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Sunspots - SST.jpgSunspots72 visiteCaption NASA originale:"This stunning image shows remarkable and mysterious details near the dark central region of a planet-sized sunspot in one of the sharpest views ever of the surface of the Sun. Just released, the picture was made using the Swedish Solar Telescope now in its first year of operation on the Canary Island of La Palma. Along with features described as hairs and canals are dark cores visible within the bright filaments that extend into the sunspot, representing previously unknown and unexplored solar phenomena". Set 15, 2004
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North_Polar_Regions-North_Pole.jpgThe North Pole of Mars (Natural Colors; credits: NASA/MGS/MSSS)311 visiteNon ci sono parole sufficienti per descrivere questa meravigliosa immagine ad HD del Polo Nord di Marte ed il volume di dettagli che risultano percepibili è davvero enorme. EccoVi il testo originale di commento al frame:"Spring reached the North Pole of Mars (foto del Maggio 2002) and brought with it the usual dust storms. As the North Polar Cap begins to thaw, a temperature difference occurs between the cold frost region and recently thawed surface, resulting in swirling winds between the adjacent regions. In the above image mosaic from the Mars Global Surveyor spacecraft, the white material is frozen carbon dioxide that covers much of the extreme north. The choppy clouds of at least three dust storms can be identified". Che altro dire???Set 15, 2004
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Mars-013.jpgMars: Yesterday and Today249 visiteDoes Mars have canals? A hot debate topic of the late 1800s, several prominent astronomers including Percival Lowell not only claimed to see an extensive system of long straight canals on Mars, but used them to indicate that intelligent life exists there. The relatively close opposition of 1894 was used to make drawings like the one digitally re-scaled on the above left. The above map was originally prepared by Eugene Antoniadi and redrawn by Lowell Hess for the book Exploring Mars, by Roy A. Gallant. In more modern times, the latest Mars opposition has allowed the Hubble Space Telescope to capture a picture of similar orientation. Comparison of the two images shows that large features were impressively recorded, but that an extensive system of long and straight canals just does not exist. Satellites orbiting Mars have now shown conclusively that the red planet does indeed have surface features similar to canals, but that these are usually smaller, curved, and less extensive than that previously claimed. Real canyon systems like Noctis Labyrinthus are most likely cracks caused by surface stress.
Set 14, 2004
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Solar Flares.jpgSolar Flares63 visiteCaption NASA originale:"On June, 14th, 1999, SOHO observatory recorded this stunning view of an immense prominence erupting from the Sun's southern latitudes. The false-color image was made in the extreme Ultraviolet light produced by ionized Helium atoms in the solar plasma". Set 14, 2004
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Sunflare.jpgA Sunflare from the Skylab78 visiteUn'immagine d'epoca: l'anno è il 1973 e dallo Skylab (allora conosciuto come "Il Laboratorio Spaziale") ci arriva l'immagine di una "fiaccola" o, se preferite, di un "Solar Flare".Set 14, 2004
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Coronal Mass Ejection.jpgA "Coronal Mass Ejection"75 visiteCaption NASA originale:"Magnetic fields buckle releasing previously constrained hot material from the upper atmosphere of the Sun. As a result, hot gas streams out into the Solar System, impacting planets, moons, spacecraft, and making space a dangerous place for astronauts. Known as "Coronal Mass Ejections" (CMEs), billions of tons of scathing plasma can be accelerated to millions of miles per hour. CMEs are more common but less intense than solar flares".Set 14, 2004
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ZA-Green flash from the Sun (2).jpgA "Green Flash" from the Sun (Portugal)93 visiteCaption NASA originale: "Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood. Just as the setting Sun disappears completely from view, a last glimmer appears startlingly green. The effect is typically visible only from locations with a low, distant horizon and lasts just a few seconds".Set 14, 2004
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Sun & Comet (dtl-mgnf).jpgA comet approaching the Sun (from SOHO) - detail mgnf61 visiteCaption NASA originale:"Based on their similar orbits, as first worked out by 19th century German astronomer Heinrich Kreutz, all "sungrazers" are believed to originate from a single large "parent comet" which broke up during a perihelion passage perhaps 2.000 years ago. Over time, pieces have continued to split off producing a family of smaller comets which seem to travel in the same orbit". Set 14, 2004
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Sun & Comet (2).jpgA comet approaching the Sun (from SOHO)66 visiteCaption NASA originale:"SOHO, the space-based SOlar and Heliospheric Observatory, has become by far the reigning champion facility for discovering comets, its total having reached more than 200. As might be expected of a solar observatory, most of the SOHO discovered comets are "sungrazers", such as comets destined to dive within a mere 50.000 Km or so of the solar photosphere.
At that range the intense heat and gravitational forces make it unlikely these primitive chunks of ice and dust will survive".Set 14, 2004
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Sun & Comet.jpgA comet approaching the Sun (from SOHO)64 visiteCaption NASA originale:"These 3 frames from SOHO's coronograph were taken two hours apart from each other on April 29, 2000. They show a "sungrazer" (SOHO comet discovery number 111) with a long, bright tail headed toward its fiery encounter.
The Sun itself is hidden behind the coronograph's occulting disk at each frame's upper right". Set 14, 2004
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Saturn & family-PIA06475_modest.jpgSaturn and Family62 visiteCaption NASA originale:"Satellites visible in this image are (clockwise from upper left): Dione (1.118 Km or 695 miles wide), Enceladus (499 Km or 310 miles wide), Tethys (1.060 Km or 659 miles wide), Mimas (398 Km or 247 miles wide) and Rhea (1.528 Km or 949 miles wide).
The image was taken in visible red light on Aug. 1, 2004, at a distance of 7.8 MKm (4.8 million miles) from Saturn. The image scale is 464 Km (288 miles) per pixel". Set 14, 2004
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vo1-PIA00300_modest.jpgOlympus Mons (False Colors; credits: NASA)99 visiteShown here is a digital mosaic of Olympus Mons, the largest known volcano in the Solar System. It is 27 Km high, over 600 Km at the base, and is surrounded by a well-defined scarp (scarp--->"scarpata") that is up to 6 Km high. Lava flows (lava flow--->"colata lavica") drape over the scarp in places. Much of the plains surrounding the volcano are covered by the ridged (to ridge--->verb.:"increspare"; ridge--->sost.:"crinali") and grooved (to groove--->verb.:"scanalare" o "incavare"; groove--->sost.:"solco" o "scanalatura") 'aureole' of Olympus Mons.Set 13, 2004
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