What are the Northern Lights?
Kids ASK! about Anything & Everything
I have always dreamed of seeing the Northern Lights, not quite a possibility from this part of the world. You need to be quite far up north to be able to see it or south if the Southern Lights are your cup of tea. So… what exactly are the Northern Lights, also known as the Aurora Borealis?
The Aurora is caused by collision of atoms and molecules from gases with charged particles that exist in the Earth’s magnetic field. The light of the Aurora falls in the range of blue, green and red and should not be mistaken for sunlight. The different light colours are a result of the nature of the atmosphere at different altitudes as well as the slower speed at which oxygen emits light. Oxygen takes nearly a second to release green light and up to two minutes to release red light. However, if the oxygen molecule collides with another molecule, the energy from the initial collision with the charged particle is passed and no light is emitted. Combinations of gases present also give rise to different coloured light displays.
At lower altitudes, the atmosphere is a lot more dense and a high density means the oxygen particles are not given a chance to emit light due to the higher possibility of colliding with another molecule and the ones likely to be responsible for the emission of light would be nitrogen, which gives the Aurora its pink. Therefore, when we look at a whole Aurora light display, the colours higher up would be from oxygen which is red and green, the middle greenish and white (from a combination of oxygen and nitrogen) and at the lower edge, pinkish.
The Aurora is not still. It moves, like a soundless sheet of light across the sky. The movement is caused by the Earth’s magnetic field being compressed by solar wind (streams of charged particles from the sun) forming distortions in the magnetic field. These distortions are responsible for the patterns and movements of the Aurora.
By the way, the Southern Lights are known as Aurora Australis.
Reference:
1. Akasofu, Dr. S. (2003). Frequently asked questions about the aurora. Retrieved July 21, 2008, from Asahi Aurora Web site: http://asahi-classroom.gi.alaska.edu/aurfaq.htm
2. The Aurora Australis - Southern Lights. Retrieved July 22, 2008, from Antarctic Connection Web site: http://www.antarcticconnection.com/ antarctic/weather/aurora.shtml
If you want to read more about the Northern Lights, here are books you can check out at our libraries.
For Children:
![]()
Image retrieved from www.amazon.com
Northern lights by Deborah Underwood
Publisher: San Diego, Calif. : KidHaven Press, c2004
Call Number: J English 538 UND
![]()
Image retrieved from www.bn.com
Earth by Elaine Landau
Publisher: New York : Children’s Press, 2008
Call Number: J English 525 LAN
![]()
Image retrieved from www.amazon.ca
Earth’s journey through space by Trudy E. Bell
Publisher: New York, N.Y. : Chelsea House Publishers, c2008
Call Number: Y English 525 BEL
All websites are last accessed on 21 July 2008. Please refer to the terms and conditions on the homepages for use.
For the availability of the above book titles, please check the library catalogue.
Answered by Felicia Chan,
Librarian, Children’s Services
















