This panoramic photograph captures the ESO Very Large Telescope (VLT) against a beautiful twilight on Cerro Paranal. The enclosures of the VLT stand out in the picture as the telescopes in them are readied for a night of studying the Universe. The VLT is the world’s most powerful advanced optical telescope, consisting of four Unit Telescopes with primary mirrors 8.2 metres in diameter and four movable 1.8-metre Auxiliary Telescopes (ATs), which can be seen in the left corner of the image.

The telescopes can also work together as a single giant telescope, the ESO Very Large Telescope Interferometer (VLTI), which allows astronomers to observe the finest possible detail. This configuration is only used for a limited number of nights per year. Most of the time, the 8.2-metre Unit Telescopes are used individually.

Over the past 13 years, the VLT has had a huge impact on observational astronomy. With the advent of the VLT, the European astronomical community has experienced a new age of discoveries, most notably, the tracking of the stars orbiting the Milky Way’s central black hole and the first image of an extrasolar planet, which are two of the top three of ESO’s Top 10 Astronomical Discoveries.

The VLT’s four Unit Telescopes are named after celestial objects in Mapuche, which is an ancient native language of the indigenous people of Chile and Argentina. From left to right, we have Antu (UT1; the Sun), Kueyen (UT2; the Moon), Melipal (UT3; the Southern Cross) and Yepun (UT4; Venus).