Saturn: the "Ringed Beauty" and His Moons
|
|
|
Dione-PIA06164-detail mgnf.jpgThe anomalous "straight tectonic fracture" on Dione - detail mgnf100 visiteLa vedete la "frattura" anomala ora? Guardatela e studiatela con molta attenzione: si tratta di una configurazione della superficie di Dione davvero molto strana e, se si tratta davvero di una tectonic fracture, allora occorre dire che essa è molto differente, da tantissimi punti di vista, da tutte le altre che possiamo vedere nelle immagini HR di Dione.
|
|
Dione-PIA06199.jpgDione and Rhea: full sequence of their "dance"53 visiteCaption NASA originale:"Rhea (1.528 Km across) is larger than Dione (1.118 Km), but also is farther away as seen here, which explains why the two moons appear to be roughly the same angular size.
The view shows principally the anti-Saturn side of Dione, and the Saturn-facing side of far-off Rhea.
The images in this mosaic were taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 20, 2005, at a distance of approximately 1,5 MKM (approx. 900.000 miles) from Dione and about 2,3 MKM (approx. 1,4 MMs) from Rhea.
The image scale is approximately 9 Km per pixel on Dione and 14 Km per pixel on Rhea".
|
|
Dione-PIA06513_modest.jpgDione53 visiteCaption originale NASA: "Dione shows Cassini some of the bright wispy streaks that cover much of the moon's trailing hemisphere. The streaks are thought to be deposits of icy material that has been extruded onto the moon's surface from the interior. Dione's diameter is 1.118 Km across.
The image was taken in visible light with the Cassini spacecraft narrow angle camera on Sept. 28, 2004, at a distance of 7.3 MKMs from Dione and at a Sun-Dione-spacecraft, or phase, angle of 79°. The image scale is 44 Km per pixel. The image has been magnified by a factor of four to aid visibility".
|
|
Dione-PIA06528_modest.jpgDione from approx. 1.200.000 Km53 visiteA gorgeous Dione poses for Cassini, with shadowed craters and bright, wispy streaks first observed by the Voyager spacecraft 24 years ago. The wispy areas will be imaged at higher resolution in mid-December 2004. Subtle variations in brightness across the surface of this moon are visible here as well. Dione's diameter is 1.118 Km. The image shows primarily the trailing hemisphere of Dione, which is the side opposite the moon's direction of motion in its orbit. The image has been rotated so that north is up.
The image was taken in visible light with the Cassini spacecraft narrow angle camera on Oct. 27, 2004, at a distance of about 1.2 MKMs from Dione and at a Sun-Dione-spacecraft, or phase, angle of 28°. The image scale is 3.5 Km per pixel.
|
|
Dione-PIA06542_modest.jpgA line of craters on Dione and a crater with "something" inside...53 visiteAl di là della oggettiva bellezza e della grande suggestione che suscita questa immagine, la domanda (scherzosa, naturalmente) sorge in noi spontanea: ma dentro il "cratere maggiore" (proprio in centro, a ridosso del terminatore), che cosa c'è?!?
|
|
Dione-PIA06611.jpgStreaks on Dione53 visiteCaption NASA originale:"Wispy streaks curl over the horizon on Saturn's moon Dione, caught here in a distant view from Cassini. The streaks were first revealed by NASA's Voyager spacecraft and subsequently were shown by Cassini to be an immense system of linear fractures in the moon's surface. The image was taken with the Cassini spacecraft narrow-angle camera using a filter sensitive to wavelengths of ultraviolet light centered at 338 nnmts. The image was acquired on Feb. 18, 2005, at a distance of approximately 1,3 MKM from Dione and at a phase angle of 118°. The image scale is 8 Km per pixel".
|
|
Dione-PIA06626.jpgSaturnshine54 visiteCaption NASA originale:"This Cassini image shows the night side of Saturn's moon Dione, dimly lit by "Saturnshine": that is, reflected light from the planet lying off to the left in Cassini's field of view when this image was taken.
The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on Feb. 18, 2005, at a distance of about 1,3 MKM (approx. 808.000 miles) from Dione and at a phase angle of 118°. The image scale is 8 Km (approx. 5 miles) per pixel".
|
|
Dione-PIA07511.jpgDione unmagnified53 visiteCaption NASA originale:"This unmagnified view of Saturn's moon Dione shows the moon's bright, wispy terrain, along with several large impact craters. Two of the craters have central peaks. North on Dione is up.
This view shows principally the anti-Saturn hemisphere on Dione.
It is now clear why low-resolution NASA Voyager spacecraft images gave the impression that the Dionian wispy terrain might be bright ice deposits: HR Cassini images have shown these to be complex systems of braided (to braid--->intrecciare) tectonic fractures.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 25, 2005, at a distance of approx. 2,8 MKM (such as approx 1,7 MMs) from Dione and at a phase angle of 60°.
The image scale is 17 Km (approx. 11 miles) per pixel".
|
|
Dione-PIA07581.jpgThe "Old Face" of Dione53 visiteOriginal NASA caption"Dione's Southern Polar Region (as shown here) contains fractures whose softened appearance suggests that they have different ages than the bright braided fractures seen in the image to the North. This Region is also notably brighter than the near equatorial terrain at the top of the image. At center, several of the bright, radial streaks mark a feature named Cassandra, which may be a rayed crater or a tectonic feature.
This view of Dione (1118 Km across) captures high southern latitudes on the Moon's trailing hemisphere.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Aug. 1, 2005, at a distance of approx. 269.000 Km(about 167.000 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 41°. Image scale is 2 Km (about 1,2 miles) per pixel".
|
|
Dione-PIA07603.jpgDione: the "Aeneidian Moon", from 1,1 MKM53 visiteOriginal caption:"When naming features on other worlds, scientists like to follow themes, and Dione is no exception. Dione possesses numerous features with names from Virgil's 'Aeneid'. The prominent crater showing a central peak below the center is Dido, a 118-Km-wide (about 73-mile) crater named after the supposed founder of Carthage. The crater just above Dido is Antenor, an 82-Km-wide (about 51-mile) impact crater named after the nephew of Priam who founded the Italian city of Padua. At the upper right is the 97-Km-wide (about 60-mile) impact crater Turnus, which lies at the western end of Carthage Linea, a region of bright, fractured terrain. The sunlit terrain seen here shows some of the wispy markings on the Moon's trailing hemisphere. Cassini revealed that these markings are actually a complex system of fractures. North on Dione is up and rotated 25° to the left (...)".
|
|
Dione-PIA07618.jpgCanyonland70 visiteOriginal caption:"The Cassini spacecraft views the far-off wispy canyons of Saturn's moon Dione and sees an interesting dichotomy between the bright wisps and the bright South Polar Region at the bottom. The view looks toward the trailing hemisphere on Dione. North is up.
The image was taken with the Cassini spacecraft's narrow-angle camera on Sept. 20, 2005, through a filter combination sensitive to polarized green light. The image was acquired at a distance of approx. 2,1 MKM (about 1,3 MMs) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 64°. Resolution in the original image was 12 Km per pixel. The image has been magnified by a factor of two to aid visibility".
Nota: un'immagine "modesta" di Dione, ripresa da una grande distanza e che - stranamente - evidenzia davvero molto bene la "profondità" dei rilievi Dioniani. Curioso, trattandosi di un frame NON 3D.
|
|
Dione-PIA07627.jpgDione and the F-Ring (in natural colors)53 visiteOriginal caption:"Saturn's moon Dione is about to swing around the edge of the thin F-Ring in this color view. More than one thin strand of the F-Ring's tight spiral can be seen here.
The terrain seen on Dione is on the moon's Saturn-facing hemisphere.
Images taken using infrared, green and ultraviolet spectral filters were composited to create this color view. The images were taken with the Cassini spacecraft narrow-angle camera on Sept. 20, 2005, at a distance of approx. 2 MKM (about 1,2 MMs) from Dione and at a phase angle of 48°.
The image scale is of about 12 Km (such as roughly 7 miles) per pixel".
|
|
2245 immagini su 188 pagina(e) |
|
|
|
|
|
16 | |
|
|
|
|