Picture of the Week

17 May 2010: The Santiago Central Office building, the soon-to-be headquarters of the Atacama Large Millimeter/submillimeter Array (ALMA) project in the Vitacura district of the Chilean capital. The new building is rapidly approaching completion and is adjacent to ESO’s Santiago offices. It was built by ESO as part of its responsibilities as the European ALMA partner. The ALMA Santiago Central Office building covers nearly 7000 square metres, stands two storeys tall, and includes an underground parking area for 130 cars. ALMA, the largest astronomical project in existence, is a revolutionary astronomical telescope, comprising an array of 66 giant 12-metre and 7-metre diameter antennas observing at millimetre and submillimetre wavelengths. The facility is currently under construction on the 5000-metre high Chajnantor plateau in the Chilean Andes. ALMA is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile.

10 May 2010: High in the Chilean Andes, at 5000 metres above sea level, one of the giant Atacama Large Millimeter/submillimeter Array (ALMA) antenna transporters contemplates an unexpected sight — a delicate dusting of snow whitens the breathtaking landscape of the Chajnantor plateau, home of the ALMA project. Snow is a very rare event at this extremely arid site and is a consequence of the Altiplanic winter, caused when the jet stream reverses and comes from the chill east. Chajnantor is one of the driest sites in the world, making it excellent for astronomical observations. The hill in the background is Toco, a 5600-metre mountain toward the north. This image was taken on 30 April 2010. The ALMA transporters, two giant custom-built vehicles, can move the antennas across the Chajnantor plateau, allowing different configurations of the array. Since late 2009, there have been three antennas at 5000 metres. Eventually ALMA will have a ...

3 May 2010: This picture looks like a scene from a science fiction movie, with strange, distant structures rising over a desolate alien valley. In fact, this is the barren Atacama Desert in northern Chile, and the oddly shaped buildings silhouetted against the sky are part of ESO’s Very Large Telescope (VLT) observatory, the world’s most advanced ground-based observatory. The four 8.2-metre Unit Telescopes stand out to the right on the summit of Mount Paranal. To the left looms the new 4.1-metre Visible and Infrared Survey Telescope for Astronomy (VISTA), the largest survey telescope in operation. The extremely arid conditions and high altitude of the Paranal region make it an optimum site to locate an astronomical observatory. The otherworldliness and remoteness of the area add to the adventure of conducting cutting-edge astronomy.

26 April 2010: NGC 253, also known as the Sculptor Galaxy, is the brightest of the Sculptor Group of galaxies, found in the constellation of the same name, and lying approximately 13 million light-years from Earth. The Sculptor Galaxy is known as a starburst galaxy for its current high rate of star formation, one result of which is its superwind, a stream energetic material spewing out from the centre of the galaxy out into space. The purple light comes from that frenzy of star formation, which originally began 30 million years ago, while the yellowish colour is created by dust lit up by young, massive stars. This image combines observations performed through three different filters (B, V, R) with the 1.5-metre Danish telescope at the ESO La Silla Observatory in Chile.

19 April 2010: Gas and dust condense, beginning the process of creating new stars in this image of Messier 8, also known as the Lagoon Nebula. Located four to five thousand light-years away, in the constellation of Sagittarius (the Archer), the nebula is a giant interstellar cloud, one hundred light-years across. It boasts many large, hot stars, whose ultraviolet radiation sculpts the gas and dust into unusual shapes. Two of these giant stars illuminate the brightest part of the nebula, known as the Hourglass Nebula, a spiralling, funnel-like shape near its centre. Messier 8 is one of the few star-forming nebulae visible to the unaided eye, and was discovered as long ago as 1747, although the full range of colours wasn’t visible until the advent of more powerful telescopes. The Lagoon Nebula derives its name from the wide lagoon-shaped dark lane located in the middle of the nebula that divides it into two ...

12 April 2010: Home to some of the largest stars ever discovered, the open stellar cluster Pismis 24 blazes from the core of NGC 6357, a nebula in the constellation of Scorpius (the Scorpion). Several stars in the clusters weigh in at over 100 times the mass of the Sun, making them real monster stars. The strange shapes taken by the clouds are a result of the huge amount of blazing radiation emitted by these massive, hot stars. The gas and dust of the nebula hide huge baby stars in the nebula from telescopes observing in visible light, as well as adding to the hazy appearance of the image. This image combines observations performed through three different filters in visible light (B, V, R) with the 1.5-metre Danish telescope at the ESO La Silla Observatory in Chile.

5 April 2010: This panoramic image shows the La Silla observatory glistening under the cool glow of moonlight. Because the image wraps around almost a full 360 degrees, the angle of the lighting becomes downright surreal; notice how the photographer’s shadow seems to stretch towards the Moon, and how the shiny ESO 3.6-metre telescope in the foreground appears to reflect light from a source located opposite the Moon. Fortunately, such optical trickery does not trouble La Silla’s fleet of telescopes, which reside at an altitude of 2,400 metres in the arid Chilean Atacama Desert. In fact, La Silla’s MPG/ESO 2.2-metre telescope has snapped some of astronomy’s iconic images with the Wide Field Imager (WFI) camera. Also at this observatory, the 3.58-metre New Technology Telescope (NTT) broke new ground for telescope engineering and design and was the first in the world to have a computer-controlled main mirror (active optics), a technology developed at ESO ...

29 March 2010: A European antenna for ALMA, the Atacama Large Millimeter/submillimeter Array, is placed on its base. The 12-metre diameter reflecting dish is attached to the base, with the whole structure weighing over 100 tonnes. When complete, the reflecting surface of the dish will be accurate to less than the thickness of a sheet of paper, and the antenna will be able to point precisely enough to pick out a golf ball at a distance of 15 kilometres. This is the second European antenna to be assembled at the 2,900-metre altitude Operations Support Facility in Chile. The antennas will ultimately be transported to the Chajnantor plateau, 5000 metres above sea level in the Chilean Andes. ALMA, which will comprise 66 giant 12-metre and 7-metre diameter antennas observing the Universe at millimetre and submillimetre wavelengths, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ESO ...

22 March 2010: NGC 5189 is a planetary nebula with an oriental twist. Similar in appearance to a Chinese dragon, these red and green cosmic fireworks are the last swansong of a dying star. At the end of its life, a star with a mass less than eight times that of the Sun will blow its outer layers away, giving rise to a planetary nebula. Some of these stellar puffballs are almost round, resembling huge soap bubbles or giant planets (hence the name), but others, such as NGC 5189 are more intricate. In particular, this planetary nebula exhibits a curious “S”-shaped profile, with a central bar that is most likely the projection of an inner ring of gas discharged by the star, seen edge on. The details of the physical processes producing such a complex symmetry from a simple, spherical star are still the object of astronomical controversy. One possibility is that the ...

15 March 2010: Solargraphy, the art of using a single long-term exposure with a pinhole camera to photograph the movement of the Sun over the course of many weeks, helps show just why Cerro Paranal in northern Chile makes the perfect home for ESO’s Very Large Telescope (VLT). The pinhole camera, made from a small film canister and a piece of photographic paper, was placed on the roof of the VLT control building by Gerd Hüdepohl from 15 October to 26 December 2009, covering spring in the southern hemisphere. The white streaks across the top of the image are the Sun’s progress across the sky over the whole period. When clouds come between the Sun and the camera, breaks in the streak form but, as can be seen here, no clouds obscured the sky during the entire exposure. Perfect astronomy weather in other words! The VLT’s Unit Telescope 1 is visible as a ...

8 March 2010: The European Southern Observatory’s Headquarters chills out in the snow beneath the full Moon one late afternoon in January. The winter snows at the Garching technical campus north of Munich, Germany make a stark contrast to the dry deserts of ESO’s observatories in Chile. ESO Headquarters is the scientific, technical and administrative centre of ESO and is where technical development programmes are carried out, providing the observatories with the most advanced instruments in the world. It is also home to the Space Telescope — European Coordinating Facility, operated jointly by ESO and the European Space Agency. This image is available as a mounted image in the ESOshop.

1 March 2010: Glowing in the cosmos at a distance of about 50 million light-years away, the galaxy NGC 936 bears a striking resemblance to the Twin Ion Engine (TIE) starfighters used by the evil Dark Lord Darth Vader and his crew in the epic motion picture Star Wars. The galaxy’s shiny bulge and a bar-like structure crossing it bring to mind the central engine and cockpit of the spacecraft; while a ring of stars surrounding the galactic core completes the parallel, corresponding to the wings of the TIE fighters that are equipped with solar panels. This galaxy harbours exclusively old stars and shows no sign of any recent star formation. Bars such as that observed in NGC 936 are common features of galaxies; however, this one is significantly more marked than average. Although a perfect symbol for the dark side of the “Force”, it is still debatable whether this galaxy is dominated, ...

22 February 2010: In this dazzling image, the galaxy NGC 1427A is seen as it travels through the Fornax cluster of galaxies, to which it belongs. NGC 1427A is an example of a dwarf irregular galaxy, a type of galaxy that is significantly less bright than regular galaxies and characterised by a peculiar shape. In this particular case, the shape of the galaxy has been forged by its rapid, upwards motion through the cluster: with a speed of two million kilometres per hour relative to the cluster, NCG 1427A is being torn apart and will eventually be disrupted. The interaction with the Fornax cluster has led to the birth of many stars, seen here as a boomerang-shaped region of young, glowing stars in the galaxy. NGC 1427A exhibits a striking resemblance to one of our galactic neighbours, the Large Magellanic Cloud, which has undergone similar episodes of star formation, triggered by its interaction ...

15 February 2010: Portrayed in this image is the spiral galaxy NGC 4945, a close neighbour of the Milky Way. Belonging to the Centaurus A group of galaxies, it is located at a distance of almost 13 million light-years. Showing a remarkable resemblance to our own galaxy, NGC 4945 also hides a supermassive black hole behind the thick, ring-shaped structure of dust visible in the picture. But, unlike the black hole at the centre of our Milky Way, the million-solar-mass black hole inside NGC 4945 is an Active Galactic Nucleus that is frantically consuming any surrounding matter, and so releasing tremendous amounts of energy. This image combines observations performed through three different filters (B, V, R) with the 1.5-metre Danish telescope at the ESO La Silla Observatory in Chile.

8 February 2010: A bird soaring over the remote, sparsely populated Atacama Desert in northern Chile — possibly the driest desert in the world — might be surprised to come upon the technological oasis of ESO’s Very Large Telescope (VLT) at Paranal. The world’s most advanced ground-based facility for astronomy, the site hosts four 8.2-metre Unit Telescopes, four 1.8-metre Auxiliary Telescopes, the VLT Survey Telescope (VST), and the 4.1-metre Visible and Infrared Survey Telescope for Astronomy (VISTA), seen in the distance on the next mountain peak over from the main platform. This aerial view also shows other structures, including the Observatory Control Room building, on the main platform’s front edge.

1 February 2010: This aerial photograph shows the summit of Cerro Paranal in northern Chile, the home of ESO’s Very Large Telescope (VLT). This flagship facility for ground-based astronomy hosts four 8.2-metre Unit Telescopes along with four mobile 1.8-metre Auxiliary Telescopes. These can work together, in groups of two or three, as one giant telescope, known as the VLT Interferometer, or VLTI. This image displays the winding access road that leads up to the observing platform as well as the Observatory Control Room in the front. The picture helps give a sense of the remoteness of the VLT site, which is located in the extremely arid Atacama Desert at an altitude of 2600 metres. The first Unit Telescope began operations at Paranal in 1999. The VLT Survey Telescope, which is scheduled to begin observations in 2010, is missing from this photo, taken in 2004.

25 January 2010: This impressive vertical panorama shows the ESO 3.6-metre telescope in great detail. The telescope is located on the 2400 m high La Silla mountain, home of ESO’s first observing site in the southern edges of the Atacama Desert. Equipped with HARPS, the best exoplanet finder in the world, the ESO 3.6-metre telescope was commissioned in 1977 and completely upgraded in 1999. The primary mirror is located below the dark protective cover, and the large black structure above holds the secondary mirror. The white cube on top of the secondary mirror mount contains the computer that controls the secondary mirror.

18 January 2010: This architectural concept drawing of ESO’s planned Extremely Large Telescope (ELT) shows the world’s largest planned optical telescope gazing heavenwards. Slated to begin operations early in the next decade, the ELT will tackle the biggest scientific challenges of our time. A chief goal will be to track down Earth-like planets around other stars in the “habitable zones” where life could exist — one of the Holy Grails of modern observational astronomy. The ELT will also make fundamental contributions to cosmology by measuring the properties of the first stars and galaxies and probing the nature of dark matter and dark energy. On top of this, astronomers are also planning for the unexpected — new and unforeseeable questions will surely arise from the discoveries made with the ELT. With a primary mirror measuring an astounding 39 metres across, the ELT will collect 25 times more light than one 8.2-metre telescope at ESO’s ...

11 January 2010: This image beautifully captures the zodiacal light, a triangular glow seen best in night skies free of overpowering moonlight and light pollution. The photograph was taken at ESO’s La Silla Observatory in Chile in September 2009, facing west some minutes after the Sun had set. A sea of clouds has settled in the valley below La Silla, which sits at an altitude of 2400 metres, with lesser peaks and ridges poking through the mist. The zodiacal light is sunlight reflected by dust particles between the Sun and Earth, and is best seen close to sunrise or sunset. As its name implies, this celestial glow appears in the ring of constellations known as the zodiac. These are found along the ecliptic, which is the eastward apparent “path” that the Sun traces across Earth’s sky.

4 January 2010: This image shows the interior of one of the four 8.2-metre Unit Telescopes at ESO’s Very Large Telescope (VLT) in Paranal, Chile. Designated Unit Telescope 1, or UT1, and named Antu, this complex science machine has been in operation at Paranal since 1999. Just before sunset, technicians retract UT1’s windshield and work to finalise the preparations at the telescope for the night-time observation run. During the day, the enclosure is kept shut to protect the delicate and valuable scientific equipment inside, as well as to ensure minimal temperature differences between the telescope and the atmosphere at opening. To the left of the telescope’s main mirror housing, in the centre of the image, is the Infrared Spectrometer And Array Camera (ISAAC), which was, until recently, attached to this instrument. It has now been moved to another of the Unit Telescopes, UT3 or Melipal. This image is available as a mounted image ...