Going Underground

Difficult as it may be, given the view above, when at Paranal Observatory make sure you keep your eyes on the ground — or you might just take a tumble. This Picture of the Week shows an entrance to one of the laboratories beneath the ESO’s Very Large Telescope (VLT) platform, used to carry out an astronomical technique known as interferometry.

The VLT is composed of four large Unit Telescopes and four smaller Auxiliary Telescopes (ATs) — two of the latter are imaged here. Astronomers can use various combinations of these telescopes to pool their observing power and, using the technique of interferometry, achieve imaging resolutions much greater than is possible by any of them alone. This clever trick is performed beneath the platform in a network of tunnels filled with specialised equipment to direct and process the light gathered by the telescopes.

Paranal Observatory is located in northern Chile atop its mountain namesake, Cerro Paranal. The remote location and high altitude here provide ideal conditions for the kinds of astronomy undertaken at the facility, whether that be peering into star nurseries in the Milky Way or observing the ferociously active cores of distant galaxies.