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SPACE-MARS-SALTS
This NASA handout image released January 15, 2014 shows dunes, captured by the HiRISE instrument on board the Mars Reconnaissance Orbiter, on the rim of the Hellas Impact Basin on Mars. Sand dunes like those seen in this image have been observed to creep slowly across the surface of Mars through the action of the wind. These are a particular type of dune called a "barchan," which forms when the wind blows in one direction (here, east to west) for long periods of time. Barchan dunes are common on Mars and in the desert regions of the Earth.These barchan dunes are located on the western rim of the Hellas impact basin, in the Southern Hemisphere of Mars. This area is covered by extensive deposits of layered rocks that were initially deposited as loose sediments and over time formed these rock layers. Portions of these layered rocks were subsequently eroded away and the remaining layers now form numerous flat-topped hills called "mesas." The barchan dunes are forming in the lee (or downwind) of the mesas. AFP PHOTO / HO == RESTRICTED TO EDITORIAL USE / MANDATORY CREDIT: "AFP PHOTO / NASA/JPL-Caltech/U of Arizona / NO SALES / NO MARKETING / NO ADVERTISING CAMPAIGNS / DISTRIBUTED AS A SERVICE TO CLIENTS ==
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Detalii fotografie |
| Loc: |
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Mars, SPACE |
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| Sursa: |
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AFP / Mediafax Foto |
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| Fotograf: |
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HO |
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| Data: |
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16 Ianuarie 2014 |
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| Dimensiuni: |
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3500 x 2625 (1.46 MB) |
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