Space Physics

Space physics is not that hard. If I get it (or at least some of it…) most of us can.

Really? Well, let’s have a go. We looked at the Earth geomagnetic field last week. How does it look like from outer space? Like a huge pumpkin. Imagine the Earth is an orange with a magnet (yes, North pole pointing South) in the middle of it. Then put it in the centre of the pumpkin. This gives you a fair idea of what the field lines look like. Or at least what they would look like if we switched off the Sun for a while.

The Sun constantly bombards us with high-speed electrons and ions. This is called the solar wind. This can be nasty. Get an overdose of it and your DNA can change. Besides, it could blow away our atmosphere, which is what happened to Mars ages ago. Why? Because Mars does not have a magnetic field.

The Earth magnetic field deflects the solar wind. The pumpkin gets a bit distorted in the process but who cares. Most of the wind goes harmlessly past us, some of it gets trapped in banana shaped regions called the radiation belts. Sometimes the Sun sends more wind. That is a magnetic storm. The bananas overflow and some particles get thrown into the auroral rings. And yes, we get beautiful auroras! Macquarie Island sits bang smack under the Southern auroral ring. In-between the clouds this is where I saw the most beautiful auroras.