Magnetic Fields and Earth as a Magnetic Field
What is a magnetic field? Did
you know that the Earth has one?
A magnetic field is a way of mathematically describing how magnetic materials and electric currents interact. Magnetic fields have both a direction and a magnitude, or strength. Magnets have a "north" pole and a "south" pole. Opposite poles attract each other and alike poles repel each other. These poles are referred to as a magnetic dipole. Magnetic dipoles and electric currents both give rise to magnetic fields.
The iron-cored Earth behaves like
a great magnet, generating a huge
magnetic field around the planet
that protects it from blasts and harmful radiation from the sun.
The field lines of the
magnetosphere are not actually visible to humans, but they can be detected by sensors that count atomic particles charged protons and electrons moving in the space around Earth.
The magnetosphere bulges on one side and tapers off on the other because it is pushed in on the side facing the sun by the solar wind and stretched out in the Earth's shadow. The solar wind is a stream of high-speed particles flowing out from the sun and carrying the signature of its own magnetic field.
Like the ozone layer, the magnetosphere is important to life on Earth because it protects us from most of the harmful radiation and hot plasma from the sun, deflecting it into space.
The interaction of solar flares and other emissions from the sun with the magnetic field can disrupt radio transmissions and damage satellites in a phenomenon known as space weather. They can also produce beautiful auroras .
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