The Northern Lights (Aurora)

The Northern Lights, also known as polar auroras, are natural light displays observed in the skies over the Arctic and Antarctic regions, caused by the interaction between the Earth’s magnetic field and charged particles from the Sun. In northern latitudes, these displays are known as the Northern Lights or ‘Aurora Borealis’. In the southern latitudes, the formation of the southern polar lights, known as the “Aurora Australis”, shares almost the same characteristics as the northern lights.

Most auroras form within a band known as the “auroral zone”. This band is typically found at latitudes between 3° and 6°. The lights are most clearly visible at night against a dark sky. The region currently displaying an aurora is known as the “auroral oval”, a band that shifts towards the night side of the Earth driven by the solar wind.

Auroras display dynamic patterns of bright lights appearing as veils, rays, spirals or dynamic ripples that cover the entire sky. They also occur as scattered patches or arcs extending towards the poles of the auroral zone. When a geomagnetic storm temporarily expands the auroral oval, they can occasionally be seen at latitudes below the auroral region. Major geomagnetic storms, however, are most commonly observed during the peak of the 11-year solar cycle or in the three years following the peak. Most planets in the Solar System, some natural satellites, brown dwarfs and even comets also host auroras.

The colours of auroras vary depending on altitude. At higher altitudes, the colour is predominantly red due to oxygen; as one descends, the colours change. Auroras are generally red, green or blue. Yellow, pink and, in rare cases, orange and gold may also be seen. In addition to these, it is possible for different colour combinations of unimaginable beauty to emerge.

The earliest known depiction of the aurora may be found in Cro-Magnon cave paintings in northern Spain, dating back to around 30,000 BC. The earliest known written record of the aurora, however, is found in a Chinese legend dating from around 2600 BC. The first studies of aurora observations were conducted in 1949 by the University of Saskatchewan using the SCR-270 radar.

The Aurora Australis can be seen from high southern latitudes in Antarctica, the Southern Cone, South Africa and Australia, and under exceptional conditions as far north as Uruguay. The Aurora Borealis can be seen from regions or countries around the North Pole, such as Alaska, Canada, Iceland, Greenland, the Faroe Islands, Scandinavia, Scotland and Russia. In rare instances, they can even be seen as far south as the Mediterranean and the southern states of the USA. During the ‘Carrington Event’ – the largest geomagnetic storm ever observed – auroras were even seen in tropical regions.

If you wish to experience one of the most special moments of your life, you can visit the places where the colourful Northern Lights are best seen.