Shift of Earth's Magnetic Field Explained

Earth's magnetic field shields the planet from charged particles streaming from the sun, keeping it from becoming a barren, Mars-like rock.
For more than 300 years, scientists have recorded a westward-drifting feature in the field that models have been unable to explain.
The magnetic field that encases the planet is caused by interactions deep inside Earth's core.
The inner core is solid, while the outer core features flowing liquid iron, which generates currents that in turn lead to magnetic fields.
Understanding how the Earth's core and magnetic field have changed in the past can help scientists to understand its future evolution.