| Piú votate - Saturn: the "Ringed Beauty" and His Moons |
Telesto-N00047270.jpgTelesto58 visiteOriginal caption:"N00047270.jpg was taken on December 25, 2005 and received on Earth December 26, 2005. The camera was pointing toward TELESTO that, at the time, was approximately 20.919 kilometers away, and the image was taken using the CL1 and UV3 filters".
(5 voti)
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Janus-N00047277.jpgThe "Runners": Janus and Epimetheus (1)59 visiteOriginal caption:"N00047277.jpg was taken on December 25, 2005 and received on Earth December 26, 2005. The camera was pointing toward Epimetheus (and Janus) that, at the time, was approximately 450.089 Km away. The image was taken using the CL1 and CL2 filters".
(5 voti)
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Rhea-N00047118.jpgRhea59 visiteOriginal caption:"N00047118.jpg was taken on December 23, 2005 and received on Earth December 24, 2005. The camera was pointing toward RHEA that, at the time, was approximately 341.537 Km away.
The image was taken using the CL1 and CL2 filters".
(5 voti)
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Hyperion-N00047027.jpgHyperion? (1)61 visiteOriginal caption:"N00047027.jpg was taken on December 23, 2005 and received on Earth December 23, 2005. The camera was pointing toward HYPERION that, at the time, was approx. 227.969 Km away.
The image was taken using the CL1 and CL2 filters".
Saranno scherzi della luce, dell'angolo di fase (o di quello di ripresa), della distanza...Chissà. L'unica cosa che a noi sembra evidente è che Hyperion, in questo frame (e nel successivo) non assomiglia per nulla al corpo celeste che avevamo già visto in passato ed ammirato durante l'ultimo fly-by di Cassini.
Diremmo che assomiglia ad Epimetheus e, comunque, ricorderete anche Voi un altro "face-change" che rilevammo qualche mese fa analizzando alcune immagini MGS di Phobos (un "cambio-faccia" del quale Vi abbiamo già parlato in passato, nella Sezione "Mars and His Moons").
Le possibili cause di questi (apparenti?) "cambi-faccia"? Ripetiamo: la luce, l'angolo di ripresa, l'angolo di fase...senza dimenticare le "sviste": nostre e non solo!
(5 voti)
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Rhea-PIA07769.jpgRhea and Dione (false colors)59 visiteOriginal caption:"Saturn's cratered, icy moons, Rhea and Dione, come alive with vibrant color that reveals new information about their surface properties. To create these false-color views, ultraviolet, green and infrared images were combined into a single black and white picture that isolates and maps regional color differences. This "color map" was then superimposed over a clear-filter image of each moon. The combination of color map and brightness image shows how the colors vary across the moon's surface in relation to geologic features. The origin of the color differences is not yet understood, but may be caused by subtle differences in the surface composition or the sizes of grains making up the icy soil. (...) The images have not been scaled to show the moons' proper relative sizes".
(5 voti)
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Janus-N00044721.jpgJanus and Epimetheus (4)58 visitenessun commento
(5 voti)
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Janus-N00044715.jpgJanus and Epimetheus (3)58 visitenessun commento
(5 voti)
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Enceladus-N00043480.jpgEnceladus, Rings and...photoartifact?87 visiteAttenzione: lo streak bianco che abbiamo evidenziato in questo frame è, con ogni probabilità, un artefatto fotografico. Questa immagine, tuttavia, ci serve per rammentare e rammentarVi che, nell'espressione di giudizi, teorie e/o sensazioni su quanto taluni frames mostrano (o sembrano mostrare), occorre usare sempre la massima cautela e la più grande prudenza, se si vuole rimanere credibili. Gli UFO, a nostro avviso, sono un argomento delicato ed importante che richiede, per essere analizzato in maniera adeguata, prudenza e competenza. In una parola: l'Ufologia è materia da trattare con estrema serietà ed attenzione.
Una serietà ed un'attenzione che, tuttavia, nei media e, ahinoi..., anche nella grande maggioranza degli Appassionati (Siti e Forum pieni di ufologi da strapazzo ce ne sono a migliaia), non si vede.
(5 voti)
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Epimetheus&Janus-N00043522.jpgJanus and Epimetheus (1)58 visiteN00043522.jpg was taken on November 29, 2005 and received on Earth November 29, 2005. The camera was pointing toward Epimetheus that, at the time, was approximately 1.095.193 Km away, and the image was taken using the CL1 and CL2 filters.
(5 voti)
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Enceladus-PIA07760.jpgThe "Fountains" of Enceladus59 visiteA fine spray of small, icy particles emanating from the warm, geologically unique province surrounding the South Pole of Enceladus was observed in a Cassini narrow-angle camera image of the crescent moon taken on Jan. 16, 2005. Taken from a high phase angle of 148° - a viewing geometry in which small particles become much easier to see - the plume of material becomes more apparent in images processed to enhance faint signals.
Imaging scientists have measured the light scattered by the plume's particles to determine their abundance and fall-off with height. Though the measurements of particle abundance are more certain within 100 Km of the surface, the values measured there are roughly consistent with the abundance of water ice particles made by other Cassini instruments (reported in 09/2005) at altitudes as high as 400 Km above the surface.
At present, it is not clear if the plume particles emanating from the south pole arises because of water vapor escaping from warm ice that is exposed to the surface. Another possibility is that at some depth beneath the surface, the temperatures are hot enough for water to become liquid, which then, under pressure, escapes to the surface like a cold Yellowstone geyser.
The image at the left was taken in visible green light. A dark mask was applied to the moon's bright limb to make the plume feature easier to see.
The image at the right has been color-coded to make faint signals in the plume more apparent. Images of other moons, such as Tethys and Mimas, taken in the last 10 months from similar lighting and viewing geometries, and with identical camera parameters, were closely examined to demonstrate that the plume towering above Enceladus' south pole is real and not a camera artifact.
The images were acquired at a distance of about 209,400 kilometers (130,100 miles) from Enceladus. Image scale is about 1 kilometer (0.6 mile) per pixel.
(5 voti)
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Enceladus-PIA07759.jpgThe "Fountains" of Enceladus60 visite"...this greatly enhanced and colorized image shows the enormous extent of the fainter, larger-scale component of the plume..."
Nota: dal tenore del commento NASA, oltre ad una leggera sorpresa, non pare trasparire alcunchè. Allora: se abbiamo capito bene c'è qualcosa che viene "spruzzato" nel cielo dalla superficie di Encelado e che forma una sorta di "fontana" di corpuscoli che si disperdono nello spazio.
Qualcosa di incredibile e di assolutamente "alieno" (nel senso di lontano dal nostro modo di vedere e di immaginare le cose) sta accadendo, ma la NASA si limita a darci un commentino secco e asciutto, come la risposta ad un quesito di Scienze Planetarie che verrebbe data al Professore da uno studente non troppo preparato. Abbiamo letto, recentemente, della costante caduta di interesse da parte dell'opinione pubblica in generale e dei giovani in particolare verso lo Spazio e l'esplorazione del Sistema Solare. Onestamente, visto l'atteggiamento costantemente bolso di ESA e NASA, non ce ne meravigliamo...
(5 voti)
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Rhea-N00043376.jpgFeatures on the Terminator58 visiteN00043376.jpg was taken on November 26, 2005 and received on Earth November 27, 2005. The camera was pointing toward Rhea that, at the time, was approximately 69,991 Km away.
The image was taken using the CL1 and UV3 filters.
(5 voti)
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