Picture of the Week

31 August 2020: This image shows a beautiful nighttime scene at ESO’s Paranal Observatory in Chile. The bright band of the Milky Way cuts prominently through the centre of the scene, crammed with bright gas, dark dust, and sparkling stars, seemingly diving downwards to meet the glowing horizon. The boxy structure of UT1 (Antu), one of the four Unit Telescopes comprising the ESO’s Very Large Telescope (VLT), can be seen at the centre of the frame, while a smaller Auxiliary Telescope is visible to the right, its dome wide open as it scans the skies. With its eight telescopes, four of which — the auxiliaries — are movable, the VLT can act as a highly sensitive interferometer — so sensitive, in fact, that it can distinguish between the two headlights of a car at the distance of the Moon! The beautiful and oft-photographed skies above the VLT are some of the clearest in ...

24 August 2020: The MUSE instrument on ESO’s Very Large Telescope (VLT) in Chile has observed NGC 1365, a double-barred spiral galaxy located about 56 million light-years away in the Fornax galaxy cluster, allowing us to construct this spectacular colour image. The galaxy is also known as the Great Barred Spiral Galaxy, after its two central bar-shaped structures, made up of stars. The two bars of NGC 1365 are a rare phenomenon and are thought to have originated by the combined effects of galaxy rotation and the complex dynamics of the stars. Its largest bar of stars, too large for its structure to be visible in this image, connects its outer spiral arms to its centre. What we can see is the much smaller second bar of stars, nestled within the main bar. It is likely this secondary bar acts independently of the main bar, rotating more rapidly than the rest of the ...

17 August 2020: Incredible splashes of colour — greens, reds, blues, and every colour in between — paint the night sky above ESO’s Paranal Observatory in Chile, illuminating the barren desert landscape below. The light from billions of stars, glowing nebulae, and other cosmic phenomena creates the giant arch of the Milky Way, which stretches across the sky and perfectly frames the Very Large Telescope (VLT) sitting atop the peak at the centre of the image (Cerro Paranal). This particular view was taken from the site of ESO’s Visible and Infrared Survey Telescope for Astronomy (VISTA). The winding road between VISTA and the VLT can be seen below, illuminated by faint yellow lights. These are, notably, the only human-made lights visible in the entire scene — Paranal staff take great care not to create unnecessary light pollution that may hinder the astronomical work at the world-class observing site. The Milky Way is not ...

10 August 2020: Clouds may not be an astronomer’s best friend, but they are often a welcome sight for photographers in the rare moments when they grace the desert skies! This unusual scene shows a fiery sky above ESO’s Paranal Observatory in the dry Atacama Desert in Chile, home to the Very Large Telescope (VLT). The VLT comprises four Unit Telescopes, which are larger and squarer, and four smaller and rounder Auxiliary Telescopes, three of which can be seen here sitting quietly, their domes closed, towards the right of the frame. The cloud is not the only atmospheric phenomenon visible here. On the left of the image, a bright shaft of light can be seen shooting upwards, creating an illuminated column. This is a sun pillar, and is caused by tiny particles of ice within the atmosphere that reflect ambient light. These columns usually appear just above or below a bright source ...

3 August 2020: During one of his visits to ESO’s Very Large Telescope (VLT) at Paranal Observatory in Chile, astrophotographer and ESO Photo Ambassador Yuri Beletsky was fortunate enough to capture this breathtaking sight: three celestial spheres — each very different! — lined up beautifully in the sky. The largest sphere in this photo is one of the VLT’s four Auxiliary Telescopes. These movable telescopes can be arranged in different configurations to achieve different scientific goals. Floating above the auxiliary telescope is the Moon. The setting Sun illuminates only a sliver of our rocky satellite, though some of the lunar maria — the dark, sea-like remnants of lava flows from the Moon’s early days — are visible, too. Near the top of the image is Venus, the second planet from the Sun and our planetary neighbour.

27 July 2020: The bright sky above Chile’s Chajnantor plateau is sliced in two by the vast, vibrant ripple of the Milky Way. Here in the southern hemisphere, the magnificently rich centre of our galaxy is often directly overhead, its brilliant cloudy length stretching from horizon to horizon. Beneath its glow, a cluster of white antennas peers keenly up at the sky, illuminated by a bright yellow light that indicates to technicians whether or not it is safe to approach. These telescopes are part of the Atacama Large Millimeter/submillimeter Array (ALMA), a giant interferometer made up of 66 individual antennas. These antennas work together over distances of up to 16 kilometres to study the Universe in remarkable detail. ALMA is designed to “see” light invisible to the human eye — at wavelengths of around a millimetre, between infrared light and radio waves. Such light comes from the coldest and most distant places in ...

20 July 2020: This outstanding picture taken in Chile’s Atacama Desert shows the Sun setting behind three of the four unit telescopes of ESO's Very Large Telescope (VLT). The prime observing conditions are due to the location of the observatory. At an altitude of 2600m, ESO’s Paranal Observatory is hosted in one of the driest areas in the world, with incredibly clear skies. Taken only a dozen minutes after sunset, stars already scatter across the cloudless sky in this image. The bright star Sirius is visible, while the famous constellation of Orion, the hunter, hovers over the dome of the unit telescope in the foreground. As the darkness deepens, the starry skies will be revealed in more and more detail, until the conditions are perfect for world-leading science observations.

13 July 2020: A comet from the outer reaches of the Solar System, nicknamed NEOWISE, was photographed by two ESO staff members — who are also keen astrophotographers — on 8 July 2020 in the skies over the ESO Supernova and ESO Headquarters in Garching, Germany. This rare treat was also accompanied by another night-time phenomena: the very unusual noctilucent clouds — shiny, icy clouds that look remarkably like water ripples in the night sky. Officially called C/2020 F3, NEOWISE was first discovered by the NASA NEOWISE space mission in March this year. It is expected to dim as the month goes on, but to remain visible to the naked eye throughout July. It will reach its closest point to Earth on 23 July, at a distance of just over 100 million km. The comet’s spectacular bright tail is caused by heat from the Sun, which is evaporating the outer layers of the ...

6 July 2020: This beautiful image, captured with the FOcal Reducer and low dispersion Spectrograph (FORS) on ESO’s Very Large Telescope (VLT), shows a field of stars of all ages — some looming close in the foreground, and others lurking in the far distance. The distinct red and blue hues are thanks to the use of filters, which allow the selection of specific wavelength ranges of light. The images collected with different filters can be combined in order to create colourful composite images: by assigning a particular color to each filter; colouring the images according to the filter used; then combining the separate images. The result is a spectacular image which colourfully represents the various wavelengths of light. This patch of sky is found in the constellation of Crux (The Southern Cross), an extremely bright section of the Milky Way. It was imaged as part of the ESO Cosmic Gems programme, an outreach ...

29 June 2020: On 2 July 2019, ESO’s La Silla Observatory was host to a rare astronomical event, a total solar eclipse. Inaugurated in 1969, La Silla Observatory led ESO to the front line of astronomical science. The 50th anniversary last year celebrated La Silla’s continued contribution to science, and coincided fortuitously with the shadow of the total solar eclipse, or umbra, passing over the site. Captured in this image is the stunning view of the total solar eclipse, a rare event which lasted for less than two minutes that day. During a total solar eclipse, the Sun and Moon cross paths in the sky, overlapping perfectly, a feat only possible because the Sun and Moon happen to be the right distance from the Earth to take up the same portion of the sky. A few stars shine bright for a moment while the Sun’s brilliant corona halos the Moon, like shimmering strands ...

22 June 2020: The onset of early morning reveals the ESO Residencia hotel, where astronomers and engineers stay while working with the ESO telescopes at the Paranal Observatory in Chile’s Atacama Desert. These telescopes include the Very Large Telescope (VLT), the VLT Survey Telescope (VST) — which are visible in the background — and VISTA (Visible and Infrared Survey Telescope for Astronomy). Because of the arid desert that surrounds it, the Residencia is sometimes called an “oasis in the desert”. The scenery is so striking that the building was featured in the 2008 James Bond film Quantum of Solace. The views from the western side of the Residencia towards the Pacific Ocean are spectacular, and the architecture itself is also award-winning. Guests staying at the Residencia are well provided for, with over a hundred bedrooms, a restaurant, a swimming pool and even a sauna available. There is also an artificial garden that acts ...

15 June 2020: ESO’s La Silla Observatory boasts a remarkably high number of cloud-free nights a year. The billions of stars that make up the Milky Way is a very common sight indeed. The dome shown in this image houses one of three 60-centimetre telescopes that make up the ExTrA project, which had its first light in late 2017. This small group of telescopes is primarily designed to detect distant exoplanets transiting in front of bright and nearby red dwarf stars. The project aims to discover as many transiting planets as possible — including Earth-size planets in the habitable-zone — and to determine their structure and composition. These planets will then be observed by the world’s largest telescopes, in order to characterise their atmospheres.

8 June 2020: In 2016, a team of four world-class astrophotographers and videographers journeyed to ESO’s Paranal Observatory in Chile. Their goal? To capture striking views of the Universe in ultra high definition (UHD) and fulldome formats — perfect for use in planetarium shows! Over the course of a few weeks, the photographers gathered UHD stills, fulldome timelapses, 360-degree panoramas, and more, including a whole host of breathtaking shots of their surroundings. One such shot is this ESO Picture of the Week, which shows Paranal — home to ESO’s Very Large Telescope (VLT) — at night. The stargazer visible to the right of the frame, pointing to the beautiful arc of the Milky Way curving overhead, is ESO Photo Ambassador Babak Tafreshi, one of the aforementioned expedition members. The constituent telescopes of the VLT can be seen scattered across the left of the frame (the four boxy Unit Telescopes, and three of the ...

1 June 2020: One of the most exhilarating results in modern astronomy is the knowledge that the Universe is full of worlds beyond our Solar System, known as exoplanets. Increasing evidence suggests that the majority of stars in the Universe have planets whizzing around them; one such system can be seen in this majestic Picture of the Week. The antennas here are among the 66 that make up the Atacama Large Millimeter/submillimeter Array (ALMA), located on the Chajnantor plateau in Chile. Two bright stars sit directly above the centre antenna; the brightest of these two stars is a triple star system known as Alpha Centauri. An exoplanet named Proxima b was recently discovered orbiting within the habitable zone of one these three stars (Proxima Centauri) by ESO telescopes and other facilities. As Alpha Centauri is the closest star system to Earth, Proxima b is the closest exoplanet to Earth ever discovered. Another world ...

25 May 2020: Posing here under the splendours of the southern sky is Babak A. Tafreshi, one of ESO’s Photo Ambassadors. Babak is standing on part of the massive Miñiques volcanic complex, located in the Antofagasta region of Chile’s Atacama Desert. This region is also home to ESO’s Paranal Observatory, where the Very Large Telescope (VLT) gazes up at the sky, observing exotic phenomena such as gamma-ray bursts, extrasolar planets, and supermassive black holes. Each of the VLT’s constituent telescopes can detect objects roughly four billion times fainter than the naked eye can see, giving it a far richer view of the Universe than is available to humans. However, the skies above the Atacama are some of the clearest and darkest in the world — so it’s little wonder that Babak stands in awe beneath it all. The spectacular swirl of blue above Babak’s head is the Large Magellanic Cloud (LMC), a dwarf ...

18 May 2020: This image shows a pair of interacting galaxies known as Arp 271. Individually, these galaxies are named NGC 5426 and NGC 5427; both are spirals, and both are roughly the same size. Some astronomers believe that these galaxies are in the process of merging to form a single entity. This interaction will create increasing numbers of new stars over the next few million years, some of which can be seen within the “bridge” of gas connecting the two galaxies. This kind of collision and interaction might also happen to our own galaxy, the Milky Way, which is likely to collide with the neighbouring Andromeda Galaxy in about five billion years time. These galaxies lie over 120 million light years away from us, and were discovered by the German-British astronomer William Herschel in 1785. Herschel was a prolific scientist, also discovering both infrared radiation and the planet Uranus. Link: Previous release ...

11 May 2020: Some self-portraits are better than others — and this image of ESO Photo Ambassador Petr Horálek is certainly one of the more impressive! Here, the photographer basks in the light of the glowing Milky Way, dwarfed by the scale and wonder of the view overhead. Horálek is standing at one of the highest and driest locations on Earth, amid the vast array of antennas that make up the Atacama Large Millimeter/submillimeter Array (ALMA). ALMA is located on the 5000-metre-high Chajnantor plateau in the Chilean Atacama Desert.The array sees the Universe in wavelengths of light between infrared and radio — key to observing extremely cold and distant objects — and studies the building blocks of stars, planetary systems, galaxies and life itself. ALMA probes right out to the edge of the observable Universe, and allows astronomers to explore and understand how our cosmos came to be. The dark, clear, dry skies ...

4 May 2020: The arrival of daylight at ESO’s La Silla Observatory reveals the splendour of the Universe beyond our little planet in dazzling detail. The Milky Way stretches overhead as a streaming banner of dust backlit by the light of billions of stars. Clouds of interstellar dust grow thickest towards the constellation of Sagittarius (The Archer), which marks the centre of the galaxy — the core around which the spectacular spiral arms rotate. The Galactic Centre also houses a supermassive black hole that produces huge amounts of energy as it consumes its surroundings (Sagittarius A*). ESO’s telescopes helped to characterise this monstrous black hole. An almost three-decade-long study used several of ESO’s flagship telescopes — including one of the Very Large Telescope’s 8.2-metre Unit Telescopes (Yepun) situated at ESO’s Paranal Observatory, and the 3.5-metre New Technology Telescope (NTT) at La Silla — to track the motions of stars orbiting the centre of ...

27 April 2020: This beautiful Picture of the Week shows the magnificent Milky Way stretching over the Very Large Telescope (VLT) at ESO’s Paranal Observatory, demonstrating the astounding level of detail visible in the night sky from this remote site in the Chilean Atacama Desert. At Paranal, the star-studded Milky Way is so bright that on a dark night it can cast shadows of the people and objects beneath it! This image shows countless stars, dark lanes of dust, and glowing clouds of celestial gas. These clouds are sites of star formation; energetic radiation emanating from newborn stars ionizes the hydrogen in the gas clouds, causing them to glow a rosy red. Below the Milky Way is the Large Magellanic Cloud, a dwarf galaxy orbiting the Milky Way. The night sky is observed every night by the world’s most advanced optical observatory the VLT. This telescope is actually made up of four Unit ...

20 April 2020: This picture of the week shows two of the three new ExTrA telescopes hosted at ESO’s La Silla Observatory in Chile. Situated over 2000 meters above sea level, these telescopes scour the skies for Earth-sized worlds around M class stars, which are stars smaller than the Sun. A “shooting star” flashes across the night sky above the telescopes and towards the horizon of the Atacama Desert in Chile. Shooting stars are not actually stars, but small bits of rock or dust that enter the Earth’s orbit and burn up in the atmosphere. Before they enter Earth’s atmosphere, these tiny celestial bodies are called meteoroids. The dramatic streaks of light caused by meteoroids burning up are not just beautiful and exciting, but also informative. Scientists look at the path and brightness of a meteoroid to determine where in the Solar System it came from and what it is composed of. If ...