Take a peek inside

Ever wondered what the inside of the Very Large Telescope (VLT) looks like? Wonder no more! In this Picture of the Week we invite you into the dome of the Unit Telescope 3 (Melipal) to take a closer look.

With this fisheye view of the internal structure of Melipal, the whole telescope and its dome is caught on camera. The main mirror, measuring an impressive 8.2 metres in diameter, weighs in at more than 23 tonnes. To support the mirror and other components and make sure they’re kept steady during observations, a sturdy steel frame is required.

The whole movable structure of the telescope weighs about 430 tonnes, like a ​​a fully loaded jumbo jet! Yet, it can be smoothly moved by hand because it’s perfectly balanced and rests on oil-film bearings. The dome containing the telescope is a sturdy steel enclosure; it not only provides protection from the harsh Chilean Atacama Desert, but also controls the temperature and air flow to minimise turbulence inside the dome that could degrade the images.