ESO (European Southern Observatory) 

ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. ESO provides state-of-the-art research facilities to astronomers and is supported by Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. Several other countries have expressed an interest in membership.

ESO's main mission, laid down in the 1962 intergovernmental Convention, is to provide state-of-the-art research facilities to astronomers and astrophysicists, allowing them to conduct front-line science in the best conditions.

By building and operating a suite of the world's most powerful ground-based astronomical telescopes enabling important scientific discoveries, ESO offers numerous possibilities for technology spin-off and transfer, together with high technology contract opportunities and is a dramatic showcase for European industry.

ESO is presently building the 39-metre Extremely Large Telescope, the ELT which will become "the world's biggest eye on the sky".

ESO Headquarters (comprising the scientific, technical and administrative centre of the organisation) are located in Garching near Munich, Germany. In Chile, ESO operates the Vitacura centre as well as three unique observing sites with a soon coming 4th one:

1. La Silla Observatory (ESO's first site), 600 km north of Santiago at 2400 m altitude, is equipped with several medium-sized optical telescopes, among others the 3.5-metre New Technolgy Telescope (NTT).
2. The Very Large Telescope (VLT) on Paranal, a 2600 m high mountain south of Antofagasta, is the flagship facility of European astronomy. It is an array of 4 telescopes, each with a main mirror of 8.2 metres in diameter, with the option to use it as a giant optical interferometer (VLTI) by combining the light from several telescopes, including one or more of the 4 moveable 1.8-metre Auxilliary telescopes. The observatory is operational since 1999.
3. The Atacama Large Millmeter/submilllimeter Array (ALMA), operating since 2011 on the Chajnantor plateau at 5000 m elevation near San Pedro de Atacama, comprises an array of 66 giant 12-metre and 7-metre diameter antennas. This observatory is a partnership between Europe (ESO), Japan and North America in cooperation with Chile.
4. As a next step, ESO is building a 39,3-metre Extremely Large optical – near infrared Telescope (ELT ) on Cerro Armazones, some 130 kilometres south of the town of Antofagasta and about 20 kilometres from Cerro Paranal. This "biggest eye on the sky" should see its first light in 2025.

All Belgian research teams active in the field of astronomy and astrophysics are represented in the Belgian National ESO-Committee (BNEC). It serves as an information and coordination platform in order to optimise the Belgian participation in ESO activities.