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| Piú viste - Saturn: the "Ringed Beauty" and His Moons |
Rhea-PIA09799.jpgRising Rhea (natural colors; credits: Lunexit)77 visiteCaption NASA:"The low illumination angle near the Terminator makes visible the steep topography of craters on Rhea's battered surface. This view is centered on 10° North Latitude, 128° West Longitude.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Nov. 16, 2007. The view was obtained at a distance of approx. 313.000 Km (such as about 195.000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 128°. Image scale is 2 Km (a little more than 1 mile) per pixel".MareKromium
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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)77 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
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Saturn + 4 Moons-PIA05435_modest.jpgSaturn and 4 Moons from 8.900.000 Km76 visitecaption NASA originale:"Saturn's Moons visible in this image are (clockwise from upper left): Tethys (1060 Km wide); Dione (1118 Km wide); Enceladus (499 Km wide) and Mimas (398 Km wide).
The image was taken in visible red light at a distance of 8,9 MKM (5.5 million miles) from Saturn".
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Japetus-N00091976.jpgThe Mountains of Japetus (Transition Zone; possible natural colors - elab. Lunexit)76 visiteCaption NASA:"N00091976.jpg was taken on September 10, 2007 and received on Earth September 11, 2007. The camera was pointing toward Japetus that, at the time, was approx. 1722 Km away, and the image was taken using the CL1 and CL2 filters. This image has not been validated or calibrated".MareKromium
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Dione-N00119794.jpgCross-Worlds! (10)76 visitenessun commentoMareKromium
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Japetus-PIA12697.jpgJapetus76 visiteCaption NASA:"With its light and dark Surface, Japetus appears almost like a "Yin & Yang" symbol or a comma punctuation mark in this Cassini image. This view looks toward the Saturn-facing side of Japetus. North on is up and rotated 41° to the right.
The image was taken in VL with the Cassini Spacecraft narrow-angle camera on May 12, 2010. The view was acquired at a distance of approx. 1,5 MKM (about 932.000 miles) from Japetus and at Phase Angle of 74°. Image scale is roughly 9 Km (about 5,8 miles) per pixel".MareKromium
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Dione-EB-LXTT2~0.jpgIn the "Scars" of Dione... (an Image-Mosaic in possible Absolute Natural Colors by Elisabetta Bonora - Lunexit Team)76 visitenessun commentoMareKromium
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Saturn-Lightning-PIA14921.jpgSaturnian Lightning76 visiteThese false-color mosaics from NASA's Cassini spacecraft captured a Lightning striking within the huge storm that encircled Saturn's Northern Hemisphere for much of the AD 2011. The larger mosaic on the left of the panel shows the Lightning Flash, which appears as a blueish dot. The smaller mosaic on the right is composed of images taken 30 minutes later, and the Lightning is (let's say OBVIOUSLY...) not flashing at that time.
The white arrow points to the location where the Lightning occurred in the Clouds. The Optical Energy of this and other Flashes on Saturn is comparable to the strongest of the flashes on Earth. The flash is approx. 120 miles (about 200 Km) long when it exits the Clouds Tops. From this, scientists deduced that the Lightning Bolts originated in the Clouds deeper down in Saturn's Atmosphere where Water Droplets freeze. This is the analogous Region of the Atmosphere where Lightnings are created on Earth.
This Lightning Flash appeared only in the filter sensitive to Blue Visible Light, and the images were enhanced to increase the visibility of the Lightning. Images taken using red, green and blue spectral filters are usually combined to create a Natural Color View. Since Visible Red-Light images were not available, images taken using a spectral filter sensitive to wavelengths of Near-InfraRed Light centered at 752 nanometers were used in place of red. Also, the blue filter image was enhanced to increase the visibility of the lightning. The result is a type (as a matter of fact, just one of the VERY many...) of False Color Image.
The images were obtained with the Cassini Spacecraft narrow-angle camera on March 6, 2011, at a distance of approximately 2 MMs (such as about 3,3 MKM) from Saturn and at a Sun-Saturn-Spacecraft, or Phase, Angle of 83°. These mosaics are simple Cylindrical Map Projections, defined such that a square pixel subtends equal intervals of Latitude and Longitude. At higher Latitudes, the pixel size in the North-South direction remains the same, but the pixel size (in terms of physical extent on the Planet) in the East-West direction becomes smaller. The pixel size is set at the Equator, where the distances along the sides are equal. This map has a pixel size of approx. 12 miles (such as about 20 Km) at the Equator.MareKromium
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Phoebe-PIA06064-PCF-LXTT-IPF-1.jpgPhoebe (Absolute Natural Colors - Credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)76 visitePhoebe's possibole true nature is partly revealed in this image-mosaic of two frames taken during the NASA - CASSINI Spacecraft's Fly-By that occurred on June 11, 2004. The image shows evidence for the emerging view that Phoebe may be an ice-rich Celestial Body coated with a thin Layer of Dark Material (probably Dust). This phenomenon has been observed on other Icy Satellites, such as Ganymede, in the Jovian System: when an impactor slammed into the Surface of Phoebe, the collision excavated fresh, bright Material - probably Water Ice - underlying the Surface Layer of Dust and other rocky debris. A further evidence supporting this hypothesis can be seen on some Crater Walls where the darker Material appears to have slid downwards, so to expose more light-colored Material. However, some areas of the image that are particularly bright - especially near the lower right - are just over-exposed. Small bright Impact Craters visible in the picture are probably fairly young Surface Features.
In addition to that, a number of interesting circumstances seem to indicate that Phoebe may have originated in the Outer Solar System. In fact, Phoebe's highly irregular and Dark Surface, its retrograde orbit, the presence, on its Surface, of a huge variety of large and small Impact Craters and, last but not least, its extremely low Average Density, appear consistent with the hypothesis that Phoebe was once part of the Kuiper Belt, before being captured by Saturn's Gravity (which is, most likely, the same origin of quite a few Minor moons of the Gas-Giant Planets Uranus, Neptune, Saturn and Jupiter).
This spectacular view was obtained at a Phase, or Sun-Phoebe-Spacecraft, Angle of 84°, and from a distance of approximately 32.500 Km (such as aabout 20.200 miles). The image scale is approximately 190 meters (624 feet) per pixel.
These image-mosaic (which is made of two Original NASA - CASSINI Spacecraft b/w frames published on the NASA - Planetary Photojournal with the ID n. PIA 06064) have 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 Outer moon, Phoebe), 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 Phoebe, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
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Saturn-PIA10413-PCF-LXTT-IPF.jpgNorthern Swirls (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)76 visiteSinuous and swirling Clouds (which appear to be extremely dense) and Hurricane-sized Vortices, mingle in Saturn's Northern Skies (in fact, this view looks toward a Region of Saturn that is located at about 70° North Latitude). Despite the level of detail that is visible here, the Region shown in today's APOD is wide enough to contain the planet Mars comfortably.
The image was taken with the NASA - Cassini Spacecraft's CB1 Spectral Filter, which is sensitive to Wavelengths of Visible Red Light centered at 619 nanometers. The view was acquired with the Spacecraft's Narrow-Angle Camera on May 23, 2008 at a distance of approximately 1,2 Million KiloMeters (such as about 745.200 miles) from Saturn. Image scale is roughly 7 Km (about 4,3 miles) per pixel.
This frame (which is a NASA - CASSINI Spacecraft Original b/w frame published on the NASA - Planetary Photojournal and identified by the serial n. PIA 10413) has been additionally processed 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 Upper Atmosphere 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 Upper Atmosphere of Satun, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
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Telesto-PIA07702-PCF-LXTT-IPF.jpgTiny Telesto (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 passed within a cosmic "stone's throw" (---> meaning very close, in cosmic terms) from the Saturnian moon Telesto in October of the AD 2005, capturing this shot of this tiny Trojan moon. Telesto (which is approx. 24 Km, such as a little less than 15 miles across) appears to be mantled in fine, Icy (and/or "Dusty") Material, although a few shallow Impact Craters and some Rocky Outcrops (and/or large Boulders) are visible. Its smooth Surface does not appear to retain the record of intense cratering that most of Saturn's other moons possess.
The original image was taken in Polarized Green Light with the NASA - Cassini Spacecraft Narrow-Angle Camera on October 11, 2005, at a distance of approximately 14.500 Km (such as a little more than 9004 miles) from Telesto. The image scale is roughly 86 meters (283 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 07702) has been additionally processed and then colorized, according to an educated guess 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
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AC-The Third Light in the Sky of Saturn-W00001252.jpgA bright light in the Space of Saturn: Saturn overexposed (4)75 visiteIn questo caso, come nel caso precedente (per quanto curioso l'effetto luminoso risulti), dobbiamo dire che, forse, si tratta dello stesso fenomeno e forse no.
Ma il nostro status di Ricercatori ci impone di essere, in casi come questo, un pò più pragmatici del solito e quindi, nel dubbio, optiamo per l'effetto ottico da sovraesposizione.
Se Voi aveste idee migliori, non dovete far altro che scriverci!
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