As the particles escape, they are thrown out by the rotating sun in an ever-widening spiral. This solar plasma escapes as a stream of particles with enormous velocity. As the particles speed through space, they act like miniature magnets. In two to five days, when they reach Earth's magnetic field, the two forces push against each other like opposite poles of two magnets. The sun s particles sweep around Earth's field and fan out like water passing around a rock in a stream.
Some particles flow almost around the end of the field.
Others spiral down toward the North Pole. We see the auroras near the Earth s poles because the magnetic fields are open only at the poles. Sometimes the lights look like a faint glow in the sky. At other times, the lights appear as a sparkling curtain, a twisting, twirling ribbon, or pockets of color. The colors undulate across the sky.