The Aurora

Do the aurorae affect us?

There are three ways in which the aurorae can cause problems...

1. Radio communications

High up in the Earth's atmosphere is a layer called the "ionosphere". If you send a radio wave up in the air, it will bounce off this layer, like light reflecting off a mirror. On realising this, scientists were able to send radio signals from one side of the Earth to the other by just firing them into the air and letting them bounce along until they arrive!

.... or with an ionosphere ...

Diagrams courtesy HAARP, Alaska

Now you know how radio waves travel, you'll realise that if the ionosphere is disturbed in some way, it can interfere with the radio signals you receive.

When an aurora occurs, this is exactly what happens, and so it's important to warn people when they are likely to take place.

This cartoon shows ways that the Sun can affect us, causing problems with power cables, TV, satellite etc. Courtesy of the British Antarctic Survey

2. Electricity

Aurorae are bright because they give out a lot of visible light, but they also give out a lot of radio waves . These waves can be picked up by electric power lines and cause some BIG problems....A few years ago in Canada, so much power was dumped into the Canadian electric grid, that it began to overload and burn out!

3. Falling spacecraft

There can also be problems for spacecraft - they can be badly damaged by high energy particles from solar eruptions. The Skylab space station came down with a bump after too many encounters with aurorae!

Hopefully now you can see that aurorae are more than just a pretty face!