Picture of the Week 2011

8 August 2011

Dark Sky and White Desert — Snow pays a rare visit to ESO’s Paranal Observatory

The night sky above Cerro Paranal, the home of ESO’s Very Large Telescope (VLT), is dark and dotted with the bright stars of the Milky Way, and more distant galaxies. But it is very rare to see the ground contrasting with the sky as markedly as in this photograph, which shows a gentle layer of white snow dotted with darker spots of the desert terrain beneath.

The picture was taken last week, shortly before sunrise, by ESO Photo Ambassador Yuri Beletsky, who works as an astronomer at the La Silla Paranal Observatory. He captured not only the beautiful snowy landscape of the Atacama and the mountaintop domes of the VLT, but also an incredible night sky. To the left of the VLT is a satellite trail, and to the right is the trail of a meteor.

Cerro Paranal is a 2600-metre-high mountain located in the Chilean Atacama Desert. It is a very dry place with humidity often dropping below 10 percent and rainfall of less than 10 millimetres per year. Snow, however, does occasionally fall in the desert, providing fleeting but magnificent views such as this one.



1 August 2011

Smoke Signals in Space

The hazy and aptly named Fine Ring Nebula, shown here, is an unusual planetary nebula. Planetary nebulae form when some dying stars, having expanded into a red giant phase, expel a shell of gas as they evolve into white dwarfs. Most planetary nebulae are either spherical or elliptical in shape, or bipolar (featuring two symmetric lobes of material).

But the Fine Ring Nebula — captured here by the ESO Faint Object Spectrograph and Camera mounted on the New Technology Telescope at the La Silla Observatory in Chile — looks like an almost perfect circular ring. Astronomers believe that some of these more unusually shaped planetary nebulae are formed when the progenitor star is actually a binary system. The interaction between the primary star and its orbiting companion shapes the ejected material.

The stellar object at the centre of the Fine Ring Nebula is indeed thought to be a binary system, orbiting with a period of 2.9 days. Observations suggest that the binary pair is almost perfectly face-on from our vantage point, implying that the planetary nebula’s structure is aligned in the same way. We are looking down on a torus (doughnut shape) of ejected material, leading to the strikingly circular ring shape in the image.

Planetary nebulae are shaped by the complex interplay of many physical processes. Not only can these celestial objects be admired for their beauty, but the study of precisely how they form their striking shapes is a fascinating topic in astronomical research.

This image was made using multiple filters: light observed through B and O-III filters is shown in blue, V is shown in green, R is shown in orange, and H-alpha in red. The image is approximately 200 arcseconds across.

25 July 2011

Very Large Telescope Ready for Action

This unusual 360-degree panoramic projection reveals the observing site from a fresh perspective. In the centre of the image, staff at Paranal have gathered to watch the sunset. On the right, the enclosures of the VLT’s Unit Telescopes can be seen: vast machines, each with a primary mirror 8.2 metres across and weighing 23 tonnes. Also visible are several of the smaller 1.8-metre Auxiliary Telescopes, which complement the Unit Telescopes. On the left of the picture is the control building, from where the telescopes are operated remotely during observations. No one remains inside the telescope domes after they are opened.

Since first light in 1998 the Very Large Telescope has been used by ESO astronomers to study the Universe, including some of the most exotic phenomena known, such as exoplanets, supermassive black holes, and gamma-ray bursts.

An amazing interactive virtual tour of Paranal is available here.

18 July 2011

Hidden Treasure on Our Doorstep

The MPG/ESO 2.2-metre telescope at La Silla in Chile is a powerful instrument that can capture distant celestial objects, but it has been used here to image a heavenly body that is much closer to home: the Moon. The data used for this image were selected by Andy Strappazzon from Belgium, who participated in ESO’s Hidden Treasures 2010 astrophotography competition. Andy’s composition of the Moon was the fourth highest ranked entry in the competition.

This image of the crescent Moon shows sunlight skimming across the heavily pocked surface, filling its craters with shadows. This is a fairly flat region of the Moon, but elsewhere, high mountains can be found, with some peaks reaching about 5000 metres. When backlit by the Sun, these mountains cast long shadows on the lunar surface. In the 1600s, Galileo Galilei used these long shadows to determine the height of the peaks.

At the Moon’s poles (not seen in this picture), some craters are permanently shadowed and the floors of some may have not seen sunlight for billions of years. Scientists had long suspected that these dark and constantly cold regions of the Moon could harbour water ice, but it wasn’t until late 2009 that evidence for this was found.

In a NASA mission called LCROSS (Lunar Crater Observation and Sensing Satellite), a spent rocket booster was sent on a one-way collision course to the Moon’s south pole, while the remaining part of the spacecraft hunted for evidence of water in the ejected debris. The mission was a success and its findings confirmed the presence of water ice within these dark craters. The finding has important implications for the future of human exploration of the Moon and elsewhere in the Solar System.

This view of the Moon was taken through a narrowband red filter (H-alpha). The height of the image is about 30 arcminutes.

This image was processed by ESO using the observational data found by Andy Strappazzon (Belgium) [1], who participated in ESO’s Hidden Treasures 2010 astrophotography competition [2], organised by ESO in October–November 2010, for everyone who enjoys making beautiful images of the night sky using astronomical data obtained with professional telescopes.


[1] Andy searched through ESO’s archive and identified datasets that he used to compose his image of the Moon, which was the fourth highest ranked entry in the competition, out of almost 100 entries. His original work can be seen here.

[2] ESO’s Hidden Treasures 2010 competition gave amateur astronomers the opportunity to search through ESO’s vast archives of astronomical data, hoping to find a well-hidden gem that needed polishing by the entrants. To find out more about Hidden Treasures, visit http://www.eso.org/public/outreach/hiddentreasures/.

11 July 2011

A Galactic Embrace

Two galaxies, about 50 million light-years away, are locked in a galactic embrace — literally. The Seyfert galaxy NGC 1097, in the constellation of Fornax (The Furnace), is seen in this image taken with the VIMOS instrument on ESO’s Very Large Telescope (VLT). A comparatively tiny elliptical companion galaxy, NGC 1097A, is also visible in the top left. There is evidence that NGC 1097 and NGC 1097A have been interacting in the recent past.

Although NGC 1097 seems to be wrapping its companion in its spiral arms, this is no gentle motherly giant. The larger galaxy also has four faint jets — too extended and faint to be seen in this image — that emerge from its centre, forming an X-shaped pattern, and which are the longest visible-wavelength jets of any known galaxy. The jets are thought to be the remnants of a dwarf galaxy that was disrupted and cannibalised by the much larger NGC 1097 up to a few billion years ago.

These unusual jets are not the galaxy’s only intriguing feature. As previously mentioned, NGC 1097 is a Seyfert galaxy, meaning that it contains a supermassive black hole in its centre. However, the core of NGC 1097 is relatively faint, suggesting that the central black hole is not currently swallowing large quantities of gas and stars. Instead, the most striking feature of the galaxy’s centre is the ring of bright knots surrounding the nucleus. These knots are thought to be large bubbles of glowing hydrogen gas about 750–2500 light-years across, ionised by the intense ultraviolet light of young stars, and they indicate that the ring is a site of vigorous star formation

With this distinctive central star-forming ring, and the addition of numerous bluish clusters of hot, young stars dotted through its spiral arms, NGC 1097 makes a stunning visual object.

The data were originally taken in 2004 (see eso0438) with the VIMOS instrument on the VLT, and additional colour information from an image taken by amateur astronomer Robert Gendler has been superimposed. The VLT data were taken through three visible-light filters: R (at a wavelength of 652 nanometres, and shown here in red), V (a wavelength of 540 nanometres, shown in green), and B (456 nanometres, shown in blue). The image covers a region of approximately 7.7 x 6.6 arcminutes on the sky.

4 July 2011

A VLT Auxiliary Telescope and Cerro Armazones

ESO Photo Ambassador Gianluca Lombardi was in the perfect position to capture a crisp dusk view of Auxiliary Telescope (AT) 2, on Cerro Paranal. Once the Sun sets, the cloudless skies above the Chilean desert will be filled with stars, and AT2 will begin its work. In the background on the left is Cerro Armazones, with a road zigzagging to its peak, home of the future European Extremely Large Telescope. Site-testing equipment can be seen on the peak. The lower peak to the right of Cerro Armazones is the site of smaller telescopes operated by the Instituto de Astronomía of the Universidad Católica del Norte.

There are four ATs on Cerro Paranal, which form part of the Very Large Telescope (VLT). They are used for a special technique called interferometry, which allows multiple ATs, or the even larger Unit Telescopes, to combine their power and see details up to 25 times finer possible than with the individual telescopes.

The round AT enclosure shown in the photo is made from two sets of three segments, which were closed at the time the picture was taken. Its job is to protect the delicate 1.8-metre telescope from the desert conditions. The enclosure is supported by the boxy transporter section, which also contains electronics cabinets, liquid cooling systems, air-conditioning units, power supplies, and more. During astronomical observations the enclosure and transporter are mechanically isolated from the telescope, to ensure that no vibrations compromise the data collected.

The transporter section runs on tracks, so the ATs can be moved to 30 different observing locations. As the VLT Interferometer (VLTI) acts rather like a single telescope as large as the group of telescopes combined, changing the positions of the ATs means that the VLTI can be adjusted according to the needs of the observing project.


27 June 2011

Hiding in Plain Sight — the elusive Carina Dwarf Galaxy

It’s one of the closest galaxies to Earth, but the Carina Dwarf Galaxy is so dim and diffuse that astronomers only discovered it in the 1970s. A companion galaxy of the Milky Way, this ball of stars shares features with both globular star clusters and much larger galaxies.

Astronomers believe that dwarf spheroidal galaxies like the Carina Dwarf are very common in the Universe, but they are extremely difficult to observe. Their faintness and low star density mean that it is easy to simply see right through them. In this image, the Carina Dwarf appears as many faint stars scattered across most of the central part of the picture. It is hard to tell apart stars from the dwarf galaxy, foreground stars within the Milky Way and even faraway galaxies that poke through the gaps: the Carina Dwarf is a master of cosmic camouflage.

The Carina Dwarf’s stars show an unusual spread of ages. They appear to have formed in a series of bursts, with quiet periods lasting several billion years in between them. It lies around 300 000 light-years from Earth, which places it further away than the Magellanic Clouds (the nearest galaxies to the Milky Way), but significantly closer to us than the Andromeda Galaxy, the closest spiral galaxy.

So, despite being small for a galaxy, its proximity to Earth means that the Carina Dwarf appears quite large in the sky, just under half the size of the full Moon — albeit very much fainter. This makes it fit comfortably within the field of view of ESO’s Wide Field Imager, an instrument designed for making observations of large parts of the sky. Although this image in itself is not so striking, it is likely the best image of the Carina Dwarf Galaxy to date.

The image was made using observations from the Wide Field Imager on the MPG/ESO 2.2-metre telescope at La Silla, and from the Victor M. Blanco 4-metre telescope at the Cerro Tololo Inter-American Observatory.

20 June 2011

A Blood Moon over ESO’s Headquarters

After nightfall on 15 June 2011 in Garching, near Munich, Germany, a blood-red Moon rose above the horizon. This striking phenomenon was caused by a total lunar eclipse in progress at moonrise, and it was captured in the skies over the European Southern Observatory’s Headquarters.

A lunar eclipse takes place only when the Moon, Earth and Sun are exactly aligned. When the Moon passes through the shadow cast by the Earth, our planet blocks the path of direct sunlight to the lunar surface and a total eclipse occurs. This event can only happen on the night of a full Moon.

Unlike the better known solar eclipses, the Moon doesn’t completely disappear from sight during a total lunar eclipse. Instead it appears painted blood red, giving it the ominous nickname of “blood Moon”. The reddish colour is caused by scattered sunlight that has passed through the Earth’s atmosphere — the same effect that causes sunsets and sunrises to turn the sky a reddish colour.

Last week’s eclipse was rare in that it was the longest total lunar eclipse in more than a decade, lasting almost two hours. The year 2000 saw the last lunar eclipse lasting as long as this one, while the next won’t occur until 2018.

ESO’s Headquarters in Garching function as an administrative and technical centre for ESO’s operations, with astronomers from all over the world gathering here to carry out cutting-edge scientific research.

13 June 2011

By the Light of the Moon

ESO Photo Ambassador Gianluca Lombardi used a remote shutter release and a 30-second exposure to take this night-time shot of himself sitting on a railing on the observing platform of the ESO Very Large Telescope (VLT). The VLT is on Cerro Paranal, at an altitude of 2600 metres in Chile’s Atacama Desert, one of the driest regions on Earth. The viewing conditions at Paranal are so superb that on a clear moonless night it is possible to see shadows cast by the light of the Milky Way alone.  

In this photograph, however, the Moon is up, appearing as a bright light due to the long exposure. It is about to dip behind the VLT’s Unit Telescope 4 (UT4), named Yepun, and the shadows thrown by the moonlight are lengthening across the 200-metre width of the observing platform. The other three UTs stand in the background. From left to right they are known as Antu (UT1), Kueyen (UT2), and Melipal (UT3) in the indigenous Mapuche language. One of the four 1.8-metre Auxiliary Telescopes, distinguishable by its round enclosure, is visible in front of Antu, on the left.


6 June 2011

A Slice of the Sky

This spectacular approximately 230-degree panoramic photograph of ESO’s Very Large Telescope (VLT), taken by ESO Photo Ambassador Gerhard Hüdepohl, gives us an inspiring view of a slice of the sky, encompassing both our nearest celestial neighbour and star clusters hundreds of light-years away.

The VLT’s four large Unit Telescopes dominate the foreground. With gigantic mirrors 8.2 metres across, they allow us to peer into space and see things four billion times fainter than we can see with our eyes alone. Also visible are the round enclosures of the four 1.8-metre Auxiliary Telescopes, one to the left of the Unit Telescopes and three to the right. This observatory has an excellent location, on Cerro Paranal in the Chilean Atacama Desert. It is so high, at 2600 metres altitude, that what looks like the rippling ocean to the west, on the left of the image, is in fact the cloud layer below the mountaintop. The Pacific Ocean is indeed in this direction, but lies below the clouds. 

The slice of sky visible in the photograph contains a wealth of astronomical objects, including several that are well known. The bright orb above the blanket of cloud is actually the Moon, which is illuminating the telescopes, and also the sky. Soon it will dip below the horizon and a deeper darkness will cover the mountain.

Just above the Moon is what appears to be a bright star, but is in fact the planet Jupiter. A large gas giant, it is one of the brightest celestial objects in the night sky. The tightly grouped collection of stars near the top middle of the photograph is a cluster called the Pleiades, often known as the Seven Sisters. Above the Unit Telescope second from the left is the bright star Capella, while the stars Pollux and Castor, which represent the heads of Gemini (The Twins), can be seen above and slightly to the right of the right-most Unit Telescope. Above the shadowed Auxiliary Telescope to the right is the open cluster Praesepe, also known as the Beehive Cluster, or Messier 44. Above it, near the top of the image, is the bright star Procyon.


30 May 2011

European Antennas Under Construction

This is a helicopter view of the Atacama Large Millimeter/submillimeter Array (ALMA) Operations Support Facility (OSF) site. In the foreground is the AEM Consortium’s [1] facility where the European antennas are assembled and tested. Seven of the 25 European antennas can be seen, pointing towards the sky. More parts, including a receiver cabin and antenna base, await the next assembly. Each antenna has a dish 12 metres in diameter, and weighs about 95 tonnes.

Once an antenna is assembled and ready, it is handed over to the ALMA project and moved to the nearby OSF technical area, which is the area in the background, where more antennas can be seen. Here, it is integrated into the rest of the observatory’s systems. Finally, after further tests by the ALMA team, it is moved from the 2900 metres high OSF to its workplace, the Array Operation Site (AOS), located at an altitude of 5000 metres on the Chajnantor Plateau.

Also in the background, the two bright yellow ALMA antenna transporter vehicles, which are responsible for moving the antennas around and between the OSF and AOS sites, can be seen in their parking area. Further in the distance are the majestic snow-covered peaks of the high Andes, with the distinctive conical shape of the 5920-metre Licancabur volcano on the right.

ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ESO, the European partner in ALMA, is providing 25 12-metre antennas through a contract with the European AEM Consortium. ALMA will also have 25 North American antennas, and 16 East Asian antennas.


[1] The AEM Consortium is composed of Thales Alenia Space, European Industrial Engineering, and MT-Mechatronics.

23 May 2011

First 7-metre ALMA Antenna Handed Over to Observatory

The first of twelve 7-metre antennas has been handed over to the Atacama Large Millimeter/submillimeter Array (ALMA) observatory in Chile. ALMA will have an array of fifty antennas with 12-metre diameter dishes, as well as a system known as the Atacama Compact Array (ACA), provided by Japan, of which this new 7-metre antenna is part. The ACA will have a total of twelve 7-metre dishes and four 12-metre dishes, and will be particularly important for ALMA’s observations of the broader structure in extended astronomical objects such as giant clouds of molecular gas.

The 7-metre antenna is seen here at the ALMA Operations Support Facility (OSF), at an altitude of 2900 metres in the foothills of the Chilean Andes. These antennas are being provided by Japan through a contract with MELCO (Mitsubishi Electric Corporation).

The antennas are manufactured in Japan, then disassembled and shipped to Chile. They are reassembled and tested at the OSF, before being handed over to the observatory. After further testing, and the installation of sensitive receivers, each of the antennas will take its place — together with antennas from the other ALMA partners — on the plateau of Chajnantor at 5000 metres altitude, where the ALMA telescope will operate.

ALMA is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ESO is the European partner in ALMA.


16 May 2011

The Czech President’s Galaxy

This new image of the spiral galaxy NGC 3244 was taken with the help of the President of the Czech Republic, Václav Klaus, during his visit to ESO’s Paranal Observatory [1], on the night of 6 April 2011. The Czech Republic joined ESO in 2007, and this was the first visit of the country’s President to an ESO site.

This galaxy has attracted considerable interest from astronomers over the past nine months, thanks to the violent death of one of its stars, which was discovered on 27 June 2010. This supernova explosion, now known as Supernova 2010ev (SN 2010ev), is still visible as the — now faint — blue dot nestled within one of the thick spiral arms just to the left of the galaxy’s nucleus.

To the right of  the galaxy, an unremarkable foreground star in our own Milky Way, TYC 7713-527-1, shines brightly enough to catch our attention. Although the star seems a great deal brighter than SN 2010ev, this is actually an illusion created by the large difference in the distances of the two objects. The galaxy is much further away, at a distance of about 90 million light years, while the star lies thousands of times closer, within our own galaxy.

At its brightest, SN 2010ev reached an apparent magnitude of about 14, making it about 1000 times dimmer than the naked eye can see, but it was still the third brightest supernova observed in 2010. In fact, if the supernova had been as close to Earth as TYC 7713-527-1, it would have been easily visible to the naked eye, unlike the aforementioned star.

The image was taken using the FORS2 instrument on the ESO Very Large Telescope (VLT). The filters used for the image were B, V and R, which were coloured blue, green and red respectively. A framed print of the President’s Galaxy has been presented to Václav Klaus, as a memento of his visit to Paranal.


[1] For more information about the visit of the President of the Czech Republic, Václav Klaus, see the organisation release


9 May 2011

Eclipsed Moon, Striking Night Sky

A total eclipse of the Moon is an impressive spectacle. But it also provides another viewing opportunity: a dark, moonlight-free starry sky. At Cerro Paranal in the Chilean Atacama Desert, one of the most remote places in the world, the distance from sources of light pollution makes the night sky all the more remarkable during a total lunar eclipse.  

This panorama photo, taken by ESO Photo Ambassador Yuri Beletsky, shows the view of the starry sky from the site of ESO’s Very Large Telescope (VLT) at Cerro Paranal during the total lunar eclipse of 21 December 2010. The reddish disc of the Moon is seen on the right of the image, while the Milky Way arches across the heavens in all its beauty. Another faint glow of light is also visible, surrounding the brilliant planet Venus in the bottom left corner of the picture. This phenomenon, known as zodiacal light, is produced by sunlight reflecting off dust in the plane of the planets. It is so faint that it’s normally obscured by moonlight or light pollution.    

During a total lunar eclipse, the Earth’s shadow blocks direct sunlight from the Moon. The Moon is still visible, red in colour because only light rays at the red end of the spectrum are able to reach the Moon after being redirected through the Earth’s atmosphere (the blue and green light rays are scattered much more strongly).

Interestingly the Moon, which appears above one of VLT’s Unit Telescopes (UT2), was being observed by UT1 that night. UT1 and UT2 are also known as Antu (meaning The Sun in Mapudungun, one of Chile’s native languages) and Kueyen (The Moon), respectively.



2 May 2011

Planetary Conjunction over Paranal

ESO Photo Ambassador Gerhard Hüdepohl has captured yet another rare sight.

Yesterday, in the morning of 1 May 2011, about an hour before sunrise, five of our Solar System’s eight planets and the Moon could be seen from Paranal. The four planets in the sky were Mercury, Venus, Mars and Jupiter, and they were joined by the crescent Moon to create this wonderful photo opportunity of a planetary conjunction — two or more celestial bodies seen near each other in the sky, usually from the Earth.

In this photo, the bright crescent of the Moon is illuminated by the Sun (which is just below the horizon), while the darker part receives only light reflected from the surface of the Earth. Venus is the highest and brightest planet, with Mercury below and to the right. Jupiter is directly below Venus, but much closer to the horizon. Mars can be seen just below and to the left of Jupiter; the separation in the sky was less than half a degree. The fifth planet in the photograph is of course the Earth, providing our vantage point for this spectacular conjunction.

This view from Cerro Paranal shows some nearby, and more distant, mountain peaks in the Atacama Desert, one of the driest places on this planet. Three of the ESO Very Large Telescope’s 1.8-metre Auxiliary Telescopes (ATs) are silhouetted in the foreground. Just to the right of the leftmost AT is Cerro Armazones, site of the future European Extremely Large Telescope (E-ELT). Armazones is about 20km from Paranal. Between the ATs on the right is the distant volcano Llullaillaco, on the border of Chile and Argentina. It is much further away than Armazones, at a distance of 190km, but the exceptionally clear atmospheric conditions in the Atacama Desert provide a razor-sharp view, despite the distance. These conditions also help to make the region one of the best in the world for astronomical observations.

The image without annotations can be downloaded from: http://www.eso.org/public/images/potw1118a_clean/


25 April 2011

Rare Moon Green Flash Captured

On Cerro Paranal, the 2600-metre-high mountain in Chile’s Atacama Desert that is home to ESO’s Very Large Telescope, the atmospheric conditions are so exceptional that fleeting events such as the green flash of the setting Sun are seen relatively frequently. Now, however, ESO Photo Ambassador Gerhard Hüdepohl has captured an even rarer sight: a green flash from the Moon, instead of the Sun. The photographs are very probably the best ever taken of the Moon’s green flash.

Gerhard was surprised and delighted to catch the stunning green flash in this series of photographs of the setting full Moon crossing the horizon, taken on a clear early morning from the Paranal Residencia.

The Earth’s atmosphere bends, or refracts, light — rather like a giant prism. The effect is greater in the lower denser layers of the atmosphere, so rays of light from the Sun or Moon are curved slightly downwards. Shorter wavelengths of light are bent more than longer wavelengths, so that the green light from the Sun or Moon appears to be coming from a slightly higher position than the orange and red light, from the point of view of an observer. When the conditions are just right, with an additional mirage effect due to the temperature gradient in the atmosphere, the elusive green flash is briefly visible at the upper edge of the solar or lunar disc when it is close to the horizon.

Gerhard Hüdepohl was born in Germany, and has lived in Chile since 1997, where he works as an Electronics Engineer at ESO’s Very Large Telescope.

18 April 2011

On Top of the World

Some places on Earth can seem like alien environments, as this stunning 360 degree panorama shows. It is not the strange surface of an exoplanet, but rather the Chajnantor Plateau in the Chilean Andes. This unearthly location is home to ALMA, the Atacama Large Millimeter/submillimeter Array. Chajnantor was chosen because the rarefied atmosphere above this very high site is so dry that, unlike at most other places on Earth, it is largely transparent to the wavelengths of light that ALMA is designed to detect.

At the centre of the image, the darker, rounded shape of the peak of Cerro Chajnantor, 5600 metres high, can be spotted, followed slightly to the left in the far distance by the conical shape of the 5930-metre Licancabur volcano. The flat area in front, at an altitude of 5000 metres, is the Chajnantor Plateau, the ALMA Array Operations Site. Here the 66 ALMA antennas can be arranged in different configurations, where the maximum distance between antennas can vary from 150 metres to 16 kilometres. The clustered white peaks on the right in the foreground are penitentes, formed by the sublimation of snow in an extremely high altitude and very dry environment. This area of the Chilean Andes borders Bolivia and Argentina.

ALMA will give astronomers an unprecedented window on the cosmos, enabling groundbreaking studies into areas such as the physics of the cold Universe, the first stars and galaxies, and even directly imaging the formation of planets. ALMA, which will begin scientific observations in 2011, is the largest astronomical project in existence and is a truly global partnership between the scientific communities of East Asia, Europe and North America with Chile. ESO is the European partner in ALMA.

An amazing interactive virtual tour of Chajnantor is available here.

11 April 2011

ESO Headquarters at Sunset*

This panorama photograph shows the European Southern Observatory’s Headquarters in Garching, near Munich, Germany. The image shows the view from the roof of the main building just after sunset. This is the scientific, technical and administrative centre for ESO’s operations, and the base from which many astronomers conduct their research. The scientists, technicians and administrators who work here come from many different backgrounds, but all have one thing in common: a passion for astronomy.

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive astronomical observatory. ESO operates telescopes at three observing sites in Chile: La Silla, Paranal and Chajnantor. In addition, Cerro Armazones, near Paranal has been selected as the site for the European Extremely Large Telescope (E-ELT).

ESO provides state-of-the-art research facilities to astronomers and is supported by Austria, Belgium, Brazil, the Czech Republic, Denmark, Finland, France, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. The ESO Headquarters reflects this multicultural spirit of cooperation and is the workplace for astronomers from around the globe.


This image is available as a mounted image in the ESOshop.


4 April 2011

Bridging the Abyss

Deep in the Chilean Atacama Desert, far from sources of light pollution and other people-related disturbances, there is a tranquil sky like few others on Earth. This is the site for the European Southern Observatory's Very Large Telescope, a scientific machine at the cutting-edge of technology.

In this panoramic photograph, the Large and Small Magellanic Clouds — satellite galaxies of our own — glow brightly on the left, while the VLT’s Unit Telescope 1 stands vigil on the right. Appearing to bridge the gap between them is the Milky Way, the plane of our own galaxy. The seemingly countless stars give a sense of the true scale of the cosmos. Every night ESO astronomers rise to the challenge of studying this vista to make sense of the Universe.

This awe-inspiring image was taken by ESO Photo Ambassador Yuri Beletsky. Born in Belarus, Yuri now lives in Chile where he works as an astronomer. The dark skies above the Atacama Desert provide him with splendid opportunities to reveal the majesty of our cosmos, which he is keen to share.


28 March 2011

ALMA: Greater than the Sum of its Parts

When completed, the antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) will be spread across the Chajnantor plateau in the Chilean Andes over distances of up to 16 kilometres, but they will work in unison, to form what is known as an interferometer. In doing so, ALMA will be more powerful than the sum of its parts, acting like a single giant telescope as large as the whole collection of antennas.

The 66 ALMA antennas are not all the same. A main array of fifty antennas with 12-metre dishes will be complemented by the Atacama Compact Array (ACA) of twelve smaller 7-metre dishes and four additional 12-metre dishes. The ACA dishes are being constructed by Mitsubishi Electric Corporation (MELCO). Three of them are shown in this photograph of the MELCO Site Erection Facility at the ALMA Operations Support Facility (OSF) site. The OSF is at an altitude of 2900 metres, from which the completed dishes are transported along a 28 km road to the 5000-metre altitude of the Chajnantor plateau.

On the left is one of the 7-metre dishes, clearly smaller than its neighbours. The other two dishes both have a diameter of 12 metres, but subtle differences in their design can be seen. This is because the dish on the right was originally a prototype, used for testing during the early stages of the project, which has since been retrofitted with elements from the final design of the dish in the centre. Once ready, all these dishes will take their places on the high Chajnantor plateau.

The ALMA project is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ESO is the European partner in ALMA.

This photograph was taken by ESO Photo Ambassador José Francisco Salgado.


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