The Aurora Borealis (Northern Lights), one of the most magnificent natural phenomena, usually appears in the night sky between end of August and April. Like with many other natural phenomena, Northern Lights have appeared in a number of myths and tales. Some people say that Aurora Borealis is spirits moving across heaven. Or that they are reflections of the shields of the mythical female warrior Valkyrie.
Scientists know that Aurora Borealis is caused by solar winds hitting Earth’s upper atmosphere about 100 km high in the sky. The Earth’s magnetic field directs the flow of electrons from the sun to the magnetosphere above the magnetic North and South Pole. This is the reason that best places to see Auroras are above the Arctic Circles.
Northern Lights occur also in the summer, but the Midnight Sun and the light sky of the summer nights prevents us from seeing them.