magnetosphere

American  

[mag-nee-tuh-sfeer] / mægˈni təˌsfɪər /

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.

2. such a region of another planet.

   Jupiter's magnetosphere.

---

magnetosphere British  

/ mæɡˌniːtəʊˈsfɛrɪk, mæɡˈniːtəʊˌsfɪə /

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

---

magnetosphere Scientific  

/ măg-nē′tō-sfîr′ /

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.

---

Other Word Forms

• magnetospheric
  adjective

Etymology

Origin of magnetosphere

First recorded in 1955–60; magneto- + -sphere

Example Sentences

See Examples For:

magnetosphere

A day on Earth lasts 24 hours, and the shape of Earth's magnetosphere is largely determined by the balance between pressure from the solar wind and pressure from Earth's magnetic field.

From Science Daily ● Aug. 10, 2026

Because the satellites travel in carefully coordinated orbits, they can separate magnetic signals coming from the core from signals produced by the crust, oceans, ionosphere and magnetosphere.

From Science Daily ● Aug. 7, 2026

An analysis of material collected by China's Chang'e 6 mission now suggests that Earth's magnetosphere is responsible for much of this contrast.

From Science Daily ● Jul. 21, 2026

An increase in solar wind and particles, known as a solar storm, can cause major disruptions by smashing through the magnetosphere.

From The Wall Street Journal ● Jul. 10, 2026

Anything potent enough to put on such a show could well blow away the magnetosphere, the magnetic zone high above the Earth that normally protects us from ultraviolet rays and other cosmic assaults.

From "A Short History of Nearly Everything" by Bill Bryson