magnetosphere

noun Astronomy.

1. the outer region of the earth’s ionosphere, where the earth’s magnetic field controls the motion of charged particles, as in the Van Allen belts.Compare magnetopause.
2. such a region of another planet: Jupiter’s magnetosphere.

noun

1. the region surrounding a planet, such as the earth, in which the behaviour of charged particles is controlled by the planet’s magnetic field

n.1959, from magneto- + sphere. So called because in it the magnetic field of the earth plays a dominant role in the motion of particles.

1. A highly asymmetrical region surrounding the Earth, beginning about 100 km (62 mi) above the surface on the side of the Earth facing the Sun and extending hundreds of thousands of kilometers into space on the opposite side. In this region the Earth’s magnetic field exerts a significant influence on any charged particles that encounter it. The magnetosphere deflects most of the charged particles in the solar wind, but also traps and deflects some of these particles toward the Earth’s magnetic poles, causing magnetic storms and auroras.