Stig Östlund

torsdag, juni 10, 2010

Blue Like Mars


This image shows the west-facing side of an impact crater in the mid-latitudes of Mars' northern hemisphere. Like many mid-latitude Martian craters, this one has gullies along its walls that are composed of alcoves, channels and debris aprons. The origins of these gullies have been the subject of much debate; they could have been formed by flowing water, liquid carbon dioxide or dry granular flows./NASA

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