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Saturn: the "Ringed Beauty" and His Moons
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Saturn-PIA08360.jpgFrom North to South...55 visiteCaption NASA:"Dark and sharply defined ring shadows appear to constrict the flow of color from Saturn's warmly hued South to the bluish Northern Latitudes.
Scientists studying Saturn are not yet sure about the precise cause of the color change from North to South. NASA Voyager spacecraft flybys witnessed a more evenly painted Planet in the early '80s, when Saturn was closer to Equinox. However, the bluish color was readily apparent upon Cassini's approach to the Planet in late 2003, when Saturn was just coming out of its Northern Hemisphere Winter. Scientists have speculated that the color is due to seasonal effects on the atmosphere.
Aside from the color differences, the cloud morphology is quite different in the Polar Regions compared to the mid-latitudes. Bright, isolated clouds dot the high latitudes, while Saturn's middle is characterized by flowing cloud bands and the occasional bright or dark vortex.
This view looks toward the lit side of the rings from about half a degree below the Ring-Plane.
Images taken using red, green and blue spectral filters were combined to create this natural-color view. The images were obtained with the Cassini spacecraft wide-angle camera on Feb. 4, 2007, at a distance of approx. 1,2 MKM (about 700.000 miles) from Saturn. Image scale is roughly 67 Km (about 42 miles) per pixel". MareKromium
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Saturn-PIA08361.jpgThe Ring-World in natural colors54 visiteCaption NASA:"Our robotic emissary, flying high above Saturn, captured this view of an alien copper-colored Ring-World. The overexposed planet has deliberately been removed to show the unlit Rings alone, seen from an elevation of 60°, the highest Cassini has yet attained.
The view is a mosaic of 27 images -- nine separate sets of red, green and blue images -- taken over the course of about 45', as Cassini scanned across the entire main Ring System. The Planet's shadow carves a dark swath across the Ring-Plane at the right.
Moons visible in this image: Epimetheus, at the 1 o'clock position; Pandora, at the 5 o'clock position and Janus, at the 10 o'clock position.
Bright clumps of material in the narrow F-Ring moved in their orbits between each of the color exposures, creating a chromatic misalignment that provides some sense of the continuous motion in the Ring System.
Radially extending lens flare artifacts, which result from light being scattered within the camera optics, are present in the view.
The images in this natural-color view were obtained with the Cassini spacecraft wide-angle camera on Jan. 21, 2007, at a distance of approx. 1,6 MKM (1 MMs) from Saturn. Image scale is 90 roughly Km (about 56 miles) per pixel".
MareKromium
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Saturn-PIA08362.jpgThe Ringed World, from above54 visiteCaption NASA:"Surely one of the most gorgeous sights the Solar System has to offer, Saturn sits enveloped by the full splendor of its stately Rings. Taking in the Rings in their entirety was the focus of this particular imaging sequence. Therefore, the camera exposure times were just right to capture the dark-side of its Rings, but longer than that required to properly expose the globe of sunlit Saturn. Consequently, the sunlit half of the Planet is overexposed.
Between the blinding light of day and the dark of night, there is a strip of twilight on the globe where colorful details in the atmosphere can be seen. Bright clouds dot the bluish-grey Northern Polar Region here. In the South, the Planet's night side glows golden in reflected light from the Rings' sunlit face.
Saturn's shadow stretches completely across the Rings in this view, taken on Jan. 19, 2007, in contrast to what Cassini saw when it arrived in 2004.
The view is a mosaic of 36 images -- that is, 12 separate sets of red, green and blue images -- taken over the course of about 2,5 hours, as Cassini scanned across the entire Main Ring System. This view looks toward the unlit side of the Rings from about 40° above the Ring-Plane.
The images in this natural-color view were obtained with the Cassini spacecraft wide-angle camera at a distance of approx. 1,23 MKM (about 764.000 miles) from Saturn. Image scale is roughly 70 Km (about 44 miles) per pixel".MareKromium
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Saturn-PIA08366.jpgSaturn and Rhea54 visiteCaption NASA:"A serene orb of ice is set against the gentle pastel clouds of giant Saturn. Rhea transits the face of the gas giant, whose darkened Rings and their planet-hugging shadows appear near upper right.
Rhea is the second largest of Saturn's moons.
This view looks toward the unilluminated side of the Rings from about 3° above the Ring-Plane.
Images taken using red, green and blue spectral filters were combined to create this natural color view. The view was acquired with the wide-angle camera on Feb. 4, 2007. Cassini acquired the view at a distance of approx. 1,2 MKM (about 700.000 miles) from Saturn and approx. 679.000 Km (about 422.000 miles) from Rhea.
Image scale is roughly 68 Km (about 42 miles) per pixel on Saturn and about 40 Km (about 25 miles) per pixel on Rhea".
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Saturn-PIA08367.jpgSouthern Saturn54 visiteCaption NASA:"Cassini takes in a sweeping view of Saturn's South Polar Region as the planet's shadow masks the Rings and bright, icy Mimas looks on from left.
This view looks toward the lit side of the Rings from about 28° below the Ring-Plane.
Images taken using red, green and blue spectral filters were combined to create this color view. The view was acquired with the wide-angle camera on Feb. 20, 2007, at a distance of approximately 1 MKM (about 600.000 miles) from Saturn.
Image scale is roughly 58 Km (about 36 miles) per pixel".
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Saturn-PIA08370.jpgSaturn (natural colors - elab. NASA)54 visiteCaption NASA:"Colorful Saturn tilts its darkened Ring-Plane toward Cassini. Against the dark sky, the Rings are made visible by the light that scatters through them toward the camera.
The F-Ring shepherd moon Pandora is faintly visible at the top, left of center. Pandora's brightness was increased by a factor of three to aid its visibility.
This view looks toward the unilluminated side of the Rings from about 18° above the Ring-Plane. The Planet is visible through the innermost and outermost portions of the Rings.
Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were obtained by the Cassini spacecraft wide-angle camera on April 13, 2007, at a distance of approx. 1,8 MKM (about 1,1 MMs) from Saturn.
Image scale is roughly 108 Km (about 67 miles) per pixel".MareKromium
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Saturn-PIA08387.jpgA View from Japetus55 visiteWhile on final approach for its Sept. 2007 close encounter with Saturn's moon Japetus, Cassini spun around to take in a sweeping view of the Saturn System.
Japetus is the only major moon of Saturn with a significant inclination to its orbit. From the other major satellites, the Rings would appear nearly edge-on, but from Japetus, the Rings usually appear at a tilt, as seen here.
This natural color mosaic consists of 15 red, green and blue spectral filter images acquired in five wide-angle camera footprints that swept across the scene.
Moons visible in this image: Dione at center left, Enceladus near the left side ansa (or ring edge), Mimas is a speck against the ring shadows on Saturn's Western Limb, Rhea can be seen against the bluish backdrop of the Northern Hemisphere, Tethys is near the right ansa, and Titan near lower right.
The images were obtained on Sept. 10, 2007, at a distance of approx. 3,3 MKM (such as about 2,1 MMs) from Saturn at a Sun-Saturn-Spacecraft, or phase, angle of 33°. Image scale is about 195 Km (approx. 121 miles) per pixel on the Planet. MareKromium
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Saturn-PIA08388.jpgLooking at the Giant56 visiteSaturn sits nested in its rings of ice as Cassini once again plunges toward the graceful giant. This natural color mosaic was acquired by the Cassini spacecraft as it soared 39° above the unilluminated side of the Rings.
Little light makes its way through the Rings to be scattered in Cassini's direction in this viewing geometry, making the Rings appear somewhat dark compared to the reflective Planet. The view can be contrasted with earlier mosaics designed to showcase the Rings rather than the Planet, which were therefore given longer exposure times.
Bright clouds play in the blue-gray skies of the North. The Ring shadows continue to caress the Planet as they slide farther South toward their momentary disappearance during Equinox in 2009.
The Rings' reflected light illuminates the Southern Hemisphere on Saturn's night side.
The scene is reminiscent of the parting glance of NASA's Voyager 1 as it said goodbye to Saturn in 1981 (see PIA00335). Cassini, however, will continue to orbit Saturn for many years to come.
Three of Saturn's moons are visible in this image: Mimas (about 397 Km across) at the 2 o'clock position, Janus (about 181 Km across) at the 4 o'clock position and Pandora (about 84 Km across) at the 8 o'clock position. Pandora is a faint speck just outside the narrow F-Ring.
This mosaic was constructed from wide-angle camera images taken just before the narrow-angle camera mosaic PIA08389.
The view combines 45 images -- 15 separate sets of red, green and blue images -- taken over the course of about two hours, as Cassini scanned across the entire Main Ring System.
The images in this view were obtained on May 9, 2007, at a distance of approx. 1,1 MKM (about 700.000 miles) from Saturn.
Image scale is about 62 Km (approx. 39 miles) per pixel. MareKromium
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Saturn-PIA08390.jpgMirrors of Darkness...55 visiteOur robotic explorer Cassini regards the shadow-draped face of Saturn.
This view looks toward the unilluminated side of the Rings from about 14° above the Ring-Plane. In this viewing geometry all of the Main Rings, except for the B-Ring, appear transparent. The Rings cast their mirror image onto the Planet beyond.
Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were acquired with the Cassini spacecraft wide-angle camera on June 9, 2007, at a distance of approx. 1,6 MKM (about 972.000 miles) from Saturn.
Image scale is roughly 90 Km (about 56 miles) per pixel. MareKromium
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Saturn-PIA08392.jpgShadows on the Giant55 visiteLike a silvery pearl, an icy moon crosses the face of Saturn, while 2 of its siblings cast shadows onto the Planet.
Rhea hangs in the foreground. Near upper left on Saturn is the small shadow of Mimas. Near lower right is the penumbral shadow of Japetus - the part of the moon's shadow where Japetus does not completely block the Sun.
This view looks toward the unilluminated side of the Rings from less than 1° above the Ring-Plane. The Rings' shadows drape across the Northern Hemisphere. Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were obtained with the Cassini spacecraft wide-angle camera on June 15, 2007, at a distance of approx. 1,2 MKM (such as about 744.000 miles) from Rhea and 1,7 MKM (1,1 MMs) from Saturn.
Image scale is roughly 71 Km (about 44 miles) per pixel on Rhea and 103 Km (about 64 miles) on Saturn.MareKromium
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Saturn-PIA08393.jpgThe "Opposition Effect" (again)55 visiteThe Opposition Effect, a brightness surge that is visible on Saturn's Rings when the Sun is directly behind the Spacecraft, is captured here as a colorful halo of light moving across Saturn's Sunlit Rings. The rainbow of color seen here is actually an artifact and a by-product of the spot's movement and the way the color image was produced. Cassini acquires color images by taking sequential exposures using red, green and blue spectral filters, which are then composited together to form a color view. The bright patch traveled across the Rings between exposures taken for this view, creating a series of 3 colorful spots showing its position at 3 separate moments.
This view looks toward the Sunlit side of the Rings from about 9° below the Ring-Plane.
The images in this view were acquired with the Cassini spacecraft wide-angle camera on June 12, 2007, at a distance of approx. 523.000 Km (such as about 325.000 miles) from Saturn.
Image scale is roughly 31 Km (about 19 miles) per pixel.
MareKromium
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Saturn-PIA08394.jpgMoons... (natural colors; credits: NASA)55 visiteCaption NASA:"This colorful view, taken from edge-on with the Ring-Plane, contains 4 of Saturn's attendant moons. Tethys is seen against the black sky to the left of the Gas Giant's limb. Brilliant Enceladus sits against the Planet near right.
Irregular Hyperion is at the bottom of the image, near left. Much smaller Epimetheus is a speck below the Rings directly between Tethys and Enceladus. Epimetheus casts an equally tiny shadow onto the blue Northern Hemisphere, just above the thin shadow of the F-Ring.
Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were acquired with the Cassini spacecraft wide-angle camera on July 24, 2007 at a distance of approx. 2 MKM (about 1,2 MMs) from Saturn. Image scale is 116 kilometers (72 miles) per pixel on Saturn".MareKromium
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