ESO 3.6 m Telescope, Reflecting infrared telescope in La Silla, Chile

The ESO 3.6 m Telescope is an optical reflecting telescope at La Silla Observatory in Chile, with a clear aperture of about 3.6 metres and a collecting area of 8.6 square metres. It saw first light in 1976 and entered full operations in 1977. Its main mirror is made of fused silica, and the telescope hosts the HARPS and NIRPS spectrographs.

The telescope began operating in 1977 and was one of the largest optical instruments in the Southern Hemisphere. A major modernization took place in 1999, significantly improving its capabilities.

The observatory attracts researchers from different European countries who work together on astronomical projects here. This collaboration has led to many scientific publications that are recognized around the world.

The telescope sits at La Silla Observatory, about 600 km north of Santiago and roughly 2,400 m above sea level, reached by road from the Elqui valley. Access to the telescope itself is arranged through ESO, so check visiting options with the observatory before travelling. Clear skies dominate, but nights are cold and the altitude demands a slow first day.

The instrument is equipped with the HARPS spectrograph, which leads the world in discovering exoplanets. This tool has contributed to finding hundreds of planets outside our solar system through radial velocity measurements.