A new study sheds light on the processes that transpired deep within our planet millions of years ago and led to a veritable "explosion of life" on Earth, as ScienceAlert put it.
The team behind the new research postulates that the solid inner part of Earth’s core proceeded to crystalize and turn into a much larger mass around 550 million years ago.
This process helped restore the Earth’s magnetic field, which protects life on the planet from harmful solar radiation and which had become depleted about 15 million years earlier.
"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," said John Tarduno, professor of geophysics at the University of Rochester in New York. "This research really highlights the need to have something like a growing inner core that sustains a magnetic field over the entire lifetime – many billions of years – of a planet."
Having examined feldspar crystals found in anorthosite rocks, which serve as "recorders of magnetism," and compared rocks from 565 million years ago with rocks from 532 million years ago, Tarduno and his team discovered evidence of Earth’s magnetic field regaining strength, although this shift apparently occurred over the course of tens of millions of years, the media outlet notes.
Tarduno pointed out that the magnetic field’s comeback helped preserve Earth’s water reserves.
"Earth certainly would've lost much more water if Earth's magnetic field had not been regenerated," he said. "The planet would be much drier and very different than the planet today."