| Risultati della ricerca nelle immagini - ""C"" |
42-CuvierC-AMI_EAE3_002085_L,1.jpgCuvier "C"56 visiteCaption ESA originale:"This high-resolution image, taken by the Advanced Moon Imaging Experiment (AMIE) on board ESA’s SMART-1 spacecraft, shows the young crater ‘Cuvier C’ on the Moon.
AMIE obtained this sequence on 18 March 2006 from a distance of 591 Km from the surface, with a ground resolution of 53 mt per pixel. The imaged area is centred at a Latitude of 50,1º South and a Longitude of 11,2º East, with a field of view of 27 Km. The North is on the right of the image.
Cuvier "C", a crater about 10 Km across, is visible in the lower right part of the image. Cuvier "C" is located at the edge of the larger old crater Cuvier, a crater 77 Km in diameter. The upper left quadrant of the image contains the smooth floor of Cuvier, only one fourth of which is visible in this image".
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APOLLO 15 AS 15-90-12311.jpgAS 15-90-12311 - Craters Herodotus and Wollaston "C"103 visitenessun commento
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The_Rings-PIA08855.jpgMulticolored Rings...54 visiteCaption NASA:"Both luminous and translucent the C-Ring sweeps out of the darkness of Saturn's shadow and obscures the Planet at lower left.
The Ring is characterized by broad, isolated bright areas, or "plateaux", surrounded by fainter material. This view looks toward the unlit side of the Rings from about 19° above the Ring-Plane. North on Saturn is up. The dark, inner B-Ring is seen at lower right.
The image was taken in visible light with the Cassini spacecraft wide-angle camera on Dec. 15, 2006 at a distance of approx. 632.000 Km (about 393.000 miles) from Saturn and at a phase angle of 56°.
Image scale is roughly 34 Km (about 21 miles) per pixel".
Nota: il sistema di elaborazione in "colori naturali" non è cambiato ma, come vedete Voi stessi, i colori di Saturno sono (leggermente) mutati. Come mai? La risposta, a nostro parere, deve essere rinvenuta nel tipo di filtraggio utilizzato dalla NASA per l'ottenimento dell'immagine originale in b/n. Questo vuol dire, fra l'altro, che i frames in b/n NON sono affatto tutti uguali (come molti invece ritengono). E' il tipo di flitro impiegato per l'ottenimento dell'immagine originale - ottenuta sulla scala dei grigi - che poi determinerà, in sede di trasformazione del frame in immagine a colori, il "tipo di colori"!
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The_Rings-PIA11664.jpgSpiral Corrugation across the C and D-Rings56 visiteCaption NASA:"Alternating light and dark bands, extending a great distance across Saturn’s D and C-Rings, are shown here in these Cassini images taken one month before the Planet’s August 2009 Equinox.
The C-Ring stretches across the upper left and middle of the image. The D-Ring is barely visible amid the noise in the lower right of the image.
The periodic brightness variations in the Rings have a subtler, narrow appearance in this mosaic of three Cassini images than other larger features of the Rings, such as the Columbo Gap which appears as a black arc on the left of the center frame of the mosaic. These brightness variations are almost certainly caused by the changing slopes in the rippled Ring-Plane, much like the corrugations of a tin roof.
Although previous Cassini observations (see PIA08325) had revealed corrugations in the D-Ring extending over 500 miles (about 800 Km), this image shows these features extending for 6200 miles (about 10.000 Km) into the C-Ring.
Later Equinox images revealed the true dimension of this Corrugation, extending completely across the C ring, right up to the inner B-Ring edge for a total breath of about 17.000 Km (approx. 11.000 miles) -- see PIA11670 and PIA11671.
This and other new imagery supports earlier evidence that something dramatic happened in the early 1980s to initiate this feature.
In 2006, imaging scientists speculated that a collision with a comet or asteroid may have disturbed the D-Ring. That explanation seems less likely now that this and other new images show the effect spread over a much broader radial range, extending right up to the inner B-Ring. Scientists continue to investigate the cause of this disturbance.
Whatever caused the corrugation apparently tilted a vast region of the inner rings relative to Saturn’s gravitational field in a relatively short period of time during the early 1980s. In the intervening years, the natural tendency for inclined orbits to systematically and slowly wobble at different rates, depending on their distance from Saturn, has created a tightly wound spiral corrugation in the Ring-Plane.
This view looks toward the unilluminated side of the Rings from about 24° above the Ring-Plane.
The D-Ring has been brightened relative to C-Ring to enhance visibility.
The images were taken in Visible Light with the Cassini Spacecraft narrow-angle camera on July 11, 2009. The view was acquired at a distance of approx. 470.000 Km (about 292.000 miles) from Saturn and at a Phase Angle of 25°.
Image scale is roughly 2 Km (about 1,25 miles) per pixel".MareKromium
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The_Rings-PIA11674.jpgRocky-Rain on the Rings54 visiteCaption NASA:"The bright Streaks visible in these Cassini images taken during Saturn’s August 2009 Equinox are exciting evidence of a constant rain of interplanetary projectiles onto the Planet’s Rings.
Objects, each estimated to be one meter (3 feet) in size and traveling tens of kilometers per second (tens of thousands of miles per hour), likely smashed into the Rings and created elevated clouds of tiny particles that have been sheared out, or elongated and tilted, by orbital motion into bright streaks.
The image on the left shows an impact in the A-Ring. The Streak stretches from the right of the image to the middle, and it does not quite follow the arc of the Rings. The brightest part of that Streak is about 5000 Km (approx. 3100 miles) long (its azimuthal dimension) and about 200 Km (approx. 120 miles) wide (its radial extent, tip to tip) in this image.
The image on the right shows an impact into the C-Ring. This Streak is much smaller than the A-Ring Streak, and it appears on the right of the image. The brightest part of this Streak is approx. 200 Km (about 120 miles) long (its azimuthal dimension) and approx. 10 Km (about 6 miles) wide (its radial dimension, tip to tip) in this image.
By the brightness and dimensions of the Streaks, scientists estimate the impactor sizes at roughly one meter (3 feet), and the elapsed time since impact at one to two days. These Equinox data lend more confidence to a Cassini imaging observation made in 2005 of similar Streaks seen in the C-Ring (see PIA11675).
All together, these observations constitute the visual confirmation of a long-held belief that bits of interplanetary debris continually rain down on Saturn’s Rings and contribute to the Rings’ erosion and evolution.
Although the phase angle of these images is not the best for seeing clouds of small particles, these ejecta clouds are easily seen because very little sunlight is falling on the Rings during the exceedingly low Sun-angle condition prevalent during the four days surrounding exact Saturn Equinox.
Exact Equinox is when the sun is directly overhead at the Equator. A cloud of dust rising above the dark Ring-Plane is more directly catching the Sun’s rays, and is hence well lit and easily visible by contrast.
When the Ring background is at its usual brightness, impacts such as these are very difficult to detect.
The view of the A-Ring Streak on the left looks toward the northern side of the Rings from about 20° above the Ring-Plane. The image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on Aug. 13, 2009. The view was obtained at a distance of approx. 1,2 MKM (about 746.000 miles) from Saturn and at a Phase Angle of 87°.
Image scale is 7 kilometers (4 miles) per pixel.
The view of the C-Ring Streak on the right looks toward the southern side of the Rings from about 22° below the RingPlane. The image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on Aug. 11, 2009. The view was obtained at a distance of approx. 263.000 Km (about 164.000 miles) from Saturn and at a Phase Angle of 135°.
Image scale is roughly 1 Km (4007 feet) per pixel".MareKromium
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as15-93-12704.JPGAS 15-93-12704 - The "Herschel" Legacy55 visiteImage Collection: 70mm Hasselblad
Mission: 15
Magazine: 93
Magazine Letter: P
Latitude: 38,0° North
Longitude: 33,0° West
Film Type: SO-368
Film Width: 70 mm
Film Color: color
Feature(s): HERSCHEL "C", HERSCHEL "U" and HERSCHEL "V"MareKromium
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