Step outside on a clear night almost anywhere in Britain and look up. For roughly a third of the global population, the Milky Way is simply gone, permanently bleached out by the orange glow of our own making. But light pollution is no longer just an astronomer's complaint, it has become a public health crisis, an ecological emergency, and a regulatory blind spot all at once. The Royal Astronomical Society has had enough and, following a major conference on light pollution held earlier this year, the RAS is now calling for artificial light at night to be legally recognised as a pollutant placing it alongside air, water, and plastic in the hierarchy of environmental threats requiring urgent legislation. World map of light pollution. False colours show intensities of skyglow from artificial light sources around the world (Credit : David Lorenz) The case for doing so is compelling.…