这是航天飞机第二次试飞时成象雷达拍摄的撒哈拉沙漠照片。从照片上可以看出掩藏在地表底下的古代地形特征。雷达波透过沙漠揭开了几千年来掩埋在地下的自然景物。从雷达在苏丹北部拍摄的这张照片中,可以看到:(A)一条约在3-4千万年以前形成的9英里宽的干涸河谷;(B)一个网状的固定水系成了较大的地理特征;(C)一条似乎是沿构造断裂带形成的干涸河床;(D)古代的干涸湖或 This is a photograph of the Sahara Desert taken by Imaging Radar during the second test flight of the space shuttle. From the photo you can see the ancient terrain hidden beneath the surface. Radar waves uncover the natural beauty buried underground for thousands of years through the desert. From the radar photograph taken in northern Sudan, you can see: (A) a 9-mile-wide dry valley dating from 3-4 million years ago; (B) a reticulated, fixed water system Large geographical features; (C) a seemingly dry riverbed formed along structural fault zones; (D) ancient dry lakes or