Viikon kuva

17. maaliskuuta 2014: Another clear night at ESO’s Paranal Observatory in Chile — perfect for sitting back and taking in the sight of our galaxy, the Milky Way. Many of us living in living in crowded, light-polluted cities no longer get to see our cosmic home in such detail. We now know this stunning view to be our home galaxy, but the Ancient Greeks thought that it was the work of the Gods. Their legends told that this cloudy streak across the sky was really the breast milk of Hera, wife of Zeus. The Ancient Greeks are also to thank for the name “Milky Way”. The Hellenistic phrase Γαλαξίας κύκλος, pronounced galaxias kyklos, means “milky circle”, and provides the root for our modern name. This 360 degree panorama image was taken by ESO Photo Ambassador Gabriel Brammer. An astronomer visiting Paranal can be seen standing towards the right hand side of this image ...

10. maaliskuuta 2014: On 20 January 2014, ESA's Rosetta spacecraft emerged from a long deep-space hibernation to approach its target — comet 67P/Churyumov-Gerasimenko (67P/CG). From our vantage point on Earth, comet 67P/CG has only just reappeared from behind the Sun. On 28 February 2014 ESO's Very Large Telescope (VLT) directed its gaze towards the comet as soon as it became visible from ESO's Paranal Observatory in Chile. ESO is collaborating with ESA to monitor the comet from the ground as it is approached by Rosetta over the coming months. These observations will prepare for the spacecraft's major rendezvous with the comet, planned for August of this year (see potw1403a). This new image, and many more to come, will be used by ESA to refine Rosetta's navigation, and to monitor how much dust the comet is releasing. The image on the left was created by stacking the individual exposures to show the background stars ...

3. maaliskuuta 2014: High on the Chajnantor Plateau in the Chilean Andes lies the Atacama Large Millimeter/submillimeter Array (ALMA), an observatory surrounded by large expanses of dry landscape. Perhaps surprisingly, the region is home to a number of different wildlife species, many of which occasionally pop up near to the observatory. Further south, ESO’s La Silla Observatory recently had visits from a South American grey fox (potw1406a), and wild horses (potw1344a). The most recent cute visitor to ALMA is this vicuña fawn, found on 16 February 2014 by ALMA workers. The fawn was only a few weeks old, weakened after it was chased by foxes until it lost sight of its herd. After a couple of unsuccessful attempts the following day to return the fawn to its herd, the workers transferred it to the Wildlife Rescue and Rehabilitation Center at the Universidad de Antofagasta, where it is being treated so that it can ...

24. helmikuuta 2014: Bereft of colour in this striking infrared image, the sweeping curves of ESO's Headquarters clash with the frosty natural beauty of the surrounding trees. The extreme curvature visible in this image is due to the photographer's use of a fisheye lens, which distorts the view and causes the building to encircle the pale foliage and frame the sky above. The foliage appears to be bright as it reflects the infrared light, and the pale white hue comes from the photographer applying a white colour balance to the tree leaves. The precise curves of concrete, glass, and steel give clues as to the Headquarters building's peculiar structure. In 1981 an article in ESO's The Messenger described the ESO building as "a labyrinth of the kind used to test the intelligence of rats". But, fortunately for ESO, the writer soon noted that "human beings are on average cleverer than rats, and the ...

17. helmikuuta 2014: These new images from ESO's Very Large Telescope Survey Telescope (VST) show ESA's Gaia spacecraft in its position some 1.5 million kilometres beyond Earth's orbit. Launched on the morning of Thursday, 19 December 2013, the satellite is on a quest to build a 3D map of our galaxy over the next five years. Mapping the sky has been one of humanity's quests since the dawn of time, and Gaia will take our understanding of our stellar neighbourhood to a whole new level. It will measure very precisely the positions and motions of about one billion stars in our galaxy, to explore the Milky Way's composition, formation and evolution. These new observations are the result of a close collaboration between ESA and ESO to monitor the spacecraft from the ground. Gaia is the most accurate astrometric device ever built, but in order for its observations to be useful it needs to ...

10. helmikuuta 2014: Perched precariously on the edge of the habitable world, life manages to cling on. On the outskirts of the hot, dry Atacama Desert, this hardy South American grey fox has just awoken, stretching leisurely. These foxes are generally active during the night, making the most of the drop in temperature that comes with a respite from the hot Chilean Sun. In the background there are other signs of life. This white dome houses the Swiss 1.2-metre Leonhard Euler Telescope, which is protected from the harsh conditions by its outer shell. As the skies grow darker at ESO’s La Silla Observatory another famously nocturnal species, the astronomer, wakes up, stretches, and gets ready to scan the skies with buzzing and whirring technology. This image was taken by ESO Photo Ambassador Malte Tewes and submitted to the Your ESO Pictures Flickr group. The Flickr group is regularly reviewed and the best photos ...

3. helmikuuta 2014: This beautiful panorama of ESO's Paranal Observatory was taken on 5 July 2012, and marks one of the driest days ever recorded at the Very Large Telescope complex. Paranal sits like an island in the middle of the frame, with massive cloud banks floating below, over the distant Pacific Ocean. The extremely low humidity at Paranal during this period was recorded by a water vapour radiometer known as LHATPRO, which monitors the atmosphere to support the observations carried out at the observatory [1]. Meteorologists from two Chilean universities identified the cause for these unusually dry conditions: high-altitude Antarctic air moving far to the north, and descending over Paranal. This cold front lingered around Paranal for over 12 hours, causing a record-low level of humidity in the air above the observatory [2]. Florian Kerber (ESO) and colleagues analysed this unusual weather, publishing the results in a paper in the Monthly Notices ...

27. tammikuuta 2014: Astronomers do not always swim at the swimming pool at the Paranal Observatory Residencia, but when they do, they like to show how physical principles work. In this picture the French ESO astronomer Jean-Baptiste Le Bouquin is demonstrating how waves — not light waves, but water waves — can combine, or interfere, to create larger waves. The combination of light waves is the main principle behind the VLT Interferometer: the light waves captured by each one of the four 8-metre telescopes are combined using a network of channels and mirrors. This way the spatial resolution of the telescope is vastly increased and, with enough exposure time, the cameras and instruments can reveal the same level of detail as a telescope with a 130-metre diameter mirror could, far bigger than any telescope in existence. This image was taken by award-winning editorial and commercial photographer Max Alexander. See also Tribute to ESO’s ...

20. tammikuuta 2014: ESA's Rosetta spacecraft will wake up today, 20 January, after 31 months in deep space hibernation, to finally close in on comet 67P/Churyumov-Gerasimenko (67P/CG). This image shows the most recent observations of the 4-kilometre diameter comet, taken on 5 October 2013 by ESO's Very Large Telescope (VLT) when the comet was around 500 million kilometres away — before it passed behind the Sun and out of view from Earth's perspective. For this image, a long series of observations was processed to reveal both the comet without the background stars (on the left panel), and the star field with the track of the comet marked (on the right). Viewed against a crowded star field towards the centre of the Milky Way, the comet was still so far from the Sun that the icy nucleus was not releasing any gas or dust, and appears as a simple spot. As it approaches the ...

13. tammikuuta 2014: Thanks to ESO’s Photo Ambassadors we can enjoy sensational images taken at the ESO sites on the remote mountaintops of Chile. Babak Tafreshi has captured this fine panoramic view of the antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) at twilight. Resembling a frame from a science fiction movie, the technological spectacle of ALMA against the raw natural power of the landscape on the Chajnantor Plateau, 5000 metres above sea level, results in fascinating images like this one. There are a few details you shouldn't miss in this panoramic photo of ALMA (seen more clearly in the zoomable version), all lying between the two groups of antennas: the "Earth's shadow" and "Belt of Venus" phenomena, visible as the dark blue and light pink bands stretching across the sky, and the planet Jupiter, seen right above the mountain in the background. ALMA, an international astronomy facility, is a partnership of Europe, ...

6. tammikuuta 2014: Gaze up at the night sky from ESO's Paranal Observatory in Chile, and you will be greeted with a stunning view like this one. Flecks of blue, orange, red; each a different star, galaxy, nebula, or more, together forming a sparkling sky overhead. Astronomers peer at this beautiful backdrop, trying to unravel the mysteries of the Universe. To do this, they use telescopes like the ones shown here, the VLT Auxiliary Telescopes. This image shows three of the four moveable units that feed light into the Very Large Telescope Interferometer, the world's most advanced optical instrument. Combining to form one larger telescope, they are greater than the sum of their parts: they reveal details that would be visible with a telescope as large as the distance between them.

30. joulukuuta 2013: When night falls, ESO's observatories spring to life. Astronomers and technicians take their positions, and telescopes are pointed skywards. This image shows the pristine skies over ESO's Paranal Observatory in the Chilean Atacama Desert, far away from city lights. Here, ESO photo ambassador Gabriel Brammer has captured the serene beauty of the Milky Way from the platform of the Very Large Telescope. The four massive blocks in the bottom of the image are the four VLT Unit Telescopes, each of them housing incredibly precise 8.2-metre mirrors. Scattered around are the VLT's Auxiliary Telescopes, easily identifiable due to their round, white domes. The bright spot to the left is the Moon, shining as brightly as if it were the Sun, and to the right, the shadow of the photographer can be seen, waving to the viewer with outstretched arms. The entire night sky is visible due to Brammer's use of a ...

23. joulukuuta 2013: Season's Greetings on behalf of everyone at the European Southern Observatory! We wish you a jolly end of the year and a fruitful 2014! Link Christmas card 2013

16. joulukuuta 2013: This image was taken by Babak A. Tafreshi, one of ESO’s Photo Ambassadors, at ESO’s Paranal Observatory. It shows three of the four Auxiliary Telescopes (ATs) of the Very Large Telescope Interferometer (VLTI). Above them, the long bright stripes are star trails, each one marking the apparent path of a single star across the dark night sky, due to the rotation of the Earth. This technique also enhances the natural colours of the stars, which gives an indication of their temperature, ranging from about 1000 degrees Celsius for the reddest stars to a few tens of thousands of degrees Celsius for the hottest, which appear blue. The sky in this remote and high location in Chile is extremely clear and there is no light pollution, offering us this amazing light show.

9. joulukuuta 2013: Alpha and Beta Centauri, two of the brightest stars in the southern sky, had a new companion in late 2013 — the naked eye Nova Centauri 2013. This photo was taken by ESO Photo Ambassador Yuri Beletsky at ESO's La Silla Observatory in the Chilean Atacama Desert in the morning hours of Monday 9 December 2013. The nova was discovered by John Seach from Australia on 2 December 2013 as it approached naked eye brightness. Nova Centaurus 2013 is the brightest nova to have occurred so far this millennium. This particular event is known as a classical nova, and is not to be confused with a supernova. Classical novae occur in binary star systems when hydrogen gas from the orbiting stellar partner is accreted onto the surface of the main star, causing a runaway thermonuclear event resulting in the brightening of the main star. In a classical novae the main ...

2. joulukuuta 2013: This impressive photograph, taken at the site of ESO’s Very Large Telescope (VLT) at Paranal Observatory in Chile, shows, towards the centre left, the Milky Way — with its share of nebulae, stars, and gas clouds — rising above the VLT Unit Telescopes. To the right, competing for attention as it arcs above the horizon, a beautiful, almost triangular band of diffuse light lies along the ecliptic, which is the apparent path of the Sun in the sky as seen from the Earth. This glow originates in the scattering of sunlight by dust located between the planets that are spread through the plane of the Solar System. This coincides in the sky with the band known as the Zodiac, which extends for eight degrees of arc on either side of the ecliptic and contains the traditional zodiacal constellations.

25. marraskuuta 2013: Babak Tafreshi, one of the ESO Photo Ambassadors, has captured the antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) in an enthralling image combining the beauty of the southern sky with the amazing dimensions of the biggest astronomical project in the world. Thousands of stars are revealed to the naked eye in the clear skies over the Chajnantor Plateau. Its dry and transparent night sky is one of the reasons ALMA has been built here. Surprisingly bright in the upper left corner of the picture, there is a tightly packed bunch of young stars, the Pleiades Cluster, which was already known to most ancient civilisations. The constellation of Orion (The Hunter) is clearly visible over the closest of the antennas — the hunter’s belt is formed by the three blue stars just to the left of the red light. According to classic mythology, Orion was a hunter who chased the ...

18. marraskuuta 2013: This new view of Comet C/2012 S1 (ISON) was taken with the TRAPPIST–South national telescope at ESO's La Silla Observatory on the morning of Friday 15 November 2013. Comet ISON was first spotted in our skies in September 2012, and will make its closest approach to the Sun in late November 2013. TRAPPIST–South has been monitoring comet ISON since mid-October, using broad-band filters like those used in this image. It has also been using special narrow-band filters which isolate the emission of various gases, allowing astronomers to count how many molecules of each type are released by the comet. Comet ISON was fairly quiet until 1 November 2013, when a first outburst doubled the amount of gas emitted by the comet. On 13 November, just before this image was taken, a second giant outburst shook the comet, increasing its activity by a factor of ten. It is now bright enough ...

11. marraskuuta 2013: ESO Photo Ambassador, Babak Tafreshi captured this panoramic view of the antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) under the clear sky over the Chajnantor Plateau, in the Chilean Andes. The rosy patch prominent at the left of the image is the Carina Nebula. It lies in the constellation of Carina (The Keel), about 7500 light-years from Earth. This cloud of glowing gas and dust is the one of brightest nebulae in the sky and contains several of the brightest and most massive stars known in the Milky Way, such as Eta Carinae. For some beautiful recent images of the Carina Nebula from ESO, see eso1208, eso1145, and eso1031. ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by ...

4. marraskuuta 2013: On a dark September night at ESO’s La Silla Observatory, after spending the night at the telescope, astronomer Klaas Wiersema was returning to the restaurant. Most of the work at an observatory takes place at night, so it is not rare to have scientists and technicians walking around in the darkness. This time, something unexpected happened. Suddenly, Klaas heard a loud snort behind him and the sound of massive feet chasing him. He was convinced that some kind of angry animal had emerged from its lair and was trying to hunt him down, so he ran like the wind. He couldn’t imagine what kind of beast was chasing him on the desolate slopes of the Atacama Desert, at 2400 metres above sea level, so he spent the rest of the night trying figure out the mystery. When daylight came he went exploring, only to find that he had passed too ...