The magnetic field of a planet; the volume around the planet in which charged particles are subject more to the planet's magnetic field than to the solar magnetic field.
Volume of space, surrounding a planet, controlled by the planet’s magnetic field, and acting as a magnetic shell”. The Earth’s magnetosphere extends 64,000 km/40,000 mi toward the Sun, but many times this distance on the side away from the Sun.
The extension away from the Sun is called the magnetotail. The outer edge of the magnetosphere is the magnetopause. Beyond this is a turbulent region, the magnetosheath, where the solar wind is deflected around the magnetosphere. Inside the magnetosphere, atomic particles follow the Earth’s lines of magnetic force. The magnetosphere contains the Van Allen radiation belts. Other planets have magnetospheres, notably Jupiter.