Saturn: the "Ringed Beauty" and His Moons
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Saturn_s Clouds-V2-PIA01958_modest.jpgSaturn's Clouds from Voyager 255 visiteCaption NASA originale:"In this Voyager 2 observation of Saturn’s northern mid-latitudes is seen a strangely curled cloud attached by a thin ribbon to the bright white cloud region to the north. The cloud has been monitored for seven rotations around the planet. It appears to be forming a closed loop. Other discrete clouds are seen to the east. Also evident is the “ribbonlike” structure at 47 north latitude in the white cloud region. The spacecraft took this image from a distance of about 9.300.000 Km".
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Saturn_s F-Ring+Mimas-PIA06471_modest.jpgLonely Mimas...57 visiteCaption NASA originale:"Mimas swings around Saturn, seeming to gaze down at the planet's splendid rings. The outermost, narrow F ring is visible here and exhibits some clumpy structure near the bottom of the frame. The shadow of Saturn's southern hemisphere stretches almost entirely across the rings. Mimas is 398 Km (247 miles) wide.
The image was taken with the Cassini spacecraft narrow angle camera on August 15, 2004, at a distance of 8,8 MKM (5.5 million miles) from Saturn".
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Saturn_s Rings in color - PIA06114_modest.jpgSaturn's Rings in natural colors from Cassini-Huygens55 visiteCaption NASA originale:Saturn's faintly banded atmosphere is delicately colored and its threadbare rings cross their own shadows in this marvelous natural color view from Cassini.
The planet and its rings would nearly fill the space between Earth and the Moon. Yet, despite their great breadth, the rings are a few meters thick and in some places, very translucent. In this image, we can see through the C-Ring, which is closest to Saturn, and through the Cassini division, the 4.800-Km wide gap that arcs across the top of the image and separates the optically thick B-Ring from the A-Ring. The part of the atmosphere seen through the gap appears darker and more bluish due to scattering at blue wavelengths by the cloud-free upper atmosphere.
The different colors in Saturn's atmosphere are due to particles whose composition is yet to be determined.
The image was obtained with the Cassini spacecraft narrow angle camera on July 30, 2004, at a distance of 7.6 MKM from Saturn".
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Saturn_s Rings-PIA06237.jpgS/2005 S1: The "Wave-Maker" (1)57 visiteLa NASA conferma che le curiose ed enigmatiche "onde" le quali caratterizzano il margine esterno dell'Anello "A" di Saturno, proprio a ridosso della "Divisione Keeler" sono, con ogni probabilità, causate da una piccola luna del diametro di circa 7 Km, dotata di una discreta albedo (al pari delle particelle che formano il vicino Anello) e che è stata temporaneamente chiamata S/2005 S1.
Caption NASA originale:"Imaging scientists predicted the moon's presence and its orbital distance from Saturn after July 2004, when they saw a set of peculiar spiky and wispy features in the Keeler Gap's outer edge. The similarities of the Keeler Gap features to those noted in Saturn's F-Ring and the Encke Gap led the scientists to conclude that a small body, a few Km across, was lurking in the center of the Keeler Gap, awaiting discovery".
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Saturn_s Rings-PIA06239.jpgS/2005 S1: The "Wave-Maker" (2)56 visiteCaption NASA originale:"In the vicinity of the newly discovered little moon, the Keeler Gap's edges bear striking similarities to the scalloped edges of the 322 Km-wide (approx. 200-mile) Encke Gap, where the small moon Pan (25 Km, or approx. 16 miles across) resides.
From the size of the waves seen in the scalloped edges of the Encke Gap, imaging scientists were able to estimate the mass of Pan.
They expect to do the same, eventually, with S/2005 S1".
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Saturn_s Rings-PIA06533_modest.jpgSaturn's Rings from about 631.000 Km56 visiteCaption NASA originale:"The usually bright B-Ring (at center) appears very dim in this view of the rings taken on the side of the rings that is not illuminated. The scene resembles a photographic negative, with bright and dark areas reversed (although in some places in the rings, the blackness of space is seen). From this viewing angle, the rings are lit from below: both dense and empty regions are dark, and regions of intermediate particle density are bright.
The image was taken with the Cassini spacecraft wide angle camera on Oct. 27, 2004, at a distance of about 631.000 Km from Saturn through a filter sensitive to wavelengths of visible violet light. The image scale is 34 Km per pixel".
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Saturn_s Sky-W00011343.jpgBright Stars in the sky of Saturn55 visiteOriginal caption:"W00011343.jpg was taken on October 23, 2005 and received on Earth October 24, 2005. The camera was pointing toward SATURN-E-RING at approximately 1.242.596 kilometers away and the image was taken using the CL1 and GRN filters. This image has not been validated or calibrated".
Nota: una sola cosa ci pare certa: questa non è un'immagine dell'Anello G di Saturno. Che cosa rappresenti...tiriamo ad indovinare: il Sole ed un Satellite Saturniano sovraesposto. Che ne dite? E' plausibile?!?
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Saturn_s South-Pole.jpgSaturn's South-Pole from approx. 8.900.000 Km55 visiteMacchie di nuvole bianche e svariate tempeste "scure" dominano le regioni polari dell'emisfero sud di Saturno in questa immagine ripresa il 18 Agosto 2004 da una distanza di circa 8.9 milioni di Km e con l'uso di un filtro sensibile alle lunghezze d'onda proprie della luce infrarossa. La scala dell'immagine è di 54 Km (33 miglia) per pixel.
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Saturn_s sky-N00020366.jpgThe Sky of Saturn56 visiteIl cielo di Saturno, visto da Cassini/Huygens. Queste immagini, purtroppo, non vengono molto pubblicizzate, nè dalla NASA nè da altri organi di informazione (scientifica o meramente divulgativa). Il motivo è abbastanza chiaro: frame come questo - si dice - non mostrano "nulla di particolare", se non qualche stella e qualche satellite di Saturno. Secondo noi, frame come questo possiedono una grandissima magia ed un enorme fascino: lo Spazio visto DALLO Spazio! Qualcuno ha detto che "...Se non c'è bellezza, non ci può essere curiosità; e se non c'è curiosità, non ci può essere scienza alcuna...".
Noi siamo d'accordo.
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Saturnafterthe_Equinox.jpgAfter the Equinox... (Natural Colors; credits: NASA/JPL/Space Science Institute)55 visiteDa "NASA - Picture of the Day" del giorno 10 Novembre 2009:"The other side of Saturn's Ring-Plane is now directly illuminated by the Sun. For the previous 15 years, the Southern Side of Saturn and its Rings were directly illuminated, but since Saturn's Equinox, the orientation has reversed.
Pictured above last month, the robotic Cassini Spacecraft orbiting Saturn has captured the Giant Planet and its majestic Rings soon after Equinox. Imaged from nearly behind, Saturn and its moon Tethys each show a crescent phase to Cassini that is not visible from Earth.
As the Rings continue to point nearly toward the Sun, only a thin shadow of them is visible across the center of the Planet.
Close inspection of Saturn's Rings, however, shows superposed bright features identified as "Spokes" that are thought to be groups of very small electrically charged ice particles. Understanding the nature and dynamics of Spokes is not fully understood and remains a topic of research".MareKromium
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SaturnandCompanions-PIA07538.jpgSaturn's Space Panorama57 visiteCaption NASA originale:"Three of Saturn's icy moons are seen here, along with the magnificent water-ice rings and the cold gaseous envelope of the Planet's atmosphere. Saturn's dark shadow stretches completely across the rings.
At nine and a half times farther from the Sun than Earth, Saturn inhabits the deep cold of the outer Solar System. The Sun appears only 1% as bright there as it appears at Earth, creating an environment where ice dominates over rock.
The icy Moons visible here, from left to right are: Janus (181 kilometers, or 113 miles, across), Enceladus (505 kilometers, or 314 miles, across), and Epimetheus (116 kilometers, or 72 miles, across).
The image was taken in visible green light with the Cassini spacecraft wide-angle camera on June 1, 2005, at a distance of approximately 2,4 MKM from Saturn. The image scale is 139 Km per pixel".
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Saturnian Aurora.jpgSaturnian Aurora - HST55 visiteDa "NASA - Picture of the Day" del 22 Febbraio 2005:
"Are Saturn's auroras like Earth's? To help answer this question, the Hubble Space Telescope and the Cassini spacecraft monitored Saturn's South Pole simultaneously as Cassini closed in on the gas giant in January 2004. Hubble snapped images in ultraviolet light, while Cassini recorded radio emissions and monitored the solar wind. Like on Earth, Saturn's auroras make total or partial rings around magnetic poles. Unlike on Earth, however, Saturn's auroras persist for days, as opposed to only minutes on Earth. Although surely created by charged particles entering the atmosphere, Saturn's auroras also appear to be more closely modulated by the solar wind than either Earth's or Jupiter's auroras. The above sequence shows 3 Hubble images of Saturn each taken two days apart".
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