Picture of the Week

17 November 2014: Have you ever wondered what the inside of ESO's Very Large Telescope looks like? Well, wonder no more, as this picture of the week shows the internal structure of one of the VLT's Unit Telescopes (UTs) — specifically UT3, otherwise known as Melipal. Seen here, lit by moonlight, is the main steel structure of the Unit Telescope's optical assembly. The main mirror, measuring 8.2 metres in diameter and weighing in at more than 23 tonnes, requires a sturdy frame to allow it to rotate within the structure, while maintaining high optical resolution. This movable steel frame itself weighs over 430 tonnes, about the same as a fully loaded jumbo jet! The structure, optics and electronics are housed within a further steel enclosure, which provides protection from the harsh Atacama environment. Melipal is named after the Mapuche term for the constellation of the Southern Cross. All four of the VLT's Unit ...

10 November 2014: This week removal of the temporary office buildings at the ESO Headquarters in Garching, Germany began. This image shows them being dismantled, and captures both the beginning, and end, of an era. The ESO staff members who had been working in the temporary buildings — seen here in this aerial photo taken earlier this year — moved into the new Headquarters extension at the beginning of this year. The removal of the containers marks the end of this transition period. It also marks the beginning of the construction of the ESO Supernova Planetarium & Visitor Centre. In a few months, on the site once occupied by the temporary office buildings, the construction of ESO’s newest building will begin. The ESO Supernova is scheduled to open in spring 2018 and will offer its visitors a modern, interactive astronomical exhibition and one of the most advanced planetariums in the world. The removal ...

3 November 2014: The smokey black silhouette in this new image is part of a large, sparse cloud of partially ionised hydrogen — an HII region — known as Gum 15. In wide-field images this nebula appears as a striking reddish purple clump dotted with stars and slashed by opaque, weaving dust lanes. This image homes in on one of these dust lanes, showing the central region of the nebula. These dark chunks of sky have seemingly few stars because lanes of dusty material are obscuring the bright, glowing regions of gas beyond. The occasional stars that do show up in these patches are actually between us and Gum 15, but create the illusion that we are peering through a window out onto the more distant sky. Gum 15 is shaped by the aggressive winds flowing from the stars within and around it. The cloud is located near to several large associations of ...

27 October 2014: A solitary laser beam cuts through the night sky. It streaks upwards from Unit Telescope 4 of ESO's Very Large Telescope, located at Paranal Observatory in Chile. The two Magellanic Clouds are visible to the left of the beam as faint, fuzzy patches against the starry background. The particularly bright star to the right of the beam is Canopus, the second brightest star in our night sky after Sirius. When ground-based telescopes view stars, the light they collect must travel through the layers of our atmosphere. The same water vapour, pollution, and turbulence that causes the stars in the sky to twinkle also result in blurred images — so in comes a technique known as adaptive optics. Adaptive optics systems use sophisticated deformable mirrors to counteract the negative effects of our atmosphere. The laser shines up into the sky, creating an artificial star about 90 kilometres from the ground. Astronomers ...

20 October 2014: This photograph from the ESO Open House Day 2014 shows children and adults listening to the adventures of Space Rock Pedro. This was one of the sixteen activities available when ESO Headquarters in Garching, Germany, opened its doors to the public on 11 October 2014. In conjunction with the other facilities based at the science campus in Garching, ESO invited visitors to experience at first hand the work of the world-leading ground-based astronomy organisation. Before the doors had even opened at 11:00 people were waiting outside, eager to look around the new headquarters and experience all the main activities available. In total, 3300 people took the chance to have their questions answered by experienced astronomers; see live experiments; join guided tours through the new office and technical buildings; listen to talks about ongoing astronomical research; and even participate in live interviews with astronomers in the Chilean Atacama Desert. Also included ...

13 October 2014: This colourful picture resembles an abstract painting, or perhaps a contemporary stained-glass window. But it is actually an unusual view of a galaxy taken with the new MUSE instrument on ESO’s Very Large Telescope. Colours in astronomical pictures are usually related to the real colour of an object. In this image, however, the colours represent the motion of the stars that form the giant elliptical galaxy Messier 87 — one of the brightest galaxies in the Virgo Cluster which lies about 50 million light-years away. Red in the image indicates that stars in that part of the object are, on average, moving away from us, blue means they are coming towards us, and yellow and green are in between. This new map of Messier 87 from MUSE shows these trends more clearly than ever before. It reveals a slow rotation of this massive object — the upper left part (in ...

6 October 2014: This aerial image shows a 1:1 scale model of the European Extremely Large Telescope's primary mirror, assembled next to the Asiago Astrophysical Observatory near Asiago, Italy. The Italian observatory, founded in 1942, is dwarfed by the gargantuan E-ELT mirror… in fact, you could fit the entire Asiago building inside the footprint of the E-ELT mirror and still have enough room to swing a proverbial cat (and a big cat too)! Around the edge of the mock-up mirror are the children who volunteered to participate in the task of positioning the 800 1.4-metre cardboard hexagons used to form the 39-metre E-ELT mirror mock-up.

29 September 2014: Sitting atop Cerro Paranal high above the Atacama Desert in Chile, two of the Very Large Telescope's Unit Telescopes quietly bask in the starlight, observing the Milky Way as it arches over ESO's Paranal Observatory. Several interesting objects can be seen in this picture. Some of the most prominent are the two Magellanic Clouds — one Small (SMC), one Large (LMC) — which appear brightly in between the two telescopes. By contrast, the dark Coalsack Nebula can be seen as an obscuring smudge across the Milky Way, resembling a giant cosmic thumbprint above the telescope on the left. The Magellanic Clouds are both located within the Local Group of galaxies that includes our galaxy, the Milky Way. The LMC lies at a distance of 163 000 light-years from our galaxy, and the SMC at 200 000 light-years. The Coalsack Nebula, on the other hand, is a mere stone's throw away ...

22 September 2014: The 15-metre diameter Swedish–ESO Submillimetre Telescope (SEST) was built in 1987, and was operated at ESO's La Silla Observatory in Chile until it was decommissioned in 2003. At the time of construction, SEST was the only radio telescope in the southern hemisphere that was designed to observe the submillimetre Universe, and it paved the way for later telescopes such as the Atacama Pathfinder Experiment telescope (APEX), and the Atacama Large Millimeter/submillimeter Array (ALMA), both located at Chajnantor. In this image, we see a crowded night sky filled with star trails, a result of the camera's long exposure time. The starlight is reflected back at numerous different angles towards the camera from the giant parabolic dish. In the background, the ESO 3.6-metre telescope stands in its dome, silently surveying the cosmos. This dizzying picture of the SEST telescope at La Silla was taken by ESO Photo Ambassador José Joaquín Pérez. Links ...

15 September 2014: Here we see ESO's La Silla Observatory with a backdrop of the Milky Way. Established in the 1960s, La Silla was ESO's first observatory to be built in Chile. Visible on the hill in the centre of this image is the rectangular New Technology Telescope (NTT) on the left, and the domed ESO 3.6-metre telescope to the right. The 3.58-metre NTT was inaugurated in 1989, and was the first in the world to have a computer-controlled main mirror. The main mirror is flexible, and its shape is actively adjusted during observations to preserve the optimal image quality. This technology, known as active optics, is now applied to all major modern telescopes — including the Very Large Telescope at Cerro Paranal, and the future European Extremely Large Telescope. La Silla is home to several other telescopes, including the Swedish–ESO Submillimetre Telescope (SEST), and the robotic TAROT, which is used to monitor ...

8 September 2014: The bright, hazy smudge at the centre of this image is a comet known as 67P/Churyumov-Gerasimenko, or 67P/C-G for short. This is not just any comet; it is the target for ESA’s Rosetta spacecraft, which is currently deep within the comet’s coma and less than 100 kilometres from its nucleus [1]. With Rosetta so close to the comet, the only way to view the whole of 67P/C-G now is to observe it from the ground. This image was taken on 11 August 2014 using one of the 8-metre telescopes of ESO’s Very Large Telescope (VLT) in Chile. It was composed by superimposing 40 individual exposures, each lasting 50 seconds, and removing background stars, to obtain the optimal view of the comet. Rosetta is contained within the central pixel of this image, and is too small to resolve. The VLT is made up of four individual Unit Telescopes that can work ...

1 September 2014: This groovy and psychedelic photograph shows a night of observing the Northern Celestial Pole from the Allgäu Public Observatory in Ottobeuren, Germany. Pictured here is the facility's 0.6-metre Cassegrain reflector telescope, which was installed in 1996. The brilliant yellow laser beam, which appears to fan out across the sky in this long-exposure image, is ESO's Wendelstein laser guide star unit which was tested at the site in Allgäu. It is a precursor, experimental version of the fibre laser that has been installed on the Very Large Telescope in Paranal, Chile. A Laser guide star is used to create a bright spot in the sky, which can be used as an artificial reference star, allowing astronomers to measure how the real stars blur or twinkle, as normally seen from the ground. The measurements are then used to correct this blurring and enable sharper images to be taken, in a process is ...

25 August 2014: In the Atacama Desert in Chile, it rarely rains. Only once every few years does significant rain or snow precipitate on ESO’s La Silla Observatory, generally coinciding with an anomalously warm weather event such as an El Niño event. This desert is one of the driest places on Earth, making it a fantastic site from which to observe the night sky. Although there may be very little real rain, some photography tricks can instead make the stars appear to rain onto the surrounding mountains, as seen in this image taken on 21 May 2013 by Diana Juncher, a PhD student in astronomy at the Niels Bohr Institute, Denmark. Diana was at La Silla for two weeks in May 2013, observing exoplanets towards the centre of our galaxy as part of her research. During her stay she managed to take this image of star trails, taken only around 20 metres away ...

18 August 2014: A rare patch of wispy white clouds streak across the sky over ESO’s La Silla Observatory in this photograph, taken on 11 June 2012 by astronomer Alan Fitzsimmons. This dry, desolate environment with occasional strong gusts of wind may not be the best place for people to set up home, but it is the ideal location for telescopes. Dry, arid conditions help astronomers to avoid common observing problems like atmospheric disturbance, light pollution, humidity, and (most of the time!) clouds, allowing them to gain a clearer view of the cosmos above. Even on this rare day of cloud the sky had cleared by nightfall and observations took place as usual. The telescopes that call La Silla home — including two major ESO-operated telescopes: the ESO 3.6-metre telescope and the New Technology Telescope (NTT) — are equipped with state of the art instruments, enabling them to fully exploit the unique viewing ...

11 August 2014: At present ESO hosts three observatories in the Atacama Desert region of Chile: La Silla, Paranal and Chajnantor. Visible in the background of this image is Paranal, ESO’s flagship facility and home of the Very Large Telescope (VLT) array. In coming years, this trio will be joined by a fourth observatory: Cerro Armazones, future site of the European Extremely Large Telescope (E-ELT). With its 39-metre-diameter mirror, the E-ELT will be the world’s biggest eye on the sky when construction is completed around 2024. Cerro Armazones is currently only linked to Paranal by a dirt track — but, as shown in this image, construction is underway. The Chilean company ICAFAL Ingeniería y Construcción S.A. (ICAFAL) began construction in March (ann14019), and is due to take around 16 months to complete a new 7-metre-wide asphalt road. As well as carving a new road through the Chilean landscape, ICAFAL will level off the ...

4 August 2014: At 5000 metres above sea level, high upon the Chajnantor Plateau in Chile, the antennas of the ALMA Observatory peer skywards, scanning the Universe for clues to our cosmic origins. This plateau is one of the highest observatory sites on Earth. Visible amongst the thousands of stars on the right side of this image are the Small and Large Magellanic Clouds, appearing as luminous smudges in the sky. These cloud-like objects are both galaxies — two of the closest galactic neighbours to our galaxy, the Milky Way. ALMA's main aim is to observe the coldest and most ancient objects in the cosmos — known as the "cold Universe". The array measures radiation emitted in the millimetre and submillimetre wavelengths, which lie in between infrared and radio waves in the electromagnetic spectrum. It features 66 mobile antennas which can be moved and configured over the ALMA site to meet the scientists' ...

28 July 2014: Close to ESO's ALMA Observatory, a tour bus creates a cloud of dust as it makes its way across the Chilean desert. This bus carries staff heading to the ALMA Operations Support Facility for the start of an 8-day shift. In the background we see two volcanoes, their snow-covered peaks obscured by clouds. Located on the border between Bolivia and Chile, these two inactive volcanoes, despite being just a short distance from each other, were created in different geological epochs — Licancabur, the volcano on the left, is much younger than its smaller neighbour Juriques. Licancabur is famous for its near-symmetrical shape, and for being home to one of the highest lakes in the world. At an altitude of 5916 metres, the lake in Licancabur’s caldera is host to a variety of rare flora and fauna, and has been studied to see how life is coping in this extreme environment. ...

21 July 2014: This panoramic view of ESO’s flagship facility in northern Chile was taken by ESO Photo Ambassador Gabriel Brammer. The Very Large Telescope (VLT) is seen setting to work at ESO’s Paranal Observatory, visible against a backdrop of clear skies with the Milky Way overhead. To create this picture, Brammer combined several long-exposure shots in order to capture the faint light of the Milky Way as it circled above the massive enclosures of the VLT’s Unit Telescopes. Each of these giants is 25 metres tall, and they are named after prominent features of the sky in the language of the local Mapuche tribe: the Sun, the Moon, the constellation of the Southern Cross, and Venus — Antu, Kueyen, Melipal, and Yepun respectively. On the left of the frame, the smaller Auxiliary Telescopes can be seen in their white round, domes, with the large and small Magellanic Clouds above them. The combination ...

14 July 2014: Can you count the number of bright dots in this picture? This crowded frame is a deep-field image obtained using the Wide Field Imager (WFI), a camera mounted on a relatively modestly sized telescope, the MPG/ESO 2.2-metre located at the La Silla Observatory, Chile. This image is one of five patches of sky covered by the COMBO-17 survey (Classifying Objects by Medium-Band Observations in 17 filters), a deep search for cosmic objects in a relatively narrow area of the southern hemisphere's sky. Each one of the five patches is recorded using 17 individual colour filters. Each one of the five COMBO-17 images covers an area of the sky the size of the full Moon. The survey has already revealed thousands of previously unknown cosmic specimens — over 25 000 galaxies, tens of thousands of distant stars and quasars previously hidden from our view, showing just how much we still have ...

7 July 2014: This aerial photograph shows the sprawling site of the European Southern Observatory’s (ESO) Headquarters in Garching bei München, Germany. While ESO operates telescopes scattered across Chile in the southern hemisphere, Garching houses the scientific, technical and administrative centre of ESO, where development programmes are carried out to provide the observatories with the most advanced instruments. The buildings in the centre of the frame, both with sleek, curved designs, are the two main ESO Headquarters buildings — the top-right building was the organisation’s sole base for many years before it was recently joined by the lower red-roofed extension, which was inaugurated in December 2013. The black, rounded building is the technical building, where work on new instruments is carried out. Each of the individual Headquarters buildings are connected by curved bridges, seen here as the three-armed black shape in the centre of the frame. The new extension, designed by architects Auer+Weber, ...