Around 565 million years ago, just when life was getting seriously underway:
The finding, reported online January 28 in Nature Geoscience, supports an idea previously proposed by simulations that Earth’s inner core is relatively young. It also provides insight into how, and how quickly, Earth has been losing heat since its formation 4.54 billion years ago —key to understanding not only the generation of the planet’s magnetic shield but also convection within the mantle and plate tectonics.Carolyn Gramling, “Earth’s core may have hardened just in time to save its magnetic field” at ScienceNews
The powerful recent phase protects lifefrom damaging radiation.
Paper. (open access)
See also: Researchers: The Moon made life on Earth possible
What becomes of science when the evidence does not matter?
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