An aurora (also known as aurora borealis in the northern hemisphere and aurora australis in the southern hemisphere) is a luminous display of colours in the night sky, predominatly of green colour.Auroras are caused by the interaction between the charged particles of the solar wind and the atoms in the upper atmosphere. The auroras occur mainly in the regions near the poles in an area aptly named as”auroral zone” (between 65 and 75 ° latitude). In case of intense magnetic activity, the auroral arcs expand and begin come much closer to the equatoral areas. The polar aurora came “down” till Honolulu in September 1859 and till Singapore in September 1909 . In November 2003, an aurora was observed in southern Europe.
However, the regions most affected by this phenomenon are Greenland, Lapland, Alaska, Antarctica, Northern Canada and Iceland.
