| Piú votate - Saturn: the "Ringed Beauty" and His Moons |
Hyperion-N00078297.jpgTumbling Hyperion (2 - natural colors, elab. Lunexit)58 visiteCaption NASA:"N00078297.jpg was taken on February 15, 2007 and received on Earth February 17, 2007. The camera was pointing toward Hyperion that, at the time, was approximately 224.256 Km away.
The image was taken using the CL1 and UV3 filters".MareKromium
(4 voti)
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Rhea-PIA08871.jpgRhea (natural & false colors)87 visiteSide-by-side natural color and false-color views highlight the wispy terrain on Rhea's Trailing Hemisphere. The extreme false color image makes it clear that the wisps - likely networks of fractures as on Dione - cut across older, cratered terrain.
In addition, a set of thin, North-South trending lineaments (also likely fractures) is visible on the left side of both views.
The natural color view was created by compositing images taken using red, green and blue spectral filters.
To create the false-color view, ultraviolet, green and infrared images were combined into a single picture that isolates and maps regional color differences. This "color map" was then superimposed over a clear-filter image that preserves the relative brightness across the body.
The combination of color map and brightness image shows how colors vary across the surface of Rhea. 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 surface material. North on Rhea (1,528 kilometers, or 949 miles across) is up.
The images were taken with the Cassini spacecraft narrow-angle camera on Jan. 17, 2007 at a distance of approximately 597,000 kilometers (371,000 miles) from Rhea. Image scale is 4 kilometers (2 miles) per pixel.
(4 voti)
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Mimas-N00077787.jpgOccultation? (6)59 visiteCaption NASA:"(...) The camera was pointing toward Mimas that, at the time, was at approximately 1.344.455 Km away, and the image was taken using the CL1 and CL2 filters (...)".
(4 voti)
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Mimas-N00077788.jpgOccultation? (7)56 visiteCaption NASA:"(...) The camera was pointing toward Mimas that, at the time, was at approximately 1.344.230 Km away, and the image was taken using the CL1 and CL2 filters (...)".
(4 voti)
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Mimas-N00077785.jpgOccultation? (4)57 visiteCaption NASA:"(...) The camera was pointing toward Mimas that, at the time, was at approximately 1.344.896 Km away, and the image was taken using the CL1 and CL2 filters (...)".
(4 voti)
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The_Rings-PIA08863.jpgWhat's inside the F-Ring?!?61 visiteCaption NASA:"These 2 images, taken about 8' apart, show clump-like structures and a great deal of dust in Saturn's ever-changing F-Ring. The images show an object-interior to and detached from the bright core of the F-Ring that appears to be breaking up into discrete clumps.
Cassini scientists have been monitoring clumps in the F-Ring for more than 2 years now, trying to understand whether these represent small permanent moonlets or transient aggregates of material. This view looks toward the unlit side of the Rings from about 35° above the Ring-Plane.
The images were taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 23, 2006 at a distance of approx. 2 MKM (about 1,2 MMs) from Saturn. Image scale is roughly 12 Km (about 7 miles) per pixel".
(4 voti)
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Saturn-PIA08858.jpgInfrared Saturn (elab. NASA)58 visiteCaption NASA:"This psychedelic view of Saturn and its Rings is a composite made from images taken with the Cassini spacecraft wide-angle camera using spectral filters sensitive to wavelengths of infrared light centered at 728, 752 and 890 nanometers.
Cassini acquired the view on Dec. 13, 2006 at a distance of approx. 822.000 Km(such as about 511.000 miles) from Saturn. Image scale is roughly 46 Km (approx. 28 miles) per pixel". MareKromium
(4 voti)
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The_Rings-PIA08855.jpgMulticolored Rings...57 visiteCaption NASA:"Both luminous and translucent the C-Ring sweeps out of the darkness of Saturn's shadow and obscures the Planet at lower left.
The Ring is characterized by broad, isolated bright areas, or "plateaux", surrounded by fainter material. This view looks toward the unlit side of the Rings from about 19° above the Ring-Plane. North on Saturn is up. The dark, inner B-Ring is seen at lower right.
The image was taken in visible light with the Cassini spacecraft wide-angle camera on Dec. 15, 2006 at a distance of approx. 632.000 Km (about 393.000 miles) from Saturn and at a phase angle of 56°.
Image scale is roughly 34 Km (about 21 miles) per pixel".
Nota: il sistema di elaborazione in "colori naturali" non è cambiato ma, come vedete Voi stessi, i colori di Saturno sono (leggermente) mutati. Come mai? La risposta, a nostro parere, deve essere rinvenuta nel tipo di filtraggio utilizzato dalla NASA per l'ottenimento dell'immagine originale in b/n. Questo vuol dire, fra l'altro, che i frames in b/n NON sono affatto tutti uguali (come molti invece ritengono). E' il tipo di flitro impiegato per l'ottenimento dell'immagine originale - ottenuta sulla scala dei grigi - che poi determinerà, in sede di trasformazione del frame in immagine a colori, il "tipo di colori"!
(4 voti)
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Mimas-PIA08842.jpgMonochrome Mimas56 visitenessun commento
(4 voti)
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Saturn-PIA08833.jpgNorthern Latitudes of Saturn and the B-Ring's shadow56 visiteCaption NASA:"Streaks of cloud are overlain with graceful ring shadows in this view of Saturn's Northern Latitudes.
Structure is visible in the shadow of the A-Ring and Cassini Division, which widen at the highest latitudes, near lower right. The lower left half of the image does not show the blackness of space, but rather the shadow of the B-Ring, which is perfectly dark here.
The image was acquired from a high inclination above the Planet's Ring-Plane and looks obliquely toward the limb. (...)
The image was taken with the Cassini spacecraft narrow-angle camera using a spectral filter sensitive to wavelengths of infrared light centered at 938 nanometers on Oct. 30, 2006. Cassini was then at a distance of approx. 1,2 MKM (about 700.000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 142°.
Image scale is roughly 7 Km (a little more than 4 miles) per pixel".
(4 voti)
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Saturn-PIA08822.jpgSaturn's limb (NASA - natural colors)59 visiteCaption NASA originale:"From its unique perspective high above the Planet, the Cassini spacecraft looks down upon Saturn's murky Northern Hemisphere. The bluish hues seen in some Cassini views of Saturn's North are notably absent in this viewing geometry.
The dark side of Saturn's extensive Rings is just visible in the top half of the image.
The view looks toward the unlit side of the Rings, from about 44° above the Ring-Plane.
Images taken using red, green and blue spectral filters were combined to create this natural color view.
The images was taken with the Cassini spacecraft wide-angle camera on Oct. 30, 2006, at a distance of approx. 1,4 MKM (about 900.000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 150°. Image scale is roughly 78 Km (about 49 miles) per pixel".
(4 voti)
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Japetus-N00071141.jpgJapetus in natural colors56 visiteCaption NASA:"N00071141.jpg was taken on November 27, 2006 and received on Earth November 28, 2006. The camera was pointing toward Japetus that, at the time, was approximately 1.998.833 Km away.
The image was taken using the CL1 and IR3 filters. This image has not been validated or calibrated".
(4 voti)
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