Privileged Planet: magnetic field protects life early on (Introduction)

by David Turell , Wednesday, December 11, 2019, 19:25 (1810 days ago) @ David Turell

The field was up and running early so life could survive:

https://www.nature.com/articles/d41586-019-03807-7?utm_source=Nature+Briefing&utm_c...

"Magnetic minerals in ancient Greenlandic rocks suggest that Earth’s magnetic field arose at least 3.7 billion years ago. The finding pushes back the time of the magnetic field’s birth to about 200 million years earlier than the commonly accepted estimate — around the time life first appeared on Earth.

"Scientists think that having a magnetic field makes Earth more hospitable to life. The field, which is generated by liquid iron sloshing about in the planet’s core, shields Earth from energetic particles flowing from the Sun. It helps the planet hold on to its atmosphere and maintain liquid water on its surface.

***

"Nichols led two expeditions to western Greenland in the summers of 2018 and 2019. She was targeting a set of ancient rocks in the Isua region, north of the capital city Nuuk, that researchers have long studied in search of clues to early life. The Isua rocks have inspired fierce debates, including whether they contain fossils of complex organisms from 3.7 billion years ago.

"Geological forces have squeezed and heated the rocks so much over the past few billion years that most scientists thought the rocks had lost most of their magnetism. But Nichols and her team travelled to the northernmost part of Isua to study rocks that had been least affected by this squeezing and heating.

"Iron minerals in those rocks yielded information on the direction of Earth’s magnetic field when the minerals formed. Because the rocks are 3.7 billion years old, the magnetic signal must be, too, Nichols said.

"Her team ran various tests to try to confirm that the signal was real and not some sort of weak magnetism introduced later as the rocks were heated and squeezed."

Comment: Finding not yet fully confirmed, but the evidence continues that the Earth was fully designed for life from its beginning.