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. |