Saturn: the "Ringed Beauty" and His Moons
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Rhea-N00146883_to_938-MF.jpgRhea (Image-Mosaic and Natural Colors; credits: Dr M. Faccin)55 visiteE questo image-mosaic, infine, oltre che ai Ragazzi di Pasadena ed allo Space Science Institute, lo dedichiamo anche ai Curatori della prestigiosa Rubrica "NASA - Picture of the Day" (caso mai avessero voglia di pubblicare qualcosa di VERAMENTE spettacolare, eseguito a Regola d'Arte e, soprattutto, di grandissimo valore tecnico e didattico).
Grandissimi Complimenti a Marco Faccin e Gianluigi Barca per i loro grandissimi sforzi (questo mosaico è costato poco più di due ore di lavoro), i quali vengono SEMPRE coronati da - a dire poco - grandissimi risultati (ancorchè detti risultati sono conosciuti e riconosciuti, purtroppo, solo da pochissimi...).MareKromium
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Rhea-N00154965-66-67-EB-LXTT.jpgCraterland (an Image-Mosaic by Elisabetta Bonora - Lunexit Team)79 visitenessun commentoMareKromium
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Rhea-N00164515-EB-LXTT.jpgThe "Old Face" of Rhea (an Image-Mosaic in possible True Colors by: Elisabetta Bonora - Lunexit Team)57 visitenessun commentoMareKromium
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Rhea-PIA06525_modest.jpgRhea from about 1.700.000 Km55 visiteCaption NASA originale:"Saturn's moon Rhea shows off the moon equivalent of a black eye: a bright, rayed crater near its eastern limb.
Rhea is about half the size of Earth's moon. At 1.528 Km across, it is the second-largest moon orbiting Saturn.
The image was taken in visible light with the Cassini spacecraft narrow angle camera on Oct. 24, 2004, at a distance of about 1.7 MKMs from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 40°. The image scale is approximately 10 Km per pixel. Cassini will image this hemisphere of Rhea again in mid-January 2005 with an approx. 1 Km resolution".
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Rhea-PIA06555_modest.jpgRhea's craters57 visiteCaption NASA originale: "The sunlight angle in this sharp view of Saturn's second-largest moon, Rhea, highlights the moon's crater-strewn surface. Cassini will fly past Rhea on Nov. 26, 2005, at a distance of only 500 Km (such as 311 miles) and will obtain very high resolution images at that time. Rhea's diameter is 1.528 Km(or 949 miles).
This view shows mainly the hemisphere of Rhea that faces away from Saturn. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Nov. 1, 2004, at a distance of 1,6 MKM (or 994.000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 102°. North is up. The image scale is about 10 Km (6 miles) per pixel. The image has been slightly contrast enhanced to aid visibility of surface features.
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Rhea-PIA06620.jpgRhea and Enceladus: which is which?59 visiteCaption NASA originale:"Though much farther away from Cassini when the spacecraft acquired this image, Saturn's second-largest moon Rhea still dwarfs the brightest icy moon Enceladus in this scene. Rhea is 1.528 Km (approx. 949 miles) across. Enceladus is 505 Km (approx. 314 miles) across.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 21, 2005, at a distance of approx. 2 MKM (approx. 1,3 million miles) from Enceladus and 2,5 MKM (approx. 1,6 MMs) from Rhea. The image scale is 12 Km (approx. 7 miles) per pixel on Enceladus and 15 Km (approx. 9 miles) per pixel on Rhea".
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Rhea-PIA06630.jpgRhea, from 1,8 MKM56 visiteCaption NASA originale:"The ancient and battered surface of Saturn's moon Rhea shows a notable dark swath of territory near the eastern limb in this image from Cassini.
This view shows principally the Saturn-facing hemisphere on Rhea (1.528 Km across). North is up and tilted 40° to the right.
The image was taken with the Cassini spacecraft narrow-angle camera on March 7, 2005, through a filter sensitive to wavelengths of ultraviolet light centered at 338 nnmts. The view was acquired at a distance of approx. 1,8 MKM (approx. 1,1 MMs) from Rhea and at a phase angle of 30°. Resolution in the original image was 10 Km per pixel.
The image has been contrast-enhanced and magnified by a factor of two to aid visibility".
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Rhea-PIA06641.jpgTirawa impact basin on Rhea56 visiteCaption NASA originale:"The large Tirawa impact basin on Saturn's moon Rhea is visible at the two o'clock position in this Cassini image. This view shows principally the trailing hemisphere on Rhea and is centered on the moon's equator. North is up and tilted 25° to the left.
The image was taken with the Cassini spacecraft narrow-angle camera on March 13, 2005, through a filter sensitive to wavelengths of ultraviolet light centered at 338 nnmts.
The image was obtained at a distance of approximately 1,7 MKM(such as 1,1 MMs) from Rhea and at a phase angle of 90°. Resolution in the original image was 10 Km (approx. 6 miles) per pixel. The image has been contrast-enhanced and magnified by a factor of two to aid visibility".
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Rhea-PIA06648.jpgWhite young crater on Rhea55 visiteCaption NASA originale:"Looking closely at Saturn's moon Rhea during a distant flyby, Cassini provides this view of what appears to be a bright, rayed and therefore relatively young crater. This crater was also observed by Cassini at much lower resolution in the fall of 2004 and in spring of 2005. For comparison, viewing the same crater near the terminator (the line between day and night) would highlight the crater's topography (vertical relief), compared to its brightness, which is highlighted in this view where the Sun is at a higher angle.
North on Rhea is up and rotated about 15° to the left. This view shows principally the leading hemisphere on Rhea".
Nota: guardate molto bene il bordo di Rhea e poi chiedeteVi se esso sembri di più il bordo di una 'sfera' o di uno 'sferoide'. Poi, se avete tempo e voglia, provate a rileggere i commenti del Prof. Hoagland sulla forma di Giapeto e sulle sue possibili cause ed implicazioni.
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Rhea-PIA07517.jpgRhea and the Rings56 visiteCaption NASA originale:"Saturn's brightly sunlit moon Rhea commands the foreground in this image from Cassini; the Gas Giant Planet's Rings are discernible in the background. The spacecraft was just above the Ringplane when it acquired this image, and thus captured the darkened appearance of the dense B-Ring when viewed with sunlight filtered through the Rings. From this perspective, bright areas in the Rings are regions of low density, containing very small particles that effectively scatter light toward Cassini.
North on Rhea is up and rotated about 25° to the left. This view shows principally the anti-Saturn hemisphere on Rhea. It is very clear that the right side of Rhea is highly overexposed.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 18, 2005, at a distance of approx. 540.000 Km (such as approx 340.000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 110°. The image scale is 3 Km (2 miles) per pixel".
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Rhea-PIA07554.jpgRhea's "Bright Splat"69 visiteCaption NASA originale:"This view of Saturn's moon Rhea shows the tremendous "Bright Splat" that coats much of the moon's leading hemisphere. The bright feature may be impact-related and is visible in other Cassini images of Rhea.
The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on June 25, 2005, at a distance of approx. 1,1 MKM from Rhea and at a phase angle of less than 1°. Resolution in the original image was 7 Km (about 4 miles) per pixel (...)".
Nota: in qualità di Ricercatori nel campo delle Scienze Planetarie e quindi al di fuori di ogni intendimento strumentalmente polemico nei confronti della NASA e degli Scienziati che attribuiscono il 99,99% dei crateri presenti sui corpi celesti attualmente più conosciuti (dalla nostra Luna alle lune di Nettuno) all'azione di impatti, desideriamo sottolineare che un "Bright Splat" come questo, al 99,99%, NON è attribuibile ad un impatto (a meno che l'agente impattante non fosse una gigantesca palla di fango).
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Rhea-PIA07572.jpgRhea, from about 342.000 Km56 visiteCassini looks upward at the South Polar Region on Rhea during a recent distant encounter. Rhea's icy surface is so heavily saturated with impact craters that the moon's limb, or edge, has a rugged, bumpy appearance. The bright splotch seen here near the upper right is impact material (or ejecta) from a relatively fresh crater.
The image was taken with the Cassini spacecraft narrow-angle camera on July 14, 2005, at a distance of approx. 342.000 Km (about 212.000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 36°. The image was obtained using a filter sensitive to wavelengths of infrared light centered at 298 nnmts. The image scale is 1,6 Km per pixel
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