If all the compasses in the world started pointing ... Such reversals in the Earth's magnetic field, they'd tell you, are, roughly speaking, as common as ice ages. That is, they're terrifically ...

Magnetotactic bacteria synthesize magnetic iron nanominerals, which function as tiny compasses that allow the microbes to navigate using Earth's geomagnetic field. Earth's iron cycle is a very ...

Of course, there's Earth's magnetic field, which deflects dangerous cosmic radiation, wiggles our compasses, and guides flocks of migrating birds. But other planets and stars have magnetic fields ...

When I learned recently that our planet's magnetic shield is rapidly weakening and may be ready to reverse its polarity, causing compasses to point south, I immediately wondered what that would ...