The European Space Agency has confirmed the principle of a new space thruster that may ultimately give much more thrust than today’s electric propulsion techniques. The concept is an ingenious one, inspired by the northern and southern aurorae, the glows in the sky that signal increased solar activity. “Essentially the concept exploits a natural phenomenon we see taking place in space,” says Dr Roger Walker of ESA’s Advanced Concepts Team. "When the solar wind, a ‘plasma’ of electrified gas released by the Sun, hits the magnetic field of the Earth, it creates a boundary consisting of two plasma layers. Each...