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| Piú votate - Saturn: the "Ringed Beauty" and His Moons |
Rhea-IMG004709-br500-PCF-LXTT-IPF.jpgFarewell to Rhea (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)75 visiteOn its fourth and final targeted Fly-By of Rhea, the NASA - Cassini Spacecraft provided many stunning views its ancient, tormented and heavily cratered Surface. Billions of years of impacts, in fact, have sculpted Rhea's Surface into the form we see today and, with a diameter of approx. 950 miles (such as about 1528,8 Km), Rhea is the second-largest moon of Saturn.
In the EDM here (is on the lower right - Dx - of the CTX Frame), you can see an extremely interesting and, in a way, really mysterious and bizarre-looking Horizontal Linear Structure that looks like a Wall and whose upper edge is still illuminated by the Sun; the Structure - whose origin is and, most likely, will remain unknown - is located within a relatively small-sized and Unnamed Impact Crater and it extends for about one/third of its Inner Diameter. This view was taken in Visible Light on December 22, 2012, at a distance of approximately 16.805 miles (such as a little less than 27.045 Km) from the Surface of Rhea.
This frame (which is an Original NASA - Cassini Spacecraft b/w image identified by the serial n. N00199484) has been additionally processed, contrast enhanced, and then colorized in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Cassini Spacecraft and then looked down, towards the Surface of the Saturnian moon Rhea), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among others, the existence of different Elements present on the Surface of Rhea, each having a different Albedo (---> Reflectivity) and Chemical Composition.
Note: it is possible (but we, as IPF, have no way to be one-hundred-percent sure of such a circumstance), that the actual luminosity of the Surface of Rhea - as it is presented in this image - would appear, to an average human eye, way lower than it has been shown (or, better yet: interpreted) here.MareKromium
(3 voti)
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Rhea-PIA14647-PCF-LXTT-IPF.jpgCrescent Rhea (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)76 visiteThe NASA - Cassini Spacecraft captured, about four months ago, Saturn's moon Rhea during its Crescent Phase: a view, this one, which will never be visible from Earth. Near the Terminator, a few of Rhea's many Impact Craters show up their sharp and well defined outlines. With a diameter of approx. 950 miles (such as almost 1529 Km) Rhea is the Saturnian second-largest moon. This view looks toward the Leading Hemisphere of Rhea; North is up and rotated 12° to the right.
The image was taken in Visible Light with the NASA - Cassini Spacecraft Narrow-Angle Camera on November 6, 2012. The view was obtained at a distance of approximately 1,2 Million Miles (such as about 1,93 Million KiloMeters) from Rhea and at a Sun-Rhea-Cassini Spacecraft, or Phase, Angle of 129°. Scale in the original image was roughly 7 miles (approx. 11,26 Km) per pixel but, afterwards, the picture was magnified by a factor of 1.5 in order to enhance the visibility of some Surface Features.
This picture (which is an Original NASA - Cassini Spacecraft b/w frame published on the NASA - Planetary Photojournal with the ID n. PIA 14647) has been additionally processed, magnified (by applying a further 4.01 enlargement's factor) and then colorized, according to an educated guess carried out by Dr Paolo C. Fienga (LXTT-IPF), in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Cassini Spacecraft and then looked outside, towards the Saturnian moon Rhea), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among others, the existence of different Elements present on the Surface of Rhea, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
(3 voti)
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Mimas-PIA12572-PCF-LXTT-IPF.jpgIn and around the Magnificent Herschel Crater (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunar Explorer Italia/Italian Planetary Foundation)78 visiteRemarkable color differences on the Saturnian moon Mimas are apparent in this (enhanced) Absolute Natural Color view of Herschel Crater that was captured by the NASA - Cassini Spacecraft during its closest (so far) Fly-By of that Celestial Body which occurred on February 13, 2010. The image shows Terrain-dependent color variations and, in particular, the contrast between the light-gray (with slightly pale blue nuances) Surface Materials which are found in and around Herschel Crater and the brownish cast that, on the other hand, is found on older and more heavily Cratered Terrain elsewhere.
The origin of the color differences between these two types of Terrain is not yet understood, but it is quite logical to assume that it should be caused by the existence of some considerable differences in the Surface Elements which form the Terrains themselves (and a few false color images which were obtained from Cassini's previous closest encounter with Mimas, during the AD 2005, also showed such variations, which are, therefore, something real and NOT a simple optical effect caused, for instance, by the Illumination Geometry existing at the time whan the different pictures were taken). The huge Herschel Crater (approx. 130 Km, or a little more than 80 miles, wide) covers most of the bottom of the image.
To create the original false-color view of Mimas, UltraViolet, Green and InfraRed images were combined into a single picture that was fit to exaggerate the color differences of the photographed Terrains; these data were then combined with a High-Resolution image taken in Visible Light so to obtain a mix between the High-Resolution information coming from the Clear-Filter image and the color information coming from the UltraViolet, Green and InfraRed filter images.
During the Fly-By, the NASA - Cassini Spacecraft came within about 9500 Km (such as about 5900 miles) of Mimas and this view looks toward the Northern part of the Hemisphere that leads the moon in its orbit around Saturn (---> Leading Hemisphere, in contrast with the Trailing Hemisphere). The images were obtained with Cassini's Narrow-Angle Camera at a distance of approximately 16.000 Km (such as 9936 miles) from Mimas. Afterwards, the images were re-projected into an Orthographic Map Projection. Furthermore, a black and white image, taken in Visible Light with the Wide-Angle Camera, was also used to fill in parts of the mosaic. The global scale of the mosaic is 90 meters (295 feet) per pixel.
This frame (which is an Original NASA - Cassini Spacecraft false color image mosaic published on the NASA - Planetary Photojournal with the ID n. PIA 12572) has been additionally processed, contrast enhanced, and then re-colorized in (slightly enhanced) Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Cassini Spacecraft and then looked outside, towards the Surface and Limb of the Saturnian moon Mimas), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among others, the existence of different Elements present on the Surface of Mimas, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
(3 voti)
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Dione-N00199629-33-EB-MF-LXTT-IPF.jpgThe Many faces of Dione (Superdefinition and Natural Colors; credits for the additional process. and color.: Elisabetta Bonora and Marco Faccin/Lunar Explorer Italia/Italian Planetary Foundation)175 visiteThe Icy Surface of the Saturnian moon Dione includes, among other things, some Heavily Cratered Terrain, Moderately Cratered Plains, Lightly Cratered Plains, and several Areas which show the presence of deep and wide Tectonic Fractures (notice that all these Geological Features are well visible in this beautiful picture). The Heavily Cratered Terrain shows a number of Impact Craters which are larger than 100 Km (a little more than 62 miles) in diameter. The Plain Areas, on the other hand, tend to have Impact Craters which are less than 30 Km (such as about 18,6 miles) in diameter. Some of the Plains, however, are more Heavily Cratered than others. Much of the Heavily Cratered Terrain is located on the Trailing Hemisphere of Dione, while the less Cratered Plains are found on the Leading one.
This characteristic of Dione tells us just the opposite of what a few scientists would have expected; Shoemaker and Wolfe, for instance, proposed a Cratering Model for a Tidally Locked Satellite with the highest Cratering Rates on its Leading Hemisphere and the lowest ones on the Trailing Hemisphere. This Model, therefore (if it is one-hundred-percent correct - a fact, this one, that we have no way to prove with absolute cetainty), suggests that during the period of heavy bombardment, Dione was (better yet: could have been) tidally locked to Saturn in an opposite orientation as to the present one. Just because Dione is a relatively small Celestial Body (approx. 1120 Km - such as about 695,5 miles - in diameter), we can assume that an impact causing an approx. 35-Km-diameter Impact Crater should have been strong enough to alter the Course (---> Motion and Orientation) of the moon, as to its Parent Planet. Now, since there are so many Impact Craters on Dione which are way larger than 35 Km (such as about 21,7 miles), we can logically speculate that Dione itself might have changed both its Motion and Orientation a few times during the aforementioned period of heavy bombardment. Eventually, once that the bombardment ended, the moon was finally able to set itself on a definitive and stable Course around Saturn.
As a matter of fact, the Pattern of Cratering and the bright Albedo of its Leading Side suggest that Dione has remained in its current Course for several billion years. Like the Jovian moon Callisto, Dione's Impact Craters lack the high Central Features (---> Peaks/Uplifts) that are often seen, instead, on the Moon and Mercury; this circumstance, in our opinion, is probably due to slumping (---> Mass Wasting) of the weak Icy Crust over Geologic Times, but a final answer to this kind of question, as you can imagine, will probably never given with an absolute certainty. Just out of curiosity, if you pay special attention to the visible portion of the Limb of Dione, as it appears in this highly defined picture, you may realize that its shape is NOT, in fact, perfectly spherical.
This image, which is a combination of 5 (five) Original NASA - CASSINI Spacecraft b/w frames whose ID numbers are N00199629/30/31/32 and 33, has been additionally processed and then colorized in Natural Colors (such as the colors that a perfect human eye - or an Electronic Eye - would have perceived while looking at Dione from Cassini's vantage point) by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among others, the existence of different Elements present on the Surface of Dione, each having a different Albedo (---> Reflectivity) and Chemical Composition. MareKromium
(3 voti)
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Telesto-PIA07696-PCF-LXTT-IPF.jpgTelesto (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunar Explorer Italia/Italian Planetary Foundation) 82 visiteThis view - obtained by the NASA - CASSINI Spacecraft - shows us a few interesting Surface Features (mostly old Impact Craters and Mountains) as well as fine color variations that are found on the Trojan Saturnian moon Telesto. The smooth Surface of this moon suggests that, like Pandora, even Telesto is covered by a mantle of fine, dust-sized Icy Material. The origin of the color differences is not yet understood, but it may reasonably be caused by extremely subtle variations in the Mineralogical Composition of its Surface, or by the (extremely small) size of the Dusty Grains which make up the Icy Soil. Tiny Telesto is a Celestial Body that is approx. 24 Km (such as about 15 miles) wide only.
The image was acquired with the NASA - Cassini Spacecraft Narrow-Angle Camera on December, 25th, 2005 at a distance of approximately 20.000 Km (such as about 12.000 miles) from Telesto and at a Sun-Telesto-CASSINI Spacecraft, or Phase, Angle of 58°. Image scale is 118 meters (387 feet) per pixel.
This picture (which is an Original NASA - CASSINI Spacecraft b/w frame published on the NASA - Planetary Photojournal with the ID n. PIA 07696) has been additionally processed and then colorized, according to an informed speculation carried out by Dr Paolo C. Fienga (LXXT/IPF), in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - CASSINI Spacecraft and then looked outside, towards the Saturnian moon, Telesto), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among other things, the existence of different Elements (Minerals) present on the Surface of Telesto, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
(3 voti)
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Enceladus_and_Titan-PIA14617-PCF-LXTT-IPF.jpgSo close, and yet so far... (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunar Explorer Italia/Italian Planetary Foundation)95 visiteThe Saturnian moon Enceladus can be seen partially (as a matter of fact, we have to say almost completely) eclipsed by the shadow of its Gas-Giant Parent Planet, in this really fascinating view, taken by the the NASA - Cassini Spacecraft, which also features another Saturnian moon, such as Titan, in the distance. The Cassini Spacecraft flew by Enceladus, shown in the upper left of the picture, at a distance of about 16.000 miles (such as approx. 26.000 Km).
The Terminator - such as the Line separating the day from the night side - of Enceladus (whose dimension is approx. 313 miles, or about 504 Km across) can be barely seen on the very far left of the moon itself, while the shadow of Saturn runs all the way across from its Middle Northern, until the South Polar Regions. Titan (whose dimension is approx. 3200 miles, or about 5150 Km across), as we already mentioned hereabove, is well visible in the lower right of the frame, and, at the time that the picture was taken, it was about 684.000 miles (such as approx. 1,1 Million KiloMeters - MKM) away from the Spacecraft.
This view looks toward the Saturn-facing Sides of both Enceladus and Titan; North is up (obviously for both moons) and the image was taken in Visible Light, with the Cassini Spacecraft Wide-Angle Camera on October, 1st, 2011. The view was obtained at a Sun-Enceladus-CASSINI Spacecraft, or Phase, Angle of 29°. The Scale in the original image was approx. 2 miles (such as a little more than 3 Km) per pixel on Enceladus. The original image was also contrast enhanced and magnified by a factor of 1.5, so to enhance the visibility of a few Enceladian Surface Features (and in fact, if you look carefully, while Titan is - as usual, when observed from a great distance - completely featureless, a few Impact Craters and some Surface Striations, can actually be seen in the Northern Regions of the icy moon Enceladus).
This picture (which is an Original NASA - Cassini Spacecraft b/w frame published on the NASA - Planetary Photojournal with the ID n. PIA 14617) has been additionally processed and then colorized, according to an informed speculation carried out by Dr Paolo C. Fienga (LXTT-IPF), in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Cassini Spacecraft and then looked outside, towards the Saturnian moons Enceladus and Titan), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among others, the existence of different Elements present on the Surface of Enceladus and in the Atmosphere of Titan, respectively, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
(3 voti)
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Enceladus-PIA14599-PCF-LXTT-IPF.jpgEnceladian Night (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)74 visiteBelow an almost completely darkened Enceladus, huge Plumes of Water Ice, coming from at least 4 (four) different Sulci (---> cracks of the Surface) located its South Polar Regions, are backlit in this view of one of Saturn's most dramatic moons. The lit Terrain seen here is on the Leading Hemisphere of Enceladus (whose diameter is approx. 313 miles - such as about 504 Km). North is up.
The picture was taken in Visible Light with the NASA - Cassini Spacecraft Narrow-Angle Camera, on February 20, 2012. The view was acquired at a distance of approximately 83.000 miles (such as approx. 134.000 Kilometers) from Enceladus, and at a Sun-Enceladus-CASSINI Spacecraft (also known as "Phase"), Angle of 165°. Image scale is 2628 feet (801 meters) per pixel.
This picture (which is an Original NASA - CASSINI Spacecraft b/w frame published on the NASA - Planetary Photojournal with the ID n. PIA 14599) has been additionally processed and then colorized, according to an informed speculation carried out by Dr Paolo C. Fienga (LXXT/IPF), in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - CASSINI Spacecraft and then looked outside, towards the Saturnian moon, Enceladus), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among other things, the existence of different Elements (Minerals) present on the Surface of Enceladus, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
(3 voti)
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The_Rings-PIA08306-PCF-LXTT-IPF.jpgThe beautiful and colorful Rings of Saturn (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunar Explorer Italia/Italian Planetary Foundation) 83 visiteThis is a spectacular view - obtained by the NASA - Cassini Spacecraft - that shows us the subtle golden and gray/whitish colors which characterize the Outer B-Ring, the Cassini Division and the inner part of the A-Ring of the Giant Gas-Planet Saturn. In this viewing geometry, the brightest feature in the Cassini Division is the (relatively) recently discovered diffuse Ringlet which lies near the Outer Edge of the Division (and this diffuse Ringlet shows a quite peculiar bluish cast). The colors of the Rings, as they look in this picture, appear more golden than ever because of the Viewing Geometry that was adopted: as a matter of fact, an increased scattering in the ice and rock particles forming the Rings was brought about not only by the high Phase Angle (such as the angle drawn and defined by the Sun, the Rings and the NASA - Cassini Spacecraft), but also by the circumstance that this view was obtained while the Spacecraft was watching towards the Unlit Side of the Rings, from about 30° above the Ring-Plane. The images used to create this frame were acquired by the NASA - Cassini Spacecraft narrow-angle camera on Sept. 29, 2006, at a distance of approx. 1,8 MKM (about 1,13 MMs) from the Rings of Saturn and the image scale is roughly 11 Km (such as about 7 miles) per pixel.
Remember that the NASA - CASSINI Original b/w frame has been additionally processed and then re-colorized, according to an informed speculation carried out by Dr Paolo C. Fienga (LXTT-IPF), in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Cassini Spacecraft and then looked outside, towards the Rings of Satun), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among others, the existence of different Elements in the Rings of Satun, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
(3 voti)
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The_Rings-N00191888-N00191985-GB-LXTT-IPF.gifIn the Rings (a GIF-Movie by Dr Gianluigi Barca - Lunar Explorer Italia/Italian Planetary Foundation)104 visiteSince all the Beauties of the Universe in general - as well as many of the ones of our Solar System in particular - cannot always be adequately understood nor explained (and, please, forgive us if and when we say that those who state and declare that today's Science can really explain everything, in our opinion, as IPF, do not have the least idea of what they are talking about...), we have learned that, sometimes, and in front of certain phenomena which, as we just said, are not only impossible to recreate but (and for now), are also impossible to be observed from a REALLY close distance (thus making them extremely difficult to be fully understood and therefore explained in a satisfying way), it is Science itself that calls for some speculation.
This small foreword was absolutely necessary because the very few lines that shall follow (and which relate to the possible origin of Saturn's Rings) are, in our humble opinion, almost pure Scientific Speculation. Yes, of course we know that the hypothesis which we shall try to illustrate do represent an "informed Scientific Speculations", but still we have no actual proof (and, likely, we shall never have it) that even one of them is correct, either in full or just in part.
Given all that, we can start by saying that, according to several (either recent and/or less recent) Theories, the Rings of Saturn should be EXTREMELY old, meaning that they could be dating to the formation of Saturn (as well as of the whole Solar System) itself. Furthermore (and as a matter of fact), nowadays there are just 2 (two) Main Theories regarding the origin of Saturn's Rings which are thought to be sufficiently believable: the first one, originally proposed by the French Astronomer Édouard Robert Roche in the 19th Century, is that the Rings were once a moon of Saturn (named "Veritas", after a Roman Goddess) whose orbit, for (obviously...) unknown reasons, decayed (however, we suggest, as IPF and among many other possibilities, the occurrence of a powerful impact, that was strong enough to disrupt Veritas' orbit but NOT to disintegrate - at least, not entirely - the moon itself), until the moon came close enough to its Parent Planet so to be litterally ripped apart by the Saturnian Tidal Forces (in other words, and assuming that this Theory is basically correct, "Veritas" must have been some sort of a "Rubble-pile moon", such as a Celestial Body which was so fragile that it could not pass the so-called "Roche Limit" without being - almost - completely disintegrated). A variation of this first Main Theory (a variation that, however, we believe - as IPF - to be extremely unlikely) is that the "Veritas" moon simply disintegrated after being struck by a large Comet or an Asteroid.
The second Main Theory is that the Rings of Saturn were never part of a moon, but they are, instead, some physical leftovers of the original Proto-Planatary Nebula (i.e.: Nebular-like Material) from which Saturn itself was formed.MareKromium
(3 voti)
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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)98 visitenessun commentoMareKromium
(3 voti)
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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)90 visitenessun commentoMareKromium
(3 voti)
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Enceladus-PIA14578-PCF-LXTT.jpgEnceladus' Southern Regions (Absolute Natural Colors; credits for the additonal process. and color.: Dr Paolo C. Fienga - Lunar Explorer Italia)191 visiteCaption NASA:"This image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on Sept. 13, 2011. The view was acquired at a distance of approx. 26.000 miles (such as about 41.842,84 Km) from Enceladus and at a Phase Angle of 52°. Image scale is roughly 830 feet (253 meters) per pixel".
MareKromium
(3 voti)
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