Record of 3.7 billion-year-old magnetic field gives clues about the formation of life on Earth

Researchers from Oxfordin the United Kingdom, and the Massachusetts Institute of Technology (MIT), in the United States, found evidence that the magnetic field of Earth it has existed for at least 3.7 billion years. The study, which sought data from Greenlandmay provide clues to the formation of life on Earth.

The magnetic field is one of the factors that made the planet habitable. This mechanism protects the lives of radiation harmful radiation from space and helps keep the oceans and atmosphere stable for long periods of time.

Previous studies had shown that the magnetic field was at least 3.5 billion years old. The addition of another 200,000 years to this date indicates that the magnetic field may have played a critical role in making the Earth habitable, as this is the period that scientists calculate for the emergence of life.

Scholars suspect that the strength of the magnetic field billions of years ago enabled an atmosphere capable of supporting life and protected the planet from solar radiation.

Scientists also concluded that Earth’s magnetic field was about the same strength as today’s. The magnitude of the Ancient Earth was 15 microtesla and today’s magnitude is 30 microtesla. The study was published this week in Geophysical Research Magazine: Solid Earth.

According to one of the authors of the research, Claire Nichols, although the force is half, it is still the same order of magnitude. “The fact that (the magnetic field) is similar in strength to today’s indicates that what the Earth’s magnetic field is directed at has not changed massively in terms of power in billions of years,” he says.

Today, the generation of the magnetic field occurs through a moving fluid in the planet’s outer core, which is liquid. This results in electrical currents capable of generating magnetic field lines.

The Earth’s rotational motion also helps to stretch and twist these lines. This mechanism extends around the planet like a protective bubble.

The results found also raise new questions about how the Earth in ancient times would have been able to form such a robust magnetic field. 3.7 billion years ago, the inner core – which enhances the strength of the magnetic field – had not yet solidified. This indicates that there are other ways to create a magnetic field, including for other planets.

Read the full study at Geophysical Research Magazine: Solid Earth.