The Magnetosphere

Artist's impression of Earth's magnetic field. (c) UCL

The Earth has a magnetic field that is generated by electric currents flowing in its liquid outer core. It can be detected using a simple magnetic compass - from the UK a compass points north if you hold it horizontally and into the ground if you hold it vertically. If you were to do this experiment at lots of points on the Earth's surface you'd find out that the Earth's magnetic field look like that of a bar magnet - a magnetic dipole.

The Earth's magnetic field extends far into space, where it meets the interplanetary magnetic field, which is carried throughout the solar system by the solar wind, a gusty stream of plasma that flows through the solar system at typical speeds of 450km/s. The solar wind is diverted around the Earth's magnetic field, which compresses the Earth's magnetic field on the side facing the sun and stretches into a long tail on the side pointing away from the Sun. The region of space containing the Earth's magnetic field is called the magnetosphere

Artist's impression of the magnetosphere. (c) UCL

Page last modified on 09 sep 11 13:58