Fact Check: The Great Wall of China is not visible from space

Fact Check: "The Great Wall of China is not visible from space"

What We Know

The claim that the Great Wall of China is not visible from space has been supported by various astronauts and scientific studies. Notably, Yang Liwei, China's first astronaut, stated upon his return from space in 2003 that he could not see the Great Wall, which sparked widespread discussion and confusion regarding the visibility of the wall from space (source-1). This assertion contradicts earlier claims made by some astronauts, including Eugene Cernan, who suggested that the wall could be seen under certain conditions, although this was later clarified as being inaccurate due to atmospheric and lighting factors (source-1).

NASA has also weighed in on the matter, stating that the Great Wall is not visible from the moon and is difficult or impossible to see from low Earth orbit without high-powered lenses (source-2). The wall's width, typically less than 6 meters, makes it nearly impossible to distinguish from such distances, as the human eye lacks the necessary visual acuity to perceive such thin structures from space (source-1).

Analysis

The evidence supporting the claim that the Great Wall of China is not visible from space is robust and comes from credible sources. The European Space Agency (ESA) and NASA both acknowledge the limitations of human vision in space. According to studies, even under optimal conditions, the Great Wall would require a visual acuity far exceeding that of the human eye to be seen from space (source-1).

Furthermore, the assertion made by some astronauts that the wall could be seen is often attributed to misinterpretations or specific conditions that do not apply universally. For example, while Cernan's comments suggested visibility, they were later clarified to indicate that atmospheric conditions could obscure the wall (source-1).

Other sources, including Scientific American and Travel China Guide, reiterate that the wall cannot be seen with the naked eye from space, emphasizing that the myth persists despite scientific evidence to the contrary (source-6, source-7).

The consensus among experts is that while the Great Wall is an impressive structure, its visibility from space is greatly exaggerated and not supported by scientific evidence.

Conclusion

Verdict: True
The claim that "The Great Wall of China is not visible from space" is true. The evidence from astronauts, NASA, and scientific studies consistently supports this assertion, highlighting the limitations of human vision and the wall's physical characteristics that prevent it from being seen from space.