planet had experienced an almost-complete collapse of its magnetic field in the early Cambrian period. Shockingly, it too a a period of about 15 million years for it to get restored. Tarduno said, “Right before the inner core started to grow, the magnetic field was at the point of collapse, but as soon as the inner core started to grow, the field was regenerated.”
Though the cause of that collapse and the restoration of the field is still a mystery, the study suggests that earth restored its magnetic field due to the large amount of molten iron swirling around 2800 kilometers below the earth’s surface. This magnetic field is invisible but it shields the planet from streams of sun’s radiation also known as solar wind.
The study published in Nature Communications, has shared several key dates in the Earth’s core’s history after which it evolved from a deserted planetary body to a habitable place in the universe. If Earth’s magnetic field hadn’t regenerated, our planet would have lost a lot of its water and would be much drier, similar to Mars. According to researchers, the red planet too once had a magnetic field strong enough for the existence of life but due to the loss of strength, it became a dry and inhabitable planet.