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Aurorae
describe aurorae and recall from where on Earth they are most likely to be observed
explain how aurorae are caused.
The aurora borealis are otherwise known as the northern lights. It is now understood that they are
caused by charged particles from the solar wind striking the atmosphere and making the molecules
they hit emit light. The aurora australis occurs close to the south pole.
The Sun emits a huge amount of charged particles all the time, this is the solar wind. These particles
take about 2 days to reach Earth. When they do they are deflected by the Earth's magnetic field and
many particles enter the atmosphere at the poles. Aurorae are usually just observed at extreme
northern or southern latitudes, e.g. in countries like Alaska and Antartica.
pic NASA