Auroras unlock the physics of energetic processes in space

A close study of auroras has revealed new ways of understanding the physics of explosive energy releases in space, according to new UCL-led research. Auroras are an incredible light show caused by electrically charged particles in near-Earth space spiralling down Earth's magnetic field and colliding with gases in the atmosphere, causing them to glow. They are also a tell-tale sign of physical processes in space, acting like TV screens by showing what happens millions of kilometres away from Earth where our planet's magnetic field stretches into a long tail facing away from the Sun. For the study, published today , the team from UCL and the University of Reading remotely observed rapidly evolving aurora to understand the physics behind why, when and how energy is released as the source of the aurora explosively reconfigures. "Somewhere in the huge volume of space into which Earth's magnetosphere stretches, this energy release occurs via instability which is really hard to pinpoint. They cause substorms whereby charged particles surf into the Earth's atmosphere on electromagnetic waves, releasing large amounts of energy and lighting up the aurora" explained study author Dr Jonathan Rae (UCL Space & Climate Physics). "By studying auroras closely, we can map back to where in space the instabilities are occurring and study the physics that cause them.