This animation shows how particles from the Sun are diverted by the Earth's magnetic field.
Movie provided courtesy of Professor Patricia Reiff, Rice University Connections Program

How Does the Earth's Magnetic Field Protect Us From Space Radiation?

Dangerous particles are not able to penetrate to the Earth's surface but are forced by the magnetic field to move around the Earth. Particles gain entry through the cusps that are shaped like funnels over the polar regions or they gain entry far downstream from the Earth. The particles that enter downstream travel toward the Earth and are accelerated into the high-latitude ionosphere and produce the auroral oval light shows. Since the most intense auroras occur at solar maximum, it was once thought that the Sun hurled material out during these raised times of solar activity and that that material funneled directly into the polar cusps. However, we now understand that the electrons that cause the auroras come in downstream or from the Earth's magnetic tail. These electrons that enter at the magnetotail are energized locally within the magnetosphere.

Other higher energy particle radiation that could pose a danger to life here on Earth, is forced to drift around the Earth within two large donut-shaped regions called the radiation belts. Invisible magnetic fields are the reason that particle radiation moves in this way. Click here for basic facts about particle motions in the Earth's magnetic field.

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