StarDate

Magnetic Flip-Flop

Earth’s magnetic field sometimes does a flip. The north magnetic pole becomes the south pole, and vice versa. On average, it happens once every few hundred thousand years. But sometimes, it’s more of a flip flop — the field flips right back over. One flip-flop took place about 42,000 years ago. Known as the Laschamps Excursion, the flip lasted only a few hundred… Play episode