Saturn: the "Ringed Beauty" and His Moons
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The Rings-PIA08290.jpgThe F-Ring (detail mgnf)53 visiteCaption NASA:"For some time, scientists have suspected the presence of tiny moonlets that orbit Saturn in association with the clumpy and braided-looking Ring. As the small satellites move close to the F-Ring core they leave a gravitational signature. In some cases they can draw out material in the form of a "streamer" - a miniature version of the interaction Cassini has witnessed between Prometheus and the F-Ring material. The dynamics of this interaction are the same, but the scale is different.
Scientists speculate that there could be several small moons with a variety of sizes involved in the creation of structures like the one seen here.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 25, 2006 at a distance of approx. 255.000 Km (about 159.000 miles) from Saturn and at phase angle of 29°. Scale in the original image was 1 Km (about 3.873 feet) per pixel. The image has been magnified by a factor of two and contrast enhanced".
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The Rings-PIA08295.jpgWhat's inside the Rings?53 visiteThe 2 prominent dark gaps in Saturn's A-Ring contain small embedded moons and a host of other intriguing features. Here, 3 unique ringlets are visible in the Encke Gap (about 325 Km wide). The innermost ringlet (topmost here) is faint but continuous. The center ringlet brightens substantially toward upper left and displays a few slight kinks. This ringlet is coincident with the orbit of Pan (about 26 Km across). The outermost ringlet is discontinuous, with two bright regions visible.
The narrower Keeler Gap (about 42 Km wide) hosts the moon Daphnis (7 Km across - not visible in this image), which raises waves in the Gap edges as it orbits Saturn. At lower left, faint ringlets flanking the bright F-Ring core are visible. These features were found by the Cassini spacecraft to be arranged into a spiral arm structure that winds around the Planet like a spring. The spiral may be caused by tiny moonlets or clumps of material that have smashed through the F-Ring core and liberated material.
This view looks toward the unlit side of the rings from about 23 degrees above the ringplane.
The image was taken in visible red light with the Cassini spacecraft narrow-angle camera on Sept. 11, 2006 at a distance of approximately 1.1 million kilometers (700,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 151 degrees. Image scale is about 6 kilometers (4 miles) per pixel.
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The Rings-PIA08330.jpgNew "Ringlets" (1)100 visiteCaption NASA:"HR Cassini images show an astonishing level of structure in Saturn's Cassini Division, including two ringlets that were not seen in NASA Voyager spacecraft images 25 years ago.
This image shows a new ringlet at right, just interior to the bright outer edge of the Cassini Division. This diffuse structure is about 50 Km (approx. 31 miles) wide.
The second new ringlet is roughly at center in this view. It is a very narrow feature, about 6 Km (apprx. 4 miles) wide, between the familiar broad bands of material in the Cassini Division, and displays a great deal of variation in brightness along its length.
This image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 9, 2006, at a distance of approx. 414.000 Km (such as about 257.000 miles) from Saturn. This view looks toward the lit side of the Rings from about 17° below the Ring-Plane. The phase angle, or Sun-Saturn-spacecraft angle, was 96°.
Image scale on the sky at the distance of Saturn is roughly 2 Km (a little more than 1 mile) per pixel".
This image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 9, 2006, at a distance of approximately 414,000 kilometers (257,000 miles) from Saturn. This view looks toward the lit side of the rings from about 17 degrees below the ringplane. The phase angle, or sun-Saturn-space
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The Rings-PIA08331.jpgNew "Ringlets" (2)81 visiteCaption NASA:"HR Cassini images show an astonishing level of structure in Saturn's Cassini Division, including two ringlets that were not seen in NASA Voyager spacecraft images 25 years ago.
This view was taken with the Sun almost directly behind Saturn and its Rings, a viewing geometry in which microscopic ring particles brighten substantially. The image shows the diffuse new ringlet in the Cassini Division as the brightest feature in that Region.
This image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 15, 2006, at a distance of approx. 2,2 MKM (such as about 1,4 MMs) from Saturn. This view looks toward the unlit side of the Rings from about 15° above the ringplane. The phase angle, or Sun-Saturn-spacecraft angle, was 179°. Image scale on the sky at the distance of Saturn is roughly 13 Km (such as about 8 miles) per pixel".
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The Rings-W00017896.jpgAn enormous "clump" in Saturn's Rings? No: that's Enceladus!53 visiteCaption NASA:"W00017896.jpg was taken on September 15, 2006 and received on Earth September 17, 2006. The camera was pointing toward the Rings of Saturn that, at the time, were approximately 2.227.319 Km away.
The image was taken using the CL1 and IRP90 filters. This image has not been validated or calibrated".
Wispy fingers of bright, icy material reach tens of thousands of kilometers outward from Saturn's moon Enceladus into the E-Ring, while the moon's active South Polar jets continue to fire away. This astonishing, never-before-seen structure is made visible with the Sun almost directly behind the Saturn System from Cassini's vantage point. The phase angle here is 175°, a viewing geometry in which structures made of tiny particles brighten substantially. These features are very likely the result of particles injected into Saturn orbit by the Enceladus geysers: those injected in the direction of the moon's orbital motion end up on larger, slower orbits and trail Enceladus in its orbit, and those injected into the opposite direction end up smaller, faster orbits and lead Enceladus. (Orbital motion is counter-clockwise.) In addition, the configuration of wisps may hint at an interaction between Saturn's magnetosphere and the torrent of particles issuing from Enceladus.
In addition to the wisps, another unexpected detail is the dark gore in the center of the ring, following the moon in its orbit, likely brought about by the sweeping action of Enceladus as it orbits in the center of the E ring.
The view looks down onto Enceladus (505 kilometers, or 314 miles across) from about 15 degrees above the ringplane. Tethys (1,071 kilometers, or 665 miles across) is visible to the left of Enceladus.
The image was taken in visible light with the Cassini spacecraft wide-angle camera on Sept. 15, 2006, at a distance of approximately 2.1 million kilometers (1.3 million miles) from Enceladus. Image scale is 128 kilometers (80 miles) per pixel.
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TheRings-G-Ring-PIA07643.jpgThe G-Ring's "Glow"55 visiteOriginal caption:"Saturn's G-Ring glows like a neon garland in this lovely narrow angle camera image from Cassini. The comparison between the diffuse outer boundary and the sharp inner edge of this Ring, which consists of fine, dust-sized icy particles, is particularly noteworthy. Close Cassini views such as this should provide Ring scientists with clues about how this Ring is produced and confined.
The G-Ring extends from 166.000 to 173.200 Km (about 103.100 to 107.600 miles) from Saturn's center. (remember: Saturn is 120.500 Km [about 74.900 miles] wide at its equator).
The image was taken in visible light with the Cassini narrow-angle camera on Oct. 24, 2005, at a distance of approx. 2,1 MKM (about 1,3 MMs) from Saturn. The image scale is 12 Km (about 8 miles) per pixel".
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TheRings-GIF-W00059891.gifSaturn's "Moons-Carousel" (GIF-Movie; credits: Dr G. Barca)54 visitenessun commentoMareKromium
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TheRings-N00114226-N00114326.gifThe Rings, with "noise", "cosmic rays" and "unknown objects" - GIF Movie (credits: Dr Gianluigi Barca)53 visiteUno splendido filmato GIF il quale, oltre a darci la sensazione visiva del "movimento" degli Anelli (rectius: di Cassini rispetto agli Anelli), ci fornisce un gran numero di esempi di possibili Anomalìe e "disturbi" di segnale.
In tre parole: un Filmato Didattico. Congratulazioni, come sempre, al Dr Barca!
...e per gli Esperti: riuscite a distinguere alcune "Spikes"?MareKromium
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TheRings-PIA07522.jpgFour versions of the "F-Ring"54 visiteCaption NASA originale:"This montage of 4 images of Saturn's knotted F-Ring shows different locations around the Ring itself. Even though all the images were taken within a few hours of each other, there is remarkable variation in the structure of the F-Ring at these four locations.
For example, the number of ring strands differs from image to image and in some images, kinks are clearly visible in the F-Ring, while other regions appear more smooth.
Astronomers believe that the structure of Saturn's F-Ring is governed by its shepherding moons, Prometheus and Pandora. The F-Ring's appearance is expected to vary depending on how recently a ring section has encountered each moon and how close the moon came to the ring".
Nota: nel primo quadro (in alto a Sx) c'è qualcosa, posto proprio al di sopra del 'nodo' centrale visibile sull'intreccio più luminoso dell'Anello F, che sembra un 'filamento' o, comunque, un oggetto estraneo all'Anello F stesso, ma reale (NON crediamo che sia un photo-artifact). Cos'è?
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TheRings-PIA09865.jpgRings and Companions (natural colors; credits: NASA)53 visiteCaption NASA:"From on high, the Cassini spacecraft spies a group of 3 Ring Moons in their travels around Saturn. Janus (181 Km, or 113 miles across) is seen at top, while Pandora (84 Km, or 52 miles across) hugs the outer edge of the narrow F-Ring. More difficult to spot is Pan (26 Km, or 16 miles across), which is a mere speck in this view. Pan can be seen in the Encke Gap, near center left.
The speck seen between the A and F-Rings at left is a background star.
This view looks toward the unilluminated side of the Rings from about 40° above the Ring-Plane. Images taken using red, green and blue spectral filters were combined to create this natural color view.
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.
The images were obtained with the Cassini spacecraft wide-angle camera on Feb. 7, 2008 at a distance of approx. 1,1 MKM (about 700.000 miles) from Saturn. Image scale at the center of the view is roughly 74 Km (about 46 miles) per pixel in the radial, or outward from Saturn, direction".MareKromium
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TheRings-PIA10581.jpgBright Spokes (Natural Colors; credits: Lunar Explorer Italia)53 visiteCaption NASA:"Signaling a return to the bright Spokes first encountered by the Cassini Spacecraft in 2005, three large white Spokes stretch out across the B-Ring. Throughout most of the last year, Cassini captured views of dark Spokes.
This image of bright Spokes was taken Jan. 14, 2009 in Visible Light with the Spacecraft's wide-angle camera.
The small moon Atlas (about 30 Km, or approx. 19 miles across) has been brightened by 30% but still appears as a faint dot between the A and F Rings in the top right quadrant of the image.
This view looks toward the sunlit side of the Rings from about 6° below the Ring-Plane. The view was acquired at a distance of approx. 551.000 Km (about 342.000 miles) from Saturn and at a Sun-Saturn-Spacecraft, or Phase, Angle of 155°. Image scale is roughly 29 Km (such as about 18 miles) per pixel".MareKromium
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TheRings-PIA11635.jpgAegaeon and the G-Ring54 visiteCaption NASA:"The bright arc within Saturn's G-Ring is shown truncated by the shadow of the Planet at the bottom of this image.
Although it can't be seen here, the tiny moonlet Aegaeon (formerly known as S/2008 S 1) orbits within the bright arc.
This view looks toward the northern, sunlit side of the Rings from about 4° above the Ring-Plane. Many background stars are visible elongated by the motion of the Spacecraft during the image's exposure.
The image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on Oct. 9, 2009. The view was obtained at a distance of approx. 2,1 MKM (about 1,3 MMs) from Saturn. Image scale is roughly 12 Km (a little more than 7 miles) per pixel".MareKromium
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