China Wall Can–and Cannot–Be Seen from Space
Chinese textbooks have always boasted that the Great Wall of China, built in the 5th century BC, is so big that it can be seen from space, but Chinese astronaut Yang Liwei, who was the first Chinese person in space, says he couldn’t see it from his spacecraft Shenzhou V. However, Apollo 17 astronaut Gene Cernan, who walked on the moon in December 1972, claims he saw the wall from space. He says, "At Earth orbit of (100 miles) to (200 miles) high, the Great Wall is indeed visible to the naked eye."
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