Europa-Ridges-PIA17737-PCF-LXTT-IPF-1.jpgFeatures of Europa (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)95 visiteThis image, taken by the NASA - Galileo Spacecraft on February, 2, 1999, shows us huge Cracks and Ridges on the Surface of the Jovian moon Europa. These (absolutely fascinating) Features reveal a complex Geologic History of Europa. Some Ridges, such as the prominent one, at the top right of the frame, develop into several long, arc-shaped "Cycloids" (---> a Cycloid is the curve traced by a point on the rim of a circular wheel as the wheel rolls along a straight line), that could reasonably be related to the changing Tidal Forces as Europa orbits the Gas-Giant Planet Jupiter. The Wall of this Ridge stands perhaps a third of a mile (approx. 0,5 Km) above the surrounding Ridged Plains, although their Edges are - likely - NOT as steep as they appear in this view.
The view was captured by the NASA - Galileo Spacecraft on February 2, 1999, during its E19 orbit, when the spacecraft was about 2500 miles (such as approx. 4023 km) from the Surface of Europa. The Resolution in the scene is roughly 295 feet (such as approx. 89.91 meters) per pixel. North is toward bottom left side of the picture.
This frame (which is a crop taken from an Original NASA - Galileo Spacecraft enhanced color image published on the NASA - Planetary Photojournal with the ID n. PIA 17737) has been additionally processed, contrast enhanced, magnified to aid visibility of the Surface details and then re-colorized, according to an educated guess carried out by Dr Paolo C. Fienga/LXTT/IPF, in what they should be its Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Galileo Spacecraft and then looked outside, towards the Surface of the Jovian moon Europa), 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 others, the existence of different Elements present on the Surface of Europa, 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 Europa- 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.MareKromium
(3 voti)
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Europa-Craters-Tyre_Crater-PIA00702-PCF-LXTT-IPF.jpgTyre Crater (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunexit Team/Italian Planetary Foundation)143 visiteThis unbelievably complex Surface Feature located on the Jovian moon Europa was originally seen as a dark, diffuse Circular Patch on a previous NASA - Galileo Spacecraft's global image of Europa's Leading Hemisphere taken on April 3, 1997. The "Bulls-Eye" pattern appears to be a 140- Km-wide Impact "Scar" (about the size of the island of Hawaii) which formed as the Surface of Europa fractured minutes after a (probably) mountain-sized Asteroid or Comet slammed into this fascinating Celestial Body.
This approx. 214-Km-wide picture is the product of the combination of 3 (three) images which have originally been processed in false colors, so to enhance shapes and compositions of the photographed Surface. North is toward the top of this picture, which is illuminated from Sunlight coming from the West. This composite reveals a sequence of events which have deeply modified the Surface of Europa. The earliest event was the impact which formed the Tyre Structure, located at 34° North Latitude and 146,5° West Longitude. The impact was then followed by the formation of the brown/reddish lines superposed on Tyre. The brown/reddish color, in fact, designates areas that are probably made of (or covered by) some kind of a "dirty" Water-Ice Mixture. On the other hand, the fine light blue-gray lines crossing the whole Region from West to East appear to be Ridges which (obviously) formed after the Crater.
The images forming this composite were taken on April 4, 1997, at a resolution of 595 meters (1950 feet) per picture element and a range of approx. 29.000 Km (such as about 18.000 miles) from Europa. The frames were taken by Galileo's Solid State Imaging (CCD) System.
This frame (which is the Original NASA - Galileo Spacecraft false-color image composite published on the NASA - Planetary Photojournal with the ID n. PIA 00702) has been additionally processed and then re-colorized, according to an educated guess carried out by Dr Paolo C. Fienga (LXTT-IPF), in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Galileo Spacecraft and then looked outside, towards the Surface of the Jovian moon Europa), 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 others, the existence of different Elements present on the Surface of Europa, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
(3 voti)
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Europa-Ice_Floes-PIA00578-PCF-LXTT-IPF.jpgEuropa's Ice Floes (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunexit Team/Italian Planetary Foundation)130 visiteJupiter's moon Europa, as seen in this image taken on June 27, 1996 by the NASA - Galileo Spacecraft, displays a few Surface Features that, in some areas, seem to resembe to Ice Floes (---> usually large, flat, and free masses of floating Sea Ice ) seen in the Polar Seas of our Home Planet Earth. Europa, which is about the size of Earth's Moon, possesses an Icy Crust that has been severely fractured, as indicated by the dark linear, curved, and wedged-shaped bands seen here. These Fractures have broken the Crust into Plates which are as large as 30 Km (such as about 18,6 miles) across. The Areas between the Plates are filled with Material that is probably Icy "Slush", contaminated with Rocky Debris. Some individual Plates were separated and rotated into new positions. Europa's density indicates that this Celestial Body has a shell of Water Ice thicker than approx. 100 Km (such as about 62 miles), parts of which could be liquid. Currently, Water Ice could extend from the Surface down to the Rocky Interior of Europa, but the Features seen in this image suggest that the motion of the disrupted Icy Plates was lubricated by soft Ice or perhaps liquid Water that was just below the Surface at the time of disruption.
This image covers part of the Equatorial Zone of Europa and was taken from a distance of approx. 156.000 Km (such as about 96.876 miles) by the Solid-State Imaging Subsystem onboard the NASA - Galileo Spacecraft. North is up and the Sun is nearly directly overhead. The area shown here is about 510 by 989 Km (such as approx. 317-by-614 miles), and the smallest visible Surface Feature is about 1,6 Km (approx. 1 mile) across.
This frame (which is the Original NASA - Galileo Spacecraft b/w image published on the NASA - Planetary Photojournal with the ID n. PIA 00578) has been additionally processed and then colorized, according to an educated guess carried out by Dr Paolo C. Fienga (LXTT-IPF), in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Galileo Spacecraft and then looked outside, towards the Surface of the Jovian moon Europa), 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 others, the existence of different Elements present on the Surface of Europa, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
(3 voti)
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Ganymede-V1-PIA02233-PCF-LXTT-IPF.jpgFeatures of Ganymede (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)92 visiteThis frame was acquired by the NASA - Voyager 1 Spacecraft during its approach to Ganymede, from a distance of about 272.000 Km; the center of the picture lies at approx. 13° North Latitude and and 359° East Longitude. Ganymede (also known as Jupiter III) is the largest moon in the Solar System and the seventh moon (and third Galilean Satellite) outward from the Gas-Giant Planet Jupiter. Completing an orbit in roughly 7 (seven) Earth days, Ganymede participates in a 1:2:4 Orbital Resonance with the other Jovian moons Europa and Io, respectively. Ganymede has a diameter of about 5268 km (such as approx. 3273 miles), and, even though Ganymede is something like 8% larger than the planet Mercury, it only has about 45% of Mercury's mass; furthermore, its diameter is about 2% larger than the one of the Saturnian moon Titan, which is the second largest moon in the Solar System. Ganymede also has the highest mass of all Planetary Satellites, with approx. 2,02 times the mass of the Earth's Moon. This image shows detail on the Surface of Ganymede with a resolution of approx. 4,5 Km per pixel. What we see here, is a portion of a Region of Ganymede located in its Northern Hemisphere, near the Terminator. It shows a variety of Impact Structures, including both Rayed and Unrayed Impact Craters, as well as some odd-looking, Groove-like Surface Features (already discovered by the NASA - Voyager 1 Spacecraft in the lighter Regions of this Jovian moon). The most striking Surface Features, however, are the Bright Rayed Impact Craters which show a distinct light blueish color that, to some Observer, may also also appear white, with pink nuances, against the darker background. Ganymede's Surface is known to contain large amounts of Surface Water Ice and it appears that these (relatively) young Craters might have spread bright and (always relatively speaking) fresh Ice Materials all over the place. Likewise, the lighter color and Albedo (---> reflectivity) of the Grooved Areas suggests that over there, too, some cleaner and fresh Water Ice Material can be found. In fact, and as far as we know at the present day, Ganymede is composed of approximately equal amounts of Silicate Rock and Water Ice. It is a fully differentiated Celestial Body with an Iron-rich and still liquid core. Very recent studies suggest that, just like it has been speculated about the other Jovian moon Europa, even Ganymede may host a Subterranean Ocean, nearly 200 Km below its frozen Surface, somehow "sandwiched" between several different Layers of Rock and Ice. In addition to the above, the Surface of Ganymede is composed of two main types of Terrain: the Dark Terrain, saturated with Impact Craters and dated up to 4 (four) Billion Years ago (a Terrain that covers about a third of the moon), and the Lighter Terrain, which is crosscut by extensive Grooves and Ridges and that could be, likely, much less ancient. The cause of the Light Terrain's so-called "Disrupted Geology" is not yet fully known, but it could reasonably be the result of some powerful Tectonic Activity brought about by Tidal Heating (and let us not forget that Tidal Heating - due to Tidal Friction - may also be the primary reason why a Liquid Ocean can exist, deep down and inside the otherwise Frozen Crust of Ganymede). The NASA - Voyager 1 Spacecraft Original b/w frame has been additionally processed and then colorized, according to an informed speculation carried out by Dr Paolo C. Fienga (LXTT-IPF), in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Voyager 1 Spacecraft and then looked outside, towards the Jovian moon Ganymede), 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 others, the existence of different Elements present on the Surface of Ganymede, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
(3 voti)
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