• Question: What did you learn whilst you were studying the Northern Lights?

    Asked by RandomKitty to Miriam on 13 Nov 2018.
    • Photo: Miriam Hogg

      Miriam Hogg answered on 13 Nov 2018:

      We learnt about how they occurred.
      The Sun gives off lots of excited particles (which are quite dangerous) which stream out in every direction. When they come to Earth they hit our magnetic field which surrounds us. They put a lot of pressure on the field and eventually the outer layers snap and the particles stream down the field lines and hit the poles of Earth (which is why the lights are always at the north and south pole). They hit the atmosphere and throw off their energy as light which is why we see the northern lights.

      Interestingly we get different colours depending on how high they are in the atmosphere and what element they hit! Typically, when the particles collide with oxygen, yellow and green are produced. Interactions with nitrogen produce red, violet, and occasionally blue.

      So if you think about it you can get different colours based on different elements, so you can tell what an atmosphere is made of by looking at its Northern or Southern Lights! (we’ve done this with Jupiter and Saturn)