What would it be like to travel to the center of the Earth? It is a place of unimaginable heat and pressure, where no life could survive. Yet without it we would perish for it holds the key to our existence on this planet. Thousands of miles below the surface, Earth's core generates a protective magnetic shield around the planet. Now, scientists have uncovered evidence that this armor could be fading. Are weak spots in this shield a sign that our planet's magnetic poles are on the verge of flipping?