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its a strange partnership,but a very effective one: satellites and space-shuttle-carried radar are helping archeologists.how?byseeingthrough sand or through treetops to locate important archeological sites. the traditional tools of archeologists are shovels and picks.but high technology is making the archeologists work and time far more productive. take,for example,the second 1981 flight of the space shuttle challenger.during that mission,a powerful,experimental radar was pointed at a lifeless stretch of desert in egypt called the selima sand sheet.to everyones surprise,the radar penetrated through the sand to the harder rock beneath.on the surface,there is a little indication that africas sahara desert was never anything but a desert.when the archeologists studied the radar images,they saw what seemed to be impossible: there was sand-buried landscape that was shaped by flowing water; traces of ancient riverbeds appeared to be over nine miles wide,far wider than most sections of the present-day nile river.today,the area is one of the hottest,driest desert in the world. archeologists dug pits along the old river banks and found clues to the past: stream-rounded pebbles,stone-age axes,broken ostrich eggshells,and the shells of land snails.the archeologists were quite pleased with these findings.for years,theyd been finding stone axes scattered through the desert,and couldnt understand why.now we know that early humans were living on the banks of old rivers,and left their beautiful tools behind.some are so sharp that you could shave with them. | 
