Extending from Earth like invisible spaghetti is the planet’s magnetic field. Created by the churn of Earth’s core, this field is important for everyday life: It shields the planet from solar particles, it provides a basis for navigation and it might have played an important role in the evolution of life on Earth.
But what would happen if Earth’s magnetic field disappeared tomorrow? A larger number of charged solar particles would bombard the planet, putting power grids and satellites on the fritz and increasing human exposure to higher levels of cancer-causing ultraviolet radiation. In other words, a missing magnetic field would have consequences that would be problematic but not necessarily apocalyptic, at least in the short term.
And that’s good news, because for more than a century, it’s been weakening. Even now, there are especially flimsy spots, like the South Atlantic Anomaly in the Southern Hemisphere, which create technical problems for low-orbiting satellites.