The Great Wall of China is an enormous structure, its width approaching 7.0 m at the widest point. Some people claim that it is possible to identify the separate sides of the Great Wall from the Moon with the unaided eye. Evaluate this claim in the following way: Assume that green light (λ vac = 555 nm) reflects from the Great Wall and enters the eye of an astronaut (D = 2.5 mm, n = 1.36). Determine the maximum distance this astronaut could be from Earth and still resolve the two sides at their widest point. Compare this maximum distance to the distance between Earth and Moon (3.85 x10 8 m).

The Great Wall of China is an enormous structure, its width approaching 7.0 m at the widest point. Some people claim that it is possible to identify the separate sides of the Great Wall from the Moon with the unaided eye. Evaluate this claim in the following way: Assume that green light (λ vac = 555 nm) reflects from the Great Wall and enters the eye of an astronaut (D = 2.5 mm, n = 1.36). Determine the maximum distance this astronaut could be from Earth and still resolve the two sides at their widest point. Compare this maximum distance to the distance between Earth and Moon (3.85 x10 8 m).