|
|
|
In the Saturnshine... (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)
|
The Saturnian moon Enceladus looks as if it is half lit by Sunlight in this view from the NASA - Cassini Spacecraft; but looks, as you know, can be (as they often are) deceiving.
In fact, the kind of pinkish area of Enceladus visible on the right (Dx) of the frame, where MANY Surface Features can be made out (---> seen/identified), is actually illuminated by the light reflected off of Saturn (such as the so-called "Saturnshine"). On the other hand, a sliver of the Enceladian Surface that is actually illuminated by direct Sunlight is visible - and also highly overexposed! - on the left (Sx) of the picture. Images like this one are designed to capture the extended Plumes of Icy Materials spraying from huge cracks located the moon's South Polar Region. Such images need to be taken with the NASA - Cassini Spacecraft looking toward the Icy moon's Night Side, since the small particles that form the Plumes (however, just barely visible in this picture) are most easily seen when backlit by the Sun.
This view looks toward the Leading Hemisphere of Enceladus; North is up. The image was taken in Visible Light with the NASA - Cassini Spacecraft's Narrow-Angle Camera on May 10, 2015. Enceladus is roughly 313 miles (such as about 503,72 Km) across. The view was acquired at a distance of approximately 226.000 miles (such as approx. 363.7210,84 Km) from Enceladus and at a Sun-Enceladus-Cassini Spacecraft, or Phase, Angle of 152°. Image scale is roughly 1,4 miles (about 2,2530 Km) per pixel.
This frame (which is an Original NASA - CASSINI Spacecraft's b/w and NON Map-Projected image published on the NASA - Planetary Photojournal with the ID n. PIA 18328) has been additionally processed, contrast enhanced, magnified, in order to allow the vision of the slightest details of the Surface, Gamma corrected and then re-colorized - according to an educated guess (or, if you wish, an informed speculation) carried out by Dr Paolo C. Fienga - 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, toward the Saturnian moon "Enceladus"), 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 Enceladus, each having a different Albedo (---> Reflectivity) and Chemical Composition.
Note: it is possible (but we, as IPF, have no way to be one-hundred-percent sure of such a circumstance), that the actual luminosity of Enceladus - as it is in this frame - would appear, to an average human eye, a little bit lower than it has been shown (or, better yet: interpreted) here.
|
|
(Dettagli)
Una volta sembrava impossibile anche la presenza di acqua oltre la Terra.
Oggi sappiamo che c'è acqua sulla Luna, su Marte,su Encelado e chissà quanti altri
Niente, il numero è vecchio ...
infatti, speravo passasse da queste parti ma mi sa che è molto tempo che non scrive più qua.
Aspettiamo e speriamo ci siano buone nuove.
Un abbraccio a tutti e sempre Forza Paolo.
Giorgio
Grazie.
Spero stia bene.
Un abbraccio
Giorgio