The aurora borealis is a colorful light display that occurs in high latitudes. High latitudes mean that it is found in regions near the North Pole. The aurora australis can be found in south polar regions. During these displays, the sky is lit up with patterns of green, blue and red lights.
Photo: Northern Lights or the Aurora Borealis (Creative Commons: Visit Finland).
Earth’s Magnetic Field
The earth is surrounded by a magnetic field. The earth’s interior contains molten iron around the planet’s core. As the molten material moves it creates electric currents. In turn, the electric currents create a magnetic field. Thus, the earth is like a giant magnet with north and south magnetic poles.
Night of the Northern Lights Video
Video: Night of the Northern Lights (source: YouTube).
The Solar Wind
The outer layer of the sun is called the corona. It has a temperature of over 1 million degrees Celsius. Particles within the corona are hot and moving at very high speeds. The gravity of the sun cannot hold on to these rapidly moving particles.
As a result, material from the corona streams outwards into space. It obtains speeds of up to 400 kilometers per second. This stream of charged particles creates the solar wind.
The solar wind travels across space and eventually reaches the earth. Most of the charged particles are deflected away from the earth by its magnetic field. However, the magnetic fields at the north and south poles are relatively weak.
As a result, some of the particles in the solar wind enters the earth’s atmosphere. Thus, charged particles from the sun collide with particles in the earth’s atmosphere. These collisions create lights of different colors. This produces the aurora borealis near the north pole. And, the aurora australis is created near the south pole.
Improving Your Reading and Thinking Skills
Think for a few moments. Try to recall the major ideas in this article. When you are done, click the box below for a list of main ideas.
How did you do? With practice, you should be able to identify many of the major ideas. You may even discover some important ideas that aren’t listed.
Northern Lights, Northern Lights Centre.