Spectacular auroral displays are seen in the atmosphere at Earth’s North and South poles and also from planets across the solar system. These dancing displays of lights indicate the interaction between the planet’s atmosphere and its magnetosphere (the mysterious region around a planet controlled by its magnetic field). In school, we typically learn about 3 states of matter (solid, liquid and gas), but actually the most common state of observed matter in the Universe is plasma (in which elements are split into ions and electrons). Magnetospheres are full of plasma and so by studying the Northern lights, we get irreplaceable insights into both the processes that govern the Universe and into the composition of the atmospheres of planets.

Jupiter produces the most powerful Northern Lights in the Solar System. The figure below shows the scale of Jupiter’s aurora compared with Earth’s. At times, Jupiter’s aurora can reach terawatt powers – surpassing power production by all of Human civilization. How the interaction of magnetic fields and plasma generates such extreme events remains unknown.