Picture of the Week

31 January 2011: What looks like a barren and inhospitable alien landscape in this 360-degree panorama is in fact the site for ESO’s European Extremely Large Telescope, or E-ELT for short. When construction begins the uninhabited mountaintop left of the centre will become a hive of activity as engineers, technicians and scientists work on building the world’s biggest eye on the sky. In many ways Chile’s Cerro Armazones may seem like an alien world. The environment is harsh, with low humidity and air pressure, a blazing Sun during the day, but breathtaking skies at night. Cerro Armazones is in the Atacama Desert — one of the driest places on Earth. These conditions, combined with its remoteness, are what make the region such an excellent location for telescopes. Armazones is an isolated peak, 3046 metres above sea level. It is about 20 km away from Cerro Paranal, home of ESO's famous Very Large Telescope. ...

24 January 2011: As the Sun sets over Cerro Armazones, plans are well advanced for building the world's biggest “eye on the sky”: ESO's European Extremely Large Telescope (E-ELT). With a primary mirror 39 metres in diameter, the E-ELT will dwarf all existing visible-light telescopes. Site selection has been a vital part of the plans for the E-ELT. Over the course of several years a team of experts investigated locations around the world, looking for the best place to host such an ambitious project. The site for the E-ELT must be remote enough not to be influenced by problems such as light pollution, but also needs the necessary infrastructure for the construction and operation of the observatory, and to accommodate the over 150 staff who will eventually work there. Monitoring stations, such as the one shown here, were set up to test site conditions scientifically by measuring parameters that included atmospheric turbulence and ...

17 January 2011: Like the bow of a ship sailing a rolling ocean of red hills, the southeast corner of the observing platform at Paranal stands over the Mars-like landscape of the Chilean Atacama Desert. This panorama shows the breathtaking view of the horizon, and conveys the feeling of immensity experienced when looking from the top of Cerro Paranal, a remote 2600-metre-high mountain located in one of the driest regions on Earth. Atop Cerro Paranal is the ESO Very Large Telescope (VLT), the world’s most advanced optical and near infrared ground-based astronomical facility, composed of four 8.2-metre Unit Telescopes (UTs) and four 1.8-metre Auxiliary Telescopes (ATs). The fourth Unit Telescope (UT4), named Yepun in the Mapuche language, is most prominent in this photograph, while UT3 (Melipal) and UT1 (Antu) are just visible on the right-hand edge of the picture. Three of the smaller ATs can also be seen on the 200-metre-wide observing platform. ...

10 January 2011: Before another clear, starry night falls at ESO's Paranal Observatory, home of the Very Large Telescope (VLT), the sky produces a palette of intense colours, putting on a beautiful show for observers. These colours can only be seen with such depth from sites such as Paranal, where the atmosphere is extraordinarily pure. Looking to the west, over the Pacific Ocean, the sunset sky turns bright orange and red. However, this photograph shows the view to the east instead, looking away from the Sun after it has just set. The grey-bluish shadow above the horizon is the shadow of our own planet. Above this is a pinkish glow known as the "Belt of Venus", a phenomenon produced by the reddened light of the setting Sun being backscattered by the Earth's atmosphere. In the centre of the image is the fourth 8.2-metre Unit Telescope (UT4), part of the VLT. The Mapuche name ...

3 January 2011: Rolling red hills stretch out below the exceptionally clear blue sky that is typical of ESO's Paranal Observatory. Although the telescope domes close at dawn, and nothing seems to move on the surface of this barren desert, the ESO Very Large Telescope (VLT) never rests. Since early morning, a team of engineers and technicians has been working hard to prepare the telescopes and instruments for another "perfect night". The 2600-metre-high Cerro Paranal stands out at the centre of this panoramic view, taken looking towards the south. This flattened mountaintop is home to the VLT, the world's most advanced ground-based optical and near infrared astronomical facility. The VLT has four 8.2-metre Unit Telescopes (UTs), plus four 1.8-metre Auxiliary Telescopes (ATs). In this picture, only two of the UT enclosures, together with the smaller 2.6-metre VLT Survey Telescope (VST) are visible. To the right of Cerro Paranal, the sea of clouds that ...

27 December 2010: This splendid picture shows the European Southern Observatory's Very Large Telescope (VLT) on Cerro Paranal in the Chilean Atacama desert. The mountaintop, 120 km south of the town of Antofagasta, is a remote haven for scientific exploration.Its distance from populated areas means that light pollution is essentially non-existent, which helps to guarantee clear views for the telescopes. It also ensures that activity is not disturbed by other human activities, such as traffic on nearby roads or dusty air from mines. The desert location means that moisture in the atmosphere is at a very low level, which contributes to the excellent atmospheric conditions. As well as the VLT, Paranal Observatory is also home to the VISTA telescope on an adjacent peak, from which this photograph was taken. The road which links the two peaks can be seen in the centre of the image, winding through the desert landscape.The two distinct bright ...

20 December 2010: On a remote mountaintop, 2600 metres above sea level in the Chilean Atacama Desert, lies the world’s most advanced visible-light observatory. The European Southern Observatory’s Very Large Telescope (VLT) is not only a window on the Universe; it is also a celebration of modern science and technology. This photograph shows two of the four Unit Telescopes that make up the VLT. With its giant 8.2-metre diameter mirrors, sensitive detectors, and state-of-the art adaptive optics system, the VLT uses cutting-edge technology at every opportunity. Even the telescope enclosures — the domes — are highly advanced, being thermally controlled to reduce air turbulence in the telescope structure. Every night the VLT studies the sky to make discoveries about the Universe. Visible in this photo, sweeping between the two Unit Telescopes, is the plane of the Milky Way. Containing billions of stars, it is our own corner of the cosmos, but the VLT's ...

13 December 2010: As soon as the Sun sets over the Chilean Atacama Desert, ESO’s Very Large Telescope (VLT) begins catching light from the far reaches of the Universe. The VLT has four 8.2-metre Unit Telescopes such as the one shown in the photograph. Many of the photons — particles of light — that are collected have travelled through space for billions of years before reaching the telescope’s primary mirror. The giant mirror acts like a high-tech “light bucket”, gathering as many photons as possible and sending them to sensitive detectors. Careful analysis of the data from these instruments allows astronomers to unravel the mysteries of the cosmos. The telescopes have a variety of instruments, which allow them to observe in a range of wavelengths from near-ultraviolet to mid-infrared. The VLT also boasts advanced adaptive optics systems, which counteract the blurring effects of the Earth's atmosphere, producing images so sharp that they could ...

6 December 2010: Imagine being a fly on the wall of ESO's Very Large Telescope (VLT) at the world's most advanced optical observatory. You could have a view a little like this. Fish-eye photography gives this unusual view of the 8.2-metre diameter telescope, poised and ready to begin gathering light from the deep recesses of the Universe as soon as the dome opens and starlight pours in. The VLT has four of these 8.2-metre Unit Telescopes, called Antu, Kueyen, Melipal and Yepun. These are the Mapuche names for the Sun, Moon, Southern Cross and Venus. This photograph shows Yepun. The names are from the native language of the indigenous people who live mostly in the area south of the Bio-Bio River, some 500 km south of Santiago de Chile. The VLT is so powerful that it allows us to see objects four thousand million times fainter than those that can be seen with ...

29 November 2010: NGC 520 — also known as Arp 157 — looks like a galaxy in the midst of exploding. In reality, it’s the exact opposite. Two enormous spiral galaxies are crashing into each other, melding and forming a new conglomerate. This happens slowly, over millions of years — the whole process started some 300 million years ago. The object, about 100 000 light-years across, is now in the middle stage of the merging process, as the two nuclei haven’t merged yet, but the two discs have. The merger features a tail of stars and a prominent dust lane. NGC 520 is one of the brightest interacting galaxies in the sky and lies in the direction of Pisces (the Fish), approximately 100 million light-years from Earth. This image was taken by the ESO Faint Object Spectrograph and Camera attached to the 3.6-metre telescope at La Silla in Chile. It is based on ...

22 November 2010: The centre of our own galaxy, the Milky Way, is again in the sights of ESO telescopes. This time it’s the turn of ISAAC, the VLT’s near- and mid-infrared spectrometer and camera. From Chile’s Atacama Desert, site of the ESO observatories, the Milky Way offers magnificent views, particularly in the southern hemisphere winter, when the central region of our galaxy is most visible (see eso0934). However, the Galactic Centre itself, located about 27 000 light-years away in the constellation of Sagittarius, hides behind thick clouds of interstellar dust, which appear as dark obscuring lanes in visible light, but which are transparent at longer wavelengths such as the infrared. In this image, the infrared observations clearly reveal the dense clustering of stars in the galactic core. ESO telescopes have been tracking stars orbiting the centre of the Milky Way for more than 18 years, getting the highest resolution images of this ...

15 November 2010: Among the myriad of stars in this image shines NGC 2257, a collection of cosmic gems bound tightly by gravity. Many billions of years old, but still sparkling brightly, it is an eye-catching astronomical object. NGC 2257 is a globular cluster, the name given to the roughly spherical concentrations of stars that orbit galactic cores, but are often found far out from the centres in the halo areas of galaxies. Globular clusters contain very old stars, being typically over 10 billion years old, and can therefore be used like a "fossil record" to learn more about the Universe’s past. They are densely packed, with tens to hundreds of thousands of stars gathered within a diameter of just a few tens of light-years. NGC 2257 lies on the outskirts of the Large Magellanic Cloud (LMC), a satellite galaxy of our own Milky Way. It is one of 15 very old globular ...

8 November 2010: This impressive image, taken on 10 May 2010 by ESO astronomer Yuri Beletsky, beautifully depicts the sky above Paranal. One of the 8.2-metre telescopes of ESO's Very Large Telescope, Yepun, Unit Telescope 4, is seen against the wonderful backdrop of the myriad of stars and dust that makes up the Milky Way. A laser beam is coming out of Yepun, aiming perfectly at the Galactic Centre. When used with the adaptive optics system the artificial star created by the beam allows the telescope to obtain images and spectra that are free from the blurring effect of the atmosphere. When this image was taken, astronomers Stefan Gillessen and Hauke Enkel were using the SINFONI instrument, together with the laser guide star facility, to study the centre of our Milky Way, where a supermassive black hole is lurking. The field of view of the image is very wide, about 180 degrees. One ...

1 November 2010: Astronomers using data from ESO's Very Large Telescope (VLT), at the Paranal Observatory in Chile, have made an impressive composite of the nebula Messier 17, also known as the Omega Nebula or the Swan Nebula. The painting-like image shows vast clouds of gas and dust illuminated by the intense radiation from young stars. The image shows a central region about 15 light-years across, although the entire nebula is even larger, about 40 light-years in total. Messier 17 is in the constellation of Sagittarius (the Archer), about 6000 light-years from Earth. It is a popular target for amateur astronomers, who can obtain good quality images using small telescopes.These deep VLT observations were made at near-infrared wavelengths with the ISAAC instrument. The filters used were J (1.25 µm, shown in blue), H (1.6 µm, shown in green), and K (2.2 µm, shown in red). In the centre of the image is a ...

25 October 2010: The stars rotate around the southern celestial pole during a night at ESO’s La Silla Observatory in northern Chile. The fuzzy parts in the trails on the right are due to the Magellanic Clouds, two small galaxies neighbouring the Milky Way. The dome seen in the image hosts ESO’s 3.6-metre telescope and is home to HARPS (High Accuracy Radial velocity Planet Searcher), the world’s foremost exoplanet hunter. The rectangular building seen in the lower right of the image contains the 0.25-metre TAROT telescope, designed to react very quickly when a gamma-ray burst is detected. Other telescopes at La Silla include the 2.2-metre MPG/ESO telescope, and the 3.58-metre New Technology Telescope, the first telescope to use active optics and, as such, the precursor to all modern large telescopes. La Silla was ESO’s first observing site and is still one of the premier observatories in the southern hemisphere. #L

18 October 2010: The Sun sets at ESO’s Very Large Telescope (VLT) in this image. Taken at the observatory on Cerro Paranal in the dry Atacama Desert of Chile, the observatory’s four 8.2-metre telescopes can be seen preparing for the night ahead. Three of the VLT’s four Auxiliary 1.8-metre Telescopes (AT), used for interferometry, are also visible. The telescopes are seen reflected in the protection cover of one of the AT stations. The ATs are mounted on tracks and can be moved between precisely defined observing positions from where the beams of collected light are combined in the interferometric laboratory. The ATs are very unusual telescopes, as they are self-contained in their own ultra-compact protective domes, and travel with their own electronics, ventilation, hydraulics and cooling systems. Each AT has a transporter that lifts the telescope and moves it from one position to the other. At 2600 metres above sea level, the observing ...

11 October 2010: ESO has grown significantly since 1980, when its European staff originally moved from offices at CERN to a dedicated headquarters building in Garching, near Munich, Germany. In the intervening three decades the number of ESO’s member states has increased from six to fourteen, and the organisation has achieved milestones such as the First Light of the New Technology Telescope at La Silla and of the Very Large Telescope at Paranal, becoming in the process the most productive observatory in the world. Today, ESO is constructing the Atacama Large Millimeter/submillimeter Array at Chajnantor in collaboration with international partners, and is in the detailed design phase of a 40-metre-class European Extremely Large Telescope, which will be “the world’s biggest eye on the sky”. Over the years, the number of ESO staff working in Garching has increased from about 100 to about 450, as the organisation has grown and tackled these exciting new ...

4 October 2010: Two of the Atacama Large Millimeter/submillimeter Array (ALMA) 12-metre antennas gaze at the sky at the observatory’s Array Operations Site (AOS), high on the Chajnantor plateau at an altitude of 5000 metres in the Chilean Andes. Eight antennas have been installed at the AOS since November 2009. More antennas will be installed on the Chajnantor plateau during the next months and beyond, allowing astronomers to start producing early scientific results with the ALMA system around late 2011. After this, the interferometer will steadily grow to reach its full scientific potential, with at least 66 antennas. ALMA is the largest ground-based astronomy project in existence, and will comprise a giant array of 12-metre submillimetre quality antennas, with baselines of up to about 16 kilometres. An additional, compact array of 7-metre and 12-metre antennas will complement the main array. The ALMA project is an international collaboration between Europe, East Asia and North ...

27 September 2010: This unusual and artistic image, made using a technique known as "solargraphy" in which a pinhole camera captures the movement of the Sun in the sky over many months, was taken from the Atacama Pathfinder Experiment (APEX) telescope on the plateau of Chajnantor. The plateau is also where ESO, together with international partners, is building the Atacama Large Millimeter/submillimeter Array (ALMA). The solar trails in the image were recorded over half a year and clearly show the quality of the 5000-metre altitude site, high in the Chilean Andes, for astronomical observations. The idea for creating the solargraphs at ESO's telescopes came from Bob Fosbury, an astronomer based at ESO Headquarters in Germany, after learning about the technique from Finnish artist Tarja Trygg. Trygg provided the cameras, known as "cans". The cans are constructed from small black plastic canisters used for storing 35 mm film cassettes. A pinhole in a sheet ...

20 September 2010: After the Sun sets at ESO’s Paranal Observatory darkness descends, but the black sky is speckled with a glorious myriad of sparkling stars. This 15-second exposure demonstrates just how dazzling the skies above Paranal are. Located high in the Atacama Desert in Chile far from any sources of light pollution, on a clear moonless night it is possible to see your shadow cast by the light of the Milky Way alone. Says visual artist and ESO Photo Ambassador José Francisco Salgado, “The skies at Paranal are among the darkest and steadiest I have photographed. I love photographing observatories and at Paranal it's incredible how you can still see just with starlight and zodiacal light!” In the image the stars of the Milky Way seem to be pouring forth from the open dome of the telescope. The brightest patch close to the telescope is the Carina Nebula (NGC 3372), which contains ...