Member state flags

ESO was founded by Belgium, Germany, France, the Netherlands and Sweden. Since 1962, many other countries have joined: Denmark (1967), Switzerland and Italy (1982), Portugal (2001), the United Kingdom (2002), Finland, Spain and the Czech Republic (2007), Austria (2009), Poland (2015) and Brazil (pending ratification by the Brazilian government). As the host nation, Chile is of course also part of ESO – Chilean astronomers have preferential access to all ESO telescopes.