People have been inspired by the colourful shifting lights of the Aurora Borealis and Aurora Australis for thousands of years, with modern-day adventurers travelling to 'aurora hotspots' in the hope of getting a glimpse of them. Bryony Lanigan, Astronomer at Royal Observatory Greenwich, brings together many fields of research, from astronomy and solar physics to geology and atomic physics, as she explores the science behind these magical displays. Along the way, we take a whistle-stop tour through the electromagnetic spectrum, learn some elementary atomic physics, meet a mysterious phenomenon with a decidedly un-mysterious name and get to grips with the fundamental role of magnets (very, very large ones) in auroral activity. Lanigan doesn't just stay on Earth, though - she reveals that the spectacle has been observed elsewhere in our Solar System, too! Of course, nothing is simple and aurorae on other planets often confound the explanations we've worked so hard to come up with.