The European Southern Observatory (ESO) is an intergovernmental research organisation for astronomy which is supported by fifteen countries. Established in 1962 it operates some of the most technologically advanced telescopes in the world. Their mission is to provide state-of-the-art research facilities to astronomers and astrophysicists, allowing them to conduct front-line science in the best conditions.

Have you ever heard of the European Southern Observatory? Well, if you have ever seen James Bond  movie Quantum of Solace then you will have seen a glimpse of this amazing facility! If it’s good enough for Bond, then it must be quite a place, so I decided to see what exactly it is, where it is and what work is done there!

When I first heard about the ESO, I thought it was similar to our very own Armagh Observatory and based in one place. However on reading that their headquarters were in Germany imagine my surprise to learn that their observing areas where based in Chile. But wait, there is more! They have three huge separate observing sites in La Silla, Paranal and Chajnantor.

Firstly let’s looks at La Silla which is situated on a 2400 metre high mountain 600 km north of Santiago de Chile. It was originally named the Cinchado, however it was renamed La Silla which translates to “the saddle” after its saddle-like shape. It boasts a 3.5-metre “New Technology Telescope” which was the first telescope in the world to have a computer-controlled main mirror, a technology which was developed at the ESO and now applied to most of the world’s current large telescopes

image of La Silla

Amazing telescopes at the La Silla site. (Image credit: ESO)


La Silla has had many “firsts” in terms of scientific discoveries. The HARPS spectrograph is the undisputed master at finding low-mass extrasolar planets. It detected the system around a star called Gliese 581, which contains what may be the first known rocky planet in a habitable zone, outside the Solar System! Could it contain life forms? Telescopes based at La Silla have also been involved in linking gamma-ray bursts with the explosions of massive stars. It’s recent ‘claim to fame’ came on February 2, 2011, when astronomers using the Wide Field Imager discovered an unusual pure disk galaxy which they christened NGC 3621.

Next, let us investigate the Llano de Chajnantor site which is a 5,100 meters high facility about 50 kilometers east of San Pedro de Atacama. It hosts some of the largest and the most expensive telescopes in the world. At the moment it is constructing a large ground-based astronomy project which will be a revolutionary facility for astronomy across the globe. This project is called the Atacama Large Millimetre/submillimetre Array or ALMA for short. Construction of ALMA started in 2003 and it will start scientific observations at the end of this year with it being fully operational by 2012.


The ESO’s last site that we will look at is the 2600 metre high Paranal site which is described as the flagship facility of European astronomy. The Paranal Observatory is located on top of Cerro Paranal in the Atacama Desert in the northern part of Chile. Its amazing backdrop was used in the 2008 movie “Quantum of Solace”, so next time the movie is on TV you’ll be able to tell all your friends!

Paranal boasts the Very Large Telescope (VLT) which is an array of four individual telescopes. One such telescope images objects as faint as magnitude 30 which is four billion times fainter than those seen with the naked eye. The telescope’s scientific discoveries include imaging an extrasolar planet for the first time, tracking individual stars moving around the supermassive black hole at the centre of the Milky Way galaxy, and observing the afterglow of the furthest known gamma-ray burst

image of VLT

The amazing VLT in action. (Image credit: ESO/S. Brunier)


For a long time the four telescopes of the VLT were imaginatively named UT1, UT2, UT3 and wait for it…. UT4. But in March 1999, four meaningful names of objects in the sky in the Mapuche language were chosen to represent the four telescopes. UT1 is now called Antu (The Sun), UT2 now goes by the name Kueyen (the Moon), Melipal (the Southern Cross) is UT3’s name, and final UT4 was labeled Yepun (Venus).

Image of Paranal

Early morning on Paranal ( Image credit: ESO)


The next step beyond the VLT is to build a European Extremely Large optical/infrared Telescope (E-ELT). The E-ELT will be the largest optical/near-infrared telescope in the world and ESO is drawing up detailed construction plans as we speak. The E-ELT will address many of the most pressing unsolved questions in astronomy and could even revolutionise our perception of the Universe, much like Galileo’s telescope did 400 years ago. The final go-ahead for construction is expected in 2011, with the start of operations planned for early in the next decade. The site has already been chosen and will be located on the Cerro Armazones mountain in Chile. This mountain has a height of 3,064 meters and is located in a prime zone for optical astronomysince it receives almost 350 cloudless nights a year

image of E-ELT

Concept drawing of what the E-ELT will look like. (Image credit: Swinburne Astronomy Productions/ESO)


So as you can see the ESO is a huge operation which employs 700 staff members and receives annual member state contributions of approximately 135 million Euros. That is quite a lot of money, but do you think it is worth it? Well when you look at some of the advancements in astronomy and discoveries made I think it is money well spent.

Some of the discoveries made by ESO been the observation of stars orbiting the Milky Way’s black hole. Several of the ESO’s flagship telescopes were used in a 16-year long study to obtain the most detailed view ever of the surroundings of a black hole at the heart of our galaxy. The first image of an exoplanet was obtained by the VLT. This exoplanet orbits a brown dwarf star. Two independent research teams have also shown that the expansion of the Universe is accelerating based on observations of exploding stars with telescopes at La Silla.

Omega Centauri: an amazing view of a globular cluster (Image credit: ESO/INAF-VST/OmegaCAM)


The VLT detected carbon monoxide molecules in a galaxy located almost 11 billion light-years away! This telescope also measured the age of the oldest star known in our galaxy. At 13.2 billion years old, the star was born in the earliest era of star formation in the Universe. Meanwhile, astronomers using the ESO’s HARPS have discovered a planetary system containing at least five planets. These planets orbit a Sun-like star HD 10180.

It is possible to visit the sites of the ESO and get special tours during the year, so why not get saving and you never know, you could be visiting the most technologically advanced area in astronomy research in the near future!

Image of Sinead McNicholl

Sinead McNicholl, Education Support Officer (Image credit: Armagh Planetarium)

(Article by Sinead McNicholl)


Moshe Chaleun · August 15, 2015 at 03:13

This actually answered my problem, thanks!

ALMA Antennae sees Antennae Galaxies | Astronotes · April 29, 2013 at 07:36

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