Consistency of Earth's magnetic field history surprises scientists
Wednesday, February 3, 2016 - 12:45
in Astronomy & Space
Earth's magnetic field is generated by the motion of liquid iron in the planet's core. This "geodynamo" occasionally reverses its polarity—the magnetic north and south poles swap places. The switch occurs over a few thousand years, and the time between reversals can vary from some tens of thousands to tens of millions of years.