Northern Lights

The first thing that comes to my mind when I think of northern Canada (besides snow) is the northern lights: the amazing light show created by the sun.

Of course, the northern lights can only be seen when the sky is dark and since the sun doesn’t set  in the summer, it is only visible from September to March.

The lights also depend on activity on the sun. They are powered by particles that are thrown out by the sun and solar flares tend to make the lights brigher. These particles hit atoms in the earth’s atmosphere which then light up. The colour depends on what gases are being hit by the particles. Oxygen tends to glow red or green, and nitrogen red or blue.

This activity produces enormous amounts of electricity. In fact, they produce 1000 times what the largest generator in the world can produce.

Sometimes this can interfere with things on the earth, confusing radio signals, making compasses point the wrong way, and sometimes overloading power and telephone lines with electrical current.

The lights occur in the thermosphere around earth. The lowest edge of the curtain of light is around 96 km above the earth (10 times higher than most airplanes fly) and it can reach up 321 km.

When the northern lights or aurora borealis is happening in the north, the same show is happening in the far south and is called the aurora australis.

Watch the northern lights in a real-time film by Alexis Coram.

Activity: Make some northern light art using chalk and black paper.

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