Into the night

As the Moon and the Milky Way band fall below the horizon, the sky darkens and many more stars appear. The Unit Telescopes of ESO's Very Large Telescope (VLT) begin preparing for another night of observations of the sky above their home, the Paranal Observatory, which is located on Cerro Paranal, a 2600-metre high mountain south of Antofagasta, Chile. This site offers excellent viewing conditiions, experiencing about 300 clear nights per year. As the world's most advanced optical instrument, the VLT is well placed to make the most of these conditions to study the Universe in detail. The bright stripe visible crossing the sky from the horizon towards "up" is a natural phenomenon called zodiacal light, the reflection of sunlight from particles of ice and dust within the plane of the Solar System.