Paranal Observatory
Cerro Paranal (main-peak) with the VLT and VST
Cerro Paranal is the observatory's main-peak where the VLT (four units) and VST (right) are located
Alternative namesESO's Paranal Observatory Edit this at Wikidata
OrganizationEuropean Southern Observatory
Observatory code 309 Edit this on Wikidata
LocationCerro Paranal, Chile
Coordinates24°37′38″S 70°24′15″W / 24.62722°S 70.40417°W / -24.62722; -70.40417
Altitude2,635 metres (8,645 ft)
Established1 April 1999 Edit this on Wikidata
Very Large Telescope8.2 m reflector (×4)
VLT Auxiliary Telescope1.8 m reflector (×4)
VISTA Telescope4.0 m reflector
VLT Survey Telescope2.6 m reflector
Next-Generation Transit Survey0.2 m array (×12)
Paranal Observatory is located in Chile
Paranal Observatory
Location of Paranal Observatory
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Paranal Observatory is an astronomical observatory operated by the European Southern Observatory (ESO). It is located in the Atacama Desert of Northern Chile on Cerro Paranal at 2,635 m (8,645 ft) altitude, 120 km (70 mi) south of Antofagasta. By total light-collecting area, it is the largest optical-infrared observatory in the Southern Hemisphere; worldwide, it is second to the Mauna Kea Observatory on Hawaii.

The Very Large Telescope (VLT), the largest telescope on Paranal, is composed of four separate 8.2 m (320 in) telescopes. In addition, the four main telescopes can be used simultaneously for extra light gathering capacity, and for interferometry. Four auxiliary telescopes of 1.8 m (71 in) each are also part of the VLTI to make it available when the main telescopes are being used for other projects. The site also houses two survey telescopes with wide fields of view, the 4.0 m (160 in) VISTA and the 2.6 m (100 in) VLT Survey Telescope for surveying large areas of the sky; and two arrays of small telescopes called NGTS and SPECULOOS which are dedicated to searching for exoplanets.

Two major new facilities are under construction nearby: the southern part of the Cherenkov Telescope Array gamma-ray telescope (not owned by ESO) will be sited in the grounds 10 km south-east of Paranal; while ESO's future E-ELT will be on the nearby peak of Cerro Armazones 20 km east of Paranal, and will share some of the base facilities.


Aerial view

The four VLTs and ATs and the VST on the main peak and VISTA in the background
The four VLTs and ATs and the VST on the main peak and VISTA in the background

From an aerial view of the Paranal Observatory, the four large units of the VLT with their four small, dome-shaped auxiliary telescopes can be clearly seen. The Survey Telescope, VST, is immediately adjacent to the VLT and seen in between two of its units, while VISTA is located on a secondary peak, some 1,500 m away in the background (see image).

Very Large Telescope

Main article: Very Large Telescope

The Very Large Telescope (VLT) consists of four 8.2-metre telescopes operating in the visible and infrared. These telescopes, along with four smaller auxiliary telescopes, are also combined to operate as an optical interferometer on certain nights of the year. All of the 8.2-metre telescopes have adaptive optics and a full suite of instruments. The primary mirrors of the main telescopes are 8.2 meters in diameter but, in practice, the pupil of the telescopes is defined by the secondary mirrors, effectively limiting the usable diameter to 8.0 meters.[1]

VISTA Survey Telescope

Main article: VISTA (telescope)

VISTA is the Visible & Infrared Survey Telescope for Astronomy, a 4.0-metre telescope with a wide field of view, focusing on infrared surveys of the sky. It was built close to ESO's VLT by a consortium of 18 universities from the United Kingdom, led by Queen Mary University of London. VISTA was handed over to the European Southern Observatory in December 2009.

VLT Survey Telescope (VST)

Main article: VLT Survey Telescope

The VLT Survey Telescope or VST is a 2.6-metre telescope with a wide field imager intended to aid the four Very Large Telescope (VLTs) in their scientific aims.

Next-Generation Transit Survey (NGTS)

Main article: Next-Generation Transit Survey

The Next-Generation Transit Survey (NGTS) is an exoplanet-survey facility located a few kilometers from the main peak. It consists of an array of twelve 0.2-meter robotic telescopes with a very large field of view of 96 square degrees or several hundred times the area of the full moon. The survey aims to discover numerous super-Earths and Neptune-sized planets around nearby stars, using transit photometry to detect them. NGTS is managed by a partnership of seven academic institutions from Chile, Germany, Switzerland and the United Kingdom and its design is based on the SuperWASP project. Science operations began in early 2015.[2][3]

SPECULOOS Southern Observatory (SSO)

Main article: SPECULOOS

The SPECULOOS Southern Observatory (SSO) consists out of four telescopes, called Europa, Io, Callisto, and Ganymede. ESO hosts the 1-meter telescopes and the project is led by the University of Liège. The project aims to find exoplanets around ultracool dwarf stars and brown dwarfs. The project builds on the success of the TRAPPIST telescope. The telescopes are located next to the NGTS.[4]

Other buildings

Further information: ESO Hotel

As well as the telescopes, control buildings and maintenance facilities, Paranal has a Residencia which provides accommodation for staff and visitors. This is located 200 m lower and 3 km from the telescopes. It is built half into the mountain with the concrete coloured to blend into the landscape. It has gym facilities, a swimming pool, a restaurant and two gardens. The construction was decorated by the Chilean architect Paula Gutiérrez Erlandsen, Marchioness of la Pica.[5]


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Popular culture and other uses

To illustrate the isolation of the Paranal Observatory from the lights of civilization, it is located 38 kilometres (24 mi) in straight-line distance north of Paposo, population 259, the nearest community to the observatory.[8]

The VLT hotel, the Residencia, served as a backdrop for part of the 2008 James Bond film Quantum of Solace.

The observatory's facilities were used to stage the Pacific Alliance's fourth summit in June 2012, formally launching the organization.

On 14 March 2013, Frederik, Crown Prince of Denmark, accompanied by his wife, Princess Mary, visited ESO's Paranal Observatory, as part of an official visit to Chile. Their tour of Paranal's astronomical facilities was led by ESO's Director General, Tim de Zeeuw.

The visit of the Prince and Princess of Asturias to the observatory
The Crown Prince of Denmark visits the observatory.

See also


  1. ^ "Very Large Telescope: Requirements for Scientific Instruments on the VLT Unit Telescopes" (PDF). Retrieved 4 January 2024.
  2. ^ "New Exoplanet-hunting Telescopes on Paranal". European Southern Observatory. Retrieved 22 May 2015.
  3. ^ "About NGTS". Next Generation Transit Survey. Archived from the original on 31 May 2015. Retrieved 3 September 2015.
  4. ^ "Paranal map and safety". Retrieved 2020-03-10.
  5. ^ "Proyectos—Hoteles". Paula Gutiérrez Erlandsen. Retrieved 3 September 2015.
  6. ^ "Tour the Skies". Retrieved 27 January 2020.
  7. ^ "Colour in the air". Retrieved 11 February 2020.
  8. ^ Google Earth