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| Piú viste - Uranus and His Moons |
Titania-PIA01978-PCF-LXTT-IPF.jpgOn the Limb of Titania (Possible Absolute Natural Colors; credits for the additional process. and color. Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)82 visiteLike their semi-divine namesakes, Dione's twin Impact Craters Romulus and Remus (just above-right of the center) stand together while Dido, the larger Impact Crater showing a magnificent and impressive Central Peak, lies to the South/East, on the lower left Limb of Dione and almost half-way on top of the Terminator. The lit Terrain seen here is on the Saturn-facing Hemisphere of Dione and North is up.
The image was taken in Visible Light with the NASA - Cassini Spacecraft Narrow-Angle Camera on April 28, 2013. The view was obtained at a distance of approximately 870.000 miles (such as a little more than 1,4 Million KiloMeters) from Dione and at a Sun-Dione-Cassini Spacecraft, or Phase, Angle of 77°. Image scale is roughly 5 miles (a little more than 8 Km) per pixel.
This frame (which is an Original NASA - Cassini Spacecraft b/w frame published on the NASA - Planetary Photojournal with the ID n. PIA 17126) has been additionally processed, contrast enhanced, magnified to aid visibility of the Surface details and then colorized, according to an educated guess carried out by Dr Paolo C. Fienga/LXTT/IPF, in what they should be its Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Cassini Spacecraft and then looked outside, towards the Saturnian moon Dione), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among others, the existence of different Elements present on the Surface of Dione, each having a different Albedo (---> Reflectivity) and Chemical Composition.
Note: it is possible (but we, as IPF, have no way to be one-hundred-percent sure of such a circumstance), that the actual luminosity of Dione - as it is in this frame - would appear, to an average human eye, a little bit lower than it has been shown (or, better yet: interpreted) here.MareKromium
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URANUS from HST.jpgUranus from the Hubble Space Telescope81 visiteUrano, il terz'ultimo Pianeta del Sistema Solare, fa parte della famiglia dei "Giganti Gassosi", assieme a Giove, Saturno e Nettuno. In ordine di grandezza Urano è il terzo Pianeta dopo Giove e Saturno e, dal punto di vista della sua struttura, esso assomiglia (quasi) come una goccia d'acqua a Nettuno.
Al pari di questo, infatti, la (spessissima) atmosfera di Urano appare costituita principalmente da Idrogeno ed Elio con una sensibile presenza, nei suoi strati più alti, di Metano (il quale conferisce al Pianeta il suo caratteristico colore azzurrino).
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Miranda-PIA01354_modest.jpgMiranda (close-up of the Verona Rupes Region) - HR81 visiteCaption NASA originale:"Miranda, innermost of Uranus' large satellites, is seen at close range in this Voyager 2 image, taken Jan. 24, 1986, as part of a HR mosaicing sequence. Voyager was some 36.000 Km (22.000 miles) away from Miranda. This clear-filter, narrow-angle image shows an area about 250 Km (150 mi) across, at a resolution of about 800 meters (2.600 feet). Two distinct terrain types are visible: a rugged, higher-elevation terrain (right) and a lower, striated terrain. Numerous craters on the rugged, higher terrain indicate that it is older than the lower terrain. Several scarps, probably faults, cut the different terrains.
The impact crater in the lower part of this image is about 25 Km (15 mi) across".
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AAA-Uranus&Co..jpgThe Uranus' "Family"81 visitenessun commento
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VA-UranusRings-2.jpgUranus, from HST (Clouds, Rings & Moons - False Colors; credits: NASA)80 visiteLa causa di un simile evento rimane tuttora sconosciuta anche se molti Studiosi pensano che questa abnorme inclinazione dell'asse di rotazione del Pianeta (guardate questa immagine per renderVi conto di che cosa intendiamo) sia anch'essa - al pari del sistema di anelli - il "ricordo" di un impatto cosmico con un altro (grande!) corpo celeste, avvenuto qualche centinaio di milioni di anni fa.
Se sottoposto ad un'osservazione visuale diretta Urano, come già accennavamo in precedenza, si mostra come un disco grigiastro, assolutamente privo di caratteristiche superficiali.
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Titania from Voyager 2.jpgTitania from Voyager 2 (2)80 visitenessun commento
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Miranda-PIA00042-PCF-LXTT-IPF.jpgMiranda's Southern Hemisphere (Possible Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)76 visiteThis image-mosaic of the Uranian moon Miranda was taken by the NASA - Voyager 2 Spacecraft on January 24, 1986, from a distance of approx. 147.000 Km (such as about 91.287 miles). This image-mosaic was constructed from images taken through the Spacecraft's Narrow-Angle Camera's Green, Violet and UltraViolet Filters.
Miranda, just about 480 Km (such as approx. 299 miles) across, is the smallest of Uranus' five Major natural satellites. Miranda's Regional Geologic Provinces are shown very well in this view of its Southern Hemisphere, imaged at a resolution of roughly 2,7 Km (such as 1,67 miles) per pixel. The dark- and bright-Banded Region with its curvilinear traces, covers about half of the frame. Higher-resolution pictures taken some time later showed many Fault Valleys and Ridges, all parallel to these "Bands". Near the Terminator Line (on the right - Dx), another system of Ridges and Valleys abuts the Banded Terrain; furthermore, many Impact Craters pockmark the Surface of Miranda all over this Region. The largest of these Craters are about 30 Km (approx. 18,63 miles) in diameter and many more of them lie in the range of 5 to 10 Km (such as from 3,1 to 6,2 miles) in diameter.
This frame (which is an Original NASA - Voyager 2 Spacecraft Natural Color image-mosaic published on the NASA - Planetary Photojournal with the ID n. PIA 00042) has been additionally processed, contrast enhanced, magnified to aid visibility of the Surface details and then re-colorized, according to an educated guess carried out by Dr Paolo C. Fienga/LXTT/IPF, in what they should be its Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Voyager 2 Spacecraft and then looked outside, towards the Uranian moon Miranda), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among others, the existence of different Elements present on the Surface of Miranda, each having a different Albedo (---> Reflectivity) and Chemical Composition.
Note: it is possible (but we, as IPF, have no way to be one-hundred-percent sure of such a circumstance), that the actual luminosity of Miranda - as it is in this frame - would appear, to an average human eye, a little bit lower than it has been shown (or, better yet: interpreted) here.MareKromium
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Miranda-V2-PIA00141_modest.jpgMiranda's limb from Voyager 2 - January 24, 198675 visiteEd ecco ora Miranda, la Luna più interna di Urano. Essa ha una forma decisamente irregolare ed evidenzia molto chiaramente - come in questo frame - delle profonde "cicatrici" superficiali le quali rivelano, come dicono alla NASA, una "complessa storia geologica". EccoVi parte della caption originale NASA per questa foto:"...At least 3 terrain types of different age and geologic style are evident at this resolution of about 700 (2.300 feet) meters. Visible in this clear-filter, narrow-angle image are, from left: (1) an apparently ancient, cratered terrain consisting of rolling, subdued hills and degraded medium-sized craters (2) a grooved terrain with linear valleys and ridges developed at the expense of, or replacing, the first terrain type and (3) a complex terrain seen along the terminator, in which intersecting curvilinear ridges and troughs are abruptly truncated by the linear, grooved terrain. Voyager scientists believe this third terrain type is intermediate in age between the first two".
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VI-Puck-HR-V2.JPGPuck (possible Natural Colors; credits: Lunar Explorer Italia)75 visitenessun commentoMareKromium
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Miranda-V2-PIA01980_modest.jpgMiranda: a funny shaped Moon74 visiteIn questa seconda immagine di Miranda risulta ben visibile una vastissima depressione situata in prossimità del suo Polo Nord la quale potrebbe aver avuto origine a seguito di un impatto con un altro corpo celeste di notevoli dimensioni.
Una luna che ha "sofferto", dunque, e la cui storia risale - molto probabilmente - alle stesse origini del nostro Sistema Solare, quando gli impatti - specie nella sua "periferia" - avvenivano con una frequenza di gran lunga maggiore rispetto a quanto accade ai giorni nostri.
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VI-Puck-V2.jpgPuck - Voyager 274 visitenessun commento
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VF-Cressida, Ophoelia, Portia.jpgCressida, Ophoelia and Portia - Voyager 272 visiteUn piccolissimo commento (forse abbastanza scontato): noi non sappiamo chi, fisicamente, abbia dato i nomi a queste Lune Minori di Urano ma, certamente, si trattava di un appassionato lettore di Sir William Shakespeare.
Non credete?!?...
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