2003-10-27 • 1h 0m

What is weakening Earth’s invisible shield? Magnets have the power to attract and repel—sometimes on a massive scale. The Earth’s molten core—a violent mix of searing heat, crushing pressure, and a billion trillion tons of liquid iron—creates an invisible shield that surrounds the globe, guarding against a constant barrage of deadly radiation from space. But over the last few decades, the Earth’s magnetic field has weakened dramatically, intriguing scientists across the globe. The power generated 2000 miles beneath our feet protects us every day, but the loss of Earth’s magnetic field is a brewing storm that affects us all. While experts research and debate, persistent questions remain. Is a rare geomagnetic reversal the cause of earth’s inner turmoil? And if the magnetic field were to vanish altogether, would Earth become as lifeless as Mars?