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- Around the Earth is a comet-like, fan-shaped tail - the magnetosphere. On the
- side of the Sun (the 'dayside') it extends to some 100,000 km and in the other
- direction (the 'nightside'), due to the influence of the solar wind, it extends
- millions of kilometres.
- Without a magnetic field life, as we know it, would be impossible on Earth;
- high-energy particles originating from the Sun would destroy every form of life
- on Earth. The magnetosphere forms the Van Allen Radiation belts, which capture
- these high-energy particles.
-
- When a magnetic storm reaches the magnetosphere, the electrons, protons, and
- oxygen ions of the Van Allen radiation belts become denser, hotter, and faster.
- Due to their motion, these particles produce as much as a million amperes of
- electrical current, a jolt of power that can decrease the strength of Earth's
- magnetic field. Some of the current flows along Earth's magnetic field lines
- into the upper atmosphere, where the excited particles collide with the oxygen
- and nitrogen. These collisions cause them to become electrically excited. The
- result is a light in the night sky, known as auroras.
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