It’s a myth that has persisted for years: the Great Wall of China is the only man-made object that you can see from the Moon without assistance. Even if you haven’t heard this myth, I’m sure you’ve often wondered what the Earth looks like from a distance. If neither of these things is true….well then, you should probably get out more.
In fact, seeing the Great Wall from the Moon's surface would be the same as seeing a human hair from 2 miles away (3.2 km). Unless you have a high-powered telescope, or eyesight that is out of this world, you’re not going to be able to see such a tiny object. Given the average distance of the Moon, some 238,000 miles from the Earth (383,000 km), a feature on our planet would have to be roughly 70 miles across (113 km) for the unaided human eye to be able to discern it from the surrounding landscape. At its widest, The Great Wall is a mere 30 feet (9.1m). So it’s not even close.
When asked what features are visible from the Moon, Apollo 12 astronaut Alan Bean stated, "The only thing you can see from the Moon is a beautiful sphere, mostly white, some blue and patches of yellow, and every once in a while some green vegetation. No man-made object is visible at this scale."
But what can you see from low-Earth orbit?
Unfortunately, it is almost entirely impossible for the unaided eye to see the Great Wall of China even from this distance. Some scientists have argued that, if the conditions were *absolutely* perfect, then it would be theoretically possible. However, most scientists have rejected this notion, as it would require a visual acuity more than 5 times that of the average human eye. True, a few astronauts have said that they thought they could see the Great Wall, but most state that they couldn’t see it at all (not even a little bit).
However, there are other man-made objects that can be readily seen from low Earth orbit: the pyramids at Giza, airports, large bridges, dams, cities, the Toyota center (the lists goes on and on, really).
Want to know what else you can see from a low Earth orbit? Then I strongly suggest that you get a twitter account and follow Flight Engineer Chris Hadfield. His feed is filled with amazing images he took while he was working on the International Space Station. You can follow him here.
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