The swirling flow of molten iron and nickel around Earth's solid center triggers an electrical current, which generates the planet's magnetic field. Rapid changes in the churning movement of liquid outer core are weakening the magnetic field in some regions of the planet's surface that may suggest the possibility of an upcoming reversal of the geomagnetic field. Earth's magnetic field has reversed hundreds of times over the past billion years, and the process could take thousands of years to complete. The decline in the magnetic field also is opening Earth's upper atmosphere to intense charged particle radiation. This radiation does affect technical and radio equipment and can damage electronic equipment on satellites and airplanes.