An Aurora is a breathtakingly attractive pattern of light which can be seen in a clear night sky.
Green, red, blue and yellow colours adorn the sky. Near the north pole, this phenomenon is called Aurora Borealis or more commonly Northern lights. Near the South pole, the name for it is Aurora Australis or Southern Lights. Together, it is termed as Aurora Polaris.
The formal study and research about this phenomenon began in 1716 when a massive Aurora appeared over Europe and could be seen from any part of Europe.
English astronomer Edmund Halley was the first to establish a relation between occurrence of the phenomenon and the magnetic field of the Earth.
The most widely accepted theory of its origin is Solar wind or the electrons, protons and other particles that are suspended due to fusion in the atmosphere, are scattered in all directions. When these enter Earth’s atmosphere, they are attracted by the Earth’s magnetic field. The magnetic North and South poles change the direction and speed of these particles. These particles then collide with air molecules in the cold, thin upper atmosphere. This causes ionisation resulting in coloured lights forming an Aurora. They are most distinctive when earth’s magnetic activity is most disturbed or when solar activity is unusual.
Northern lights are seen 70 degree north latitude while Southern are seen 70 degree South latitude. They are usually seen at heights of 80km. Some might even reach 1000 km.
They are called Merry dancers because they move so fast. They appear in many shapes including curtain like, rays, fan shaped etc.
Some of the best places to view these miraculous phenomena are Hudson Bay in Canada, Northern Scotland, Southern Norway and Sweden. They can also be seen in South Australia and Sri Lanka where people regarded them as messages from Lord Buddha.