Faculty of Science and Technology

The northern lights: charged particles from the sun interacting with the Earth's atmosphere

Pupils from Bolton School were given a fascinating lecture on the Northern Lights by Dr Jim Wild from Lancaster University.

The presentation to the Sixth Form boys and girls was the second annual lecture organised by the University through a partnership with Bolton School, which is one of the largest independent schools in the country.

Dr Wild is a lecturer with the Space Plasma Environment and Radio Science Group at the Department of Communication Systems at InfoLab21. His research investigates the physics behind the aurora borealis, the impact of space weather on human technology and the interaction between the Martian atmosphere and the interplanetary environment.

He spoke of the wonder of the Northern Lights and how it is possible for the night sky to turn from pitch black to swathes of green and red light arcing or appearing as a rippling curtain.

The dancing lights are visible, to varying degrees, from the ice-caps to the Mediterranean but it is over the Arctic Circle (and Antarctica) where they can be seen most often. In such areas legends abound explaining what they are - anything from the gods playing football to the spirits of young women who died before they got married. Dr Wild explained how the lights have influenced art and culture, citing Philip Pullman's book The Northern Lights as a recent example.

Explaining the physics behind the lights, Dr Wild said the sun throws out billions of tonnes of matter and light each day, which become a solar wind of electrically charged particles which would hit the earth if it were not for the natural occurring protective magnetic field around the world. However, these fields are weaker at the very northern and southern tips of the world - these are known as the magnetic poles. Some of the charged particles break through the field at the poles and collide with gaseous particles in the earth's atmosphere. Collisions with different gases cause different light formations.

Fri 16 July 2010

Associated Links

• Dr Jim Wild - Jim Wild's personal website has details of his research and public lectures
• Space Plasma Environment And Radio Science (SPEARS) Group - combining research of the Earth's space environment, through observations of high-latitude phenomena, with innovative design and operation of ground-based space research facilities