Rock shows that magnetic field existed 3.7 billion years ago | Tech and Science

A research team from the University of Oxford in the United Kingdom found the rock in southwest Greenland. Rock changes composition as it gets warmer. This makes it difficult for researchers to find stones that can tell something about millions to billions of years ago. The rock found in Greenland is thought to be about 3.7 billion years old.

Researchers managed to analyze the iron particles of the stone. These iron particles can, as it were, ‘copy’ the force of the magnetic field when the rock was formed all those years ago.

The magnetic field protects the Earth against, among other things, cosmic radiation and flying particles from space. It makes the earth livable.

Based on the rock, the researchers conclude that the magnetic field was almost as effective 3.7 billion years ago as it is today. And that is striking, given that the sun behaved differently at that time than it does now. The sun was then a lot less stable and active, with more powerful solar winds hitting the magnetic field.

It is important for scientists to find out more about the ‘oldness’ of the magnetic field. Because the amount of protection it offered grew as time went on. Only when the magnetic field provided enough protection could life emerge on Earth. In that sense, the discovery is also important for the question of how and when life emerged on Earth.

The scientists want to continue their research into how the magnetic field has developed during that time. The latest findings have been published in the Journal of Geophysical Research: Solid Earth.