European Southern Observatory

Observatory operated jointly by Belgium, Denmark, Finland, France, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland, and the United Kingdom, with headquarters near Munich, Germany. Its telescopes are at three locations in Chile. A 3.6-m/142-in reflector, opened in 1976, and the 3.5-m/138-in New Technology Telescope, opened in 1989, are at La Silla. The Very Large Telescope (VLT) is on Mount Paranal and consists of four 8-m/26-ft reflectors mounted independently but capable of working in combination. The ‘first light’ of the first 8-m/26-ft telescope occurred in May 1998. The VLT became fully operational in 2001. The APEX submillimetre radio telescope and ALMA, an array of 64 antennae, are located at Llano de Chajnantor. The ESO receives more than 1,300 proposals annually to use its telescopes.

The VLT can produce images three times sharper than the Hubble Space Telescope, as it has active (form-changing) mirrors that compensate for the distortions of the Earth's atmosphere.