Magnetospheric physics

A magnetosphere is the region of space surrounding an astronomical object in which charged particles are manipulated or affected by that object's magnetic field. It is created by planets having active hot iron and nickel or metallic cores, whose motion generated a planetary magnetic field, but such fields can also occur in stars by the interactions of plasma.

In the space environment close to a planetary body, the magnetic field resembles a magnetic dipole. Further out, field lines can be significantly distorted by the flow of electrically conducting plasma, as emitted from the Sun or a nearby star. e.g. the solar wind. Planets having active magnetospheres, like the Earth, are capable of mitigating or blocking the effects of solar radiation or cosmic radiation, that also protects all living organisms from potentially detrimental and dangerous consequences. This is studied under the specialized scientific subjects of plasma physics, space physics and aeronomy.

Study of Earth's magnetosphere began in 1600, when William Gilbert discovered that the magnetic field on the surface of Earth resembled that on a terrella, a small, magnetized sphere. In the 1940s, Walter M. Elsasser proposed the model of dynamo theory, which attributes Earth's magnetic field to the motion of Earth's iron outer core. Through the use of magnetometers, scientists were able to study the variations in Earth's magnetic field as functions of both time and latitude and longitude.

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