Saturn: the "Ringed Beauty" and His Moons
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Enceladus-N00185224_to_N00185282-EB-MF-LXTT-IPF.gifFountains of Light (a GIF-Movie by Elisabetta Bonora and Marco Faccin - Lunexit Team)94 visitenessun commentoMareKromium
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Enceladus-N00185279-82_-_cl1cl2,bl1,red,ir1,ir3_filter-EB-MF-LXTT-IPF.jpgFountains of Light (Natural Colors; credits for the additional process. and color.: Elisabetta Bonora and Marco Faccin - Lunexit Team)86 visitenessun commentoMareKromium
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Enceladus-N005-N00037070.jpgEnceladus from approx. 545 Km (2)55 visitenessun commento
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Enceladus-N160990-91-93-EB-LXTT.jpgIs there any "Luminescence" over the "Tiger Stripes"? (Superdefinition; credits for the additional process. and color.: Elisabetta Bonora - Lunexit Team)66 visitenessun commentoMareKromium
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Enceladus-P-IMG001391-br500.jpgEnceladus, here and there!55 visiteEncelado: la piccola "Luna di Ghiaccio" ci mostra per intero il suo luminoso volto nell'immagine centrale (ripresa da una distanza di circa 180.000 Km) e poi alcune delle sue incredibili caratteristiche superficiali (canyons, crepacci, fratture, canali etc.), nei 2 frames di Dx e di Sx - ripresi da una distanza media di circa 24.000 Km (Sx) e 12.000 Km (Dx).
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Enceladus-PIA01394.jpgEnceladus, with "Pink" Nuances (by Ted Stryk)54 visitenessun commentoMareKromium
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Enceladus-PIA06188.jpgEnceladus "tormented" surface55 visiteCaption NASA originale:"This HR image from Cassini shows a region of "smooth plains" terrain on the surface of Saturn's moon Enceladus, located slightly north of the equator on the moon's Saturn-facing hemisphere. The area is about 70 by 84 Km.
The image shows a variety of tectonic features that attest to Enceladus' dynamic geological history. At the top of the image is a relatively fresh-looking crevasse system with individual fractures more than a kilometer wide. The crevasse system cross-cuts a complex NE-to-SW-trending system of older faults. A 12-Km-wide band of crudely aligned, chevron-shaped features runs down the center of the image. Among the most intriguing features in this view are a series of dark, small spots, 125 to 750 meters in diameter.
The "dark spots" often seem to be aligned in chains parallel to narrow fractures. The contrast of the dark features with the surrounding bright terrain suggests that they may be compositionally distinct, but their origin is a new mystery".
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Enceladus-PIA06189.jpgStereo-Enceladus: ridges, trough, cracks, faults and much more!55 visiteCaption NASA originale:"Images from different directions allow construction of stereo views such as this, which are helpful in interpreting the complex topography.
This view of an area about 60 Km across shows several different kinds of ridge-and-trough topography, indicative of a variety of horizontal forces near the surface of this 505-Km diameter satellite.
Several different kinds of deformation are visible and a small population of impact craters shows that this is some of the younger terrain on Enceladus. Sunlight illuminates the scene from the bottom. Interestingly, the topographic relief is only about one kilometer, which is quite low for a small, low-gravity satellite. However, this is consistent with other evidence that points to interior melting and resurfacing in Enceladus' history. The images for this anaglyph were taken in visible light with the narrow angle camera, from distances ranging from 10.750 Km - red image) to 24.861 Km - blue image) from Enceladus".
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Enceladus-PIA06191.jpgEnceladus: photomosaic56 visiteCaption NASA originale:"The view is about 300 Km across and shows the myriad of faults, fractures, folds, troughs and craters that make this Saturnian Satellite especially intriguing to planetary scientists. More than 20 years ago, NASA's Voyager spacecraft gave hints of a surface cut by tectonic features and subsequent images of other icy moons have revealed many different ways that stresses have acted on icy moon crusts. The new close-up images of Enceladus, which has a diameter of 505 Km, show some familiar-looking features and others that are brand new. Extending downward from the top center of the mosaic for hundreds of kilometers is a broad belt of complex, interwoven fractures. A huge rift 5 Km-wide dissects this belt and extends into several older-looking, distinct regions or "cells" of terrain that themselves exhibit distinct fracture patterns. The work required to unravel their origins, their formation sequence, and the implications for the evolution of icy Solar System bodies is just beginning...".
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Enceladus-PIA06206_modest.jpgEnceladus (close-up)55 visiteCaption NASA originale:"Fractures are nearly ubiquitous in this terrain, cutting across each other and across impact craters. Scientists can use the relationships between different features to determine the order in which they formed, thereby unraveling the moon's past. For example, almost all the craters in this mosaic have fractures running through their rims and floors, indicating that the craters formed first. This means that Enceladus has been geologically active relatively recently, especially compared to some of its neighbors in the Saturn system. There is an impressive variety of fractures visible here--from the wide east-west rifts near the upper left of the mosaic to the very fine north-south fractures in the center (which are approximately 100 to 400 meters). Due to the complexity of this terrain, the task of unraveling Enceladus' history promises to be a worthy challenge for planetary scientists".
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Enceladus-PIA06207.jpgEnceladus' "crispy & fractured" surface54 visite(...) The rims and interiors of many craters seem to be sliced by a pervasive system of narrow, parallel grooves into slabs or lanes that typically are about 1 Km in width. The widely varied appearances of fractures in this region attest to the fact that the surface of Enceladus has been shaped by a long history of intense tectonic activity. The oldest fractures are characterized by a soft, muted appearance and are overprinted by numerous, superimposed impact craters. More recent fractures exhibit topographic relief that is relatively "crisp" in appearance, and they appear to slice through pre-existing impact craters and older fractures. On the right side of the image is a conspicuous and twisted network of ridges and troughs forming a distinct tectonic region on Enceladus. The paucity of craters and the sharp appearance of the topography in this area indicate that this is a relatively young terrain on Enceladus. One possibility is that the walls of the fractures expose outcrops of solid ice, or ice with different grain-sizes compared to powdery surface materials that blanket flat-lying surfaces. It is also possible that the color identifies some compositional difference between buried ice and ice at the surface. The distinct coloration of "youthful" fracture walls are nearly absent in the oldest fractures. This is consistent with the possibility that the older fractures are covered with a drape of particulate material which mantles nearly all the oldest features on the satellite.
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Enceladus-PIA06208.jpgEnceladus (full-disk) - false colors55 visiteCaption NASA originale:"During its very close flyby on March 9, 2005, the Cassini spacecraft captured this false-color view of Saturn's moon Enceladus, which shows the wide variety of this icy moon's geology. Some geological regions on Enceladus are old and retain large numbers of impact craters; younger areas exhibit many generations of tectonic troughs and ridges. Subtle differences in color may indicate different ice properties, such as grain sizes, that will help unravel the sequence of geologic events leading to the current strange landscape. In the early 1980's, NASA's Voyager mission to the outer planets revealed a strikingly similar arrangement of terrains on Miranda, an icy moon of Uranus (see PIA 00141). Miranda is 470-Km-wide (290 miles), nearly as large as Enceladus (504 Km). The similarities in size and tectonic history on these objects may suggest that remarkably similar physical processes have controlled the separate geological evolutions of these bodies. The Sun illuminates Enceladus from the left, leaving part of it in shadow and blocking out part of the view of Saturn. This view shows the anti-Saturn hemisphere, centered nearly on the equator".
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