Weakening magnetic field is a return to normal, not a sign of doom
Earth is not heading toward a doomsday reversal of its magnetic field, new research assures.
The planet’s magnetic field is about 10 percent wimpier today than when physicists began keeping tabs on it in the 1800s. In the geologic past, such weakening preceded geomagnetic reversals —swaps of the north and south magnetic poles. Such reversals temporarily make the planet more vulnerable to charged particles blasted off the sun that can disrupt power grids and disable satellites.