section_path: Visibility from space/From low Earth orbit
section_name: From low Earth orbit
paragraph_text: From low Earth orbit
  
  A more controversial question is whether the wall is visible from low Earth orbit (an altitude of as little as 160 km (100 mi)). NASA claims that it is barely visible, and only under nearly perfect conditions; it is no more conspicuous than many other human-made objects.
  
  Veteran US astronaut Gene Cernan has stated: "At Earth orbit of 100 to 200 miles high, the Great Wall of China is, indeed, visible to the naked eye." Ed Lu, Expedition 7 Science Officer aboard the International Space Station, adds that, "It's less visible than a lot of other objects. And you have to know where to look."
  
  In October 2003, Chinese astronaut Yang Liwei stated that he had not been able to see the Great Wall of China. In response, the European Space Agency (ESA) issued a press release reporting that from an orbit between 160 and 320 km (100 and 200 mi), the Great Wall is visible to the naked eye. The image was actually a river in Beijing.
  
  Leroy Chiao, a Chinese-American astronaut, took a photograph from the International Space Station that shows the wall. It was so indistinct that the photographer was not certain he had actually captured it. Based on the photograph, the China Daily later reported that the Great Wall can be seen from 'space' with the naked eye, under favorable viewing conditions, if one knows exactly where to look.