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Saturn: the "Ringed Beauty" and His Moons
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Saturn-PIA08396.jpgSquashed and Colourful (natural colors; credits: NASA)55 visiteCaption NASA:"Saturn in the Cassini era has proved to be an unexpectedly colorful place, compared to the browns and golds imaged by the two Voyager spacecraft. Saturn is headed toward Equinox in 2009, followed by Springtime in the Northern Hemisphere. Having a spacecraft in orbit while such changes occur will be of great benefit in scientists' quest to understand the atmospheres of the Giant Planets.
The Planet's oblate, or squashed, shape is clearly visible in this view.
The low-density Planet rotates so fast (in about 10,5 hours) that it flattens out slightly around its middle. The bluish tint of the Northern Latitudes is presumed to be a seasonal effect and will likely disappear entirely as the North receives increasingly greater amounts of sunlight.
Images taken using red, green and blue spectral filters were combined to create this natural color view.
The images were obtained with the Cassini spacecraft wide-angle camera on July 29, 2007 at a distance of approx. 3,1 MKM (about 2 MMs) from Saturn"MareKromium
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Saturn-PIA08410.jpgElectrical Storm on Saturn's Upper Troposphere (natural colors; credits: NASA)54 visiteCaption NASA:"A bright, powerful, lightning-producing storm churns and coasts along the lane of Saturn's Southern Hemisphere nicknamed "Storm Alley" by scientists.
NASA's Cassini spacecraft detected this particular tempest after nearly 2 years during which Saturn did not appear to produce any large electrical storms of this kind. The storm appears as a bright, irregular splotch on the Planet near lower right.
Lightning flashes within the persistent storm produce radio waves, called Saturn Electrostatic Discharges, which the Cassini radio and plasma wave science instrument first detected on Nov. 27, 2007. Cassini's imaging cameras then spotted the storm, taking the images used to create this color view about a week later on Dec. 6, 2007.
This electrical storm is similar in appearance and intensity to those previously monitored by Cassini. All of these powerful electrostatic producing storms appeared at about 35° South Latitude on Saturn.
This storm has now been continuously tracked by Cassini for several months, whereas previous storms observed by the Spacecraft lasted for less than 30 days.
The view looks toward the un-illuminated side of the Rings from about 5° above the Ring-Plane. Tethys (about 1071 Km, or approx. 665 miles across) is seen here in the foreground, and casts its shadow onto the high Northern Latitudes.
Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were acquired with the Cassini spacecraft wide-angle camera at a distance of approx. 1,7 MKM (1 MMs) from Saturn.
Image scale is roughly 97 Km (about 60 miles) per pixel".MareKromium
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Saturn-PIA08411.jpgElectrical Storm on Saturn's Upper Troposphere (approx. true colors; credits: NASA)54 visiteCaption NASA:"It is no Great Red Spot, but these two side-by-side views show the longest-lived electrical storm yet observed on Saturn by NASA's Cassini Spacecraft.
The views were acquired more than 3 months after the storm was first detected from its lightning-produced radio discharges on Nov. 27, 2007.
Cassini imaging scientists believe the storm to be a vertically extended disturbance that penetrates from Saturn's Lower to Upper Troposphere.
The view at left was created by combining images taken using red, green and blue spectral filters, and shows Saturn in colors that approximate what the human eye would see. The storm stands out with greater clarity in the sharpened, enhanced color view at right. This view combines images taken in infrared, green and violet light at 939, 567 and 420 nanometers respectively and represents an expansion of the wavelength region of the electromagnetic spectrum visible to human eyes. This view looks toward the un-illuminated side of the Rings from about 3° above the Ring-Plane.
Janus (about 181 Km, or approx. 113 miles across) appears as a dark speck just beneath the Rings in both images.
These images were obtained with the Cassini spacecraft wide-angle camera on March 4, 2008, at a distance of approx. 1,3 MKM (about 800.000 miles) from Saturn.
Image scale is roughly 74 Km (about 46 miles) per pixel".MareKromium
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Saturn-PIA08414.jpgPerspectives... (natural colors; credits: NASA)54 visiteCaption NASA:"The Ringed Planet sits in repose, the center of its own macrocosm of many rings and moons and one artificial satellite named Cassini. Mimas (approx. 397 Km, or about 247 miles across) is visible at upper left. Although unseen in this view, Enceladus (approx. 504 Km, or about 313 miles across) casts its shadow upon the Planet. The Rings also block the Sun's light from the low Latitudes of the Northern Hemisphere.
During Cassini's extended mission, dubbed the Cassini Equinox Mission, which begins on July 1, 2008, the Ring shadows will slip past the Planet's Equator and into the Southern Hemisphere as Saturn passes through its Northern Vernal Equinox on August 11, 2009, and the Sun moves northward through the Ring-Plane.
This view looks down on the unilluminated side of the Rings, from about 22° above (such as North of) the Ring-Plane. Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were obtained with the Cassini Spacecraft wide-angle camera on Dec. 16, 2007, at a distance of approx. 1,4 MKM (such as about 900,000 miles) from Saturn.
Image scale is roughly 86 Km (about 53 miles) per pixel".MareKromium
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Saturn-PIA08415.jpgSpringtime's Hues - (natural colors; credits: NASA)54 visiteCaption NASA:"New hues are creeping into Saturn's Northern Cloud Bands as Winter gives way to Spring there.
During its first four years of exploration, Cassini has made the Saturn System a familiar place to us Earthlings. The intrepid craft has returned more than 150.000 images since arriving in orbit in mid-2004. In this natural color image, the blues and grays of Saturn's Northern Hemisphere, so striking in early Cassini images, are diminishing in intensity with the slow change of seasons on Saturn, and are almost imperceptibly being replaced by pale shades of the colors commonly seen by Cassini in the Planet's Southern Hemisphere.
This view looks toward the sunlit side of the Rings from about less than 1° below the Ring-Plane. Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were acquired with the Cassini Spacecraft wide-angle camera on April 23, 2008, at a distance of approx. 1,2 MKM (such as about 740.000 miles) from Saturn.
Image scale is roughly 68 Km (about 42 miles) per pixel".MareKromium
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Saturn-PIA08732.jpgThe clouds of Saturn54 visiteThis false-color mosaic of Saturn shows deep-level clouds silhouetted against Saturn's glowing interior. The image was made with data from Cassini's VIMS, which can image the Planet at 352 different wavelengths. This mosaic shows the entire Planet, including features like Saturn's Ring shadows and the Terminator, the boundary between day and night.
The data were obtained in February 2006 at a distance of 1,6 MKM (about 1 MMs) from directly over the plane of Saturn's Rings, which appear here as a thin, blue line over the equator. The image was constructed from images taken at wavelengths of 1,07 microns (blue), 2,71 microns (green) and 5,02 microns (red).
The blue-green color (lower right) is Sunlight scattered off clouds high in Saturn's atmosphere and the red color (upper left) is the glow of thermal radiation from Saturn's warm interior, easily seen on Saturn's night side (top left), within the shadow of the Rings and with somewhat less contrast on Saturn's day side (bottom right). The darker areas within Saturn show the strongest thermal radiation. The bright red color indicates areas where Saturn's atmosphere is relatively clear. The great variety of cloud shapes and sizes reveals a surprisingly active planet below the overlying sun-scattering haze.
The brighter glow of the northern hemisphere versus the southern indicates that the clouds and hazes there are noticeably thinner than those in the south. Scientists speculate that this is a seasonal effect, and if so, it will change as the northern hemisphere enters springtime during the next few years.
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Saturn-PIA08734.jpgInner Warmth, Hidden Light...54 visiteCaption NASA originale:"This false-color image of Saturn shows Ring shadows running across the upper portion of the Planet, and sunlight illuminating the lower portion of the Planet.
The upper area, in the Ring shadow, would be black in visible light but glows red in infrared because Saturn is warm inside. This light shines out through the clouds, giving scientists a look at some of Saturn's interesting atmospheric structure.
This image was taken on June 30, 2006, with Cassini's VIMS. It was constructed from images taken at wavelengths of 0,91 microns (blue); 2,25 microns (green) and at 5,01 (red).
The distance from Cassini to Saturn's center in this image is aspprox. 335.000 Km (about 208.159 miles)".
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Saturn-PIA08735.jpgThree, for one and the same: Saturn, in infrared light56 visiteCaption NASA:"This false-color image of Saturn was constructed by combining 3 images at 3 different infrared wavelengths.
The image at the upper left was taken at 1,3 microns, where both Saturn and its Rings strongly reflect light. The center image in the top panel was taken at 2,4 microns, where the Rings strongly reflect light, but Saturn, because of the methane in its atmosphere, absorbs most of the light. The third image on the right in the panel was taken at a wavelength of 5 microns where, because they are composed of almost pure water ice, the Rings absorb almost all the light, and Saturn, because its interior is warm, glows. Assigning each of the three images to blue, green and red, respectively, results in the beautiful, false-color, composite image shown here.
These images were taken on June 21, 2004, with Cassini's VIMS (Visual and Infrared Mapping Spectrometer) from a distance of approx. 6,35 MKM (about 3,94 MMs) from Saturn".
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Saturn-PIA08822.jpgSaturn's limb (NASA - natural colors)55 visiteCaption NASA originale:"From its unique perspective high above the Planet, the Cassini spacecraft looks down upon Saturn's murky Northern Hemisphere. The bluish hues seen in some Cassini views of Saturn's North are notably absent in this viewing geometry.
The dark side of Saturn's extensive Rings is just visible in the top half of the image.
The view looks toward the unlit side of the Rings, from about 44° above the Ring-Plane.
Images taken using red, green and blue spectral filters were combined to create this natural color view.
The images was taken with the Cassini spacecraft wide-angle camera on Oct. 30, 2006, at a distance of approx. 1,4 MKM (about 900.000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 150°. Image scale is roughly 78 Km (about 49 miles) per pixel".
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Saturn-PIA08823~0.jpgCrescent Saturn (Natural Colors; credits: NASA/JPL/Space Science Institute)63 visiteFrom Norther than the North Pole...
Caption NASA originale:"The Cassini spacecraft gazes down at the marvelous Rings and swirling clouds of giant Saturn from above the Planet's North Pole.
Such views are possible as the spacecraft performs its "180°-transfer," a key navigation maneuver that quickly raises the inclination of Cassini's orbit and shifts the orbital ellipse around to a different side of the Planet, before quickly lowering the inclination again.
The image was taken in visible light with the Cassini spacecraft wide-angle camera on Oct. 30, 2006. Cassini was then at a distance of approx. 1,2 MKM (about 700.000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 142°.
Image scale is roughly 67 Km (about 41 miles) per pixel".MareKromium
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Saturn-PIA08826.jpgVanishing Pan... (Natural Colors; credits: NASA/JPL/Space Science Institute)59 visiteCaption NASA originale:"The Cassini spacecraft looks down at the unlit side of the Rings as Pan heads into Saturn's shadow. The moon is accompanied by faint ringlets in the Encke Gap. At bottom, the bright F-Ring core fades slowly into darkness. This view looks toward the unlit side of the Rings from about 20° above the Ring-Plane.
The image was taken in visible light with the Cassini spacecraft wide-angle camera on Nov. 15, 2006. Cassini was then at a distance of approx. 1,7 MKM (about 1,1 MMs) from Saturn and at a Sun-Saturn-Spacecraft, or Phase, Angle of 163°. Image scale is roughly 10 Km (approx. 6 miles) per pixel".MareKromium
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Saturn-PIA08833.jpgNorthern Latitudes of Saturn and the B-Ring's shadow54 visiteCaption NASA:"Streaks of cloud are overlain with graceful ring shadows in this view of Saturn's Northern Latitudes.
Structure is visible in the shadow of the A-Ring and Cassini Division, which widen at the highest latitudes, near lower right. The lower left half of the image does not show the blackness of space, but rather the shadow of the B-Ring, which is perfectly dark here.
The image was acquired from a high inclination above the Planet's Ring-Plane and looks obliquely toward the limb. (...)
The image was taken with the Cassini spacecraft narrow-angle camera using a spectral filter sensitive to wavelengths of infrared light centered at 938 nanometers on Oct. 30, 2006. Cassini was then at a distance of approx. 1,2 MKM (about 700.000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 142°.
Image scale is roughly 7 Km (a little more than 4 miles) per pixel".
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