Il s'étend dans le sens radial de 92 000 à 118 000 kilomètres du centre de Saturne et présente une structure fine très complexe, faite d'une succession irrégulière de bandes alternativement claires et sombres de largeur variable. [3] This is as massive as about half the mass of the Earth's entire Antarctic ice shelf, spread across a surface area 80 times larger than that of Earth. Then images from the Voyager spacecraft showed radial features in the B Ring, known as spokes,[74][75] which could not be explained in this manner, as their persistence and rotation around the rings was not consistent with gravitational orbital mechanics. He had been making observations of the planet Saturn from around 1652 with the aim of explaining its appearance. The ring has a radial extent of about 5,000 km. Vous confirmez que cette photo n'est pas une photo de cuisine ou ne correspond pas à cette recette ? It contains the dense, eccentric Huygens Ringlet in the middle. Many of the other gaps between ringlets within the Cassini Division, however, are unexplained. F ring dynamism, probably due to perturbing effects of small moonlets orbiting close to or through the ring's core. Les anneaux de Saturne : nés de l’engloutissement d’un satellite ? Infall of this material causes a slight darkening and reddening of the leading hemisphere of Iapetus (similar to what is seen on the Uranian moons Oberon and Titania) but does not directly create the dramatic two-tone coloration of that moon. [n 1] Dates for its northern hemisphere autumnal equinoxes include 19 November 1995 and 6 May 2025, with northern vernal equinoxes on 11 August 2009 and 23 January 2039. Suggestions that the spokes may be a seasonal effect, varying with Saturn's 29.7-year orbit, were supported by their gradual reappearance in the later years of the Cassini mission.[78]. Files are available under licenses specified on their description page. The Cassini Division is at top. Saturne possède , en regardant cette planète on pourrait penser que saturne possède un anneau principal, cependant en y jetant un œil de plus près on constate la présence de nombreux anneaux, 14 total, d'une épaisseur moyenne mesurant 2 à 10 mètres. Notes: Notez que les anneaux ont été baptisés par des lettres en fonction de l'ordre de leur découverte et non de leur position par rapport à Saturne. [118] The E Ring is distributed between the orbits of Mimas and Titan. This process may explain the variation in silicate content of Saturn's moons out to Rhea, as well as the trend towards less silicate content closer to Saturn. [47] The second theory is that the rings were never part of a moon, but are instead left over from the original nebular material from which Saturn formed. Contextual translation of "bagues anneaux de saturne" into English. [119] Tendril-like structures observed within the E Ring can be related to the emissions of the most active south polar jets of Enceladus. Puis à 180 000 kilomètres de la surface de Saturne se trouve l'anneau E large de 240 000 kilomètres. L'origine des anneaux n'est pas bien connue, les scientifiques supposent qu'ils ne se sont pas formés à partir du nuage de poussière et de gaz qui enveloppait Saturne lors de sa formation. Elles ne sont ni légendées ni expliquées mais viennent s'insérer dans une part plus large du récit[3]. One mechanism involves gravity pulling electrically charged water ice grains down from the rings along planetary magnetic field lines, a process termed 'ring rain'. [91], The Keeler Gap is a 42-km-wide gap in the A ring, approximately 250 km from the ring's outer edge. Upper image: natural color mosaic of Cassini narrow-angle camera photos of the illuminated side of the rings taken on December 12, 2004. One of the small moons was tentatively identified as S/2004 S 6. [18], The rings are named alphabetically in the order they were discovered [19] (A and B in 1675 by Giovanni Domenico Cassini, C in 1850 by William Cranch Bond and his son George Phillips Bond, D in 1933 by Nikolai P. Barabachov and B. Semejkin, E in 1967 by Walter A. Feibelman, F in 1979 by Pioneer 11, and G in 1980 by Voyager 1). [125], In October 2009, the discovery of a tenuous disk of material just interior to the orbit of Phoebe was reported. The latter include the D Ring, extending inward to Saturn's cloud tops, the G and E Rings and others beyond the main ring system. Data from the Cassini space probe indicate that the rings of Saturn possess their own atmosphere, independent of that of the planet itself. [72][73] The total mass of the B Ring was estimated to be somewhere in the range of 7 to 24×1018 kg. Ring particles at this location orbit twice for every orbit of the moon Mimas. The rings of Saturn are the most extensive ring system of any planet in the Solar System. Il est pratiquement invisible depuis la Terre. [139][140] These putative rings have not been imaged, but their existence has been inferred from Cassini observations in November 2005 of a depletion of energetic electrons in Saturn's magnetosphere near Rhea. [8], In 1675, Giovanni Domenico Cassini determined that Saturn's ring was composed of multiple smaller rings with gaps between them; the largest of these gaps was later named the Cassini Division.

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