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Saturn-PIA03557.jpgSaturn's pressure72 visiteOriginal NASA caption:"This new view on the right side shows clouds at an altitude where pressure is nearly 2 bars. (nota---->1 bar rappresenta l'unità di misura della pressione atmosferica terrestre esistente al livello del mare). These clouds are about 30 Km underneath the clouds usually observed on Saturn. This is distinctly different from the typical view of Saturn in reflected sunlight, shown on the left.
The left view is characterized by broad expanses of clouds near the 1-bar level, such as the white cloud seen circling the Equator, with little hint of the discrete cloud complexes lying underneath (...)".
(11 voti)
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NGC-4725-SST.jpgNGC 4725 - Spiral Galaxy (SST)76 visite"...Quando parlava, la sua voce, ferma e profonda, aleggiava su quei luoghi quasi a scandirne il tempo mentre i suoi occhi, limpidi e sicuri, sembravano finalmente trovare riposo in quella tenue luce che dolcemente si spegne sulla Terra quando è sera, quando cielo e terra, in una rinnovata promessa d'Amore, giacciono insieme nel fecondo abbraccio che prepara al nuovo giorno.
E così, mentre il Silenzio con il suo mistero scendeva su quella piccola valle coprendone le distanze, gli animi concitati di quei monelli, seduti intorno al loro vecchio amico, si placavano di colpo non appena un suo cenno lasciava intendere che era giunto il momento di ricavalcare le ali della Fantasia..."
Giuseppe Spina - "Naufragio"
(11 voti)
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NGC-6745.jpgNGC 6745 - Collision of Galaxies74 visite"...Whoever welcomes one such child in my name, welcomes me..."
Matthew, 18:5
(11 voti)
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ZZ-ZZ-ZZ-ZZ-ZZ-ZZ-CTX_Moon_6Oct2004.jpgThe Moon from Mars Reconnaissance Orbiter138 visiteThis image of Earth's moon was acquired by the Mars Reconnaissance Orbiter (MRO) Context Imager (CTX) camera during calibration and testing between 2:00 and 3:00 a.m. Pacific Daylight Time (PDT) on 6 October 2004. The image was taken by CTX before it was delivered and mounted on the MRO spacecraft. It was obtained from the parking lot at the Malin Space Science Systems facility in San Diego, California. In this image, east is toward the top and south is toward the bottom. The image demonstrates the field of view of the MRO CTX camera, which is 5064 pixels across (clicking on the image above will permit download of the full 5064 pixels-wide image). When in its circular mapping orbit about Mars, the 5064 pixels will cover a swath that is about 30 kilometers (~18.6 miles) across. CTX will obtain its 30 km-wide images at a resolution of about 6 meters (~19.7 feet) per pixel. CTX images will be used to provide context for the very high resolution images (better than 1 meter per pixel) to be obtained by the MRO HiRISE camera. CTX data will also provide context for MRO's CRISM infrared imaging spectrometer as well as provide detailed observations of martian landforms and potential, future Mars landing sites.
(11 voti)
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Tenth_Planet-03.jpgThe 10th Planet? (3)58 visiteDa "NASA - Picture of the Day", del 1mo Agosto 2005:"Has a tenth planet been discovered? A newly discovered object, designated 2003 UB313 and located more than twice the distance of Pluto, is expected to be at least as large as Pluto and probably larger, given current measurements. 2003 UB313's dimness and highly tilted orbit (44°) prevented it from being discovered sooner. Many astronomers speculate that numerous other icy objects larger than Pluto likely exist in the Kuiper Belt of the far distant Solar System. If so, and if some are found closer in than 2003 UB313, it may be premature to call 2003 UB313 the tenth planet. Illustrated above is an artist's drawing showing what 2003 UB313 might look. The unusually bright star on the right is the Sun. Much of the world eagerly await the decision by the International Astronomical Union on whether 2003 UB313 will be designated a planet or given a name without subscripts".
(11 voti)
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M-004-3.jpgM 4 and the colorful clouds of Rho Ophiuchi78 visite"...Una Vittima? E chi ha parlato di una Vittima?!?..."
"...C'è sempre una Vittima.
E' la prima delle Tre Regole della Vita: le conosci?... Prima Regola: c'è sempre una Vittima; seconda regola, cerca di non esserlo tu".
"...E la Terza Regola?..."
"Me la sono scordata".
Dal film - "8 mm"
(11 voti)
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Mimas-PIA07534.jpgRound? Not really...60 visiteCaption NASA originale:"Saturn's moon Mimas, whose low density suggests that it is primarily composed of ice, has a flattened or oblate shape reminiscent of Saturn's. The moon's equatorial dimension is nearly 10% larger than the polar one due to the satellite's rapid rotation. This view shows principally the leading hemisphere on Mimas. Mimas' largest crater, Herschel (130 Km, or 80 miles wide), is centered roughly on the equator and can be seen here. North on Mimas is toward upper left.
The moon's oblateness is exaggerated by Cassini's viewing angle here -- the Sun-Mimas-spacecraft, or phase, angle was only 5° leaving a sliver of the moon's disk in shadow on the northwest limb.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on May 20, 2005, at a distance of approx. 916.000 Km (about 569.000 miles) from Mimas. Resolution in the original image was 5 Km (about 3 miles) per pixel".
(11 voti)
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M-022-2.jpgM 22 - Globular Star Cluster83 visite"...Ius est in armis..."
(Seneca)
"...La Legge è nella forza..."
Nota: Seneca non era un 'guerrafondaio' nè un assertore del 'Diritto delle Armi', come questa massima (ex "Hercul. Fur." - Atto II, Sc. I, Vers. 29) può far pensare. Egli, in realtà, si limitò a stigmatizzare che, per gli scellerati ed i tiranni, la Legge - ergo anche la Giustizia e l'Equilibrio - è fondata nella forza bruta (e quindi nella paura), mentre per i saggi (ahimè pochi, anche ai suoi tempi...) essa è posta nella capacità di usare la ragione.
(11 voti)
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ZO-Westlake3Planets061905.jpgMercury, Venus and Saturn in the Western Sky70 visiteDa "NASA - Picture of the Day" del 24 Giugno 2005:" This weekend three planets will grace the Western Sky, forming a lovely trio easily visible shortly after sunset. Saturday evening in particular will find Saturn, Venus and Mercury all within a 2° circle (about the size of your thumb held at arm's length) above the Western Horizon. Recorded last Sunday, June 19, this image shows the same 3 planets arrayed along the ecliptic plane above a Colorado Rocky Mountain skyline. Venus is easiest to pick out of the twilight, the brightest celestial beacon below picture center, with Saturn above and to the left of Venus and Mercury closest to the horizon, right of prominent Pinnacle Peak. By Saturday, the wandering planets will draw even closer together (...)".
(11 voti)
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Eta Carinae - SST.jpgEta Carinae - SST109 visite"...Saepe etiam sub palliolo sordido Sapientia est..."
(Cecilio Stazio)
"...Sovente l'Intelligenza può trovarsi anche sotto un vecchio abito..."
(11 voti)
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Sagittarius~0.jpgThe "Sagittarius' Dwarf Tidal Stream"107 visiteDa "NASA - Picture of the Day" del 29 Maggio 2005:"Recent 'Wide Field Images' and analyses indicate that our home galaxy is actually still in the process of devouring one of its closer satellite neighbors.
This unfortunate neighbor, the Sagittarius Dwarf Galaxy, is now seen to be part of a larger Sagittarius Tidal Stream, a loose filament of stars, gas, and possibly dark matter that entangles the Milky Way. Speculation also holds that the Sagittarius Dwarf was once pulled through the Milky Way disk very close to our Sun's current location. An important resulting realization is that galaxies contain a jumble of clumps and filaments of both dim and dark matter".
Che sia questo residuo di onda mareale - o forse si tratta di un corpo oscuro 'dimenticato'? - la causa delle strane ed apparentemente inspiegabili accelerazioni e decelerazioni del Voyager, ormai giunto agli estremi confini dell'area di influenza mareale del Sole?
O forse non è poi così facile riuscire a "mollare gli ormeggi solari"?...
(11 voti)
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032-Mars_Interior.jpgWhat's inside Mars?177 visiteMars interior is simply modeled as a core and mantle with a thin crust, similar to Earth. Mars' size and total mass are known. Given four parameters, the core size and mass and mantle size and mass can be determined.
The combination of Pathfinder Doppler data with earlier data from the Viking Landers has determined a very important parameter, the "Moment of Inertia", through measurement of Mars' precession rate. A fourth measurement is needed to complete the interior model. This may be achieved through future Doppler tracking of Pathfinder, since the presence of a fluid core may be detectable through its effect on Mars' nutation. The determination of the moment of inertia is a significant constraint on possible models for Mars' interior. If the core is as dense as possible (i.e. completely iron) and the mantle is similar to Earth's (or similar to the SNC meteorites thought to originate on Mars) then the minimum core radius is about 1300 Km. If the core is made of less-dense material (i.e. a mixture of iron and sulfur) than the core radius is probably no more than 2000 Km.
(11 voti)
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