Soundscape: Paranal Auxiliary Telescopes (ATs) dome closing

Like a very slow-motion Pacman pointing to the sky, the Auxiliary Telescopes (ATs) closes its round enclosure after a day test previous to a night of observations. Although the closing sound of this dome is quite discreet, this audio also captures sounds of the AT's electronic cabinets, liquid cooling system and air-conditioning units.

There are four ATs at the Very Large Telescope (VLT) platform, each of them is a 1.8-m diameter telescope that feed light into the Very Large Telescope Interferometer at Paranal observatory. ATs can be moved between 30 different stations across around the VLT platform and are self-contained.