In the two decades since the first confirmed exoplanet detection, well over a thousand planets have been discovered, many of which differ greatly to those in our solar system. Examples of such exotic planets are super-Earths, 'hot Jupiters' orbiting close to their star, and massive planets many times Jupiter's mass orbiting at much further out. A property of such exotic exoplanets that may prove to provide a novel method of detection and characterisation, is the magnetic field. The planets in the solar system which have magnetic fields exhibit auroral emission (the northern lights) and associated powerful radio waves, and it is possible to envisage exotic planets whose auroral emissions are so bright that they may be detectable across interstellar distances. In this talk we discuss the physics of these alien auroras, and what they may reveal about the planets.