The existence of a magnetic field beyond 3.5 billion years ago is still up for debate
Wednesday, April 8, 2020 - 13:00
in Paleontology & Archaeology
Microscopic minerals excavated from an ancient outcrop of Jack Hills, in Western Australia, have been the subject of intense geological study, as they seem to bear traces of the Earth's magnetic field reaching as far back as 4.2 billion years ago. That's almost 1 billion years earlier than when the magnetic field was previously thought to originate, and nearly back to the time when the planet itself was formed.