What causes the Northern Lights (Aurora Borealis)?

Kainantu

the aurora borealis is caused by particles from the sun blowing toward the earth with the solar wind. When these particles hit the earth's magnetic field, the crash of atoms and molecules creates a beautiful sight. Oxygen atoms reflect green and red light. Nitrogen atoms give off a blue and red glow. The lower edges of the lights are usually about 100 kilometres above the Earth, which is about ten times higher than a jet aircraft flies. The top of the lights sometimes reach over 350 kilometres above the Earth! In the spring and fall, when the lights are very strong, crackling noises can be heard. This sound is actually the earth's magnetic field, but you have to be far away from city noise to hear it. This great light show can also be seen in the southern part of the world, but the people there call it the aurora australis. http://www.discoverlearning.com/pole2pole/arctic/aurora.html Dec 24 02, 3:16 AM