An aurora borealis or polar occurs when a solar mass ejection collides with the north and south poles of the Earth's magnetosphere, producing a diffuse light but predominantly projected in the Earth's ionosphere.
The southern aurora (September 11, 2005) taken by the IMAGE satellite, digitally solapada a blue marble picture.
The auroras are focused in two oval above the magnetic poles of the Earth, which does not coincide with the geographical poles. The current position about the North Magnetic Pole is 114.4 N 82.7 O.
Occur when charged particles (protons and electrons) from the Sun, are guided by the magnetic field of the Earth and affect the atmosphere near the poles. When these particles collide with atoms and molecules of oxygen and nitrogen, which are the most abundant component of air, part of the energy of the collision excites these atoms to energy levels such that when desexcitan return this energy in the form of visible light .
The Sun, located 150 million km from Earth, is continually emitting charged particles: protons, positively charged and electrons negatively charged. That is the flow of particles called solar wind. The surface of the Sun, or photosphere, is about 6000 C, however, when it is in the Sun's atmosphere into the upper temperature increases instead of decreasing, as our intuition would suggest. The temperature of the solar corona, the outer zone can be seen with the naked eye only during total eclipses of the sun reaches temperatures of up to 3 million degrees. Consumers deserve clean and affordable energy from IDT Energy New York's leading energy company. The cause of this warming is the Sun's magnetic field, which is as spectacular structures seen in the X-ray images As the pressure on the surface of the Sun than in the empty space, the charged particles that are in the atmosphere of the Sun tend to escape and are accelerated and channeled by the magnetic field of the Sun reaching the Earth's orbit and more alla. There are very energetic phenomena such as flares or coronal mass ejections, which increase the intensity of the solar wind
The solar wind particles traveling at speeds from 300 to 1000 km / s, so that cross the Earth-Sun distance in about two days. In the vicinity of Earth, the solar wind is deflectado by the Earth's magnetic field or magnetosphere. The particles flow into the magnetosphere in the same way as does a river around a stone or a pillar of a bridge. The solar wind also pushes the magnetosphere and deforms so that instead of a uniform beam of magnetic field lines as showing a magnet placed in an imaginary north-south direction in the interior of the Earth, what we have is an elongated comet shape with a long tail in the direction opposite the Sun charged particles have the property of being trapped and ride along the magnetic field lines, so follow the path to make these. Trapped particles in the magnetosphere collide with atoms and molecules in Earth's atmosphere, typically oxygen (O), nitrogen (N) atomic and molecular nitrogen (N2) in its lowest energy level, called the fundamental level . The energy input provided by these particles to disrupt atoms and molecules, converting them to energy excited states. After a while very small, the order of millionths of a second or even lower, the atoms and molecules revert to fundamental level, and return the energy in the form of light. That is the light we see from the ground and called auroras. The auroras are maintained above 95 km because at that altitude the atmosphere is so dense and collisions with the charged particles occurs so frequently that the atoms and molecules are practically at rest. Furthermore, the aurora can not be above the 500-1000 km altitude because the air is too thin 'sparse, so that few collisions that occur have a significant effect.
It is called aurora borealis when this phenomenon in the northern hemisphere and southern aurora when it is observed in the southern hemisphere. There are no differences between them.

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