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SPACE-US-MARS
An image recieved from NASA on March 30, 2009 shows a Mars southern hemisphere crater with gullies on its north and northeast walls. Gullies are proposed to be carved by liquid water originating from the subsurface or melting ice/snow on the surface. Arcuate ridges, wave-shaped high-standing features, are located downslope of the gullies here. This happens frequently on Mars, although it is unknown whether the formation of gullies and arcuate ridges are related to each other.Dark dunes are visible on the crater floor. Lighter, smaller dunes rim the south side of the crater floor. The entire scene has a pitted texture, suggesting that ground ice was once present in this region. When ground ice sublimates (goes from a solid directly to a gas), it leaves behind empty spaces in the soil that turn into pits as the remaining overlying soil collapses to fill them.The image was captured on February 16, 2009 by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. AFP PHOTO/HO/NASA/JPL-Caltech/University of Arizona
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Detalii fotografie |
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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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30 Martie 2009 |
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| Dimensiuni: |
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2560 x 1920 (1.42 MB) |
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