| Piú viste - Saturn: the "Ringed Beauty" and His Moons |
Enceladus-N00118363.jpgThe Unbelievable Surface of Enceladus, from about 1500 Km!59 visiteCaption NASA:"Caption NASA:"N00118365.jpg was taken on August 11, 2008 and received on Earth August 12, 2008. The camera was pointing toward ENCELADUS that, at the time, was approximately 1564 Km away.
The image was taken using the CL1 and CL2 filters and it has not been validated or calibrated".
Nota Lunexit: osservate come l'avvicinarsi alla Linea del Terminatore rende le immagini straordinariamente affilate e dense di profondità...MareKromium
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Enceladus-PIA11106.jpgCairo Sulcus59 visiteCaption NASA:"This image is the 3rd skeet-shoot image taken during Cassini's very close flyby of Enceladus on Aug. 11, 2008.
Cairo Sulcus is crossing the southern part of the image. The terrain is littered with blocks of ice.
The image was taken with the Cassini Spacecraft narrow-angle camera on Aug. 11, 2008, a distance of approx. 2446 Km (such as about 1396 miles) above the surface of Enceladus.
Image scale is approximately 18 meters (59 feet) per pixel". MareKromium
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Enceladus-PIA11114.jpgBaghdad and Cairo Sulci on Enceladus (possible True Colors; credits: Lunexit)59 visiteCaption NASA:"Cassini shot past the surface of Saturn's moon Enceladus on Aug. 11, 2008, acquiring a set of 7 HR images targeting known hot spot locations on the moon's "Tiger Stripe" fractures, or Sulci.
Five of those images are presented in this mosaic.
Features on Enceladus are named for characters and places from "The Arabian Nights", and the four most prominent Sulci are named Alexandria, Cairo, Baghdad and Damascus. Here, Baghdad Sulcus runs across the top mosaic tile, from lower left to upper right. Cairo Sulcus runs from left to right just beneath the center tile.
One highly anticipated result of this flyby was to pinpoint previously identified source locations for the jets that blast icy particles, water vapor and trace organics into space.
The yellow circles indicate the Jets' Source Locations I and V, as identified in PIA08385" .
Scientists are using these new images to study geologic activity associated with the sulci, and effects on the surrounding terrain. This information, coupled with observations by Cassini's other instruments, may answer the question of whether reservoirs of liquid water exist beneath the surface.
The mosaic consists of five images taken with the clear spectral filters on Cassini's narrow-angle camera. The view is an orthographic projection with an image scale of 14,5 meters (47,5 feet) per pixel. The area shown here is centered on 81,6° South Latitude and 56,5° West Longitude. The original images ranged in resolution from 10 to 24 meters (33 to 79 feet) per pixel and were taken at distances ranging from 1288 to 3600 Km (such as from about 800 to approx. 2237 miles) from Enceladus".MareKromium
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The_Rings-PIA10454.jpgOut of the Darkness (natural colors; credits: NASA)59 visiteCaption NASA:"Saturn's rings burst out of shadow and curve gracefully around the Planet.
Prometheus (86 Km, or 53 about miles across at its widest point) appears as a bright speck touching the inside of the narrow F-Ring. Atlas (30 Km, or approx. 19 miles across at its widest point) is also visible, faintly, upward and to the left of Prometheus, just outside the A-Ring edge. Saturn's shadow cuts across the Rings at top right.
Several dark, narrow spokes are faintly visible near the B-Ring ansa, left of center.
This view looks toward the unilluminated side of the Rings from about 13° above 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 July 4, 2008 at a distance of approx. 1,2 MKM (about 775.000 miles) from Saturn.
Image scale is roughly 71 Km (about 44 miles) per pixel".MareKromium
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Tethys-PIA10462.jpgTethys, in full light (natural colors; credits: Lunexit)59 visiteCaption NASA:"Five hours after acquiring PIA10460, the Cassini Spacecraft turned its cameras back to Tethys for a more southerly view. The southern reaches of Ithaca Chasma are seen here, along with the large crater Telemus, just right of center.
Lit terrain seen here is on the Saturn-Facing Side of Tethys (approx. 1062 Km, or 660 miles across).
This view looks toward the Southern Hemisphere from a perspective 43° South of the moon's Equator. North is toward the top and rotated 30° to the right.
The image was taken in visible green light with the Cassini Spacecraft narrow-angle camera on July 28, 2008. The view was obtained at a distance of approx. 313.000 Km (such as about 194.000 miles) from Tethys and at a Sun-Tethys-Spacecraft, or Phase, Angle of 42°.
Image scale is roughly 2 Km (a little more than 1 mile) per pixel".MareKromium
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Rhea-PIA10464.jpgSouthern View of Rhea59 visiteCaption NASA:"Rhea's bright ray crater features prominently in this southern view. The feature is surrounded by bright ejecta — material thrown outward by the impact that formed the crater.
The view looks toward High Southern Latitudes on Rhea from a perspective 49 degrees below the icy moon's Equator. Rhea's South Pole is at bottom center.
The image was taken in visible green light with the Cassini Spacecraft narrow-angle camera on July 29, 2008. The view was acquired at a distance of approx. 413,000 Km (such as about 257.000 miles) from Rhea and at a Sun-Rhea-Spacecraft, or Phase, Angle of 44°.
Image scale is roughly 2 Km (a little more than 1 mile) per pixel".MareKromium
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Dione-N00119788.jpgCross-Worlds! (4)59 visitenessun commentoMareKromium
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Dione-N00119785.jpgCross-Worlds! (1)59 visiteI "lineamenti" superficiali di Dione sono inconfondibili; più difficile, invece, è l'individuazione del secondo Corpo Celeste che va ad incrociare Dione. Le immagini non sono perfette e la loro definizione è scarsa; tuttavia, applicando una notevole magnificazione, ci sembra di intravedere il bordo di un grande cratere, situato all'estremo Nord (dal punto di vista di Cassini - ergo dell'Osservatore) della seconda luna.
Si tratta, forse, del grande cratere Herschel, noto anche come "L'Occhio di Mimas".
Oppure, come suggerisce l'albedo della seconda luna, si potrebbe trattare di Encelado?
E Voi che ne dite?
In attesa che la NASA ci confermi o ci smentisca "l'ID" della seconda luna, le Vostre opinioni saranno profondamente apprezzate!MareKromium
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The_Rings-PIA10470.jpgGravitational Interactions or just Evidence of a recent Collision?59 visiteCaption NASA:"The three bright, finger-like jets of material seen here suggest that a small object has collided with the core of Saturn's F-Ring. Cassini Spacecraft imaging scientists have shown that the F-Ring shepherd moon Prometheus influences the structure of the Ring in 2 ways: 1) by creating streamer-channel features as it closely approaches (and partially passes into) the Ring (see PIA08397) and 2) by perturbing the orbits of small objects within the F-Ring Region which then exert their own influence on nearby Ring particles, as seen here.
These small, embedded objects could be temporary clumps of particles, but scientists think at least one of the objects could be a more permanent moonlet.
This view looks toward the sunlit side of the Rings from about 40° below the Ring-Plane. The image was taken in visible light with the Cassini Spacecraft narrow-angle camera on Aug. 20, 2008. The view was obtained at a distance of approx. 685.000 Km (such as about 426.000 miles) from Saturn and at a Phase Angle of 40°.
The image scale is about 5 Km per pixel".MareKromium
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Saturn-PIA10493.jpgSaturn (natural colors; credits: NASA)59 visiteCaption NASA:"The Cassini Spacecraft looks toward the sunlit face of Saturn's Rings, whose shadows continue to slide southward on the Planet toward their temporary disappearance during equinox in August 2009.
This two-frame color mosaic was created from images taken as part of a photometry observation of the Rings. Photometry observations are useful for determining a host of ring particle properties.
This view looks toward the sunlit side of the Rings from about 3° 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 Aug. 22, 2008 at a distance of approx. 1,2 MKM (such as about 728.000 miles) from Saturn.
Image scale is roughly 66 Km (about 41 miles) per pixel".MareKromium
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Dione-PIA10496.jpgThe Bright Canyons of Dione59 visiteCaption NASA:"Dione's defining feature, the fractures on its Trailing Side, shine brilliantly in this Cassini Spacecraft view.
The view was acquired from a position 33° South of the moon's Equator. Lit terrain seen here is on the Trailing Side of Dione (approx. 1123 Km, or about 698 miles across). North is up and rotated 8° to the right.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 11, 2008. The view was obtained at a distance of approximately 833,000 kilometers (517,000 miles) from Dione and at a Phase Angle of 67°. Image scale is about 5 Km (a little more than 3 miles) per pixel.
The image was taken with the Cassini Spacecraft wide-angle camera on Aug. 26, 2008 using a spectral filter sensitive to wavelengths of infrared light centered at 752 nanometers.
The view was acquired at a distance of approx. 397.000 Km (about 246.000 miles) from Saturn.
Image scale is roughly 20 Km (about 13 miles) per pixel".MareKromium
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Dione-PIA10500.jpgCross-Worlds: the Answer!59 visiteRicordate la sequenza (intitolata, appunto, Cross-Worlds) che pubblicammo qualche settimana fa (era il 14 Settembre 2008, per l'esattezza) e che ci mostrava (ovviamente nell'ottica di CASSINI) Dione mentre eclissava un'altra Luna non identificata?
Noi ipotizzammo che si potesse trattare di Mimas o di Encelado. La NASA, oggi, tramite il suo Planetary Photojournal, ci ha risposto: si trattava di Encelado.
Un grazie alla NASA (che, quando vuole, sa anche rispondere) ed un 6+ a noi perchè, anche se non siamo riusciti ad identificare con sicurezza assoluta la seconda luna "misteriosa" in transito, siamo stati comunque abbastanza bravi dal ridurre la rosa dei "candidati" a due soli Corpi Celesti.
Insomma...Non male!MareKromium
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