Saturn: the "Ringed Beauty" and His Moons
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Tethys-PIA08291.jpgTethys55 visiteCaption NASA:"Tethys has a crater-saturated surface, where older, larger basins have been completely overprinted by newer, smaller impacts. This state is what scientists expect to see on a very old surface, where small impactors have struck more frequently than larger ones over several billion years. Larger impacts were more common events in the early history of the Solar System.
This view looks toward the Leading Hemisphere of Tethys (1.071 Km, or about 665 miles across). North is up. The great scar of Ithaca Chasma is seen at right.
The view was captured in visible light with the Cassini spacecraft narrow-angle camera on Sept. 25, 2006 at a distance of approx. 449.000 Km (such as about 279.000 miles) from Tethys and at a phase angle of 49°. Image scale is roughly 3 Km (about 2 miles) per pixel".
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Tethys-PIA08400.jpgOdysseus is looking up!54 visiteThe vast expanse of the crater Odysseus spreads out below Cassini in this mosaic view of Saturn's moon Tethys.
The crater (about 450 Km or approx. 280 miles across) is a remarkably well-preserved example of an ancient multi-ringed impact basin: the outer ring is defined by steep, cliff-like walls that descend to generally broad internal terraces. The inner ring is formed by a prominent, crown-shaped, 140-Km (88-mile) diameter circular band of icy mountains. Multi-ring basins are seen on rocky bodies as well as icy ones.
The complex internal structure and multi-ringed nature of these very large basins are believed to arise from the rebound of intense shock waves that penetrated the body at the time of impact.
This mosaic was assembled from four clear filter, narrow-angle camera images. The view is an orthographic projection centered on 3° South Latitude, 119° West Longitude and has a resolution of 572 meters (0,35 mile) per pixel. An orthographic view is most like the view seen by a distant observer looking through a telescope. North is up.
The view was obtained by the Cassini spacecraft on Aug. 30, 2007, from a distance of approximately 97.000 Km (about 60.000 miles) and at a Sun-Tethys-Spacecraft, or phase, angle of 51°.MareKromium
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Tethys-PIA08401.jpgThe Edge of Tethys53 visiteThe cold, cratered landscape of Saturn's moon Tethys shines in stark relief in this crescent view. Aside from its obvious aesthetic beauty, this particular Cassini mosaic was obtained mainly to understand important details about how the surface of Tethys reflects light at high phase angles (the Sun-Tethys-Spacecraft viewing angle). The beautiful interplay of light with surface topographic features is an important factor in this regard. The surface is heavily cratered, and at this oblique angle the craters give the surface a highly scalloped appearance.
Unlike some HR crescent views of Saturn's moons, this image truly gives Tethys the appearance of being composed of ice and frost. There appear to be numerous sun glints sparkling across the surface. Some of these might be specular (or mirror-like) reflections off of exposed walls of solid ice inside craters, or they might be uniformly large, frosty or icy-particle covered facets of topography that are so oriented as to give exceptionally bright but diffuse reflections.
The shadows cast by most craters in the scene are not dark, but rather, they are illuminated by light bouncing off of their sunlit walls and those of other craters. This light, which has been scattered multiple times, makes visible some details along the shadowed walls and floors of craters that would not otherwise be visible in this viewing geometry.
This mosaic was assembled from four clear filter, narrow-angle camera images, with low resolution, wide-angle camera data filling a small gap in coverage. The view is an orthographic projection and has a resolution of 211 meters (692 feet) per pixel. An orthographic view is most like the view seen by a distant observer looking through a telescope. North is up.
The view was obtained by the Cassini spacecraft on June 29, 2007, from a distance of approximately 38.000 Km (about 24.000 miles) and at a Sun-Tethys-Spacecraft, or phase, angle of 152°.
MareKromium
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Tethys-PIA08967.jpgTethys (natural colors - elab. Lunexit)53 visiteCaption NASA:"The Cassini spacecraft surveys the battered surface of icy Tethys. The great impact basin straddling the Terminator is itself overprinted by many smaller impact sites.
The view in this image is toward the Southern Hemisphere on the moon's Saturn-facing side. North on Tethys is up and rotated 7° to the right.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on May 11, 2007. The view was obtained at a distance of approx. 559.000 Km (such as about 347.000 miles) from Tethys and at a phase angle of 60°.
Image scale is roughly 3 Km (about 2 miles) per pixel".MareKromium
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Tethys-PIA08974-1.jpgTethys (natural colors - elab. Lunexit)54 visiteCaption NASA:"Ithaca Chasma rips across Tethys from North to South near the center of this view. The moon's western limb is flattened, indicating the rim of the giant impact basin Odysseus.
The dark, East-West trending band often observed in this region (see PIA07571) is just visible here, but its contrast is reversed at these short, ultraviolet wavelengths -- it is bright against the already bright terrain.
North on Tethys (1071 Km, or about 665 miles across) is up and rotated 24° to the left. This view looks toward the moon's Saturn-Facing Hemisphere.
The image was taken with the Cassini spacecraft narrow-angle camera on May 27, 2007 using a combination of spectral filters sensitive to wavelengths of light centered at 298 and 338 nanometers. The view was obtained at a distance of approx. 267.000 Km (about 166.000 miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 13°.
Image scale is roughly 2 Km (5.236 feet) per pixel".MareKromium
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Tethys-PIA09017.jpgOdysseus53 visiteCaption NASA:"The Cassini spacecraft provides a stunning view of the Odysseus impact basin on Tethys. The enormous basin is about 450 Km (approx. 280 miles) wide.
The medium-sized crater Melanthius is seen along the Terminator at lower left.
This view looks toward the Leading Hemisphere of Tethys. North is up.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 21, 2007. The view was obtained at a distance of approx. 211.000 Km (such as about 131000 miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 46°.
Image scale is 1 kilometer (0.6 mile) per pixel".MareKromium
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Tethys-PIA09723.jpgThe "Scars" of Tethys...53 visiteCaption NASA:"The Cassini spacecraft spies four large impact basins on the Southern Hemisphere of icy Tethys.
Tethys (approx. 1071 Km, or 665 miles across), like the other airless worlds of the Solar System, wears the record of countless impacts experienced over the eons.
Lit terrain seen here is on the leading hemisphere of Tethys. North is up and rotated 15° to the left.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 21, 2007. The view was obtained at a distance of approx. 452.000 Km (such as about 281.000 miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 54°.
Image scale is roughly 3 Km (about 2 miles) per pixel".MareKromium
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Tethys-PIA09737.jpgCrescent Tethys53 visiteCaption NASA:"The pockmarked crescent of Tethys displays slightly darker terrain in a band at its Equator. The rim of the great crater Odysseus lurks on the Terminator.
Lit terrain seen here is on the Leading Hemisphere of Tethys. North is up.
The image was taken in visible light with the Cassini spacecraft wide-angle camera on Aug. 29, 2007. The view was obtained at a distance of approx. 56.000 Km (such as about 35.000 miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 105°.
Image scale is roughly 3 Km (about 2 miles) per pixel".MareKromium
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Tethys-PIA09766.jpgThe "Dark Belt" of Tethys123 visiteCaption NASA:"Around the Equator on its Leading Side, Tethys wears a band of slightly darker surface material. Cassini Imaging Scientists suspect that the darkened region may represent an area of less contaminated ice with differently sized grains than the material at higher latitudes on either side of the band.
Lit terrain seen here is on the Saturn-facing side of Tethys. North is up. Part of the great canyon system Ithaca Chasma can be seen near the eastern limb in this frame-filling view.
The image was taken with the Cassini spacecraft narrow-angle camera on Sept. 30, 2007 using a spectral filter sensitive to wavelengths of infrared light centered at 930 nanometers. The view was acquired at a distance of approx. 186.000 Km (such as about 116.000 miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 62°.
Image scale is roughly 1 Km (about 0,6 mile) per pixel".MareKromium
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Tethys-PIA09788.jpgTrue Colors?54 visiteCaption NASA:"As seen from the side not illuminated by the Sun, Saturn's thinner Rings are highlighted in shades of brown and gold, contrasting with the more neutral appearance of the icy moon Tethys. The A-Ring and Cassini Division are separated by the optically thick B-Ring, which does not permit sunlight to penetrate and appears as the broad, dark lane between them in this view.
This view looks toward the anti-Saturn side of Tethys.
North is up and rotated 35° to the right.
The view looks toward the unilluminated side of the rings from about 2° 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 Cassini spacecraft narrow-angle camera on Oct. 29, 2007, at a distance of approx. 2,1 MKM (about 1,3 MMs) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 21°.
Image scale is roughly 12 kilometers (8 miles) per pixel".MareKromium
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Tethys-PIA09835.jpgThe Main Surface Features of Tethys53 visiteCaption NASA:"This view of Tethys displays 3 of the moon's most notable surface features. At upper left is the giant Odysseus impact basin. At lower right is the great scar of Ithaca Chasma. Extending from east to west across the moon is the great swath of terrain that appears slightly darker than the rest of the moon's surface.
This view looks toward the Saturn-facing side of Tethys (1071 Km, or approx. 665 miles across) from 33° above the Equator. North is up.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 14, 2008. The view was obtained at a distance of approx. 1,2 MKM (such as about 715.000 miles) from Tethys and at a Sun-Tethys-Spacecraft, or phase, angle of 70°.
Image scale is roughly 7 Km (about 4 miles) per pixel".MareKromium
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Tethys-PIA09878.jpgOdysseus in the Light54 visiteCaption NASA:"The Cassini spacecraft looks down onto high Northern Latitudes on Tethys, spying the enormous impact basin Odysseus.
Lit terrain seen here is on the anti-Saturn side of Tethys. North is towards the top of the image.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March 11, 2008. The view was acquired at a distance of approx. 765.000 Km (such as about 475.000 miles) from Tethys and at a Sun-Tethys-Spacecraft angle of 97°.
Image scale is roughly 5 Km (about 3 miles) per pixel".MareKromium
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