Welcome to the official page of the European Southern Observatory, the world's most productive ground-based observatory!
ESO, the European Southern Observatory, provides state-of-the-art research facilities to European astronomers and astrophysicists. It is an intergovernmental organisation with 15 member-states.
ESO carries out an ambitious programme focused on the design, construction and operation of even more powerful observing facilities.
ESO has enabled the first picture of a planet around another star, measured the distance to the most remote object ever found, found the largest solar system yet around another star and contributed to the discovery of the Universe’s accelerating expansion due to the elusive dark energy.