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Εργαλεία Θεμάτων | Τρόποι εμφάνισης |
#2956
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 10 Image Credit: ALMA (ESO/NAOJ/NRAO), NSF Explanation: Why does this giant disk have gaps? The exciting and probable answer is: planets. A mystery is how planets massive enough to create these gaps formed so quickly, since the HL Tauri star system is only about one million years old. The picture on which the gaps were discovered was taken with the new Atacama Large Millimeter Array (ALMA) of telescopes in Chile. ALMA imaged the protoplanetary disk, which spans about 1,500 light-minutes across, in unprecedented detail, resolving features as small as 40 light minutes. The low energy light used by ALMA was also able to peer through an intervening haze of gas and dust. The HL Tauri system lies about 450 light years from Earth. Studying HL Tauri will likely give insight into how our own Solar System formed and evolved. Tomorrow's picture: gas, dust, and stars
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2957
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 11 Image Copyright: Roberto Colombari, Robert Gendler & Federico Pelliccia; Data: DSS PLOSS II Explanation: The constellation of Orion holds much more than three stars in a row. A deep exposure shows everything from dark nebula to star clusters, all embedded in an extended patch of gaseous wisps in the greater Orion Molecular Cloud Complex. The brightest three stars on the far left are indeed the famous three stars that make up the belt of Orion. Just below Alnitak, the lowest of the three belt stars, is the Flame Nebula, glowing with excited hydrogen gas and immersed in filaments of dark brown dust. Below and left of the frame center and just to the right of Alnitak lies the Horsehead Nebula, a dark indentation of dense dust that has perhaps the most recognized nebular shapes on the sky. On the upper right lies M42, the Orion Nebula, an energetic caldron of tumultuous gas, visible to the unaided eye, that is giving birth to a new open cluster of stars. Immediately to the left of M42 is a prominent bluish reflection nebula sometimes called the Running Man that houses many bright blue stars. The featured image covers an area with objects that are roughly 1,500 light years away and spans about 75 light years. Tomorrow's picture: open space Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2958
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 12 Image Credit: ESA Explanation: Today humanity will make its first attempt to land a probe on the nucleus of a comet. As the day progresses, the Philae (fee-LAY) lander will separate from the Rosetta spacecraft and head down to the surface of Comet 67P/Churyumov–Gerasimenko. Since the texture of the comet's surface is unknown and its surface gravity is surely low, Philae will then attempt to harpoon itself down, something that has never been done before. Featured here is an artist's illustration of dishwasher-sized Philae as it might look on Comet Churyumov–Gerasimenko's surface, along with explanation balloons detailing onboard scientific instruments. Many people on a blue planet across the Solar System will be eagerly awaiting news and updates. Whether Philae actually lands, whether it lands on a smooth patch, whether the harpoons take hold, and how far the robotic lander sinks into the surface should all become known as events unfold today. Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2959
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 13 Image Credit: ESA/Rosetta/Philae/ROLIS Explanation: Yesterday, the first soft landing on a comet took place some 500 million kilometers from planet Earth as the Rosetta mission lander Philae settled on the nucleus of C67/P Churyumov-Gerasimenko. The landing site, dubbed Agilkia, is located near the center of this remarkable image snapped by Philae's ROLIS (ROsetta Lander Imaging System) camera. Taken from a distance of about 3 kilometers the image has a resolution of about 3 meters per pixel at the surface. After Philae's release from the orbiter, its seven-hour long descent was made without propulsion or guidance. Following its descent the lander is in place, though its anchoring harpoon system did not fire. For 2.5 days the lander is intended to conduct its main science mission returning extensive images and data. An extended surface mission may be possible if sunlight and dust conditions allow solar panels to recharge Philae's battery. Tomorrow's picture: light-weekend Πηγή Σχόλιο : Τεράστιο επίτευγμα της ανρωπότητας, ειδικά που αυτό είναι ευρωπαϊκό!!!
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2960
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 14 Image Credit: ESA/Rosetta/Philae/CIVA Explanation: The Rosetta Mission lander is safely on a comet. One of Philae's feet appears at the bottom left of this spectacular image of the surface of C67/P Churyumov-Gerasimenko. Still a happy lander, Philae bounced twice before settling and returning images from the surface, traveling a kilometer or so after initially touching at the targeted site Agilkia. A surface panorama suggests that the lander has come to rest tilted and near a shadowing wall, with its solar panels getting less illumination that hoped. Philae's science instruments are working as planned and data is being relayed during communications windows, when the Rosetta spacecraft is above the lander's new horizon. Tomorrow's picture: lighter weekend Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2961
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 15 Image Credit & Copyright: J-P Metsävainio (Astro Anarchy) Explanation: Framing a bright emission region this telescopic view looks out along the plane of our Milky Way Galaxy toward the nebula rich constellation Cygnus the Swan. Popularly called the Tulip Nebula the glowing cloud of interstellar gas and dust is also found in the 1959 catalog by astronomer Stewart Sharpless as Sh2-101. About 8,000 light-years distant and 70 light-years across the complex and beautiful nebula blossoms at the center of this composite image. Red, green, and blue hues map emission from ionized sulfur, hydrogen, and oxygen atoms. Ultraviolet radiation from young, energetic stars at the edge of the Cygnus OB3 association, including O star HDE 227018, ionizes the atoms and powers the emission from the Tulip Nebula. HDE 227018 is the bright star very near the blue arc at the cosmic tulip's center. Glowing across the electromagnetic spectrum, microquasar Cygnus X-1 and a curved shock front created by its powerful jets lie toward the top and right. Tomorrow's picture: Sunday's Childe Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2962
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 16 Image Credit & Copyright: Juan Carlos Casado (TWAN) Explanation: Leonids Meteor Shower came to an impressive crescendo in 1999. Observers in Europe saw a sharp peak in the number of meteors visible around 0210 UTC during the early morning hours of November 18. Meteor counts then exceeded 1000 per hour - the minimum needed to define a true meteor storm. At other times and from other locations around the world, observers typically reported respectable rates of between 30 and 100 meteors per hour. This photograph is a 20-minute exposure ending just before the main Leonids peak began. Visible are at least five Leonid meteors streaking high above the Torre de la Guaita, an observation tower used during the 12th century in Girona, Spain. In 2014, over the next few nights, the Leonids meteor shower will again peak. This year, although the crescent Moon should not create much competing skyglow, the Earth is predicted to pass through a more moderate stream of debris left over from Comet Tempel-Tuttle than in 1999, perhaps resulting in as many as 15 visible meteors per hour from dark locations. Tomorrow's picture: open space Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2963
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 17 Illustration Credit: Spitzer Space Telescope, JPL, NASA Explanation: What do other star systems look like? To help find out, astronomers are carrying out detailed observations of nearby stars in infrared light to see which have dust disks that might be forming planets. Observations by NASA's Spitzer Space Telescope and ESA's Herschel Space Observatory have found that planetary system HD 95086 has two dust disks: a hot one near the parent star and a cooler one farther out. An artist's illustration of how the system might appear is featured here, including hypothetical planets with large rings that orbit between the disks. The planets may have created the large gap between the disks by absorbing and deflecting dust with their gravity. HD 95086 is a blue star about 60 percent more massive than our Sun that lies about 300 light years from Earth and is visible with binoculars toward the constellation of Carina. Studying the HD 95086 system may help astronomers better understand the formation and evolution of our own Solar System as well as the Earth. New Mirror Site: APOD is now available from Serbia in Serbian. Tomorrow's picture: stars and pillars Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2964
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 18 Image Credit: WISE, IRSA, NASA; Processing & Copyright : Francesco Antonucci Explanation: Dusty emission in the Tadpole nebula, IC 410, lies about 12,000 light-years away in the northern constellation Auriga. The cloud of glowing gas is over 100 light-years across, sculpted by stellar winds and radiation from embedded open star cluster NGC 1893. Formed in the interstellar cloud a mere 4 million years ago, bright cluster stars are seen all around the star-forming nebula. Notable near the image center are two relatively dense streamers of material trailing away from the nebula's central regions. Potentially sites of ongoing star formation in IC 410, these cosmic tadpole shapes are about 10 light-years long. The featured image was taken in infrared light by NASA's Wide Field Infrared Survey Explorer (WISE) satellite. Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2965
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 19 Image Credit: Subaru Telescope (NAOJ), Hubble Space Telescope; Processing & Copyright: Roberto Colombari & Robert Gendler Explanation: One of the brightest galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy: big, beautiful M81. This grand spiral galaxy can be found toward the northern constellation of the Great Bear (Ursa Major). This superbly detailed view reveals M81's bright yellow nucleus, blue spiral arms, and sweeping cosmic dust lanes with a scale comparable to the Milky Way. Hinting at a disorderly past, a remarkable dust lane actually runs straight through the disk, to the left of the galactic center, contrary to M81's other prominent spiral features. The errant dust lane may be the lingering result of a close encounter between M81 and its smaller companion galaxy, M82. Scrutiny of variable stars in M81 has yielded one of the best determined distances for an external galaxy -- 11.8 million light-years. Tomorrow's picture: open space Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2966
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 20 Image Credit & Copyright: Bob Franke Explanation: Obscuring the rich starfields of northern Cygnus, dark nebula LDN 988 lies near the center of this cosmic skyscape. Composed with telescope and camera, the scene is some 2 degrees across. That corresponds to 70 light-years at the estimated 2,000 light-year distance of LDN 988. Stars are forming within LDN 988, part of a larger complex of dusty molecular clouds along the plane of our Milky Way galaxy sometimes called the Northern Coalsack. In fact, nebulosities associated with young stars abound in the region, including variable star V1331 Cygni shown in the inset. At the tip of a long dusty filament and partly surrounded by a curved reflection nebula, V1331 is thought to be a T-Tauri star, a sun-like star still in the early stages of formation. Tomorrow's picture: pixels in space Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2967
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 21 Image Credit & Copyright: Martin Pugh Explanation: The Crab Nebula is cataloged as M1, the first object on Charles Messier's famous 18th century list of things which are not comets. In fact, the Crab is now known to be a supernova remnant, debris from the death explosion of a massive star, witnessed by astronomers in the year 1054. This sharp, ground-based telescopic view uses narrowband data to track emission from ionized oxygen and hydrogen atoms (in blue and red) and explore the tangled filaments within the still expanding cloud. One of the most exotic objects known to modern astronomers, the Crab Pulsar, a neutron star spinning 30 times a second, is visible as a bright spot near the nebula's center. Like a cosmic dynamo, this collapsed remnant of the stellar core powers the Crab's emission across the electromagnetic spectrum. Spanning about 12 light-years, the Crab Nebula is a mere 6,500 light-years away in the constellation Taurus. Tomorrow's picture: a sharper view Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2968
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 22 Image Credit: Solar Dynamics Observatory/AIA, NASA Explanation: Solar active region AR2192 was the largest recorded sunspot group of the last 24 years. Before rotating off the Earth-facing side of the Sun at the end of October, it produced a whopping six energetic X-class flares. Its most intense flare was captured on October 24 in this stunning view from the orbiting Solar Dynamics Observatory. The scene is a color combination of images made at three different wavelengths of extreme ultraviolet light; 193 angstroms shown in blue, 171 angstroms in white, and 304 angstroms in red. The emission, from highly ionized Iron and Helium atoms, traces magnetic field lines looping through the hot plasma of the Sun's outer chromosphere and corona. Beneath, the cooler solar photosphere appears dark at extreme ultraviolet wavelengths. The exceptionally sharp composite image has been processed with a new mathematical algorithm (NAFE) that adapts to noise and brightness in extreme ultraviolet image data to reliably enhance small details. Tomorrow's picture: on a cloudy day Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2969
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 23 Image Credit & Copyright: Eric Nguyen (Oklahoma U.), www.mesoscale.ws Explanation: The scene might have been considered serene if it weren't for the tornado. During 2004 in Kansas, storm chaser Eric Nguyen photographed this budding twister in a different light -- the light of a rainbow. Featured here, a white tornado cloud descends from a dark storm cloud. The Sun, peeking through a clear patch of sky to the left, illuminates some buildings in the foreground. Sunlight reflects off raindrops to form a rainbow. By coincidence, the tornado appears to end right over the rainbow. Streaks in the image are hail being swept about by the high swirling winds. Over 1,000 tornadoes, the most violent type of storm known, occur on Earth every year, many in tornado alley. If you see a tornado while driving, do not try to outrun it -- park your car safely, go to a storm cellar, or crouch under steps in a basement. Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2970
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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2014 November 24 Video Credit: Cassini Radar Mapper, JPL, USGS, ESA, NASA Explanation: What would it look like to fly over Titan? Radar images from NASA's robotic Cassini satellite in orbit around Saturn have been digitally compiled to simulate such a flight. Cassini has swooped past Saturn's cloudiest moon several times since it arrived at the ringed planet in 2004. The virtual flight featured here shows numerous lakes colored black and mountainous terrain colored tan. Surface regions without detailed vertical information appear more flat, while sufficiently mapped regions have their heights digitally stretched. Among the basins visualized is Kraken Mare, Titan's largest lake which spans over 1,000 kilometers long. Titan's lakes are different from Earth's lakes in that they are composed of hydrocarbons with similarities to liquid natural gas. How Titan's lakes were created and why they survive continues to be a topic of research. Tomorrow's picture: visiting creature Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
Συνδεδεμένοι χρήστες που διαβάζουν αυτό το θέμα: 2 (0 μέλη και 2 επισκέπτες) | |
Εργαλεία Θεμάτων | |
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