A.S.K. the auroral experts

Down on the ground, investigators from the School of Physics and Astronomy at the University of Southampton are using a special instrument which has three cameras looking at different electromagnetic ‘colours’ at the same time. It's called ASK, which stands for Auroral Structure and Kinetics. ASK looks at the smallest and fastest changes in the aurora, by measuring a region of the sky only 3 degrees in width, concentrated on a small circle in the ‘magnetic zenith’ which looks straight up along the Earth’s magnetic field.

Particles from the Sun spiral along the magnetic field lines, and lose energy when they collide with atmospheric oxygen and nitrogen. But this 'lost' energy doesn't simply vanish. It is converted partly into electromagnetic ‘light’ of different colours. The exact colour (or wavelength of the light) depends on how much energy the incoming particle started with, and what kind of atmospheric molecule or atom it hits.

The ASK cameras help to unravel this complicated process. One place where the ASK team does its research is Svalbard, an Arctic archipelago of Norwegian islands so far north that it’s dark all day in the winter months—ideal for sensitive optical measurements!