Northern Lights

The northern lights, also called the polar lights, can primarily be seen in the polar regions of the Earth. The are produced in the upper layers of the atmosphere when electronically charged particles from the sun meet the Earth's magnetic field, are diverted by it and when penetrating the atmosphere excite the molecules and atoms there to emit light. The northern lights can mostly be seen at a height between 100 and 200 km. Their luminosity is subject to fluctuations and colour changes. The colours reflect the individual gases found in the atmosphere. The yellow-green "northern light line" which belongs to the oxygen spectrum can almost always be seen. A violet hue comes rather from the spectrum of the nitrogen element.