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Εργαλεία Θεμάτων | Τρόποι εμφάνισης |
#2356
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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. 2013 March 4 Image Credit & Copyright: Terry Hancock Explanation: Sprawling across almost 200 light-years, emission nebula IC 1805 is a mix of glowing interstellar gas and dark dust clouds. Derived from its Valentine's-Day-approved shape, its nickname is the Heart Nebula. About 7,500 light-years away in the Perseus spiral arm of our galaxy, stars were born in IC 1805. In fact, near the cosmic heart's center are the massive hot stars of a newborn star cluster also known as Melotte 15, about 1.5 million years young. A little ironically, the Heart Nebula is located in the constellation of the mythical Queen of Aethiopia (Cassiopeia). This deep view of the region around the Heart Nebula spans about two degrees on the sky or about four times the diameter of the Full Moon. Tomorrow's picture: almost alien Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2357
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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. 2013 March 5 Image Credit & Copyright: Yuri Beletsky (ESO) Explanation: Two impressive comets will both reach their peak brightness during the next two weeks. Taking advantage of a rare imaging opportunity, both of these comets were captured in the sky together last week over the Atacama desert in South America. Comet C/2012 F6 (Lemmon), visible on the upper left of the above image, is sporting a long tail dominated by glowing green ions. Comet C/2011 L4 (PanSTARRS), visible near the horizon on the lower right, is showing a bright tail dominated by dust reflecting sunlight. The tails of both comets point approximately toward the recently set Sun. Comet Lemmon will be just barely visible to the unaided eye before sunset in southern skies for the next week, and then best viewed with binoculars as it fades and moves slowly north. Comet PanSTARRS, however, will remain visible in southern skies for only a few more days, after which it will remain bright enough to be locatable with the unaided eye as it moves into northern skies. To find the giant melting snowball PanSTARRS, sky enthusiasts should look toward the western horizon just after sunset. Deep sky observers are also monitoring the brightening of Comet C/2012 S1 (ISON), which may become one of the brightest objects in the entire night sky toward the end of 2013. Expanding Gallery: Bright Comets of 2013 Tomorrow's picture: almost alien Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2358
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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. 2013 March 6 Image Credit & Copyright: Nicole Ottawa & Oliver Meckes / Eye of Science / Science Source Images Follow APOD on: Facebook (Daily) (Sky) (Spanish) or Google Plus (Daily) (River) Tomorrow's picture: open space Πηγή Σχόλιο : Σαν να φοράει σκάφανδρο....
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2359
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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. 2013 March 7 Image Credit & Copyright: Martin Rusterholz (CXIELO Observatory) Explanation: This helmet-shaped cosmic cloud with wing-like appendages is popularly called Thor's Helmet. Heroically sized even for a Norse god, Thor's Helmet is about 30 light-years across. In fact, the helmet is actually more like an interstellar bubble, blown as a fast wind from the bright, massive star near the bubble's center sweeps through a surrounding molecular cloud. Known as a Wolf-Rayet star, the central star is an extremely hot giant thought to be in a brief, pre-supernova stage of evolution. Cataloged as NGC 2359, the nebula is located about 15,000 light-years away in the constellation Canis Major. The sharp image, made using broadband and narrowband filters, captures striking details of the nebula's filamentary structures. It shows off a blue-green color from strong emission due to oxygen atoms in the glowing gas. 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 |
#2360
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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. 2013 March 8 Credit: NASA, ESA, Hubble Heritage/ESA-Hubble Collaboration - Acknowledgment: Nick Rose Explanation: Want to use a cluster of galaxies as a telescope? It's easier than you might think as distant galaxy clusters naturally act as strong gravitional lenses. In accordance with Einstein's theory of general relativity, the cluster gravitational mass, dominated by dark matter, bends light and creates magnified, distorted images of even more distant background galaxies. This sharp infrared Hubble image illustrates the case for galaxy cluster Abell 68 as a gravitational telescope, explored by amateur astronomer Nick Rose during the ESA-Hubble Hidden Treasures image processing competition. Putting your cursor over the picture will label highlights in the scene. Labels 1 and 2 show two lensed images of the same background galaxy. The distorted galaxy image labeled 2 resembles a vintage space invader! Label 3 marks a cluster member galaxy, not gravitationally lensed, stripped of its own gas as it plows through the denser intergalactic medium. Label 4 includes many background galaxies imaged as elongated streaks and arcs. Abell 68 itself is some 2.1 billion light-years distant toward the constellation Vulpecula. The central region of the cluster covered in the Hubble view spans over 1.2 million light-years. Tomorrow's picture: light-weekend Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2361
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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. 2013 March 9 Image Credit & Copyright: John Sarkissian (CSIRO Parkes Observatory) Explanation: Sweeping quickly through southern skies on March 5, Comet PanSTARRS (C/2011 L4) follows the Sun toward the western horizon in this twilight scene. In the foreground is Australia's CSIRO Parkes Radio Telescope, a 64 meter wide steerable dish that is no stranger to the space age exploration of comets. In March of 1986 the Parkes dish tracked ESA's Giotto spacecraft as it flew by Comet Halley and received the first ever closeup images of Halley's nucleus. At naked-eye visibility, Comet PanSTARRS made its closest approach to planet Earth on March 5. Its closest approach to the Sun will be on March 10. Heading north, PanSTARRS now begins a much anticipated appearance low in the northern hemisphere's western skies after sunset. On March 12, look for the comet hugging the western horizon near a young crescent Moon. Tomorrow's picture: Mauna Kea Milky Waya Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2362
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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. 2013 March 10 Image Credit & Copyright: Wally Pacholka (TWAN) Explanation: Aloha and welcome to a breathtaking skyscape. The dreamlike panoramic view looks out from the 4,200 meter volcanic summit of Mauna Kea, Hawai'i, across a layer of clouds toward a starry night sky and the rising Milky Way. Anchoring the scene on the far left is the dome of the Canada-France-Hawaii Telescope (CFHT), with north star Polaris shining beyond the dome to the right. Farther right, headed by bright star Deneb, the Northern Cross asterism is embedded along the plane of the Milky Way as it peeks above the horizon. Both Northern Cross and brilliant white Vega hang over a foreground grouping of cinder cones. Near the center are the reddish nebulae, stars and dust clouds of the central Milky Way. Below, illumination from the city lights of Hilo creates an eerie, greenish glow in the clouds. Red supergiant star Antares shines above the Milky Way's central bulge while bright Alpha Centauri lies still farther right, along the dusty galactic plane. Finally, at the far right is the large Gemini North Observatory. The compact group of stars known as the Southern Cross is just left of the telescope dome. Need some help identifying the stars? Just slide your cursor over the picture, or download this smaller, labeled panorama. Tomorrow's picture: earth explodes Πηγή Σχόλιο : Εξαιρετική φωτογραφία. Επισκεφτείτε την σελίδα του APOD για να δείτε τις περιγραφές, που προσπάθησα να βάλω στην μικρή φωτο κάτω, αλλά δεν φαίνονται.
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2363
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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. 2013 March 11 Image Credit & Copyright: Martin Rietze (Alien Landscapes on Planet Earth) Explanation: Why does a volcanic eruption sometimes create lightning? Pictured above, the Sakurajima volcano in southern Japan was caught erupting in early January. Magma bubbles so hot they glow shoot away as liquid rock bursts through the Earth's surface from below. The above image is particularly notable, however, for the lightning bolts caught near the volcano's summit. Why lightning occurs even in common thunderstorms remains a topic of research, and the cause of volcanic lightning is even less clear. Surely, lightning bolts help quench areas of opposite but separated electric charges. One hypothesis holds that catapulting magma bubbles or volcanic ash are themselves electrically charged, and by their motion create these separated areas. Other volcanic lightning episodes may be facilitated by charge-inducing collisions in volcanic dust. Lightning is usually occurring somewhere on Earth, typically over 40 times each second. Tomorrow's picture: last swirl Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2364
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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. 2013 March 13 Image Credit: Hubble Legacy Archive, ESA, NASA; Processing - Donald Waid Explanation: Planetary nebulae can look simple, round, and planet-like in small telescopes. But images from the orbiting Hubble Space Telescope have become well known for showing these fluorescent gas shrouds of dying Sun-like stars to possess a staggering variety of detailed symmetries and shapes. This composite color Hubble image of NGC 6751, the Glowing Eye Nebula, is a beautiful example of a classic planetary nebula with complex features. It was selected in April of 2000 to commemorate the tenth anniversary of Hubble in orbit, but was reprocessed recently by an amateur as part of the Hubble Legacy program. Winds and radiation from the intensely hot central star (140,000 degrees Celsius) have apparently created the nebula's streamer-like features. The nebula's actual diameter is approximately 0.8 light-years or about 600 times the size of our Solar System. NGC 6751 is 6,500 light-years distant in the high-flying constellation of the Eagle (Aquila). Astrophysicists: Browse 550+ codes in the Astrophysics Source Code Library 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 |
#2365
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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. 2013 March 14 Image Credit & Copyright: Babak Tafreshi (TWAN) Explanation: In silhouette against the colorful evening twilight glow, clouds part in this much anticipated magic moment. The scene captures naked-eye Comet PanSTARRS peeking into northern hemisphere skies on March 12. The comet stands over the western horizon after sunset, joined by the thin, flattened crescent of a day old Moon. Posing for its own beauty shot, the subtly lit dome of the 4.2 meter William Herschel Telescope is perched above cloud banks on the Canary Island of La Palma. While PanSTARRS has not quite developed into the spectacular comet once hoped for, it is still growing easier to see in the north. In coming days it will steadily climb north, farther from the Sun into darker western evening skies. Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2366
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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. 2013 March 14 Image Credit: NRL / SECCHI / STEREO / NASA Processing - Karl Battams (NRL and @SungrazerComets) Explanation: After appearing in a popular photo opportunity with a young crescent Moon near sunset, naked-eye Comet PanSTARRS continues to rise in northern hemisphere skies. But this remarkable interplanetary perspective from March 13, finds the comet posing with our fair planet itself - as seen from the STEREO Behind spacecraft. Following in Earth's orbit, the spacecraft is nearly opposite the Sun and looks back toward the comet and Earth, with the Sun just off the left side of the frame. At the left an enormous coronal mass ejection (CME) is erupting from a solar active region. Of course, CME, comet, and planet Earth are all at different distances from the spacecraft. (The comet is closest.) The processed digital image is the difference between two consecutive frames from the spacecraft's SECCHI Heliospheric Imager, causing the strong shadowing effect for objects that move between frames. Objects that are too bright create the sharp vertical lines. The processing reveals complicated feather-like structures in Comet PanSTARRS's extensive dust tail. Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2367
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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. 2013 March 16 Image Credit & Copyright: Jean-Luc Dauvergne Explanation: Still looking for that comet? Comet PanSTARRS (C/2011 L4) naked-eye appearance in the northern hemisphere is described by successful comet spotters as a dim star with faint a tail. If you want to catch it the next few days could be your best bet. Start looking low and almost due west about 45 minutes after sunset. Of course, clear skies and a pair of binoculars should help a lot. Sky photographer Jean-Luc Dauvergne found suitable weather and western horizon for this comet and crescent Moon portrait after a road trip on March 13. Seeing PanSTARRS for the first time, he recorded the beautiful twilight scene with a telephoto lens near historical Alesia in France. Πηγή Σχόλιο : Αυτές τις φωτογραφίες τις λατρεύω... Τι να πούμε ;
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2368
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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. 2013 March 17 Image Credit: NASA, ESA, H. E. Bond (STScI) Explanation: What caused this outburst of V838 Mon? For reasons unknown, star V838 Mon's outer surface suddenly greatly expanded with the result that it became the brightest star in the entire Milky Way Galaxy in January 2002. Then, just as suddenly, it faded. A stellar flash like this had never been seen before -- supernovas and novas expel matter out into space. Although the V838 Mon flash appears to expel material into space, what is seen in the above image from the Hubble Space Telescope is actually an outwardly moving light echo of the bright flash. In a light echo, light from the flash is reflected by successively more distant rings in the complex array of ambient interstellar dust that already surrounded the star. V838 Mon lies about 20,000 light years away toward the constellation of the unicorn (Monoceros), while the light echo above spans about six light years in diameter. Tomorrow's picture: sunset comet Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2369
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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. 2013 March 18 Image Credit & Copyright: Chris Cook Explanation: Have you seen the comet? As Comet PANSTARRS fades, careful observers -- even with unaided eyes -- should still be able to find the shedding ice ball on the western horizon just after sunset. Pictured above, Comet PANSTARRS (C/2011 L4) was pointed out from a hilltop last week on First Encounter Beach in Massachusetts, USA. The comet was discovered by -- and is named for -- the Pan-STARRS astronomical sky survey that discovered it. As the comet now recedes from both the Earth and the Sun, it will remain visible further into the night, although binoculars or a small telescope will soon to be needed to find it. Πηγή
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όταν γράφεται η ιστορία της ζωής σου, μην αφήνεις κανέναν να κρατάει την πένα |
#2370
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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. 2013 March 20 Image Credit & Copyright: Reinhold Wittich Explanation: The Great Nebula in Orion, an immense, nearby starbirth region, is probably the most famous of all astronomical nebulas. Here, glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud only 1500 light-years away. In the above deep image in assigned colors highlighted by emission in oxygen and hydrogen, wisps and sheets of dust and gas are particularly evident. The Great Nebula in Orion can be found with the unaided eye near the easily identifiable belt of three stars in the popular constellation Orion. In addition to housing a bright open cluster of stars known as the Trapezium, the Orion Nebula contains many stellar nurseries. These nurseries contain much hydrogen gas, hot young stars, proplyds, and stellar jets spewing material at high speeds. Also known as M42, the Orion Nebula spans about 40 light years and is located in the same spiral arm of our Galaxy as the Sun. Πηγή Σχόλιο : Σαν να βλέπεις πίνακα μοντέρνας τέχνης...
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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: 9 (0 μέλη και 9 επισκέπτες) | |
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