Picture of the Week

30 June 2014: The Sun sets over Paranal Observatory, painting an array of subtle hues across the sky reminiscent of a Monet landscape. The sparse clouds glow warmly under the Sun's last rays, and the crisp clarity of the air is almost palpable — highlighting why ESO has selected this area of Chile for its observatory. Crepuscular rays — and shadows from the clouds — are streaming from the Sun and appear to converge at the antisolar point. Two of the four domed Auxiliary Telescopes (ATs) of the Very Large Telescope (VLT) can be seen on the left, waiting patiently for darkness to fall before conducting their survey of the cosmos. Once the Sun has set, the 1.8-metre diameter ATs will feed starlight to the Very Large Telescope Interferometer (VLTI), combining the light to produce clear images of the Universe. The mobile ATs are mounted on rails, and can be moved around the ...

23 June 2014: This new image, taken by ESO Photo Ambassador Gianluca Lombardi, shows a stunning array of colours, ranging from the haze of pink dominating the bottom of the frame to the blues and whites of the Milky Way above. The blocks visible at the foreground of the image are the Unit Telescopes of the Very Large Telescope (VLT), based at ESO's Paranal Observatory in Chile. Cutting through the scene is a harsh yellow slash. This prominent streak is the VLT's laser guide star, which is part of the telescope's adaptive optics system that compensates for the blurring effects of the atmosphere. Light from the sky is distorted as it travels through the atmosphere due to local variations. Whenever possible, astronomers hunt down a bright star to calibrate their observations, but when there is no suitable star near enough to their target, they have to rely on an artificial one — created ...

16 June 2014: This new image shows the construction progress of the road, platform, and service trench at the site of the future European Extremely Large Telescope (E-ELT) on Cerro Armazones. The basecamp can be seen to the lower right and the new road is seen curving around the base of the mountain. The Chilean company ICAFAL Ingeniería y Construcción S.A. started the civil works for the E-ELT in March 2014 when they began construction of a road to the summit of the mountain. The construction is expected to take 16 months to complete. The road will provide access for the future construction of the giant telescope, and will be 11 metres wide, with an asphalt paved driveway 7 metres wide. Construction worker for the company, Sebastián Rivera Aguila, caught this sight on Thursday 12 June 2014 from a commercial airplane flying over the mountain. He expressed his excitement: "It is really hard ...

9 June 2014: This image shows the beginning of sunrise over the Very Large Telescope (VLT) at ESO's Paranal Observatory in Chile. In this photo, one of the VLT's Unit Telescopes is visible to the bottom right, illuminated by moonlight. Further in the distance there are two Auxiliary Telescopes pointing upwards. The VLT is formed of four 8.2-metre Unit Telescopes (UTs), and four movable 1.8-metre Auxiliary Telescopes (ATs). The telescopes can work together to form a giant interferometer: the Very Large Telescope Interferometer (VLTI). The light collected by each of these telescopes is combined by the VLTI using a complex system of mirrors in underground tunnels, allowing astronomers to see details up to 16 times finer than with the individual UTs alone. The image was taken by Nicolas Blind, an astronomer who visited Paranal Observatory for a few days in December 2012. Blind may only have been at the observatory for a short ...

2 June 2014: Framed by the glow of the Moon setting, the fourth Unit Telescope (UT4) of ESO's Very Large Telescope (VLT) at Paranal Observatory is enveloped by the sky it studies night after night. Located high on Cerro Paranal, the majestic machine sits gracefully at an altitude of 2635 metres above sea level. Paranal is the world's most advanced visible-light astronomical observatory and ESO’s flagship facility, containing a suite of telescopes. UT4, otherwise known as Yepun (Venus), is one of the four Unit Telescopes that comprise the VLT, also working with their four Auxiliary Telescope companions to form the super-sensitive Very Large Telescope Interferometer (VLTI). Housed within a thermally controlled building, UT4 uses its incredibly precise 8.2-metre mirror to scan the stars and unravel the mysteries of the Universe. The other three Unit Telescopes are known as Antu (Sun), Kueyen (Moon), and Melipal (Southern Cross), from the language of the Mapuche people ...

26 May 2014: The sky over Paranal Observatory in northern Chile is a real treat for ESO's Photo Ambassadors, who are constantly experimenting with new techniques to obtain even more striking views of the unique, arid landscape and state-of-the-art facilities. On this occasion, Gianluca Lombardi has combined many long-exposure images to get this stunning result — the Very Large Telescope (VLT) and its Auxiliary Telescopes, their motion appearing as blurred flickers beneath a stream of stars, while the apparent motion of the stars across the sky has left smeared trails that are captured on camera as the Earth rotates. The VLT is ESO's flagship facility. It is of the most productive telescopes in the world, and the most advanced optical instrument ever made.

19 May 2014: A small crowd gathers by the telescopes to see the night in at ESO’s Paranal Observatory in Chile. For most, sunset marks the end of a working day — a time for rest. But not here; nighttime is when the real work is done, with a clear night’s sky as the workplace. The crowd looks tiny, dwarfed by the telescopes to their left. These domes house the four 1.8-metre-diameter Auxiliary Telescopes that are part of the Very Large Telescope array (VLT). But the real giant of the picture is at the far left; if the Auxiliary Telescopes make the crowd look small, then the VLT Unit Telescope makes them look like ants. The VLT has four 8.2-metre telescopes like this, some of the largest telescopes on the planet. But if you think that’s big, wait for the European Extremely Large Telescope (E-ELT), set for first light in the early 2020s. ...

12 May 2014: This gorgeous photograph, taken in the Atacama Desert in Chile, shows star trails circling the South Celestial Pole, over a cacti-dominated still landscape. The star trails show the apparent path of the stars in the sky as the Earth slowly rotates, and are captured by taking long-exposure shots. A final deeper exposure was superimposed over the magnificent trails, revealing many more, fainter stars and, just rising above the horizon, the southern Milky Way, with its patches of dark dust and the well-known pinkish glow of the Carina Nebula. Towards the right, the satellite galaxies of the Milky Way, the Large (top-centre) and Small (bottom-right) Magellanic Clouds, can also be seen.

5 May 2014: The Sun sets over La Silla, one of ESO's observing sites in Chile, creating a fiery orange glow along the horizon. This image, taken by David Jones, shows the alignment of three planets over the summit of ESO's telescopes in June 2013. Here the trio visible to the left of centre is composed of Jupiter (bottom left, almost invisible in orange sunset), Venus (centre), and Mercury (top right) — see labelled image. Alignments like this happen only once every several years, so it is a real treat for photographers and astronomers. When three (or more) celestial objects align like this in the sky, it is called a "syzygy". Check this syzygy image, showing almost the same scene (also from May 2013). "This image was taken during a five-night observing run with the 3.6-metre New Technology Telescope on La Silla, so I was very fortunate to be awarded observing time at ...

28 April 2014: This image shows an ancient sun-scorched boulder near ESO's La Silla Observatory in Chile, on the outskirts of this desert at a height of some 2400 metres above sea level. Visible on the boulder are several petroglyphs — rock engravings — depicting men and llamas. Llamas have historically been very important to South American cultures, being used as both a source of food and wool, and also as a pack animal for carrying goods across the land. The importance of llamas was reflected in the beliefs of the pre-Columbian people who inhabited the region — the Inca herders worshipped a multicoloured llama deity by the name of Urcuchillay, who was said to watch over the animals. The name Urcuchillay was also given to the constellation of Lyra (The Lyre) by the ancient Inca astronomers. The llama is honoured yet again in the Inca constellations. These constellations were formed from dark ...

21 April 2014: Many hands make light work, as the old saying goes, although perhaps in this case the phrase "many wheels make light work" is more appropriate. Pictured here is Otto, one of the two ALMA Transporters along with its companion Lore. Otto and Lore were responsible for carrying the ALMA antennas up to the Chajnantor Plateau, a site some 5000 metres above sea level in northern Chile. After placing the antennas, the two trucks have the additional task of repositioning them according to the scientists' requirements. Otto can be seen in action in this video. These two powerful beasts are the ultimate in custom vehicles. They were designed specifically for ESO by the German vehicle manufacturer Scheuerle Fahrzeugfabrik, who have an impressive history of transporting heavy loads like the Antares rocket and an oil platform weighing in at a staggering 15 000 tonnes! The transporters are identical except for the colour ...

14 April 2014: A curtain of stars surrounds the 3.58-metre New Technology Telescope (NTT) in this new Ultra High Definition photograph from the ESO Ultra HD Expedition [1]. It was captured on the first night of shooting at ESO's La Silla Observatory, which sits at 2400 metres above sea level on the outskirts of the Chilean Atacama Desert. The majestic telescope enclosure aligns perfectly with the Milky Way’s central region — the brightest section and the area which obscures the galactic centre. The distinctive octagonal enclosure that houses the NTT stands tall in this image — silhouetted against the glittering cosmos above and almost appearing to consume the Milky Way. This telescope housing was considered a technological breakthrough when completed in 1989. Visible to the left of the Milky Way is the bright orange star Antares at the heart of Scorpius (The Scorpion). Saturn can be seen as the brightest point to the ...

7 April 2014: This beautiful new image, taken during a time-lapse set at the Atacama Large Millimeter/submillimeter Array (ALMA) is another dramatic Ultra High Definition photograph from the ESO Ultra HD Expedition. ALMA, located at 5000 metres above sea level on the remote and empty Chajnantor Plateau in the Chilean Andes, marks the second destination for the four ESO Photo Ambassadors [1] on their 17-day trip. The ambassadors are equipped with state-of-the-art Ultra HD tools to help them capture the true majesty of sights like the one pictured here [2] [3]. Some of the 66 high-precision antennas that comprise ALMA are visible here, with dishes pointed aloft, studying the cold clouds in interstellar space, and peering deep into the past at our mysterious cosmic origins. The spectacular javelin of light over the ALMA array is a shooting star, slicing through the image in a vivid streak of colours. Emerald green, golden and faint ...

31 March 2014: This photo, taken at ESO's Paranal Observatory, is the first photograph from the ESO Ultra HD Expedition — a pioneering journey currently being undertaken by four world-renowned videographers and ESO Photo Ambassadors [1]. Equipped with state-of-the-art Ultra HD tools [2][3], the team are capturing ESO’s three unique observing sites in Chile in all their grandeur, while documenting their journey and escapades in a blog. The four Unit Telescopes — Antu, Kueyen, Melipal and Yepun — one of the Auxiliary Telescopes of the Very Large Telescope (VLT) and the VLT Survey Telescope (VST), are captured from an unusual perspective in this image. Taken using a fisheye lens, this photography technique produces a 360° view of the location — creating an immersive Paranal world with the swirling Milky Way at the centre of it. Distant cosmic gems are seen scattered above the VLT — speckling the sapphire shades of the night sky. ...

24 March 2014: ESO's observatories are privileged spots where astrophotographers can catch amazing views of the cosmos. But that's not all — sometimes, they are ideal locations from which to capture otherworldly images of our own planet, too. In this shot, ESO photo ambassador Gabriel Brammer has used a fish-eye lens to create this spectacular round effect. The clear sky over Paranal looks like a glass ball full of stars, with the Very Large Telescope (VLT) platform framing the picture. In the bottom left the four VLT Unit Telescopes, each some 25 metres tall, are observing the night sky, one of them pointing its laser up into the night. Scattered around the top left of the frame, the round domes of the VLT Auxiliary Telescopes are easily spotted under the bright Milky Way. The two blurry smudges just above the laser are the Large and Small Magellanic Clouds, two of the closest galaxies ...

17 March 2014: Another clear night at ESO’s Paranal Observatory in Chile — perfect for sitting back and taking in the sight of our galaxy, the Milky Way. Many of us living in living in crowded, light-polluted cities no longer get to see our cosmic home in such detail. We now know this stunning view to be our home galaxy, but the Ancient Greeks thought that it was the work of the Gods. Their legends told that this cloudy streak across the sky was really the breast milk of Hera, wife of Zeus. The Ancient Greeks are also to thank for the name “Milky Way”. The Hellenistic phrase Γαλαξίας κύκλος, pronounced galaxias kyklos, means “milky circle”, and provides the root for our modern name. This 360 degree panorama image was taken by ESO Photo Ambassador Gabriel Brammer. An astronomer visiting Paranal can be seen standing towards the right hand side of this image ...

10 March 2014: On 20 January 2014, ESA's Rosetta spacecraft emerged from a long deep-space hibernation to approach its target — comet 67P/Churyumov-Gerasimenko (67P/CG). From our vantage point on Earth, comet 67P/CG has only just reappeared from behind the Sun. On 28 February 2014 ESO's Very Large Telescope (VLT) directed its gaze towards the comet as soon as it became visible from ESO's Paranal Observatory in Chile. ESO is collaborating with ESA to monitor the comet from the ground as it is approached by Rosetta over the coming months. These observations will prepare for the spacecraft's major rendezvous with the comet, planned for August of this year (see potw1403a). This new image, and many more to come, will be used by ESA to refine Rosetta's navigation, and to monitor how much dust the comet is releasing. The image on the left was created by stacking the individual exposures to show the background stars ...

3 March 2014: High on the Chajnantor Plateau in the Chilean Andes lies the Atacama Large Millimeter/submillimeter Array (ALMA), an observatory surrounded by large expanses of dry landscape. Perhaps surprisingly, the region is home to a number of different wildlife species, many of which occasionally pop up near to the observatory. Further south, ESO’s La Silla Observatory recently had visits from a South American grey fox (potw1406a), and wild horses (potw1344a). The most recent cute visitor to ALMA is this vicuña fawn, found on 16 February 2014 by ALMA workers. The fawn was only a few weeks old, weakened after it was chased by foxes until it lost sight of its herd. After a couple of unsuccessful attempts the following day to return the fawn to its herd, the workers transferred it to the Wildlife Rescue and Rehabilitation Center at the Universidad de Antofagasta, where it is being treated so that it can ...

24 February 2014: Bereft of colour in this striking infrared image, the sweeping curves of ESO's Headquarters clash with the frosty natural beauty of the surrounding trees. The extreme curvature visible in this image is due to the photographer's use of a fisheye lens, which distorts the view and causes the building to encircle the pale foliage and frame the sky above. The foliage appears to be bright as it reflects the infrared light, and the pale white hue comes from the photographer applying a white colour balance to the tree leaves. The precise curves of concrete, glass, and steel give clues as to the Headquarters building's peculiar structure. In 1981 an article in ESO's The Messenger described the ESO building as "a labyrinth of the kind used to test the intelligence of rats". But, fortunately for ESO, the writer soon noted that "human beings are on average cleverer than rats, and the ...

17 February 2014: These new images from ESO's Very Large Telescope Survey Telescope (VST) show ESA's Gaia spacecraft in its position some 1.5 million kilometres beyond Earth's orbit. Launched on the morning of Thursday, 19 December 2013, the satellite is on a quest to build a 3D map of our galaxy over the next five years. Mapping the sky has been one of humanity's quests since the dawn of time, and Gaia will take our understanding of our stellar neighbourhood to a whole new level. It will measure very precisely the positions and motions of about one billion stars in our galaxy, to explore the Milky Way's composition, formation and evolution. These new observations are the result of a close collaboration between ESA and ESO to monitor the spacecraft from the ground. Gaia is the most accurate astrometric device ever built, but in order for its observations to be useful it needs to ...