Movie provided courtesy of Professor Patricia Reiff, Rice University Connections Program
Dangerous particles don’t hit the Earth’s surface because they are forced by the magnetic field to move around the Earth. Particles do enter at the funnels over the poles or they gain entry far downstream from the Earth. The particles that enter downstream or at the magnetotail cause the auroral lights.
Other higher energy particle radiation that could endanger life 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.
source: windows to the universe