The Northern Lights have been witnessed by the naked eye in the UK as far south as Dorset in the last few weeks. Usually spotted in regions nearer the North Pole (and occasionally Scotland), it has been a rare spectacle to see in the Southern parts of the country.

Also known as the Aurora Borealis, the Northern Lights are caused by geomagnetic storms. Solar flares are intense explosions which emit charged particles. These may eventually collide with the earth’s atmosphere where they are either deflected or captured. Once (/if) captured by the magnetic field of the earth, the charged particles will accelerate towards the poles. The Northern Lights are the result of the collisions between these charged particles and the molecules in the Earth’s atmosphere.

 

The magnificent colours of the Auroras vary, not only depending on which gas particles collide, but also the altitudes, creating a unique pattern of colourful luminescence.

A green colour is produced at low altitudes (<150 miles) when excited oxygen molecules collide with charged particles.

A red colour is produced at high altitudes (>150 miles) when excited oxygen atoms collide with the charged particles.

A blue colour is produced below 60 miles when ionised nitrogen molecules collide with the charged particles.

A purple colour is produced above 60 miles when ionised nitrogen molecules collide with the charged particles.

 

Didn’t get to catch the phenomenon?

 Not to worry, we have some good news for you! Scientists predict that we may be able to see more of the Northern Lights in the near future. This is because the sun goes through an 11-year solar cycle, and is currently at its height of solar activity, known as the “solar maximum.” Scientists say this means we can expect more frequent and strong geomagnetic storms over the next year, bringing more beautiful displays of the auroras.