Picture of the Week

Subscribe to esonews mailing list.
potw1228 — Picture of the Week
The Cat's Paw Remastered
9 July 2012: The Cat’s Paw Nebula is revisited in a combination of exposures from the MPG/ESO 2.2-metre telescope and expert amateur astronomers Robert Gendler and Ryan M. Hannahoe. The distinctive shape of the nebula is revealed in reddish puffy clouds of glowing gas against a dark sky dotted with stars. The image was made by combining existing observations from the 2.2-metre MPG/ESO telescope of the La Silla Observatory in Chile (see ESO Photo Release eso1003) with 60 hours of exposures on a 0.4-metre telescope taken by Gendler and Hannahoe. The resolution of the existing 2.2-metre MPG/ESO telescope observations was combined (by using their “luminance” or brightness) with the colour information from Gendler and Hannahoe’s observations to produce a beautiful combination of data from amateur and professional telescopes. For example, the additional colour information brings out the faint blue nebulosity in the central region, which is not seen in the original ESO image, while ...
potw1227 — Picture of the Week
An Oasis for Astronomers — ESO’s Paranal Residencia Then and Now
2 July 2012: ESO turns fifty this year, and to celebrate this important anniversary, we are showing you glimpses into our history. Once a month during 2012, a special Then and Now comparison Picture of the Week shows how things have changed over the decades at the La Silla and Paranal Observatory sites, the ESO offices in Santiago de Chile, and the Headquarters in Garching bei München, Germany. Since February 2002 (see eso0205), the Paranal Residencia has provided accommodation for people working shifts at ESO’s flagship observatory site. Paranal, in Chile’s Atacama Desert, is the home of ESO’s Very Large Telescope (VLT). This month, our Then and Now photographs — both taken by ESO Photo Ambassador Gerhard Hüdepohl — give us a unique view of how this oasis in the desert was built. The historical photograph shows the Residencia under construction at the end of 2000. The building was designed by German architecture ...
potw1226 — Picture of the Week
Mars, 2099?
25 June 2012: On a cold dark night on Mars, in the middle of an arid desert, a narrow road lit by artificial lights winds its way up to a lonely human outpost on the top of an old mountain. Or at least, that’s what a science fiction fan might make of this almost unearthly view. The photograph actually shows ESO’s Paranal Observatory, home to the Very Large Telescope (VLT), on Earth. Nevertheless, it’s easy to imagine it as a future view of Mars, perhaps at the end of the century. Which is why Julien Girard, who took this photograph, calls it “Mars 2099”. Located at 2600 metres altitude, ESO’s Paranal Observatory sits in one of the driest and most desolate areas on Earth, in Chile’s Atacama Desert. The landscape is so Martian, in fact, that the European Space Agency (ESA) and NASA test their Mars rovers in this region. For example, an ...
potw1225 — Picture of the Week
Yepun’s Laser and the Magellanic Clouds
18 June 2012: One of the major enemies of astronomers is the Earth’s atmosphere, which makes celestial objects appear blurry when observed by ground-based telescopes. To counteract this, astronomers use a technique called adaptive optics, in which computer-controlled deformable mirrors are adjusted hundreds of times per second to correct for the distortion of the atmosphere. This spectacular image shows Yepun [1], the fourth 8.2-metre Unit Telescope of ESO’s Very Large Telescope (VLT) facility, launching a powerful yellow laser beam into the sky. The beam creates a glowing spot — an artificial star — in the Earth’s atmosphere by exciting a layer of sodium atoms at an altitude of 90 km. This Laser Guide Star (LGS) is part of the VLT’s adaptive optics system. The light coming back from the artificial star is used as a reference to control the deformable mirrors and remove the effects of atmospheric distortions, producing astronomical images almost as ...
potw1224 — Picture of the Week
Cascading Milky Way
11 June 2012: Many astronomical photographs capture stunning vistas of the skies, and this is no exception. However, there’s something unusual about this panorama. Behind ESO’s Very Large Telescope (VLT), two streams of stars seem to cascade down like waterfalls, or perhaps rise like smoke columns to the heavens. That’s because this panorama captures the entire dome of the sky, from the zenith down to the horizon, a full 360 degrees around. The two streams are in fact a single band: the plane of our galaxy, the Milky Way, as it arcs across the sky from horizon to horizon. As it passes overhead, it appears to spread out across the whole top edge of the panorama, due to the distortion needed to squeeze the full dome of the sky into a flat, rectangular image. To understand the picture, imagine that the far left side is attached to the far right, creating a loop ...
potw1223 — Picture of the Week
Computing at ESO Through the Ages — The amazing advance of technology
4 June 2012: ESO turns fifty this year, and to celebrate this important anniversary, we are showing you glimpses into our history. Once a month during 2012, a special Then and Now comparison Picture of the Week shows how things have changed over the decades at the La Silla and Paranal Observatory sites, the ESO offices in Santiago de Chile, and the Headquarters in Garching bei München, Germany. Our pair of photographs this month show how the computing power used by ESO has changed dramatically over time. Both photographs show Austrian astronomer Rudi Albrecht in front of ESO’s computer systems, but on dates separated by decades. In the historical image, taken in 1974 in the ESO offices in Santiago, Chile, we can see Albrecht, pencil in hand, poring over code in front of a teletype. He was working on software for the Spectrum Scanner attached to the ESO 1-metre telescope [1] located at ...
potw1222 — Picture of the Week
The Southern Milky Way Above ALMA
28 May 2012: ESO Photo Ambassador Babak Tafreshi snapped this remarkable image of the antennas of the Atacama Large Millimeter/submillimeter Array (ALMA), set against the splendour of the Milky Way. The richness of the sky in this picture attests to the unsurpassed conditions for astronomy on the 5000-metre-high Chajnantor plateau in Chile’s Atacama region. This view shows the constellations of Carina (The Keel) and Vela (The Sails). The dark, wispy dust clouds of the Milky Way streak from middle top left to middle bottom right. The bright orange star in the upper left is Suhail in Vela, while the similarly orange star in the upper middle is Avior, in Carina. Of the three bright blue stars that form an “L” near these stars, the left two belong to Vela, and the right one to Carina. And exactly in the centre of the image below these stars gleams the pink glow of the Carina ...
potw1221 — Picture of the Week
Icy Penitents by Moonlight on Chajnantor
21 May 2012: Babak Tafreshi, one of the ESO Photo Ambassadors, has captured a curious phenomenon on the Chajnantor plateau, the site of the Atacama Large Millimeter/submillimeter array (ALMA). These bizarre ice and snow formations are known as penitentes (Spanish for “penitents”). They are illuminated by the light of the Moon, which is visible on the right on the photograph. On the left, higher in the sky, the Large and Small Magellanic Clouds can be faintly seen, while the reddish glow of the Carina Nebula appears close to the horizon on the far left. The penitentes are natural marvels found in high-altitude regions, such as here in the Chilean Andes, typically more than about 4000 metres above sea level. They are thin spikes and blades of hardened snow or ice, which often form in clusters, with their blades pointing towards the Sun. They attain heights ranging from a few centimetres, resembling low grass, ...
potw1220 — Picture of the Week
Getting the VLT Ready for Even Sharper Images
14 May 2012: This 360 degree panorama shows one of ESO’s Very Large Telescope (VLT) Unit Telescopes (UT4) whilst it was recently briefly held prisoner by ESO’s engineers. It was surrounded by a temporary cage of scaffolding as part of the preparations for the new Adaptive Optics Facility (AOF). This project will convert UT4 into a fully adaptive telescope. The AOF will correct for the blurring effects of the Earth’s atmosphere and will allow much sharper images to be achieved with the HAWK-I and MUSE instruments. Many new components are being added to UT4 as part of the AOF. Among these is the deformable secondary mirror (DSM):  a thin-shell mirror, 1.1 metres in diameter, but just 2 millimetres thick. This mirror is thin enough to be easily deformed by more than a thousand actuators, up to a thousand times per second in order to counteract the atmosphere’s distortions. The DSM is the largest ...
potw1219 — Picture of the Week
Three Very Different Telescopes at La Silla
7 May 2012: ESO turns fifty this year, and to celebrate this important anniversary, we are showing you glimpses into its history. Once a month during 2012, a special Then and Now Picture of the Week shows how things have changed over the decades at the La Silla and Paranal observatory sites, the ESO offices in Santiago de Chile, and the Headquarters in Garching bei München, Germany. These two photographs were taken on the highest peak of La Silla, a mountain with an altitude of 2400 metres, at the edge of the Chilean Atacama Desert. La Silla was ESO’s first observatory site. The historical photograph, taken in 1975, shows some of the trucks and other equipment used for the construction of the dome of the ESO 3.6-metre telescope, which was underway behind the photographer. On the left are the water tanks for the site. In the modern-day photograph, three new telescopes have appeared, ...
potw1218 — Picture of the Week
Sun, Moon and Telescopes above the Desert
30 April 2012: The otherworldly beauty of Chile’s Atacama Desert, home of ESO’s Very Large Telescope (VLT), stretches to the horizon in this panorama. On Cerro Paranal, the highest peak in the centre of this image, are the four giant Unit Telescopes of the VLT, each of which has a mirror with a diameter of 8.2 metres. On the peak to the left of Cerro Paranal is the VISTA survey telescope. This 4.1-metre telescope surveys broad swathes of the heavens, searching for interesting targets which the VLT, as well as other telescopes on the ground and in space, will study in greater detail. This region offers some of the best conditions for viewing the night sky found anywhere on our planet. On the right of this 360-degree panorama, the Sun is setting over the Pacific Ocean, throwing long shadows across the mountainscape. On the left, the Moon gleams in the sky. Soon, the ...
potw1217 — Picture of the Week
The Moon and the Arc of the Milky Way
23 April 2012: ESO Photo Ambassador Stéphane Guisard captured this astounding panorama from the site of ALMA, the Atacama Large Millimeter/submillimeter Array, in the Chilean Andes. The 5000-metre-high and extremely dry Chajnantor plateau offers the perfect place for this state-of-the-art telescope, which studies the Universe in millimetre- and submillimetre-wavelength light. Numerous giant antennas dominate the centre of the image. When ALMA is complete, it will have a total of 54 of these 12-metre-diameter dishes. Above the array, the arc of the Milky Way serves as a resplendent backdrop. When the panorama was taken, the Moon was lying close to the centre of the Milky Way in the sky, its light bathing the antennas in an eerie night-time glow. The Large and Small Magellanic Clouds, the biggest of the Milky Way's dwarf satellite galaxies, appear as two luminous smudges in the sky on the left. A particularly bright meteor streak gleams near the Small ...
potw1216 — Picture of the Week
APEX Stands Sentry on Chajnantor
16 April 2012: The Atacama Pathfinder Experiment (APEX) telescope looks skyward during a bright, moonlit night on Chajnantor, one of the highest and driest observatory sites in the world. Astronomical treasures fill the sky above the telescope, a testament to the excellent conditions offered by this site in Chile’s Atacama region. On the left shine the stars that make up the tail of the constellation of Scorpius (The Scorpion). The scorpion’s “stinger” is represented by the two bright stars that are particularly close to each other. Reaching across the sky and looking like a band of faint, glowing clouds is the plane of the Milky Way. Between Scorpius and the next constellation to the right, Sagittarius (The Archer), which looms over APEX’s dish, a sparkling cluster of stars can be clearly seen. This is the open cluster Messier 7, also known as Ptolemy’s Cluster. Below Messier 7 and slightly to the right is ...
potw1215 — Picture of the Week
All Around Chajnantor — A 360-degree panorama
9 April 2012: Although Cerro Chico reaches the remarkable altitude of 5300 metres above sea level, it is only a small mountain in the majestic landscape of the Andean plateaux. Indeed, its own name means simply “small mountain” in Spanish. However, due to its position on the plateau of Chajnantor, the top of Cerro Chico offers an excellent and relatively easy-to-reach vantage point from which to enjoy this stunning view. This 360 degree panorama picture is centred on the northeast, where the highest volcanoes — most of them above 5500 metres — are seen. In the centre is Cerro Chajnantor itself. To the right, on the plateau, is the Atacama Pathfinder Experiment (APEX) telescope with Cerro Chascon behind it.  Further to the right, to the southeast, the Chajnantor plateau is almost fully visible. In addition to the APEX telescope, three Atacama Large Millimeter/submillimeter Array (ALMA) antennas can be seen, on the right. Many ...
potw1214 — Picture of the Week
La Silla, the First Home for ESO’s Telescopes — ESO’s first observatory site Then and Now
2 April 2012: ESO turns fifty this year, and to celebrate this important anniversary, we are showing you glimpses into our history. Once a month during 2012, a special Then and Now comparison Picture of the Week shows how things have changed over the decades at the La Silla and Paranal Observatory sites, the ESO offices in Santiago de Chile, and the Headquarters in Garching bei München, Germany. This historical image was taken around 1970 from the La Silla dormitories, located lower on the mountain than the telescope domes. The photo looks up towards the highest point of the mountain, on the left. The metallic structure visible near the top of this peak is not a telescope, but a water tank for the site. The white dome in the centre of the image is that of the ESO 1-metre Schmidt telescope, which started work in February 1972. On the far right of the ...
potw1213 — Picture of the Week
Wish You Were Here?
26 March 2012: French photographer Serge Brunier — one of ESO’s Photo Ambassadors — has created this seamless 360-degree panorama of the Chajnantor plateau in the Atacama Desert, where the Atacama Large Millimeter/submillimeter Array (ALMA) is under construction. The panorama projection has slightly warped the shapes of the ALMA antennas, but it still gives a sense of what it would be like to stand in the middle of this impressive new observatory. The 360 degree panorama view also demonstrates the complete isolation of the Chajnantor plateau; at an altitude of 5000 metres, the backdrop is almost featureless, except for a few mountain peaks and hilltops. Although constructing such an ambitious telescope project in a remote and harsh environment is challenging, the high altitude location is perfect for submillimetre astronomy.  That’s because water vapour in the atmosphere absorbs this type of radiation, but the air is much drier at high altitude sites such as ...
potw1212 — Picture of the Week
The VLT goes lion hunting
19 March 2012: The Very Large Telescope has captured another member of the Leo I group of galaxies, in the constellation of Leo (The Lion). The galaxy Messier 95 stands boldly face-on, offering an ideal view of its spiral structure. The spiral arms form an almost perfect circle around the galactic centre before they spread out, creating a mane-like effect of which any lion would be proud. Another, perhaps even more striking, feature of Messier 95 is its blazing golden core. It contains a nuclear star-forming ring, almost 2000 light-years across, where a large proportion of the galaxy’s star formation takes place. This phenomenon occurs mostly in barred spiral galaxies such as Messier 95 and our home, the Milky Way. In the Leo I group, Messier 95 is outshone by its brother Messier 96 (see potw1143). Messier 96 is in fact the brightest member of the group and — as “leader of the ...
potw1211 — Picture of the Week
A Dusting of Snow in the Atacama Desert
12 March 2012: The domes of ESO’s Very Large Telescope sit atop Cerro Paranal, basking in the sunlight of another glorious cloudless day. But something is different about this picture: a fine layer of snow has settled across the desert landscape. This isn’t something you see every day: quite the opposite in fact, as the Atacama Desert gets almost no precipitation. Several factors contribute to the dry conditions in the Atacama. The Andes mountain range blocks rain from the east, and the Chilean Coast Range from the west. The cold offshore Humboldt current in the Pacific Ocean creates a coastal inversion layer of cool air, which prevents rain clouds from developing. A region of high pressure in the south-eastern Pacific Ocean creates circulating winds, forming an anticyclone, which also helps to keep the climate of the Atacama dry. Thanks to all these factors, the region is widely regarded as the driest place on ...
potw1210 — Picture of the Week
A Window to the Past — La Silla’s transformation through time
5 March 2012: ESO turns fifty this year, and to celebrate this important anniversary, we are showing you glimpses into our history. Once a month during 2012, a special “Then and Now” comparison Picture of the Week shows how things have changed over the decades at the La Silla and Paranal observatory sites, the ESO offices in Santiago de Chile, and the Headquarters in Garching bei München, Germany. Here are two photographs of La Silla, taken in June 1968 and the present day from near the observatory’s water tanks, looking over the rest of the site. You can examine the changes with our mouseover image comparison. In the historical image, the provisional residential area is visible in the foreground. The three telescopes in the background are, from left to right, the Grand Prism Objectif (GPO, first light in 1968), the ESO 1-metre telescope (first light in 1966), and the ESO 1.5-metre telescope (first ...
potw1209 — Picture of the Week
Spinning into Action
27 February 2012: The dynamism of ESO's Very Large Telescope in operation is wonderfully encapsulated in this unusual photograph, taken just after sunset at the moment Unit Telescope 1 starts work. An extended exposure time of 26 seconds has allowed ESO Photo Ambassador Gerhard Hüdepohl to record the movement of the dome, looking out through the opening from within, as the system swings into action. The rotating walls of the dome look like an ethereal swirl through which a slice of the Atacama Desert can be glimpsed, while the crisp dusk sky provides a splash of cool blue. The telescope structure, seen stationary in the centre of the image, houses a mirror 8.2 metres in diameter, designed to collect light from the far reaches of our Universe. The dome itself is also an engineering marvel, moving with extreme precision and allowing for careful temperature control lest warm air currents disrupt observations. Links ESO ...
Showing 121 to 140 of 334
Send us your comments!
Subscribe to ESO News