The Great Wall of China is a very extensive and large structure that is placed all throughout China. Many rumors and theories (and even pictures!) that show the Great Wall of China from space. I decided to take the time to research these claims to find out if they were true. This is the picture that came up when I looked around in Google.
The Great Wall of China shot from European Space Agency's Proba satellite on March 25. This view represents the area of the Great Wall of China from Beijing.
This area of the Great Wall of China is shown in the Inner Monglonia region. It was shot by NASA, the International Space Station on Nov. 24, 2004.
Upon analysis of these pictures and claims, they seem to be rather legitimate and not fabricated from Photoshop or any other computer program.
However, does this mean that the Great Wall of China is always visible? No, not quite. It depends on a variey of factors such as the atmospheric conditions. If it is a foggy or cloudy day, it will be difficult if not impossible to see the Great Wall of China. Futhermore, the distance by which the Great Wall of China is viewed is also important. If the Great Wall of china is viewed too far away then it will be impossible. Eugene Cernan states that "in Earth's orbit at a height of 160 to 320 kilometers [100-200 miles], the Great Wall of China is indeed visible to the naked eye."
However, the main myth circulating the web is that the Great Wall of China is the only visible man-made structure visible from space with the naked eye. However, no man-made sturucture is indeed visible from space without a technological aid.
Thus, the Great Wall of China is indeed visible from space but only to some cicrcumstances depending on visiblity and distance.