Ο λαβύρινθος του Άρη, Two Generations of Windblown Sediments on Mars

O εντυπωσιακός «λαβύρινθος» του Άρη, όπως τον κατέγραψε ο δορυφόρος MRO. This colorful scene is situated in the Noctis Labyrinthus region of Mars, perched high on the Tharsis rise in the upper reaches of the Valles Marineris canyon system. Targeting the bright rimmed bedrock knobs, the image also captures the interaction of two distinct types of windblown sediments. Surrounding the bedrock knobs is a network of pale reddish ridges with a complex interlinked morphology. These pale ridges resemble the simpler “transverse aeolian ridges” (called TARs) that are common in the equatorial regions of Mars. The TARs are still poorly understood, and are variously ascribed to dunes produced by reversing winds, coarse grained ripples, or indurated dust deposits. HiRISE observations of TARs have so far shown that these bedforms are stable over time, suggesting either that they form slowly over much longer time scales than the duration of MRO's mission, or that they formed in the past during periods of very different atmospheric conditions than the present. Dark sand dunes comprise the second type of windblown sediment visible in this image. The dark sand dune seen just below the center of the cutout displays features that are common to active sand dunes observed by HiRISE elsewhere on Mars, including sets of small ripples crisscrossing the top of the dune. In many cases, it is the motion of these smaller ripples that drives the advance of Martian sand dunes. The dark dunes are made up of grains composed of iron-rich minerals derived from volcanic rocks on Mars, unlike the pale quartz-rich dunes typical of Earth. Caption Credit: Paul Geissler. Image Credit: NASA/JPL/University of Arizona

Ο δορυφόρος MRO που βρίσκεται σε τροχιά γύρω από τον Άρη κατέγραψε νέες λεπτομερείς εικόνες από μια από τις πιο εντυπωσιακές και ενδιαφέρουσες γεωλογικές δομές του. Πρόκειται για τον «Λαβύρινθο της Νύχτας» (Noctis Labyrinthus) που βρίσκεται στο τεράστιο ηφαιστειακό υψίπεδο Tharsis.

Valles Marineris stretches over 4,000 km (2,500 mi) across Mars, mostly east-west just below the equator, as seen in this Viking 1 orbiter image mosaic. The three Tharsis Montes are at left; towards the top, an ancient outflow channel stretches northward from Echus Chasma to Kasei Valles. Similar outflow channels extend from the east end of Valles Marineris towards Mars's northern lowlands. Image Credit: NASA/USGS

Το υψίπεδο εντοπίζεται στο δυτικό άκρο του Valles Marineris , του μεγαλύτερου φαραγγιού του Κόκκινου Πλανήτη που είναι πιθανότατα και το μεγαλύτερο φαράγγι στο ηλιακό μας σύστημα. Ο Λαβύρινθος είναι μια περιοχή με βαθιές, απότομες κοιλάδες. Στη συγκεκριμένη περιοχή έχει εντοπιστεί η παρουσία πλήθους ορυκτών και μεταλλευμάτων. Οι νέες εικόνες θα βοηθήσουν τους ειδικούς να μελετήσουν την περιοχή καλύτερα.