| Piú viste - SOLAR SYSTEM |
000-vg1_p22830.jpgApproaching Saturn, from Voyager 159 visiteDifficile commentare degnamente le immagini Voyager 1 e 2 di Saturno e del suo Sistema. Quando le due Sonde Americane giunsero nello spazio di Saturno - solo per un breve passaggio, prima di dirgersi verso Urano, Nettuno ed i confini del Sistema Solare - le immagini che esse riuscirono ad ottenere affascinarono (a dir poco) il Mondo intero. I colori, ora tenui ed ora accesi, degli strati superiori dell'atmosfera Saturniana; la delicata struttura e tessitura degli Anelli, sino ad allora mai risolta da telescopi terrestri e/o da altre sonde; alcune delle lune di Saturno per la prima volta rivelarono una parte (piccola, ma significativa) dei loro segreti ai nostri Scienziati. Oggi, grazie alla Sonda Cassini-Huygens, Saturno e le sue Meraviglie sono diventati (un pò come è accaduto per la Luna e per Marte) degli elementi "quotidiani" e, quindi, meno magici e più scontati. Quasi un déjà-vu.
Noi, per restituire la giusta dignità a qualcosa che di "quotidiano" e "déjà-vu", a nostro parere, non ha proprio nulla, Vi proponiamo una piccola selezione di frames (scelti fra migliaia) che mostrano Saturno ed il Suo Sistema ora in "colori veri", ora in "colori falsi" ed ora in b/n.
Questi frames, lo ripetiamo, furono capaci - qualche annetto fa - di incantare il Mondo; noi, riproponendoli in versione originale, speriamo di ricreare la stessa magia.
Almeno per un istante.
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001-vg1_p22990c.jpgThe "texture" of the Rings59 visitenessun commento
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002-vg1_p22994c.jpgAnother "World of Clouds" (false colors)59 visitenessun commento
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003-vg1_p23073.jpgDifferent colors, different elements and different speeds...59 visitenessun commento
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004-vg1_p23254.jpgThe "Ringed Beauty" in natural colors59 visitenessun commento
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005-vg1_3469906.jpgClosing-up on the Rings59 visitenessun commento
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008-vg2_p23880c.jpgPortrait of Saturn (false colors)59 visitenessun commento
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009-vg2_p23915.jpgThe restless atmosphere of Saturn...59 visitenessun commento
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013-vg2_p23953.jpgThe Rings (HR - false colors)59 visitenessun commento
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014-vg2_p24368.jpgSaturn59 visitenessun commento
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024-vg2_4391335-4.jpgAnomalies near Japetus (Objects "B" and "C" - detail mgnf)59 visitenessun commento
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The Rings-PIA08288.jpgSpokes!59 visiteA group of bright spokes tightly cluster together in Saturn's B ring. The spokes seen here generally all exhibit the same degree of shearing, or tilting, but some deviations are apparent. In this image, the direction to Saturn is downward; orbital motion is to the left.
Ring scientists are eager for data to help them understand and eventually explain how these mysterious ring features are created. To that end, Cassini has been directed to acquire movie sequences, like the one this image is part of, that watch for these elusive radial structures.
This observation focused on the morning side of the rings, the side where the rings are rotating out from Saturn's shadow. Spokes appear most frequently at this location.
Also barely visible in this image are broader, much fainter but still bright radial regions that extend over larger radial distances than the spokes in the upper left. Where these fainter features cross ringlets in the lower part of the image, slight variations in brightness are apparent. These are probably due to tiny particles, possibly part of a former spoke, that haven't yet settled down onto the ring plane.
Although their formation is still a subject of inquiry, scientists are confident that the microscopic spoke particles are slightly electrically charged and therefore are influenced by Saturn's magnetic field.
The brightness of the spokes, when combined with viewing geometry information and estimates of their particle sizes can help researchers determine the amount of material in the spokes--a crucial quantity to constrain theories of spoke formation.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 28, 2006, at a distance of approximately 1.3 million kilometers (800,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 147 degrees. Scale in the original image was about 32 kilometers (20 miles) per pixel. The view has been magnified by a factor of two.
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