450 million years ago, Earth’s magnetic field almost collapsed — the results would have been apocalyptic - Inverse

Why did our magnetic field fade to almost 10 percent of its strength and then regenerate again? The cause was the formation of Earth’s solid inner core.

More than half a billion years ago, Earth experienced an almost-complete collapse of its magnetic field. It began in the early Cambrian period. Then, after a period of about 15 million years, the f… [+5978 chars]

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