| Piú viste - Saturn: the "Ringed Beauty" and His Moons |
Rhea-PIA08208.jpgCrescent Rhea (Super HR)55 visiteCaption NASA originale:"Rhea's devastated surface creates a jagged terminator as mountains and crater rims break-up the line between day and night. Terrain on Rhea's night side is dimly lit by reflected light from Saturn.
The view looks toward the Southern Hemisphere on the moon's trailing side. North on Rhea is up.
The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on May 22, 2006 at a distance of approximately 263.000 Km (about 164.000 miles) from Rhea and at a phase, angle of 138°. Image scale is approx. 2 Km (about 1,4 mile) per pixel".
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Polydeuces-PIA08209.jpgPolydeuces (extra detail mgnf)55 visiteThis magnified view shows tiny Polydeuces, a moon that was discovered by the Cassini spacecraft and is a mere 3 Km (a little less than 2 miles) across. Along with much larger Helene (32 Km, or 20 miles across), Polydeuces orbits Saturn at the same distance as large, icy Dione (which is 1.126 Km, or 700 miles across).
Because this body was only recently discovered and is so small, scientists presently know precious little about it. Further observations by Cassini may yield additional insights about its nature and composition.
The image was taken with the Cassini spacecraft narrow-angle camera on May 22, 2006 at a distance of approx. 73.000 Km (about 45.000 miles) from Polydeuces and at a phase angle of 41°. The image was obtained using a spectral filter sensitive to wavelengths of infrared light centered at 752 nanometers. Scale in the original image was about 434 mt (appx. 1423 feet) per pixel. The image has been magnified by a factor of 4 and contrast-enhanced to aid visibility.
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Saturn-PIA08213-br500.jpgThe "Ringed Beauty"!55 visitenessun commento
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Saturn-W00015907.jpgIn the Night of Saturn...55 visitenessun commento
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Mimas-PIA08223.jpgLand of Darkness...55 visiteCaption NASA originale:"The narrow and twisted F-Ring lights up this scene, which features Mimas against the unlit side of Saturn's Ring-Plane.
The F-Ring contains a great deal of fine, icy particles that are quite effective at scattering Sunlight at "high phase" angles.
Mimas (about 397 Km - approx. 247 miles - across) is seen as a mere crescent in the center of this haunting view.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 13, 2006 at a distance of approx. 3,9 MKM (such as about 2,4 MMs) from Mimas and at a Sun-Mimas-spacecraft, or phase, angle of 156°. Image scale is roughly 23 Km (about 15 miles) per pixel".
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Enceladus-PIA08226.jpgThe "Fountains" of Enceladus55 visiteCaption NASA originale:"The ice-jets of Enceladus send particles streaming into space hundreds of kilometers above the South Pole of this spectacularly active moon. Some of the particles escape to form the diffuse E-Ring around Saturn.
This color-coded image was processed to enhance faint signals, making the contours and extent of the fainter, larger-scale component of the plume easier to see.
The bright strip behind and above Enceladus is the E-Ring, in which this intriguing body resides. The small round object at far left is a background star.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March 24, 2006 at a distance of approx. 1,9 MKM (sucg as about 1,2 MMs) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 162°. Image scale is about 11 Km (approx. 7 miles) per pixel".
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Tethys-N00064170.jpgThe "White Face" of Tethys55 visitenessun commento
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Rhea-N00064136.jpgA rough slice of Rhea (2)55 visitenessun commento
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Sky-N00064410.jpgThe "Big Streak" is just a "bad picture"?55 visiteCaption NASA originale:"N00064410.jpg was taken on July 26, 2006 and received on Earth July 26, 2006. The camera was pointing toward Saturn's E-Ring that, at the time, was approximately 1,4 MKM away.
The image was taken using the CL1 and CL2 filters.
This image has not been validated or calibrated".
Nota: non ci sembra che la fotocamera di Cassini stesse inquadrando il debole Anello "E" di Saturno. Questo frame, a nostro avviso, è il prodotto di uno scatto casuale ed effettuato impiegando parametri errati i quali si sono risolti in una immagine mossa (come le "strisce ondulate" - che riteniamo essere stelle - dimostrano ampiamente) e, di fatto, impossibile da spiegare.
L'inclinazione del notevole streak di luce bianca (Big Streak) visibile ad ore 9 del frame - un'inclinazione incongrua rispetto a quella degli streaks lasciati dalle altre stelle riprse - ci dimostra che questo "Big Streak" non dovrebbe essere dipeso dal fatto di Cassini (che scatta mentre si muove in maniera repentina), bensì dal SUO (autonomo) movimento RISPETTO a Cassini.
Gli altri puntini che costellano l'immagine sono dei photoartifacts (noise).
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Rhea & Enceladus-PIA08237.jpgAfter the occultation...55 visiteCaption NASA originale:"Two slim crescents smile toward the Cassini spacecraft following an occultation event.
Taken only 5 minutes after Enceladus first approached the limb of Rhea, this view shows the bright little moon emerging from behind the larger moon's crescent.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 4, 2006 at a distance of approx. 1,4 MKM (about 800.000 miles) from Rhea and approx. 1,9 MKM (about 1,2 MMs) from Enceladus. The view was obtained at a Sun-moon-spacecraft, or phase, angle of about 142° relative to both moons.
Image scale is about 8 Km (5 miles) per pixel on Rhea and approx. 11 Km (about 7 miles) on Enceladus".
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Rhea-N00064808.jpgMoments of Rhea (2)55 visitenessun commento
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Rhea-N00064832-B.jpgMoments of Rhea (6) - Rhea's "Peak" (detail mgnf)55 visiteRicordate il "picco" (o la "Grande Montagna") di Oberon (Sez. "Uranus and His Moons")? Rilievi simili, per corpi celesti simili...
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