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Saturn-Exagon.jpgThe "Exagon" of Saturn's North Pole54 visiteIt is unclear how an unusual Hexagonal Cloud System that surrounds Saturn's North Pole was created, keeps its shape, or how long it will last.
Originally discovered during the Voyager flybys of Saturn in the 80s, nobody has ever seen anything like it elsewhere in the Solar System.
Although its IR glow was visible previously to the Cassini Spacecraft now orbiting Saturn, over the past year the mysterious Hexagonal Vortex became fully illuminated by Sunlight for the first time during the Cassini's visit. Since then, Cassini has imaged the rotating Hexagon in Visible Light enough times to create this full-view. (the North Pole center was not well imaged and has been excluded)
Planetary scientists are sure to continue to study this most unusual cloud formation for quite some time.MareKromium
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Dunes-20091211a.jpgSand-Sheet and Dunefield (Natural Colors; credits: Lunexit)54 visitenessun commentoMareKromium
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PSP_003710_1530_RED_browse~0.jpgHolden Crater's Rim (Natural Colors; credits: Lunexit)54 visiteThe formation of the approximately 150 Km diameter Holden Crater interrupted the Northward flowing Uzboi Vallis Channel System. Relief associated with the Rim of Holden effectively blocked the Channel.
HiRISE image PSP_003710_1530 covers the portion of Holden Crater's Rim where it was overtopped by water that had backed up in Uzboi Vallis to the South. Water flowing over the Rim in multiple locations eventually focused on a single Channel that then cut deeply into the Rim.
After the impounded water drained into the Crater, the steep Wall on the East side of the main Channel collapsed in a Landslide that remains visible along the Floor.
Several Outcroppings of variably bright material are visible in the scar produced by the Slide. MareKromium
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PSP_001666_1530_RED.jpgHolden Crater (Natural Colors; credits: Lunexit)54 visitenessun commentoMareKromium
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ESP_013951_1955_RED_abrowse-00.jpgDark Syrtis Major (CTX Frame - Natural Colors; credits: Dr Paolo C. Fienga - Lunexit Team)54 visiteOn 13 October 1659, Dutch Astronomer Christiaan Huygens turned one of his telescopes towards a bright orange spot in the sky and produced what Percival Lowell would later call “the first drawing of Mars worthy of the name ever made by man”.
Huygens included a "dark spot" in his drawing that is thought to represent Syrtis Major, a small sliver of which is visible in this HiRISE image.
Syrtis Major is a Shield Volcano and its dark color comes from the dark Basaltic Rock present in the area, visible because it lacks the Dust that paints the rest of the Planet its distinct, rusty orangish color. By tracking this "dark spot" in repeated observations, Huygens concluded that Mars rotated every 24 hours: a time not too far off from its true rotation period of approx. 24 hours and 39,58 minutes.MareKromium
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Saturnian_Sky.gifIn the Sky of Saturn (GIF-Movie; credits: Dr M. Faccin)54 visitenessun commentoMareKromium
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Saturn-PIA12513.jpgCrescent Saturn (Natural Colors; credits: NASA/JPL/Space Science Institute)54 visiteCaption NASA:"Saturn, stately and resplendent in this Natural Color view, dwarfs the icy moon Rhea.
Rhea orbits beyond the Rings on the right of the image. The moon Tethys is not shown here, but its shadow is visible on the Planet on the left of the image. This view looks toward the Northern, sunlit side of the Rings from just 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 Nov. 4, 2009 at a distance of approx. 1,3 MKM (about 808.000 miles) from Saturn.
Image scale is roughly 72 Km (about 45 miles) per pixel".MareKromium
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The_Rings-PIA12512.jpgThe "E-Ring"54 visiteCaption NASA:"The Cassini Spacecraft takes a look at Saturn's diffuse E-Ring which is formed from icy material spewing out of the South Pole of the moon Enceladus (see PIA08921 to learn more about how Enceladus creates the E-Ring). The E-Ring is seen nearly edge-on from slightly above the Northern Side of Saturn's Ring-Plane.
The image was taken in Visible Light with the Cassini Spacecraft wide-angle camera on Oct. 23, 2009. The view was acquired at a distance of approx. 2,5 MKM (such as about 1,6 MMs) from Saturn.
Image scale is roughly 149 Km (approx. 92 miles) per pixel".MareKromium
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Prometheus-N00148968-N00148985-GB.gifPrometheus adrift... (GIF-Movie; credits: Dr G. Barca)54 visitenessun commentoMareKromium
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The_Rings-091227-W00062195-96-98-EB-LXTT.jpgRings on Parade! (possible Natural Colors; credits: Elisabetta Bonora - Lunexit Team)54 visiteMareKromium
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Volcanoes-PIA00261.jpgVolcanoes in Guinevere Planitia (possible Natural Colors; credits: Dr Paolo C. Fienga - Lunexit Team)54 visiteThis image, with radar illumination from West to East, shows three unusual Volcanoes located in the Guinevere Planitia Lowland. At the center of the image is a large feature (approx. 50 Km or about31 miles in diameter) with an unusual shape; very round when viewed from above with steep slides and a flat top.
These Volcanoes are believed to be the result of relatively thick and sticky (viscous) Lava Flows that originated from a point source. Although a faint remnant of its original circular shape is preserved, the Northern Rim of this center Volcano has a steep Scarp.
The Scarp is probably the result of material that has slid away from the Volcano and subsequently has been covered by Lava Flows. This Volcano overlaps another feature to the South-West that is about 45 Km (approx. 28 miles) in diameter and disrupted by many fractures.
The South-Eastern Volcano (about 25 Km or approx. 15,5 miles in diameter) appears to be the highest of the three as its illuminated Western Edge has the brightest radar return. The scalloped Edges give this feature a bottlecap-like appearance. The highly scalloped Edges are probably the result of multiple material slides along the Volcano Margin.MareKromium
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Ovda_Regio-PIA00218.jpgOvda Regio (possible Natural Colors; credits: Dr Paolo C. Fienga - Lunexit Team)54 visiteThis Magellan image shows part of the interior of Ovda Regio, one of the large Highlands ringing the Equator of Venus.
Several tectonic events formed this complex block fractured terrain. An underlying fabric of Ridges and Valleys strikes N/E - S/W. These Ridges are spaced approx. 10 to 20 Km (such as about 6 to 12 miles) apart and may have been caused by shortening of the crust at right angles to this trend.
These structures are cut by thoroughgoing extension fractures trending N/W - S/E, suggesting a later episode of N/E - S/W extension. Lastly, the largest Valleys, particularly the about 20 Km (approx. 12 mile) wide one extending across the image, were filled with dark material, probably Lava.
The complex internal fabric of Ovda Regio attests to a long history of tectonic deformation.
This image, centered approx. at 1° South Lat. and 81° East Long., measures approx. 225 Km (about 140 miles) by approx. 150 (about 90 miles) and was acquired by Magellan in November 1990.MareKromium
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