Man-made aurorae

Human space exploration and satellite survival are compromised by the variable radiation levels encountered in near-earth space. Given our society’s ever-increasing reliance on satellite systems, there is an urgent need to protect these costly orbital assets. Extending their lifetimes makes good economic sense. Research into 'radiation belt remediation' focuses on actively injecting radio waves into the near-earth space environment, to encourage high energy radiation to fall harmlessly into the earth’s upper atmosphere.

Radio waves travelling through a plasma can accelerate electrons to high energies. This is partly how the aurorae are created naturally in the ionosphere in the first place. However, the interactions are extremely complex. They depend on many factors, such as the radio wave frequency and power, the electron’s initial energy, and the magnetic field strength and direction.

At the Department of Communication Systems, Lancaster University, the Space Plasma Environment and Radio Science group is working on an extraordinary project: to beam narrow jets of radio energy into the ionosphere and create controllable artificial aurorae. These experiments use high-power radio transmitters belonging to the US Air Force Research Lab in Alaska, the EISCAT Radar Association in Norway and the British-built SPEAR facility on Svalbard, designed and operated by the University of Leicester.

The 'glow' generated by these experiments is extremely faint, and only visible with special instruments. Even so, the controllable nature of the beams delivers a great opportunity to understand the mechanisms that trigger natural aurorae. One day we might even be able to dampen the effects of serious space weather storms, using similar techniques. It's a far-off dream, which nevertheless promises impressive scientific data in the meantime.