| Piú votate - Mars Reconnaissance Orbiter (MRO) |
PSP_003193_0850_RED_browse_00.jpgMartian Spring: the "V" Fans (context image)53 visiteSouthern Spring sunshine is causing the seasonal Carbon Dioxide (CO2) Cap at the South Pole to evaporate.
This process happens fitfully, as small and large spots expose bare ground, which warms up, causing small spots to grow.
The defrosting areas are controlled by small scale differences in topography, which cause some areas of frost to be sheltered longer than others.
Once dust has accessed the surface it is blown in directions controlled by the local winds, making a distinctive fan. When the wind changes direction the fans broaden or may show multiple orientations.
It has also been proposed that dust is carried to the top of translucent seasonal carbon dioxide ice by release of gas held under pressure by the ice cap. When the pressure is released, like pulling the cork out of a champagne bottle, the gas escapes, carrying dust with it.MareKromium
(6 voti)
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PSP_003193_0850_RED_browse_01.jpgMartian Spring: the "V" Fans (extra-detail mgnf)69 visitenessun commentoMareKromium
(6 voti)
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TRA_000878_1410_RGB.jpgTerra Sirenum53 visiteThis region receives very little sunlight in Southern Winter, and the bluish areas consist of frost. At the latitude of this image, frost is most likely composed of water because the temperature is not low enough for CO2 condensation. The reddish regions are locations where frost has been removed, most likely by sublimation. The dark, unfrosted regions (for example, in the channel of the gully on the far right) represent the most recent activity in the gullies and are possibly a result of seasonal melting.
(6 voti)
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Psp_001503_2180_red-02.jpgTricks of the Light, Tricks of the Surface... (extra-detail mgnf - 3)53 visitenessun commento
(6 voti)
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Psp_001808_1875_red.jpgSlope Streaks (or "Seeps"?) in Terra Sabaea71 visiteSlope streak formation is among the few known processes currently active on Mars. While their mechanism of formation and triggering is debated, they are most commonly believed to form by downslope movement of extremely dry sand or very fine-grained dust in an almost fluidlike manner (analogous to a terrestrial snow avalanche) exposing darker underlying material. Other ideas include the triggering of slope streak formation by possible concentrations of near-surface ice or scouring of the surface by running water from aquifers intercepting slope faces, spring discharge (perhaps brines) and/or hydrothermal activity.
Several of the slope streaks visible here, particularly the 3 longest darker streaks, show evidence that downslope movement is being diverted around obstacles such as large boulders. Several streaks also appear to originate at boulders or clumps of rocky material.
In general, the slope streaks do not have large deposits of displaced material at their downslope ends and do not run out onto the crater floor suggesting that they have little reserve kinetic energy. The darkest slope streaks are youngest and can be seen to cross cut and superpose older and lighter-toned streaks. The lighter-toned streaks are believed to be dark streaks that have lightened with time as new dust is deposited on their surface.
MareKromium
(6 voti)
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Psp_001485_2280_red-01.jpgDirty water-ice down in the crater? (EDM - False Colors)53 visitenessun commento
(6 voti)
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Terra_Sirenum-PIA09101-01.jpgSeasonal frost in Terra Sirenum (according to Lunexit)53 visitenessun commentoMareKromium
(6 voti)
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Chasma_Boreale-PSP_001374_2650_RED.jpgChasma Boreale (False Colors)108 visitenessun commentoMareKromium
(6 voti)
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Coprates_Labes_Canyon-Tra_000849_1675_red~1.jpgUnusual Landforms or...Something more?!?159 visiteUn ottimo lavoro di osservazione ed estrapolazione realizzato dal nostro caro Amico e Socio Lorenzo Leone ci riporta ad una (ormai) annosa e vexata questione: alcuni rilievi di Marte, nella loro "stranezza", restano rilievi naturali o si tratta di remnants di strutture artificiali?
Voi, cari Amici, la nostra posizione la conoscete; ma per questa volta - e diremmo con buona ragione - ci piace citare Lorenzo:"...Prendendo in esame una delle ultime immagini pubblicate, Coprates Labes, mi sono voluto divertire analizzandola nel tentativo di catturare le forme più strane (e sicuramente più fantasiose), ma di sicuro interesse.
Le immagini parlano da sole: abbiamo 2 possibili piramidi ed un "fortino".
Un gioco di luci ombre, aiutato da oggetti particolari, ma fantasticare e analizzare non nuoce certamente.
Ed è certo che Marte, almeno per me, riesce sempre a stupire...".
E noi condividiamo al 100%!MareKromium
(6 voti)
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Elysium_Planitia-Tra_000867_1875_red-01.jpgFresh Crater Cluster in Elysium Planitia (EDM - False Colors)54 visiteImage TRA_000867_1875 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on October 3, 2006. The complete image is centered at 7,4° North Latitude and 157,3 East longitude. The range to the target site was 274,6 Km (171,6 miles).
At this distance the image scale ranges from 54,9 cm/pixel (with 2 x 2 binning) to 109,9 cm/pixel (with 4 x 4 binning).
The image has been map-projected to 50 cm/pixel and north is to the right.
The image was taken at a Local Mars Time of 3:26 PM and the scene is illuminated from the West with a solar incidence angle of 52°, thus the Sun was about 38° above the horizon.
At a Solar Longitude of 115,1°, the season on Mars is Northern Summer.MareKromium
(6 voti)
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Chasma_Boreale-Psp_001412_2650_red-01.jpgChasma Boreale: the Martian "Pentagon" and other unusual surface features (2)132 visiteMareKromium
(6 voti)
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00-MRO-front-view_br~0.jpgHere is the "Mars Reconnaisance Orbiter"106 visiteThis artist's concept of the Mars Reconnaissance Orbiter features the spacecraft's main bus facing down, toward the red planet. The large silver circular feature above the spacecraft bus is the high-gain antenna, the spacecraft's main means of communicating with both Earth and other spacecraft. The long, thin pole behind the bus is the SHARAD antenna. Seeking liquid or frozen water, SHARAD will probe the subsurface using radar waves at a 15-25 MHz frequency band, "seeing" in the first few hundreds of feet (up to 1 kilometer) of Mars' crust. The large instrument (covered in black thermal blanketing) in the center is the HiRISE camera. This powerful camera will provide the highest-resolution images from orbit to date.
The other easily visible instruments are: the Electra telecommunications package which is the gold-colored instrument directly left of the HiRISE camera. It will act as a communications relay and navigation aid for Mars spacecraft. To the right of the HiRISE camera is the Context Imager (CTX).
(6 voti)
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| 2234 immagini su 187 pagina(e) |
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