Magnetic field reversal refers to the process where the Earth's magnetic field changes direction, causing the magnetic north and south poles to switch places. This phenomenon occurs over thousands of years and is recorded in geological formations, such as lava flows and sedimentary rocks, which capture the orientation of the magnetic field at the time of their formation. During a magnetic field reversal, the strength of the magnetic field may weaken, leading to increased exposure to solar radiation. While these reversals have happened many times in Earth's history, their exact causes and effects on the planet's environment and life are still subjects of scientific research.