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courtesy of NASA/JPL
Aorounga impact crater, Chad

The impact of an asteroid or comet several hundred million years ago left scars in the landscape that are still visible in this image or an area in the Sahara desert region in northern Chad. The concentric ring structure is the Aorounga impact crater, with a diameter or about 17 kilometers (10.5 miles). The original crater was buried by sediments, which were then partially eroded to reveal the current ring-like appearance. The dark streaks are deposits or windblown sand that migrate along valleys cut by thousands or years or wind erosion. The dark band in the upper right of the image is a portion or what may be a second crater. Scientists are using radar images to investigate the possibility that Aorounga is one of a string of impact craters formed by multiple impacts.

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