Composite clip showing how light pollution obscures the winter stars of the Northern Hemisphere. As the camera tilts up, it is revealed how bright the night sky actually is. The clip is a composite of three images: the horizon view was taken over a city with a ten second exposure time, the middle view was taken in the country with 180s exposure, and the zenith view was taken from the Roque de los Muchachos Observatory of La Palma, Canary Islands, with a 600s exposure. The dramatic effect of light pollution is clearly seen: in the city sky, the lights hide many of the stars, and even the brightest star in the sky, Sirius (just left of centre) is faint. From the country, far more stars are visible, and the prominent constellation Orion and the Milky Way above it are seen. From the mountains, the sky is perfectly dark and clear, and the Milky Way is prominent, running through the constellations Auriga and Perseus. Images taken from Germany, looking south.