| Piú viste - Saturn: the "Ringed Beauty" and His Moons |
The_Rings-PIA11502.jpgEncke Ringlets56 visiteAlthough Saturn's moon Pan is absent from this image of the A-Ring's Encke Gap, the moon's handiwork is still displayed.
The two ringlets seen in the gap are maintained by the gravitational action of Pan (about 28 Km, or approx. 17 miles across). To learn more about this process, see also PIA07528.
The point of light near the bottom of the image is a star.
This view looks toward the unilluminated side of the Rings from about 41° above the Ring-Plane. The image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on April 17, 2009. The view was obtained at a distance of approx. 1,3 MKM (about 808.000 miles) from Saturn and at a Sun-Saturn-Spacecraft, or Phase, Angle of 115°.
Image scale is roughly 8 Km (about 5 miles) per pixel.MareKromium
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The_Rings-PIA11658.jpgA Shadow's Traverse56 visiteCaption NASA:"Mimas' shadow traverses the sunlit side of Saturn's Rings in this mosaic showcasing the unusual sights seen at Saturn as the Planet approaches its August 2009 Equinox.
The novel illumination geometry created as the Saturnian System approaches Equinox allows moons orbiting in or near the plane of Saturn's Equatorial Rings to cast shadows onto the Rings. These scenes are possible only during the few months before and after Saturn's Equinox which occurs only once in about 15 Earth years.
Twenty images, each taken 3' and 36" apart, were combined to create this mosaic. Contiguous images were stitched together to create the mosaic showing the whole swath of the Rings across which the moon's shadow passed.
At the beginning of the sequence, the shadow starts on the bright B-Ring. It crosses the darker Cassini Division and then moves to the A-Ring. At the end, the edge of the shadow just catches the edge of the A-Ring, next to blackness of the Roche Division separating the A-Ring from the thin F-Ring.
These images have been processed, and background stars have been removed. To see a movie and mosaic of Mimas' shadow moving across the unlit side of the Rings, see PIA11660.
This view looks toward the sunlit side of the Rings from about 32° below the Ring-Plane. The images were taken in Visible Light with the Cassini Spacecraft narrow-angle camera on April 9, 2009. The view was obtained at a distance of approx. 1,1 MKM (such as about 684.000 miles) from Saturn and at a Sun-Saturn-Spacecraft, or Phase, Angle of 55°.
Image scale is roughly 6 Km (a little less than 4 miles) per pixel".MareKromium
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The_Rings-PIA11659.jpgShadow from the Dark Side56 visiteCaption NASA:"The shadow of Saturn's moon Tethys seems to disappear as it crosses the Planet's Rings, demonstrating variations in the density of particles across the Rings themselves.
These images, which were combined to create a mosaic and a movie, show Saturn's A-Ring on the left, the Cassini Division in the middle and dense outer B-Ring on the right.
The Cassini Spacecraft looks toward the unilluminated side of the Rings in these frames from about 49° above the Ring-Plane.
The densest parts of the B-Ring do not let much sunlight pass through to the Spacecraft's camera. Consequently, one might expect these dense areas to appear dark because they are on the Dark Side of the Rings and also because the moon's shadow is draped across them. However, these dense areas may appear brighter than expected in this geometry most likely from Saturnshine reflecting from them: denser regions should look brighter in Saturnshine than other regions. As a result, the moon's shadow appears cut off and diminished in these areas.
Seventeen images, each taken about 2' and 17" apart, were combined to create this mosaic. Contiguous images were stitched together to create the mosaic showing the whole swath of the Rings across which the moon's shadow passed. Tethys itself is not shown.
The novel illumination geometry created as the Saturnian System approaches Equinox allows moons orbiting in or near the plane of Saturn's Equatorial Rings to cast shadows onto the Rings. These scenes are possible only during the few months before and after Saturn's Equinox which occurs only once in about 15 Earth years. To see similar movie and mosaic of Mimas' shadow moving across the unlit side of the Rings, see PIA11660.
These images have been processed, and background stars have been removed.
The images were taken in Visible Light with the Cassini Spacecraft narrow-angle camera on April 29, 2009. The view was acquired at a distance of approx. 1,3 MKM (such as about 808.000 miles) from Saturn and at a Sun-Saturn-Spacecraft, or Phase, Angle of 52°.
Image scale is roughly 8 Km (about 5 miles) per pixel".MareKromium
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Mimas-PIA11661.jpgEclipsing Mimas56 visiteCaption NASA:"As the moon Enceladus eclipses its neighbor Mimas, Cassini records a scene possible only around the time of Saturn's approaching Equinox.
Seven images, each taken about 30" apart, were combined to create a movie which shows the shadow of Enceladus (about 504 Km, or approx. 313 miles, across) darkening Mimas (about 396 Km, or approx. 246 miles, across).
Although Saturn has eclipsed moons in previous images (see PIA11143 and PIA11508), this is the first time that Cassini has imaged one of Saturn's moons being eclipsed by another moon rather than the Planet.
The novel illumination geometry created as the Saturnian System approaches Equinox means that during this time moons orbiting in or near the plane of Saturn's Equatorial Rings can cast shadows onto the Rings and onto each other.
This image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on May 13, 2009. The view was obtained at a distance of approx. 1,3 MKM (about 808.000 miles) from Mimas and at a Phase Angle of 43°.
Image scale is roughly 8 Km (about 5 miles) per pixel".MareKromium
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Enceladus-PIA12080.jpgMelted Ice56 visiteCaption NASA:"These drawings depict explanations for the source of intense heat that has been measured coming from Enceladus' South Polar Region. These models predict that water could exist in a deep layer as an ocean or sea and also near the Surface.
Cassini scientists infer that the temperature of the ice in the South Polar Region must be close to its melting point (shown in red). A layer of liquid water (dark blue) might exist between the ice and the silicate core (brown), allowing the ice to deform independent of the rock, providing even more mechanical energy and more flexing of the icy shell for extreme tidal heating.
Tidal heating could also cause friction in faults near the surface, leading to pockets of partially melted ice".MareKromium
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Mimas-PIA11540.jpgHighlighting Herschel Crater56 visiteCaption NASA:"The Herschel crater dominates this view of Saturn's moon Mimas. The about 130-Km, or approx. 80-mile, wide crater is located in the Middle Latitudes of Mimas.
The most brightly lit Terrain seen here - lit by the Sun - is on the Leading Hemisphere of the moon. Light reflected from Saturn dimly lights the other side of the moon.
This view is centered on terrain at 37° North Lat. and 300° West Long. The North Pole of Mimas lies on the Terminator, about a quarter of the way inward from the top of the image.
Scale in the original image was 10 Km (about 6 miles) per pixel. The image has been magnified by a factor of two and contrast-enhanced to aid visibility. The image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on June 3, 2009.
The view was obtained at a distance of approx. 1,7 MKM (about 1,1 MMs) from Mimas and at a Sun-Mimas-Spacecraft, or Phase, Angle of 119°".MareKromium
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The_Rings-PIA11662.jpgAnother "Vertical Structure" in the "F"-Ring56 visiteCaption NASA:"As Saturn approaches its August 2009 Equinox, a shadow is cast by a narrow, vertically extended feature in the F-Ring.
Scientists are working to understand the origin of structures such as this one, but they think this image may show the shadow of an object on an inclined orbit which has punched through the F-Ring and dragged material along in its path.
The second (bottom) version of the image has been brightened to enhance the visibility of the ring and shadow. Background stars appear elongated in the image because of the camera's exposure time.
This image and others like it (see PIA11663) are only possible around the time of Saturn's Equinox which occurs every half-Saturn-year (equivalent to about 15 Earth years). The illumination geometry that accompanies Equinox lowers the Sun's angle to the Ring-Plane and causes out-of-plane structures to cast long shadows across the Rings. Cassini's cameras have spotted not only the predictable shadows of some of Saturn's moons (see PIA11657), but also the shadows of newly revealed vertical structures in the Rings themselves (see PIA11654).
This view looks toward the unilluminated side of the Rings from about 27° above the RingPlane.
The image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on June 11, 2009. The view was acquired at a distance of approx. 866.000 Km (about 538.000 miles) from Saturn and at a Sun-Saturn-Spacecraft, or Phase, Angle of 30°. Image scale is roughly 5 Km (a little more than 3 miles) per pixel".MareKromium
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Tethys-N00126733.jpgCrescent Tethys (Natural Colors; credits: Lunexit)56 visiteN00126733.jpg was taken on December 17, 2008 and received on Earth December 17, 2008. The camera was pointing toward TETHYS that, at the time, was approximately 527.571 Km away. This image was taken using the CL1 and CL2 filters and it has not been validated or calibrated.MareKromium
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Janus-PIA11575.jpgJanus (Natural Colors; credits: Lunexit)56 visiteCaption NASA:"The Cassini Spacecraft eyes a prominent crater on the moon Janus.
The South Pole lies on the Terminator at the bottom left of the image. This view is centered on terrain at 16° South Lat., 64° West Long.; this view looks toward the Leading Hemisphere of Janus (about 179 Km, or approx. 111 miles across). North on Janus is up and rotated 31° to the right.
The image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on July 26, 2009. The view was acquired at a distance of approx. 98.000 Km (such as about 61.000 miles) from Janus and at a Sun-Janus-Spacecraft, or Phase, Angle of 58°.
Image scale is roughly 586 meters (1922 feet) per pixel".MareKromium
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Propeller-PIA11672-b.jpgGiant "Propeller" in the A-Ring (EDM)56 visiteIt has since become a growing realization resulting from Cassini’s exploration of Saturn that the objects forming Saturn’s Rings very likely span the full spectrum of sizes, from the smallest dust-sized ring particles to the ring-moons like Daphnis and 29-Km-wide (18-mile-wide) Pan - a significant advance in divining the origin of Saturn’s Rings.
The novel illumination geometry that accompanies equinox lowers the Sun’s angle to the Ring-Plane, significantly darkens the Rings and causes out-of-plane structures to cast long shadows across the Rings. (The Rings have been brightened in this image to enhance visibility)
These scenes are possible only during the few months before and after Saturn’s Equinox which occurs only once in about 15 Earth years.
This view looks toward the Northern Side of the Rings from about 20° above the Ring-Plane.
The image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on Aug. 13, 2009.
This view was acquired at a distance of approx. 1,2 MKM (about 746.000 miles) from Saturn and at a Sun-Saturn-Spacecraft, or Phase, Angle of 87°.
Image scale is roughly 7 Km (about 4,5 miles) per pixel.MareKromium
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The_Rings-PIA11587.jpgSpokes on the B-Ring56 visiteCaption NASA:"Saturn's B-Ring shows off bright Spokes in the middle of this image taken at high phase.
This image was captured at a Phase Angle of 119°. To learn more about these ghostly radial markings, see PIA10567 and PIA11144.
This view looks toward the northern, sunlit side of the Rings from about 10° above the Ring-Plane. The image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on Aug. 20, 2009. The view was acquired at a distance of approx. 2,3 MKM (such as about 1,4 MMs) from Saturn.
Image scale is roughly 13 Km (about 8 miles) per pixel".MareKromium
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Enceladus-N00118361to64-MF.jpgEnceladus: South Polar Panorama (Image-Mosaic; credits: Dr M. Faccin - Natural Colors; credits: Lunexit)56 visitenessun commentoMareKromium
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