The European Southern Observatory (ESO), of which France is a member, has instruments on three sites in northern Chile, where the climate is particularly suitable for astronomy. The Very Large Telescope (VLT) is on the Paranal site, with four 8 m telescopes that can work together or separately, as well as four 1.8 m telescopes. The entire set of telescopes can operate as an interferometer enabling observations to be made with a much better resolution than can be done with single telescopes. The European Southern Observatory is the largest observatory in the world. A giant, 39-metre-diameter telescope, the E-ELT, currently under construction on another, nearby site, and is scheduled to come on line in 2024.
