Photo: Under the celestial arch
The European Southern Observatory (ESO) is the pre-eminent intergovernmental science and technology organisation in astronomy. It carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities for astronomy, in order to enable important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research.
ESO operates three unique world-class observing sites in the Atacama Desert region of Chile: La Silla, Paranal and Chajnantor. ESO’s first site is at La Silla, a 2400 m high mountain 600 km north of Santiago de Chile. It is equipped with several optical telescopes with mirror diameters of up to 3.6 metres. The 3.5-metre New Technology Telescope broke new ground for telescope engineering and design and was the first in the world to have a computer-controlled main mirror, a technology developed at ESO and now applied to most of the world’s current large telescopes. The ESO 3.6-metre telescope is now home to the world’s foremost extrasolar planet hunter: HARPS (High Accuracy Radial velocity Planet Searcher), a spectrograph with unrivalled precision.
While La Silla remains at the forefront of astronomy, and is still the second most scientifically productive ground-based astronomical observatory, the 2600 m high Paranal site — home to the Very Large Telescope array (VLT) — is the flagship facility of European astronomy. Paranal is situated about 130 km south of Antofagasta in Chile, 12 km inland from the Pacific coast, in one of the driest areas of the world. Scientific operations began at Paranal in 1999 and have resulted in many extremely successful research programmes.
The next step beyond the VLT is to build the Extremely Large Telescope (ELT) with a 39-metre primary mirror. The ELT will be “the world’s biggest eye on the sky” — the largest optical/near-infrared telescope in the world. The ELT will address many of the most pressing unsolved questions in astronomy. It may, eventually, revolutionise our perception of the Universe, much as Galileo’s telescope did 400 years ago. The green light for ELT construction was given in late 2014, with first light planned for 2024.
The ESO Headquarters are located in Garching, near Munich, Germany. This is the scientific, technical and administrative centre of ESO where technical development programmes are carried out to provide the observatories with the most advanced instruments.