The Short Version
This widely repeated claim is a persistent myth debunked by NASA, peer-reviewed optical studies, and multiple astronauts. The Great Wall's width—only a few meters—falls far below the threshold of human visual acuity at orbital distances, regardless of its impressive length. NASA states the Wall is "difficult or impossible to see from Earth orbit" without high-powered lenses, and China's own astronaut Yang Liwei confirmed he could not see it. A handful of contested anecdotal quotes do not overturn the scientific and observational consensus.