The northern lights are a luminescence of an upper atmosphere, owing to interaction of negatively charged particles with positively charged ions of solar wind. The northern lights sparkle multi-color spillovers of blue-green fires with impregnations of red and pink shades of flowers. Surprisingly beautiful natural phenomenon really bewitches imagination, dancing in the dark sky, like tongues of flame.
Color tapes of the northern lights can have width in 160 kilometers, at the same time their length can be in 10 times more. People observe the northern lights on Earth, however it is caused by processes which happen in the Sun. Being the huge heated gas sphere, the sun consists of atoms of helium and hydrogen. The kernel of these atoms consists of the smallest particles called protons. Around them other particles called electrons rotate. Protons are loaded positively, electrons - is negative. The cloud of incredibly hot gas which surrounded the Sun is called still a solar crown. This cloud continuously throws out in space of a particle of atoms. They fly in space with the huge speed which is brought closer to 1000 kilometers per second. Scientists called such streams of atoms solar wind. Sometimes the solar crown blows up the real whirlwind of particles. This phenomenon is called solar activity which increase can cause magnetic storms on Earth. Having reached our planet, particles of solar wind enter interaction with magnetic field of Earth which power lines meet at its poles. The earth is as a huge space magnet which attracts to itself(himself) the smallest particles. The magnetism of our planet is caused by the electric currents caused by rotation of its iron kernel. Attracted by magnetic field, particles of solar wind continue the movement along power lines, forming long "beams". Here also the most interesting begins. It is no secret that the atmosphere of Earth consists generally of nitrogen with oxygen impurity. Solar protons and electrons, having intruded in the atmosphere of the planet, face molecules of these gases. As a result of it some atoms of nitrogen lose a part of electrons, others, on the contrary, receive additional energy. After such "attack" the excited atoms "calm down", being returned to the normal power state. At the same time they let out a light photon. If nitrogen molecules, at collision with solar wind, lost a part of electrons, then being restored they radiate blue and violet light. If got additional, then there is a luminescence of a red part of a range. The same happens also to oxygen atoms of which it is much less in the atmosphere of Earth. At the same time they let out quanta of red and green color. That is why we can observe the northern lights of such color range.