Picture of the Week

26 March 2018: This week’s featured image highlights a handful of the telescopes residing at ESO’s La Silla Observatory in northern Chile. The star of the show, framed perfectly by the beautiful arch of the Milky Way, sits directly in the middle of the photograph — the Danish 1.54-metre telescope. Operational since 1979, this trusty telescope has helped astronomers to make all kinds of cosmic discoveries, from understanding more about violently merging neutron stars to detecting planets around other stars. It now performs follow-up observations of gamma-ray bursts, some of the most energetic events in the Universe. This image, taken by ESO Photo Ambassador Petr Horálek, shows the heart of the Milky Way, both the Large and Small Magellanic Clouds, the constellations of Orion (The Hunter) and the Southern Cross, and the glare of distant settlements, all of which create vibrant bursts and flashes of colour across the frame. Towards the distant horizon, ...

5 March 2018: All of ESO’s observatories are based in Chile, but the organisation’s headquarters, and the newest exciting addition sits in Garching, a small city near Munich in Germany. This image shows a striking and unusual view of this new member of the ESO family — the ESO Supernova Planetarium & Visitor Centre. The ESO Supernova has its official inauguration event on 26 April and will open for the public on 28 April. At its heart, the Supernova is a truly state-of-the-art planetarium that will visualise and project accurate, awe-inspiring, and fully immersive views of the Universe for audiences to enjoy. The building also houses a cutting-edge astronomy centre and exhibition space. To make things even more appealing, attendance and all activities will be free throughout 2018! This image was taken by ESO Photo Ambassador Petr Horálek, reveals the curved arms of ESO headquarters reaching out toward the unique Supernova building, below ...

19 February 2018: This image, taken by ESO Photo Ambassador Petr Horálek, shows the planet Venus shining brightly over ESO’s Paranal Observatory in Chile at twilight. The featured telescope is the Very Large Telescope’s Auxiliary Telescope 1, open and preparing itself to observe the night sky, which is splashed in shades of blue and orange. ESO’s Very Large Telescope (VLT) comprises four 8.2-metre Unit Telescopes, and four 1.8-metre Auxiliary Telescopes (ATs) — like the one posing in the foreground of the image — whose captured light can be combined to form the VLT Interferometer (VLTI). By combining the light from multiple telescopes positioned in different places across the observatory site, the VLTI allows astronomers to see details up to 25 times finer than with the individual telescopes. The light beams are then combined using a complex system of mirrors in underground tunnels where the light paths must be kept equal to distances less ...

27 November 2017: A clear sky, a striking sunset, and the futuristic curves of a state-of-the-art planetarium and visitor centre — what more could you ask for in an ESO Picture of the Week? However, this image has something else up its sleeve to delight us: a sun pillar. This softly-glowing column of light seems to rise from the horizon near the setting Sun, illuminating the sky above it. This illusion is created by millions of tiny ice crystals — usually flat and hexagonal in shape — in our atmosphere, which reflect sunlight to form an apparent beam. Sun pillars are typically seen when the Sun is low in the sky, or when it has dipped below the horizon. The last rays of sunlight have also interacted with particles in the clouds above, which have scattered the light to create a brilliant array of oranges, yellows, reds, and pinks in the sky above ...

4 September 2017: This image, taken by ESO Photo Ambassador Petr Horálek, captures the moment that Yepun (UT4), one of the four 8.2-metre Unit Telescopes comprising ESO’s Very Large Telescope (VLT), shoots a laser beam up into the dark night sky over ESO’s Paranal Observatory in Chile. The laser shown in this image acts as an artificial star, known as a Laser Guide Star, and it is used to help astronomers adjust for the blurring and distorting effects of the Earth’s atmosphere. When observing a patch of sky, astronomers set up a laser guide star nearby and measure the tiny fluctuations in its image. The VLT’s adaptive optics system can then use this reference to correct for the changes and distortions in the intervening atmosphere and produce the sharpest images possible in the main observations. Looming over Yepun is the Large Magellanic Cloud (LMC), a barred spiral galaxy that orbits the Milky Way. ...

14 August 2017: During the early evening of 7 August, a partial lunar eclipse was visible in the sky above the ESO Headquarters in Garching bei München, Germany. A lunar eclipse occurs when the Earth, Moon and Sun are aligned, and the Earth casts a shadow on the Moon. This time, only a small part of the Moon entered the Earth’s inner shadow, the umbra, but it still made for a stunning view. While observing from the rooftop of the ESO Headquarters building, ESO Photo Ambassador Petr Horálek captured the eclipse along with spectacular rays from the setting Sun behind him, known as anticrepuscular rays — a union of astronomical and atmospherical phenomena. The Picture of the Week shown here is a compilation of over 50 images of the eclipse, starting from the peak of the eclipse just as the Moon rose above the horizon, to the eclipse’s conclusion when the Moon was ...

24 April 2017: In this incredible panorama, the night sky above ESO’s Very Large Telescope (VLT) displays our cosmic neighbourhood in all its glory. The VLT is located 2635 metres above sea level at ESO’s Paranal Observatory in northern Chile. This image illustrates the importance, and the benefits, of placing astronomical telescopes in such remote places! Anyone making the long journey to the site — including ESO Photo Ambassador Petr Horálek, who captured this scene — is rewarded with a truly spectacular view. On the right, behind the line of four 8.2-metre Unit Telescopes that together make up the VLT, the faint red and green hues of airglow can be seen illuminating the sky above the horizon. In addition zodiacal light is illuminating the sky as well. This diffuse light is caused by microscopic particles of light-scattering space dust in the plane of the Solar System. While these features are beautiful, the most ...

13 February 2017: The sky is full of optical phenomena that can make it tricky to get a clear view of the cosmos. These present a frustrating challenge to astronomers, but for astrophotographers they can provide a real feast for the eyes! This stunning image shows the centre of the Milky Way crossed by the eerie glow of zodiacal light, and is full of dust-induced features that obstruct scientific observations — but they look so beautiful it’s difficult to mind too much. In this image, the centre of the Milky Way appears to be full of inky black gas. In fact, the dark swirling patches are simply the absence of visible light, because huge clouds of dust are obscuring the light from more distant stars. However, just as dust can give the illusion of darkness, it can also give the illusion of light. This is the case with zodiacal light, a fuzzy band ...

28 November 2016: The famously dry Atacama Desert may seem like an odd place for the Moon to take a dip — but in this intriguing image, taken by ESO Photo Ambassador Petr Horálek, it appears to do just that! Initially high, the crescent Moon slowly descends through the clear Chilean sky, before hitting the thickest parts of the atmosphere right above the horizon. It was here that a “rare theatre” began, said Horálek. The thin sliver of the Moon was optically distorted into a “weird, snaky shape” as its light passed through layers of different air densities, caused by different pressures, temperatures and humidities. The Moon lost its smooth curves and instead appeared as a rippling and squiggly zig-zag — “as if it were swimming”. The effect of the closely spaced layers in the atmosphere caused different parts of the Moon’s image to be refracted differently as it disappeared below the horizon. ...

22 August 2016: An unusual type of tourist is seen visiting ESO’s La Silla Observatory in this stunning wide-angle photograph taken in January 2015. Captured by ESO Photo Ambassador Petr Horálek, Comet C/2014 Q2 (Lovejoy) appears to streak across the sky (centre left of the image), sneaking past the two telescopes below: ESO’s 3.6-metre telescope (left) and the Swedish-ESO Submillimetre Telescope (SEST). Like most comets, Comet Lovejoy enjoys a long, elliptical and eccentric orbit around the Sun. It entered the inner Solar System for the first recorded time in 2014, and reached perihelion — its closest approach to the Sun — on 30 January 2015. The distance between the Earth and the Sun is defined as 1 astronomical unit (au), or just under 150 million kilometres; Comet Lovejoy came within 1.29 au of our star, placing it between the orbits of Earth and Mars (1.52 au). This image displays the characteristic soft green ...

11 July 2016: This stunning ultra high definition panorama, taken by ESO Photo Ambassador Petr Horálek, shows the Milky Way galaxy arching above ESO’s La Silla Observatory in Chile. La Silla is located at the southern edge of the Atacama Desert, from where the observatory’s numerous telescopes observe the night sky — one of the darkest on the Earth — perched 2400 metres above sea level, and so making the most of the unrivalled atmospheric conditions at the site to reveal the cosmos in remarkable detail. This image is certainly no different! Our galaxy’s cloudy and dusty structure appears as a brilliant and glowing coronet above the open dome of the MPG/ESO 2.2-metre telescope, which appears to be gobbling up the bright smudge of the Large Magellanic Cloud. Various clouds and nebulae, including the well-known Gum Nebula, stand out against the dark sky in the central–upper part of the image, shining in a ...

27 June 2016: This image transports you to the most advanced visible-light astronomical observatory in the world: the Very Large Telescope (VLT), located at ESO’s Paranal Observatory in Chile. The shadowy figure gazing at the dark skies is photographer Babak Tafreshi, as captured by his fellow ESO Photo Ambassador Petr Horálek. For a moment, place yourself in Babak’s — or indeed Petr’s — shoes. Here, you are king of the cosmos. The site is silent, dark, still. You stare up at the pristine Chilean night sky, which, with its extremely low levels of both light pollution and water vapour, offers spectacular nighttime scenery to delight any astrophotographer or stargazer. With your trusty camera on hand, a night of amazing photo opportunities lies ahead; you anticipate spending clear hour after clear hour documenting the heavens, with no fear of cloudy weather appearing, uninvited, to spoil the view. The Large Magellanic Cloud is visible at ...

18 April 2016: As the Sun raises at Cerro Paranal, in Chile, filling the sky with superb orange shades, two members of the ESO Fulldome Expedition, Babak Tafreshi (left) and Yuri Beletsky (right), are preparing their tripods and cameras for the day ahead. Above the silhouette of the Chilean mountains, the gentle smile of a crescent Moon and the bright planet Venus strike a pose for the cameras. Thanks to a phenomenon called earthshine, the entire disc of the Moon can be seen shining in light reflected off the Earth. The telescope in silhouette in front is an Auxiliary Telescope (AT), part of Very Large Telescope (VLT) at ESO's Paranal Observatory. This twilight moment was captured by ESO Photo Ambassador Petr Horálek, while participating in the ESO Fulldome Expedition which is gathering spectacular images for use in the ESO Supernova Planetarium & Visitor Centre, currently under construction at ESO’s Headquarters in Garching (near ...

22 February 2016: This image is unreal — literally! Rather than being a single picture, it was created by combining two separate photographs together, and shows the January sky as seen from both hemispheres. The skilled photographer was ESO Photo Ambassador Petr Horálek. Petr shot the upper part of the image from ESO’s Paranal Observatory in Chile and the lower part from the Slovakian village of Oravska Lesna, before combining the two to form this striking composite. One arm of the distinctive X-shaped structure spreading from the top right to the bottom left of the frame is the lane of the Milky Way. The other diagonal comprises glowing columns of zodiacal light. In the centre of the image, is one of the four small 1.8-metre Auxiliary Telescopes that make up part of ESO's Very Large Telescope (VLT). A significant glow can be seen in the lower part of the image, caused by light ...

2 February 2015: This unique and spectacular image of ESO’s La Silla Observatory features a cloudless sky stained with red and green airglow and bejewelled with celestial objects. Amongst the celestial cast are the Small and Large Magellanic Clouds just to the right of centre, the rosy-red glow of various star-forming regions and the faint green streak of a meteor just to the left of the Milky Way. These striking heavenly regulars are eclipsed however by the presence of something far more elusive and much closer to home. The six panels below the main image magnify a series of extremely rare atmospheric phenomenon known as sprites. A few hours before daybreak — signalled by the spire of zodiacal light rising from the base of the Milky Way — a powerful thunderstorm appeared on the distant horizon, and the Earth’s upper atmosphere became a playground for these ephemeral events. Named after Shakespeare’s mischievous sprites ...

26 January 2015: In this new ESO image, nightfall raises the curtain on a theatrical display taking place in the cloudless skies over La Silla. In a scene humming with activity, the major players captured here are Comet Lovejoy, glowing green in the centre of the image; the Pleiades above and to the right; and the California Nebula, providing some contrast in the form of a red arc of gas directly to the right of Lovejoy. A meteor adds its own streak of light to the scene, seeming to plunge into the hazy pool of green light collecting along the horizon. The telescopes of La Silla provide an audience for this celestial performance, and a thin shroud of low altitude cloud clings to the plain below the observatory streaked by the Panamericana Highway. Comet Lovejoy’s long tail is being pushed away from the comet by the solar wind. Carbon compounds that have been ...