Mars Reconnaissance Orbiter (MRO)
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ESP_013954_1780_RED_abrowse-00~0.jpgVictoria Crater (CTX Frame - Natural Colors; credits: Lunexit)54 visiteThis image has an interesting perspective because of the oblique viewing geometry. In addition, the Tracks left by the Opportunity Rover are visible just North of Victoria.MareKromium
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ESP_013954_1780_RED_abrowse-01.jpgOpportunity near Victoria Crater (by Dr M. Faccin)54 visitenessun commentoMareKromium
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ESP_013954_1780_RED_abrowse-02.jpgVictoria Crater (EDM - Natural Colors; credits: Lunexit)54 visiteVictoria Crater was explored by Opportunity Rover for more than a Mars year; HiRISE images have supported surface exploration and contributed to joint scientific studies.
HiRISE stereo data were used to measure slopes and help select safe paths for the intrepid Rover. The most interesting exposures of geologic strata are in the steep walls of the Crater, difficult to image from the overhead perspective of orbiting spacecraft like MRO. However, MRO can point to the sides, and did so in this case to get a better view of layers in the West-facing and sunlit slopes of the Crater.
Especially prominent is a bright band near the top of the Crater Wall, interpreted by some MER scientists as having formed by diagenesis (chemical and physical changes in sediments after deposition). This bright band separates the bedrock from the impact ejecta deposits of Victoria Crater.MareKromium
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ESP_013954_1780_RED_abrowse-03~0.jpgFading Rover-Tracks near Victoria Crater54 visiteIn this composite image, we show a close-up of the Rover Tracks, as well as 6 previous HiRISE views acquired since June 2007, shortly after Opportunity’s drive.
The span encompasses over a full Mars year, from Southern Spring to the following Summer. Both the Natural Color images at the top of each sequence and the False Color below show a progressive fading of the Tracks over time.
It seems that the Tracks were initially fairly red and then become bluer; this curious effect of color-change might have been due to the weight of the Rover which caused its wheels to push dark granules of rocks and dust into the relatively bright and orangish Martian Soil.
Since then, dark sand has blown out of Victoria and partially covered the Tracks, darkening the Surface.MareKromium
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ESP_013958_1170_RED_abrowse.jpgDD Tracks in Aonia Terra (Natural Colors; credits: Lunexit)54 visiteThroughout this entire image in Aonia Terra, it is possible to make out regular polygonally shaped patterns. Here on Earth, wherever ice-rich permafrost occurs (soil which stays frozen throughout the year), the ground may crack and form similar patterns to those we see on Mars.
Despite remaining below freezing, changes in seasons and ground temperature cause significant thermal-contraction stress, enough so that the terrain fractures into a honeycomb network of subsurface cracks.
Criss-crossed dark paths wind throughout this Region. Dust Devils, turbulent whirlwinds fueled by rising ground-warmed Atmosphere, track across the Surface, stripping the ground of bright surface dust as they go. Comparable to miniature tornadoes, they efficiently transport Surface Materials on Mars. Left in their passing is the darker coarse-grained soil underneath.
In this image, the Sun is low on the horizon; the shadows make it easier to see the scattered rocks and boulders.
Sometimes, these boulders occur in rings, the remnants of an ancient impact whose crater has since eroded to a flat surface. The boulders are left behind, illustrating where the form of the crater once stood.MareKromium
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ESP_014007_2030_RED_abrowse.jpgMawrth Vallis (Blue Filter ON - Red Filter OFF - Natural Colors; credits: Lunexit)54 visitenessun commentoMareKromium
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ESP_014007_2030_RED_abrowse1.jpgMawrth Vallis (Blue Filter OFF - Red Filter ON - Natural Colors; credits: Lunexit)54 visiteCon un semplice "scambio" di Filtri/Colore, ecco che un paesaggio - pur rimanendo in Colori Naturali - cambia radicalmente di aspetto.
Questo è solo un piccolissimo esempio di quanto sia facile alterare la realtà, pur rimanendo - se non altro formalmente - nell'ambito della Colorizzazione Naturale (e cioè quella colorizzazione fatta rispettando le linee RGB proprie del frame, e finalizzata a dare all'Osservatore un'idea di come il paesaggio ripreso gli apparirebbe "ad occhio nudo", e cioè senza l'ausilio di supporti idonei ad amplificare lo Spettro della Luce - normalmente - Visibile ad un essere umano).MareKromium
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ESP_014041_1145_RED_abrowse.jpgUnusually-looking Dunefield (Natural Colors; credits: Lunexit)54 visitenessun commentoMareKromium
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ESP_014072_1380_RED_abrowse.jpgStratigraphy exposed in Crater Slope (Natural Colors; credits: Lunexit)54 visitenessun commentoMareKromium
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ESP_014077_0930_RED_abrowse.jpgSouth Polar Residual Cap Monitoring (Natural Colors; credits: Lunexit)54 visitenessun commentoMareKromium
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ESP_014083_0945_RED_abrowse-00.jpgActive Geyser on Mars: the "Region" (Natural Colors; credits: Lunexit)54 visiteCoord.: 85,4° South Lat. and 104,0° East Long.
Spacecraft altitude: about 248 Km
M.L.T.: 16:08 (middle afternoon)
S.I.A.: 69° (with the Sun about 21° above the Local Horizon)
Credits: NASA/JPL/Univ. of Arizona
Additional process. and color.: Lunexit
Attività geotermica su Marte? La risposta, detta quasi sussurrando, ci arriva direttamente dalla NASA ed è "Si": su Marte si manifesta ancora CERTAMENTE un quantum (residuale?) di attività geotermica e la prova è nelle bocche ancora attive di una serie di geysers che vediamo nelle Regioni Sud-Polari (le Regioni che sembrano ospitarne di più, ma certo non le uniche Regioni ancora "vive" di Marte).
Dietro questa semplice (ed affascinante) ammissione, si apre un universo di possibilità, tutte quante accomunate da una circostanza: il sottosuolo di Marte è ancora "vivo" ed è ancora abbastanza "caldo e vivace" da sostenere la verificazione di eventi eruttivi (di modesta scala, ma non per questo di modesta importanza).
A quando la notizia che nel sottosuolo di Marte esistono ancora e, nelle ere, si sono sviluppate ed evolute delle Forme Vitali Indigene?...MareKromium
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ESP_014083_0945_RED_abrowse-01.jpgActive Geyser on Mars: the "Geysers' Field" (Natural Colors; credits: Dr M. Faccin & Lunexit)66 visitenessun commentoMareKromium
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