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.

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magnetosphere British  

/ 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

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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.

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Other Word Forms

• magnetospheric
  adjective

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Etymology

Origin of magnetosphere

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

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Example Sentences

See Examples For:

magnetosphere

A magnetosphere is the region of space around a planet where its magnetic field provides protection from these incoming particles.

From Science Daily ● Aug. 10, 2026

One day on the planet lasts approximately 10.7 hours, and its magnetosphere also contains large amounts of ionized material supplied by its moon Enceladus.

From Science Daily ● Aug. 10, 2026

These far side samples provide the first direct physical evidence that Earth's magnetosphere controls the speed of solar wind particles reaching different parts of the Moon.

From Science Daily ● Jul. 21, 2026

The Earth is protected from solar and cosmic particles by the magnetosphere, a region generated by the movement of molten iron in the planet’s core.

From The Wall Street Journal ● Jul. 10, 2026

Without the magnetosphere anyone unfortunate enough to step into sunlight would pretty quickly take on the appearance of, let us say, an overcooked pizza.

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

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