Unearthing Earth's magnetic secrets

What if the key to understanding Earth's unpredictable magnetic field lay hidden, not in geology, but in the remnants of ancient civilizations?

- ADRIJA GHOSH

In the arid expanses of Jordan, scientists have made a groundbreaking discovery within Iron Age slag heaps. These byproducts of Iron Age metal production in the Wadi Fidan region of southern Jordan provided scientists with an unexpected and precise record of changes in Earth's magnetic field thousands of years ago.

Recent research has found that this slag, formed between 1,000 and 800 BCE, contains an unusually well-preserved record of magnetic activity, capturing spikes and dips in the planet's geomagnetic strength. These findings aren't just a look into the deep past—they offer critical data that may improve how scientists model Earth's magnetic field, which still holds many mysteries even in the satellite age.

Why Earth's magnetic shields matter?

Earth's magnetic field is generated by fluid movements in the outer core, shields life from harmful solar radiation and helps guide everything from migratory birds to GPS satellites. But this invisible barrier is far from constant. It shifts, it weakens, it reverses—sometimes dramatically. Understanding these fluctuations is vital not only for scientific curiosity but for protecting modern technology that relies on geomagnetic stability.