Fact Check: "The Great Wall of China is visible from space"
What We Know
The claim that the Great Wall of China is visible from space has been widely circulated and is often regarded as a popular myth. Notably, in October 2003, Chinese astronaut Yang Liwei stated that he could not see the Great Wall from space, which contradicted the long-held belief that it was visible to the naked eye from such heights (source-1). Following this, American astronaut Eugene Cernan suggested that visibility might depend on atmospheric conditions, but this was later clarified by the European Space Agency (ESA) which acknowledged that what was thought to be the Great Wall in a photograph was actually a river (source-1).
NASA has also confirmed that the Great Wall is not visible from the Moon and is difficult to see from low Earth orbit without the aid of high-powered lenses (source-2). Furthermore, Britannica states that the Great Wall is typically not visible from space and that visibility can be affected by factors such as pollution and the wall's coloration (source-3).
Analysis
The evidence overwhelmingly indicates that the Great Wall of China cannot be seen from space with the naked eye. The human eye has limitations in visual acuity, particularly when it comes to distinguishing small objects from great distances. The Great Wall, while long (approximately 7,300 km), is generally less than 6 meters wide, making it exceedingly difficult to see from space without optical aids (source-1).
Even astronauts have confirmed that, under normal conditions, the wall is not visible from low Earth orbit. For instance, ESA astronaut Alexander Gerst captured an image of the Great Wall using an 800mm super telephoto lens, emphasizing that it is not visible to the naked eye (source-4).
The claim's persistence can be attributed to its romantic appeal and the way it has been propagated through various media, despite being scientifically debunked. The myth suggests that if one can see the Great Wall from space, then other large structures, such as the Pyramids of Egypt or the Eiffel Tower, should also be visible, which is not the case (source-1).
Conclusion
Verdict: False
The claim that the Great Wall of China is visible from space is false. Scientific evidence and firsthand accounts from astronauts confirm that the Great Wall is not discernible to the naked eye from space due to its width and the limitations of human vision. The myth has been perpetuated despite clear evidence disproving it, highlighting the gap between popular belief and scientific reality.
