Asked by: Ken Hills, Brighton
Fortunately, short of being hit by some vast celestial body, the Earth can't flip over, as the Moon's gravity field keeps our planet on a fairly even keel. But the magnetic poles can, and do, undergo complete reversals, most recently around 780,000 years ago. The weakening of the magnetic field as it undergoes a complete flip would make the Earth more vulnerable to the effects of solar radiation, which have the power to disrupt powerlines and telecommunications.
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