About ESO

The European Southern Observatory (ESO) enables scientists worldwide to discover the secrets of the Universe for the benefit of all. We design, build and operate world-class observatories on the ground. Astronomers worldwide use our telescopes to tackle exciting questions and spread the fascination of astronomy: How did the Universe come into existence? What are black holes? Are we alone in the Universe?

We are an intergovernmental organisation established in 1962 supported by 16 Member States (Austria, Belgium, Czechia, Denmark, Finland, France, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom), our host country Chile and strategic partners. ESO brings together over 750 staff from more than 30 countries, and countless more collaborators worldwide, all driven by the passion to build the best telescopes, serve the community and benefit society. We are honoured by the privilege to serve more than 22 000 users from over 130 different countries with excellent infrastructure, services, technologies and data.

All our telescopes are currently located in the Chilean Atacama Desert, a marvelous place with unique conditions to observe the sky. ESO operates three observing sites in Chile: La Silla, Paranal and Chajnantor. In addition, we are building “the world’s biggest eye on the sky”—ESO’s Extremely Large Telescope, located on Cerro Armazones, which will be operated as part of the Paranal Observatory.

At La Silla, ESO’s first observatory, we operate two of the most productive 4-metre-class telescopes in the world. Paranal is the home of ESO’s Very Large Telescope (VLT), one of the most advanced optical telescopes in the world, and its unique Very Large Telescope Interferometer (VLTI), as well as survey telescopes such as VISTA. In the future, Paranal will also host and operate the Cherenkov Telescope Array (CTA) South, the world’s largest and most sensitive gamma-ray observatory. Collaboratively with international partners, ESO operates ALMA on the Chajnantor plateau. ALMA allows scientists to investigate the Universe in the millimetre and submillimetre wavelength range of light.

ESO’s Headquarters are located in Garching, close to Munich in Germany. Here we conceive and develop cutting-edge telescope technologies together with our industry partners, and educate both children and adults in our visitor centre and planetarium, the ESO Supernova. Our central offices in Santiago are the hub from which we support the organisational operations in the country and collaborate with our host and partner country, Chile, its authorities, scientific community and society.

"An almost unique level of international cooperation is achieved at ESO, and everything is done by those who can do it best, irrespective of their country or institution. This spirit of excellence is an example for all Europe."

Mrs. Maria van der Hoeven, Former Minister of Education, Culture and Science, the Netherlands

ESO Headquarters


Sites in Chile