Photo de la semaine 2011

21 mars 2011: The night of 19 March saw an unusual coincidence of astronomical events: the full Moon occurred at almost exactly the same time as the Moon was closest to Earth in its elliptical orbit (the point called perigee). The combination of the Moon being both full and relatively close to the Earth made it look significantly bigger and brighter than usual. This panoramic photograph, taken by ESO Photo Ambassador Gerd Hüdepohl, captures this so-called "supermoon" as seen from Cerro Paranal, home of ESO's Very Large Telescope (VLT).On the right, in the east, the Moon rises over the mountains, while the setting Sun is visible on the left of the panorama, sinking in the west below the clouds over the Pacific Ocean. Its last rays illuminate the four giant VLT Unit Telescope buildings, the smaller VLT Survey Telescope building, the four round VLT Auxiliary Telescope enclosures, and the Paranal staff who have ...

14 mars 2011: The number of antennas for the Atacama Large Millimeter/submillimeter Array (ALMA) on the Chajnantor plateau has now reached double digits! The tenth antenna was moved up from the Operations Support Facility at an altitude of 2900 metres to the Array Operations Site at 5000 metres, high in the Chilean Andes, on 4 March 2011 using one of the ALMA transporter vehicles. ALMA is a telescope designed to observe millimetre- and submillimetre-wavelength light with its array of antenna dishes. Using a technique called interferometry, ALMA acts like a single giant telescope as large as the whole set of antennas. Thanks to the transporter vehicles, the antennas can be arranged in different configurations, where the maximum separation between them varies from 150 metres to 16 kilometres. The distant viewpoint of this photograph is necessary for one to see all ten of the antennas in a single shot. Nine of them, including the ...

7 mars 2011: The Atacama Large Millimeter/submillimeter Array (ALMA) antennas may look rooted to the ground in this striking image — taken at the Array Operations Site on the Chajnantor plateau, at an altitude of 5000 metres — but these dishes are surprisingly mobile. Thanks to the two antenna transporter vehicles, the antennas in the array — which will consist of a total of 66 dishes when construction is complete — can be repositioned to meet the needs of a particular observation project. The transporters, named Otto and Lore, were specially designed to transport the hefty 115-tonne antennas and position them precisely on concrete foundation pads, spread across the plateau over distances of up to 16 kilometres. Here, four antennas have been placed on closely spaced pads for testing during the Commissioning and Science Verification phase of ALMA construction. The transporter vehicles drive on 28 tyres, with two 700-HP (500 kW) diesel engines ...

28 février 2011: ALMA antennas stand side by side, built strong to withstand the unforgiving environment of the Chajnantor plateau, high in the Chilean Andes. At an altitude of 5000 m, the ALMA dishes — a total of 66 when construction is completed — will face strong winds and harsh sunlight, all without the safe haven of a protective dome. The temperature can vary by 40 degrees Celsius, dipping well below freezing and occasionally allowing snow to fall, as can be seen dusting the landscape in the background of this photograph. 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. Links ESO Photo Ambassadors webpage.

21 février 2011: Quatre antennes du Atacama Large Millimeter/submillimeter Array (ALMA) regardent ver le ciel nocturne étoilé en anticipation pour le travail qui se trouve devant soi. La Lune éclaire la scène sur la droite, tandis que la bande de la Voie Lactée s'étire en haut à gauche. ALMA est en train d'être construit à une altitude de 5000 mètres sur le plateau de Chajnantor dans le désert d'Atacama au Chili. C'est l'un des endroits le plus sec sur Terre, et cette sécheresse, combinée avec la fine atmosphère de haute altitude offre de superbes conditions pour observer l'Univers dans des longueurs d'onde du millimétrique et du sub-millimétrique. À ces longueurs d'onde, les astronomes peuvent regarder dans les nuages moléculaires qui sont des régions très denses de gaz et de poussière où de nouvelles étoiles naissent lorsque un nuage s'effondre sous sa propre gravité. Pour l'instant, l'Univers reste relativement inexploré dans les longueurs d'ondes ...

14 février 2011: This rich scattering of galaxies was captured using the Wide Field Imager attached to the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. The thousands of galaxies contained in this small area of sky give a glimpse into the Universe’s distant past, whilst also acting as a powerful reminder of the immense scale of the cosmos. This image was taken as part of the COMBO-17 project (Classifying Objects by Medium-Band Observations in 17 Filters), in which detailed surveys of five small patches of sky were made through 17 different coloured filters. The area of sky covered by each of the five regions is about the same area as that covered by the full Moon. The survey has produced a remarkable haul of celestial specimens. For example, across just three of these regions over 25 000 galaxies have been identified. Just below the bright stars in the centre of ...

7 février 2011: The HAWK-I instrument on ESO's Very Large Telescope (VLT) at the Paranal Observatory in Chile has been used to great effect in producing this distinctive image of the distant galaxy NGC 157. Boasting a central sweep of stars resembling a giant "S", reminiscent of the comic book hero Superman’s symbol, this celestial spiral is indeed a super example of how new technology is helping us to learn more about the cosmos. HAWK-I stands for High-Acuity Wide-field K-band Imager, and it is one of the latest and most powerful instruments on the VLT. It detects infrared light, allowing us to peer through the gas and dust that normally obscures our view. This reveals an otherwise hidden view of the Universe, and gives astronomers the opportunity to study dense areas of star formation. Learning more about star formation is an important step towards expanding our understanding of our own origins. The same ...

31 janvier 2011: What looks like a barren and inhospitable alien landscape in this 360-degree panorama is in fact the site for ESO’s European Extremely Large Telescope, or E-ELT for short. When construction begins the uninhabited mountaintop left of the centre will become a hive of activity as engineers, technicians and scientists work on building the world’s biggest eye on the sky. In many ways Chile’s Cerro Armazones may seem like an alien world. The environment is harsh, with low humidity and air pressure, a blazing Sun during the day, but breathtaking skies at night. Cerro Armazones is in the Atacama Desert — one of the driest places on Earth. These conditions, combined with its remoteness, are what make the region such an excellent location for telescopes. Armazones is an isolated peak, 3046 metres above sea level. It is about 20 km away from Cerro Paranal, home of ESO's famous Very Large Telescope. ...

24 janvier 2011: As the Sun sets over Cerro Armazones, plans are well advanced for building the world's biggest “eye on the sky”: ESO's European Extremely Large Telescope (E-ELT). With a primary mirror 39 metres in diameter, the E-ELT will dwarf all existing visible-light telescopes. Site selection has been a vital part of the plans for the E-ELT. Over the course of several years a team of experts investigated locations around the world, looking for the best place to host such an ambitious project. The site for the E-ELT must be remote enough not to be influenced by problems such as light pollution, but also needs the necessary infrastructure for the construction and operation of the observatory, and to accommodate the over 150 staff who will eventually work there. Monitoring stations, such as the one shown here, were set up to test site conditions scientifically by measuring parameters that included atmospheric turbulence and ...

17 janvier 2011: Like the bow of a ship sailing a rolling ocean of red hills, the southeast corner of the observing platform at Paranal stands over the Mars-like landscape of the Chilean Atacama Desert. This panorama shows the breathtaking view of the horizon, and conveys the feeling of immensity experienced when looking from the top of Cerro Paranal, a remote 2600-metre-high mountain located in one of the driest regions on Earth. Atop Cerro Paranal is the ESO Very Large Telescope (VLT), the world’s most advanced optical and near infrared ground-based astronomical facility, composed of four 8.2-metre Unit Telescopes (UTs) and four 1.8-metre Auxiliary Telescopes (ATs). The fourth Unit Telescope (UT4), named Yepun in the Mapuche language, is most prominent in this photograph, while UT3 (Melipal) and UT1 (Antu) are just visible on the right-hand edge of the picture. Three of the smaller ATs can also be seen on the 200-metre-wide observing platform. ...

10 janvier 2011: Before another clear, starry night falls at ESO's Paranal Observatory, home of the Very Large Telescope (VLT), the sky produces a palette of intense colours, putting on a beautiful show for observers. These colours can only be seen with such depth from sites such as Paranal, where the atmosphere is extraordinarily pure. Looking to the west, over the Pacific Ocean, the sunset sky turns bright orange and red. However, this photograph shows the view to the east instead, looking away from the Sun after it has just set. The grey-bluish shadow above the horizon is the shadow of our own planet. Above this is a pinkish glow known as the "Belt of Venus", a phenomenon produced by the reddened light of the setting Sun being backscattered by the Earth's atmosphere. In the centre of the image is the fourth 8.2-metre Unit Telescope (UT4), part of the VLT. The Mapuche name ...

3 janvier 2011: Des collines rougeâtres s'étendent en-dessous du ciel bleu exceptionnellement clair qui est typique à l'observatoire ESO de Paranal. Quoique les dômes des télescopes ferment à l'aube et rien ne semble bouger à la surface de ce vaste désert, le Very Large Telescope (VLT) de l'ESO ne se repose jamais. Depuis tôt le matin, une équipe d'ingénieurs et de techniciens ont travaillé dur pour préparer les télescopes et les instruments pour une autre "nuit parfaite". Cerro Paranal, culminant à 2600 mètres d'altitude se détache au centre de cette vue panoramique, pris en regardant vers le Sud. Ce sommet aplati est la demeure du VLT, l'installation de télescopes optiques et proches infrarouges terrestres le plus avancé au monde. Le VLT a quatre Unit Telescopes (UTs) de 8.2 mètres plus quatre Auxiliary Telescope (ATs) de 1.8 mètres. Dans cette image, seulement deux des coupoles des UTs avec le plus petit VLT Survey Telescope ...