Astronomy Picture of the Day
July 15, 2013

Features of Mawrth Vallis (CTX Frame)
Features of Mawrth Vallis (CTX Frame)

Credits: NASA/JPL/University of Arizona - Credits for the additional process. and color.: Dr Paolo C. Fienga/LXTT/IPF

This image, taken by the NASA - Mars Reconnaissance Orbiter on June, 3rd, 2013, shows us a very small portion of Mawrth Vallis, one of the many Martian Outflow Channels feeding North into the Chryse Basin. This ancient and extremely fascinating Valley (we say fascinating for several reasons which we, as IPF, shall explain in a near future), eons ago, hosted flowing Waters, and their erosive power rapidly cut down into the underlying Layers of Rock, so to expose a number of diverse Geologic Landforms which are very well visible today.

A focus of Geologic Studies (at this site, on Mars, as well as on many different locations on Earth) is trying to decipher the juxtaposition of various Rock Structures and Landforms; in particular, these studies are trying to explain the actual reasons of the verification of various Geologic Phoenomena, like the so-called "Superposition" of one Landform (or "Strata") above (on top of) another; the presence of Fractures and Faults that disrupt one Layer but not another one standing nearby and, last but not least, the depths of certain Mineralogical Signatures which supply us with a good number of information about both the Geological and Climatological History of this Martian Region.

Intensely Fractured Bedrock is visible at all scales (such as from meters to kilometers), revealing that the Subsurface Rock has undergone a complex history of stresses and deformations (such as, for instance, stretching, compression, and twisting). Wide Dark Ridges are also visible, crossing long distances through the aforementioned Fractured Bedrock and between the various exposed Layers. These Ridges may be what Geologists also call, sometimes, "Dikes", such as near Vertical Fissures located in the Subsurface Rock that became injected with Magma and which, quite some time later, cooled-off into what is now an exposed Vein of Dark Volcanic Rock.

These Dikes may be related to areas of dark and rough (most likely Volcanic) Cap-Rock that now covers and protects the light toned Strata standing below. Erosion through and around this Cap-Rock, though, was good to expose a myriad of light toned Layers, and these Layers revealed an Ancient Environment where some Geologic Material (perhaps Volcanic Ashes, fine Sands, and Dust) slowly settled from the air on a Solid Surface or at the bottom of a standing (---> still) Body of Water. Furthermore, the Spectroscopic Signatures of Phyllosilicate Minerals (---> Clays) indicates an History of Geochemical alterations of Primary Minerals which, in some way, involved the presence and active action of Liquid Waters.

These Geologic Structures and the processes that formed them, mostly predate the already ancient Flood Waters that carved Mawrth Vallis. However, many Geologic Processes are still continuing and they are actively changing this Landscape into what we can see at present day. For instance, overlying the Surface, we can see that there are scattered Dark Dunes and small Sand Sheets. Now, therefore, these Landforms tell us that strong Winds continue to move and shift the Dark Volcanic Sands all across the visible Surface; in addition to that, lighter-toned loose Soil and Coatings of the almost ever present orange/reddish Dust (such as very fine grained weathered Rock Particles that are continuously blown around the Red Planet), blanket much of the Surface itself. The presence of this Soil tells us that, very slowly, the exposed (---> to the harsh Open Martian Environment) Rocks continue to be weathered (---> modified), both Physically and Chemically, and that, in (however, VERY long!) time, they end-up by breaking down (---> in other words, they almost disintegrate) into the abovementioned extremely fine Soil Particles which blanket most of the Surface of the whole Planet Mars.

Mars Local Time: 14:03 (Early Afternoon)
Coord. (centered): 22,397° South Lat. and 342,812° East Long.
Spacecraft altitude: 285,8 Km (such as about 177,481 miles)
Original image scale range: from 28,6 cm/pixel (with 1 x 1 binning) to 57,2 (with 2 x 2 binning)
Map projected scale: 25 cm/pixel
Emission Angle: 3,7°
Phase Angle: 49,2°
Solar Incidence Angle: 46° (meaning that the Sun was about 44° above the Local Horizon at the time the picture was taken)
Solar Longitude: 329,7° (Northern Winter - Southern Summer)
Credits: NASA/JPL/University of Arizona
Additional process. and coloring: Lunar Explorer Italia

This picture (which is a NASA - Original Mars Reconnaissance Orbiter NON-Map Projected CTX b/w frame identified by the serial n. ESP_032125_2025) has been additionally processed and then colorized in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Mars Reconnaissance Orbiter and then looked down, towards the Surface of Mars), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team.

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